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DS1852 Optical Transceiver Diagnostic Monitor
www.maxim-ic.com
FEATURES
Implements proposals of SFF-8472 at device address A2h [Note: requires use of external EEPROM at address A0h for full compliance.] Top View Scaleable four-input muxing analog-to-digital converter (ADC) Direct-to-digital temperature converter A Programmable alarm and warning conditions Temperature-compensated, programmable three-input muxing B fast comparator C Access temperature, data, and device control through a 2-wire interface D Operates from 3V or 5V supplies E Packaging: 25-ball BGA Operating temperature: -40C to +100C Programming temperature: 0C to +70C 123 45 Three levels of security 5 x 5 BGA (0.8mm pitch) 127 bytes EEPROM for security level 1 128 bytes EEPROM for security level 2 Address space is GBIC compliant (with use of external EEPROM at device address A0h)
ORDERING INFORMATION
DS1852B-000 25-BALL BGA
DESCRIPTION
The DS1852 transceiver monitor manages all system monitoring functions in a fiber optic data transceiver module, in accordance with proposal SFF-8472. Its functions include 2-wire communications with the host system, EEPROM memory for identification, tracking, and calibration, an ADC with four muxing inputs, three fast comparators, and a temperature sensor to monitor an optical transceiver. The DS1852 has programmable alarm and warning flags for all four analog-to-digital (A/D) conversion values (three user analog inputs plus supply voltage) as well as the temperature. These conditions can be used to determine critical parameters inside each module. The three fast comparators have temperaturecompensated programmability. The temperature dependencies of the trip points aid in assessing critical conditions.
The DS1852 is offered for sale free of any royalty or licensing fees. However, users should be aware that implementation of the SFF-8472 proposed specifications may require the use of an invention covered by patent rights. Since these patents relate to the SFF-8472 specification and not to the DS1852 itself, licensing questions should be directed to Finisar Corp.
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061302
DS1852
PIN DESCRIPTIONS
Name Ball Locations VCC GND SDA D2, D4, E3 B3, C2, C4, D3 B5 Description Power-Supply Terminal. The DS1852 will support supply voltages ranging from +2.7V to +5.5V. Ground Terminal 2-Wire Serial Data. The serial data pin is for serial data transfer to and from the DS1852. The pin is open drain and may be wire-OR'ed with other open-drain or open-collector interfaces. 2-Wire Serial Clock. The serial clock input is used to clock data into the DS1852 on rising edges and clock data out on falling edges. Analog Input Pin (Bias Value). Input to A/D. Analog Input Pin (Power Level). Input to A/D. Analog Input Pin (Received Power). Input to A/D. Address Select Pin. If set to logic 0, the device address is A0h. If set to logic 1, the value in Table 3, byte D0h determines the chip address (factory default is A2h). For SFF-8472 compliance, this pin should be connected high. Digital Input Pin (TX Disable). Digital input for mirroring in memory map. Digital Input Pin (Rate Select). Digital input for mirroring in memory map. Digital Input Pin (TX Fault). Digital input for mirroring in memory map. Digital Input Pin (LOS). Digital input for mirroring in memory map. No Connect
SCL Bin Pin Rin
A5 A3 D1 A2
ASEL B2
Din RSin Fin Lin NC
C5 B4 E5 A1 A4, B1, C1, D5, E1, E2, E4, C3
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DS1852 BLOCK DIAGRAM Figure 1
VCC OUTPUT REGISTERS BIN PIN RIN
Control 3:1 MUX Control Control FAST TRIP 5:1 MUX
T
ADC
V B P R FAST ALARM WARN
ALARM and WARN
TEMP SENSOR
Control
Control
SDA SCL
2-WIRE Interface
EEPROM
CUSTOMER EEPROM CONTROL SETTINGS CONTROL LOGIC
Control Control Signals
GND
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DEVICE OPERATION
Security To prevent accidental overwrites of key device data, a data lockout feature is incorporated. A 32-bit password provides access to the "manufacturer" memory locations. These locations are in addition to the unprotected "user" memory locations: 1) User--This is the default state after power-up; it allows read access to standard IEEE identity table and standard monitoring and status functions. 2) Manufacturer Level 1--This allows access to customer data table and some selected setups (password 1). 3) Manufacturer Level 2--This allows access to all memory, settings, and features (password 2). The level 1 password is located in Table 03h EEPROM (bytes D3h to D6h) and may be changed by gaining access through the level 2 password. The level 2 password is set in protected EEPROM and is programmed during factory test. During power-up, the 32-bit password entry (addresses 7Bh to 7Eh) is set to all 1s. This is the value that is compared to the level 1 password entry in Table 03h to grant level 1 access. Therefore, the level 1 password should not be set to all 1s or the user will gain level 1 access after each power-on. By default, both passwords are factory preset to 00h. To gain access to a security level, a 4-byte password is written into Table 00h, bytes 7Bh to 7Eh. If the written data matches one of the passwords, that corresponding level of access is granted until the password entry is changed or the power is cycled. Entering the level 2 password allows access to both the level 1 data and the level 2 data. The 4-byte password is write-only.
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ANALOG-TO-DIGITAL CONVERTER
The ADC reads a total of five inputs: VCC (internal), temperature (internal), and external inputs Bin, Pin, and Rin. All conversions are updated every 13ms (nominal) or 20ms (max) in rotation. The conversions are absolute and compared to an internal reference. While the 16-bit values are read, only the upper 12 are significant. The lower four bits are undefined. The temperature and analog voltage inputs are calibrated by Dallas Semiconductor and read with the following scale: Temperature: High byte: -128C to +127C signed; low byte: 1/256C. The lower four bits should be ignored.
S 2-1 26 2-2 25 2-3 24 2-4 23 2-5 22 2-6 21 2-7 20 2-8
VCC: This reads as an unsigned 16-bit quantity at 100mV LSB, with a maximum range of 6.5535V, when using the factory default value. The lower four bits should be ignored. Bin, Pin, Rin: These read as an unsigned 16-bit quantity at 38.147mV LSB, with a maximum range of 2.500V, when using factory default values. The lower four bits should be ignored.
215 27 214 26 213 25 212 24 211 23 210 22 29 21 28 20
Each analog input has a 16-bit scaling calibration in Table 03h EEPROM. This allows the analog conversion values to be calibrated for full scale at any input voltage from 0.2V to 6.5535V. The ADC conversion value will clamp rather than roll over. Each external analog channel has a maximum input voltage of VCC independent of the calibration factor. The upper four bits of scaling select the coarse range; the lower 12 bits are for fine adjustments. The algorithm to trim the scale is described below. The scaling factors for each input (VCC, VBin, VPin, and VRin) are 16 bits wide. They are located in Table 03h at addresses C8h to CFh, respectively. The 16 bits are a combination of two trims. The lower 12 bits are binary weighted and give the high resolution trim for scaling the input to output relationship. The upper four bits are a coarse-adjust of the lower 12 bits. In other words, the upper four bits scale the LSB value of the binary weighted lower 12 bits. As an illustration, assume a value of 1V is needed to read full scale. Force a voltage less than 1V (975mV, for example) to keep clamping out of the way. The closer to max voltage the better, but not too close. 1) Set the scale trim to 0FFFh (the upper four bits to all zeros and the lower 12 bits to all ones). 2) Use a SAR approach on the upper four bits, starting with 1000b, to find the smallest 4-bit trim necessary to cause the voltage reading to be above the input (in this case, greater than or equal to 975mV). If they all clamp, that is okay. That means 0000b is the needed value for the upper four
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bits. This step has now adjusted the LSB of the lower 12 bits so that the best possible trim is acquired with the lower 12 bits. If too high a value is used in the four bits, then the resolution of the 12 bits is too high and absolute accuracy is sacrificed. If too low a value is used in the four bits, then the resolution of the 12 bits is too small, so a maximum reading is not possible and a large gain error is present through the entire range. Example code can be found near the end of this data sheet.
POWER-ON LOGIC
VCC is compared to an internal reference voltage, and if it is below VCC minimum, all internal logic and outputs are held in their reset state. When VCC rises above VCC minimum, the system reset is released. The DS1852 will not begin monitoring operations until VCC has risen above the analog minimum voltage. However, communication on the 2-wire bus can occur at a VCC level lower than the analog minimum voltage. This allows access to the power-on logic bit located in Table 00h, address 6Eh, bit 0. The analog minimum voltage is less than 2.7V but greater than the digital minimum voltage. Above the analog minimum voltage, the DS1852 will begin to function in a predictable manner but will not satisfy specifications until VCC is above 2.7V.
TEMPERATURE-DEPENDENT FAST ALARM COMPARATORS
The DS1852 has a three-input muxing fast alarm comparator with a response time of less than 10s for each input. This provides a coarse but fast approximation of whether analog inputs Bin, Pin, and Rin are above their temperature-dependent value. Each comparator has an 8-bit max value set in Table 03h, address D8h to E7h. The trip point range is adjustable from 10mV to 2.5V. Each LSB is approximately 10mV. The outputs of these comparators are readable in Table 00h (alarm bytes 1 and 0) and may be overwritten if their corresponding fast alarm override bit is set in Table 03h EEPROM. The Bin alarm can be set to eight unique temperature-dependent trip values, which allows the user to set trip points for different temperature ranges. The Pin/Rin fast alarms act similarly, but can only be set to four unique temperature-dependent values. For more information, refer to Table 03h.
HIGH-RESOLUTION ALARM COMPARATORS
There are 10 alarm comparators for the five analog channels. There is a 'high alarm' comparator whose output is active if the analog signal is above its threshold and a 'low alarm' comparator whose output is active if the analog signal is below its threshold. These comparators have a 2-byte set point in the same format as the analog converter data in Table 03h. The outputs of these comparators are readable in Table 00h (70h) and may be overwritten if their corresponding alarm override bit is set in Table 03h EEPROM.
WARNING COMPARATORS
The 10 warning comparators function the same way as the alarm comparators, but can be set to trip at different levels. Typically, they would be set to trip prior to the alarm comparators. The set points are in Table 03h and the outputs can be read from Table 00h.
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DIGITAL INPUTS
The four digital inputs (Din, RSin, Fin, and Lin) can be read through the 2-wire bus. The logic levels at these inputs are mirrored in the "logic states" byte (6Eh) in Table 00h.
2-WIRE OPERATION
Clock and Data Transitions The SDA pin is normally pulled high with an external resistor or device. Data on the SDA pin may only change during SCL low time periods. Data changes during SCL high periods will indicate a start or stop conditions depending on the conditions discussed below. See Figure 2 for further details. Start Condition A high-to-low transition of SDA with SCL high is a start condition that must precede any other command. See Figure 2 for further details. Stop Condition A low-to-high transition of SDA with SCL high is a stop condition. After a read sequence, the stop command places the DS1852 into a low-power mode. See Figure 2 for further details. Acknowledge Bit All address bytes and data bytes are transmitted through a serial protocol. The DS1852 pulls SDA low during the ninth clock pulse to acknowledge that it has received each word. Standby Mode The DS1852 features a low-power mode that is automatically enabled after power-on, after a stop command, and after the completion of all internal operations. 2-Wire Interface Reset After any interruption in protocol, power loss, or system reset, the following steps reset the DS1852: 1) Clock up to nine cycles. 2) Look for SDA high in each cycle while SCL is high. 3) Create a start condition while SDA is high. Device Addressing The DS1852 must receive an 8-bit device address word following a start condition to enable a specific device for a read or write operation. The address word is clocked into the DS1852 MSB to LSB. The address word defaults to A0h then the R/W (READ/WRITE) bit when ASEL is a logic zero. If the R/W bit is high, a read operation is initiated. If R/W is low, a write operation is initiated. The device address is changed to the internal chip address (Table 03h address D0h) when ASEL is logic one. The default internal chip address from the factory is A2h.
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Write Operations After receiving a matching address byte with the R/W bit set low, the device goes into the write mode of operation. The master must transmit an 8-bit EEPROM memory address to the device to define the address where the data is to be written. After the byte has been received, the DS1852 will transmit a zero for one clock cycle to acknowledge the receipt of the address. The master must then transmit an 8-bit data word to be written into this address. The DS1852 will again transmit a zero for one clock cycle to acknowledge the receipt of the data. At this point the master must terminate the write operation with a stop condition for the write to be initiated. If a start condition is sent in place of the stop condition, the write is aborted and the data received during that operation is discarded. If the stop condition is received, the DS1852 enters an internally timed write process (tw) to the EEPROM memory. The DS1852 will not send an acknowledge bit for any 2-wire communication during the EEPROM write process. The DS1852 is capable of an 8-byte page write. A page is any 8-byte block of memory starting with an address evenly divisible by eight and ending with the starting address plus seven. For example, addresses 00h through 07h constitute one page. Other pages would be addresses 08h through 0Fh, 10h through 17h, 18h through 1Fh, etc. A page write is initiated the same way as a byte write, but the master does not send a stop condition after the first byte. Instead, after the slave has received the data byte, the master can send up to seven more bytes using the same nine-clock sequence. The master must terminate the write cycle with a stop condition or the data clocked into the DS1852 will not be latched into permanent memory. The address counter rolls on a page during a write. The counter does not count through the entire address space as during a read. For example, if the starting address is 06h and four bytes are written, the first byte goes into address 06h. The second goes into address 07h. The third goes into address 00h (not 08h). The fourth goes into address 01h. If more than nine or more bytes are written before a stop condition is sent, the first bytes sent are overwritten. Only the last eight bytes of data are written to the page. Acknowledge Polling Once the internally timed write has started and the DS1852 inputs are disabled, acknowledge polling can be initiated. The process involves transmitting a start condition followed by the device address. The R/W bit signifies the type of operation that is desired. The read or write sequence will only be allowed to proceed if the internal write cycle has completed and the DS1852 responds with a zero. Read Operations After receiving a matching address byte with the R/W bit set high, the device goes into the read mode of operation. There are three read operations: current address read, random read, and sequential address read.
CURRENT ADDRESS READ
The DS1852 has an internal address register that contains the address used during the last read or write operation, incremented by one. This data is maintained as long as VCC is valid. If the most recent address was the last byte in memory, then the register resets to the first address. This address stays valid between operations as long as power is available.
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Once the device address is clocked in and acknowledged by the DS1852 with the R/W bit set to high, the current address data word is clocked out. The master does not respond with a zero, but does generate a stop condition afterwards.
RANDOM READ
A random read requires a dummy byte write sequence to load in the data word address. Once the device and data address bytes are clocked in by the master, and acknowledged by the DS1852, the master must generate another start condition. The master now initiates a current address read by sending the device address with the R/W bit set high. The DS1852 will acknowledge the device address and serially clocks out the data byte.
SEQUENTIAL ADDRESS READ
Sequential reads are initiated by either a current address read or a random address read. After the master receives the first data byte, the master responds with an acknowledge. As long as the DS1852 receives this acknowledge after a byte is read, the master may clock out additional data words from the DS1852. After reaching address FFh, it resets to address 00h. The sequential read operation is terminated when the master initiates a stop condition. The master does not respond with a zero. For a more detailed description of 2-wire theory of operation, see 2-WIRE SERIAL PORT OPERATION.
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DS1852
2-WIRE SERIAL PORT OPERATION
The 2-wire serial port interface supports a bidirectional data transmission protocol with device addressing. A device that sends data on the bus is defined as a transmitter, and a device receiving data as a receiver. The device that controls the message is called a "master." The devices that are controlled by the master are "slaves". A master device that generates the serial clock (SCL), controls the bus access, and generates the START and STOP conditions must control the bus. The DS1852 operates as a slave on the 2-wire bus. Connections to the bus are made through the open-drain I/O lines SDA and SCL. The following I/O terminals control the 2-wire serial port: SDA, SCL, and ASEL. Timing diagrams for the 2-wire serial port can be found in Figures 2 and 3. Timing information for the 2-wire serial port is provided in the AC ELECTRICAL CHARACTERISTICS table for 2-wire serial communications. The following bus protocol has been defined: Data transfer may be initiated only when the bus is not busy. During data transfer, the data line must remain stable whenever the clock line is HIGH. Changes in the data line while the clock line is HIGH will be interpreted as control signals.
Accordingly, the following bus conditions have been defined: Bus not busy: Both data and clock lines remain HIGH. Start data transfer: A change in the state of the data line from HIGH to LOW while the clock is HIGH defines a START condition. Stop data transfer: A change in the state of the data line from LOW to HIGH while the clock line is HIGH defines the STOP condition. Data valid: The state of the data line represents valid data when, after a START condition, the data line is stable for the duration of the HIGH period of the clock signal. The data on the line can be changed during the LOW period of the clock signal. There is one clock pulse per bit of data. Figures 2 and 3 detail how data transfer is accomplished on the 2-wire bus. Depending upon the state of the R/W bit, two types of data transfer are possible. Each data transfer is initiated with a START condition and terminated with a STOP condition. The number of data bytes transferred between START and STOP conditions is not limited and is determined by the master device. The information is transferred byte-wise and each receiver acknowledges with a ninth bit. Within the bus specifications a regular mode (100kHz clock rate) and a fast mode (400kHz clock rate) are defined. The DS1852 works in both modes. Acknowledge: Each receiving device, when addressed, is obliged to generate an `acknowledge' after the byte has been received. The master device must generate an extra clock pulse, which is associated with this acknowledge bit.
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A device that acknowledges must pull down the SDA line during the acknowledge clock pulse in such a way that the SDA line is a stable LOW during the HIGH period of the acknowledge-related clock pulse. Of course, setup and hold times must be taken into account. A master must signal an end of data to the slave by not generating an acknowledge bit on the last byte that has been clocked out of the slave. In this case, the slave must leave the data line HIGH to enable the master to generate the STOP condition. 1) Data transfer from a master transmitter to a slave receiver. The first byte transmitted by the master is the command/control byte. Next follows a number of data bytes. The slave returns an acknowledge bit after each received byte. 2) Data transfer from a slave transmitter to a master receiver. The master transmits the first byte (the command/control byte) to the slave. The slave then returns an acknowledge bit. Next follows a number of data bytes transmitted by the slave to the master. The master returns an acknowledge bit after all received bytes other than the last byte. At the end of the last received byte, a `not acknowledge' can be returned. The master device generates all serial clock pulses and the START and STOP conditions. A transfer is ended with a STOP condition or with a repeated START condition. Since a repeated START condition is also the beginning of the next serial transfer, the bus will not be released. The DS1852 may operate in the following two modes: 1) Slave receiver mode: Serial data and clock are received through SDA and SCL, respectively. After each byte is received, an acknowledge bit is transmitted. START and STOP conditions are recognized as the beginning and end of a serial transfer. Address recognition is performed by hardware after reception of the slave (device) address and direction bit. 2) Slave transmitter mode: The first byte is received and handled as in the slave receiver mode. However, in this mode the direction bit will indicate that the transfer direction is reversed. Serial data is transmitted on SDA by the DS1852 while the serial clock is input on SCL. START and STOP conditions are recognized as the beginning and end of a serial transfer. Slave Address: Command/control byte is the first byte received following the START condition from the master device. The command/control byte consists of a 4-bit control code. For the DS1852, this is set as 1010 000 (when ASEL is `0') binary for R/W operations. The last bit of the command/control byte (R/W) defines the operation to be performed. When set to a 1 a read operation is selected, and when set to a 0 a write operation is selected. Following the START condition, the DS1852 monitors the SDA bus checking the device type identifier being transmitted. Upon receiving the chip address control code, and the R/W bit, the slave device outputs an acknowledge signal on the SDA line.
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2-WIRE DATA TRANSFER PROTOCOL Figure 2
2-WIRE AC CHARACTERISTICS Figure 3
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MEMORY MAP
Memory access to the DS1852 is through the 2-wire interface. See the 2-WIRE OPERATION section. The memory within the DS1852 is organized into multiple tables. The lower 128 bytes of memory are common to all tables, the upper 128 bytes are addressed according to the table select byte at 7Fh. Valid values of the table address byte are 00h to 03h, to access Tables 00h through 03h.
00h Tables 00h - 03h Lower 128 bytes R- All W - Level 2* 7Fh 80h Table 00h Upper 128 Bytes No Physical Memory FF 80h Table 01h Upper 128 Bytes R/W - Level 1 FF 80h Table 02h Upper 128 Bytes R/W - Level 2 FF 80h Table 03h Upper 128 Bytes R/W - Level 2 FF
*For permission details of this memory block refer to following table.
The following tables detail the memory contents. Where descriptions are underlined an expanded table indicates the function of individual bits within the byte. The reserved memory locations should not be used even though R/W access may be possible. Not all memory is EEPROM; RAM cells are shaded within the tables, and denoted beneath.
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Address 00h ... ... 58h 60h 68h 70h 78h
Byte 0 bits<7-0>
Byte 1 bits<7-0>
Byte 2 bits<7-0>
Table 00h-FFh (Lower) Byte 3 Byte 4 bits<7-0> bits<7-0>
Byte 5 bits<7-0>
Byte 6 bits<7-0>
Byte 7 bits<7-0>
IEEE Data EEPROM (Read Access - All, Write Access - Level 2) Temp MSB Rin MSB Alarm flag3 Reserved Temp LSB Rin LSB alarm flag2 reserved Vcc MSB reserved alarm flag1 reserved Vcc LSB reserved alarm flag0 PWE Byte 3 Bin MSB reserved warn flag3 PWE Byte 2 Bin LSB reserved warn flag2 PWE Byte 1 Pin MSB I/O states warn flag1 PWE Byte 0 Pin LSB AD updated warn flag0 table select
Bytes 60h through 7Fh are RAM, see expanded table for access requirements. Table 00h-FFh (Lower) Expanded Bit 5 Bit 4 Bit 3 reserved B-updated V-ad hi RSin P-updated V-ad lo reserved R-updated B-ad hi
Byte Name I/O states (1) AD updated
(2)
Bit 7 Din T-updated T-ad hi
Bit 6 reserved V-updated T-ad lo
Bit 2 Fin reserved B-ad lo reserved reserved reserved B-ad lo reserved reserved reserved
Bit 1 Lin reserved P-ad hi reserved P-ft hi reserved P-ad hi reserved reserved reserved
Bit 0
power-on logic
reserved P-ad lo reserved reserved reserved P-ad lo reserved reserved reserved
alarm flag3 (3)
alarm flag2 (3) R-ad hi R-ad lo reserved reserved reserved alarm flag1 (3) reserved reserved reserved reserved B-ft hi alarm flag0 (3) R-ft hi reserved reserved reserved reserved warn flag3 (3) T-ad hi T-ad lo V-ad hi V-ad lo B-ad hi warn flag2 (3) R-ad hi R-ad lo reserved reserved reserved warn flag1 (3) reserved reserved reserved reserved reserved warn flag0 (3) reserved reserved reserved reserved reserved (1) Read Access - All, Write Access - None (2) Read Access - All, Write Access - All (The DS1852 will also write to this byte) (3) Read Access - All, Write Access - Level 2 + config bit (Table 03h, E8h)
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Memory Location (Table 00h, Lower) 00h - 5Fh 60h 61h 62h - 63h 64h - 65h 66h - 67h 68h - 69h 6Eh 6Fh
Name of Location IEEE Data Temperature MSB Temperature LSB Vcc Value Bin Value Pin Value Rin Value IO States A/D Updated
Table 00h (Lower) Function This memory block is used to store required GBIC data. This byte contains the MSB of the 15-bit 2's complement temperature output from the temperature sensor. This byte contains the LSB of the 15-bit 2's complement temperature output from the temperature sensor. These bytes contain the MSB (62h) and the LSB (63h) of the measured VCC. These bytes contain the MSB (64h) and the LSB (65h) of the measured Bin. These bytes contain the MSB (66h) and the LSB (67h) of the measured Pin. These bytes contain the MSB (68h) and the LSB (69h) of the measured Rin. Bit 0 will be 0 when the analog monitoring is active. Allows the user to verify if an update from the A/D has occurred to the five values: temperature, VCC, Bin, Pin and Rin. The user writes the byte to 00h. Once a conversion is complete for a given value, its bit will change to `1'. These bits reflect the state of the alarms as a conversion updates. High alarm bits are `1' if converted value is greater than corresponding high limit. Low alarm bits are `1' if converted value is less than corresponding low limit. Otherwise, bits are `0'. These bits reflect the state of the warnings as a conversion updates. High warning bits are `1' if converted value is greater than corresponding high limit. Low warning bits are `1' if converted value is less than corresponding low limit. Otherwise, bits are `0'. The four bytes are used for password entry. The entered password will determine the user's R/W privileges. During power-up these bits are set to all 1s. This byte determines which of the upper memory pages are selected. 00h -- No physical memory 01h -- Manufacturer EEPROM 02h -- Manufacturer EEPROM 03h -- Device settings
70h - 73h
Alarm Flags
74h - 77h
Warning Flags
7Bh - 7Eh
7Fh
Password Entry Bytes PWE Byte 3 (7Bh) MSByte PWE Byte 2 (7Ch) PWE Byte 1 (7Dh) PWE Byte 0 (7Eh) LSByte Table Select Byte
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Address 80h ... ... F8h
Byte 0 bits<7-0>
Byte 1 bits<7-0>
Byte 2 bits<7-0>
Table 00h (Upper) Byte 3 Byte 4 bits<7-0> bits<7-0> Reserved by IEEE (no physical memory)
Byte 5 bits<7-0>
Byte 6 bits<7-0>
Byte 7 bits<7-0>
Address 80h ... ... F0h F8h
Byte 0 bits<7-0>
Byte 1 bits<7-0>
Byte 2 bits<7-0>
Table 01h (Upper) Byte 3 Byte 4 bits<7-0> bits<7-0>
Byte 5 bits<7-0>
Byte 6 bits<7-0>
Byte 7 bits<7-0>
Manufacturer EEPROM (Read Access - Level 1, Write Access - Level 1) reserved
Address FFh is RAM
Address 80h ... ... F8h
Byte 0 bits<7-0>
Byte 1 bits<7-0>
Byte 2 bits<7-0>
Table 02h (Upper) Byte 3 Byte 4 bits<7-0> bits<7-0>
Byte 5 bits<7-0>
Byte 6 bits<7-0>
Byte 7 bits<7-0>
Manufacturer EEPROM (Read Access - Level 2, Write Access - Level 2)
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Address 80h 88h 90h 98h A0h A8h B0h B8h C0h C8h D0h D8h E0h E8h F0h F8h
Byte 0 Byte 1 bits<7-0> bits<7-0> HI ALARM T alarm MSB T alarm LSB V alarm MSB V alarm LSB B alarm MSB B alarm LSB P alarm MSB P alarm LSB R alarm MSB R alarm LSB reserved reserved reserved reserved reserved reserved reserved reserved
V-ad scale MSB V-ad scale LSB
Table 03h (Upper) Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 bits<7-0> bits<7-0> bits<7-0> bits<7-0> bits<7-0> bits<7-0> LO ALARM HI WARN LO WARN T alarm MSB T alarm LSB T warn MSB T warn LSB T warn MSB T warn LSB V alarm MSB V alarm LSB V warn MSB V warn LSB V warn MSB V warn LSB B alarm MSB B alarm LSB B warn MSB B warn LSB B warn MSB B warn LSB P alarm MSB P alarm LSB P warn MSB P warn LSB P warn MSB P warn LSB R alarm MSB R alarm LSB R warn MSB R warn LSB R warn MSB R warn LSB reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved
B-ad scale MSB B-ad scale LSB P-ad scale MSB P-ad scale LSB R-ad scale MSB R-ad scale LSB
chip address B Fast trip0 P Fast trip0 config/o-ride reserved reserved
reserved B Fast trip1 P Fast trip1 reserved reserved reserved
reserved B Fast trip2 P Fast trip2 reserved reserved reserved
PW1 Byte 3 B Fast trip3 P Fast trip3 reserved reserved reserved
PW1 Byte 2 B Fast trip4 R Fast trip0 reserved reserved reserved
PW1 Byte 1 B Fast trip5 R Fast trip1 reserved reserved reserved
PW1 Byte 0 B Fast trip6 R Fast trip2 reserved reserved reserved
reserved B Fast trip7 R Fast trip3 reserved reserved reserved
Address E8h is RAM. Read Access - Level 2, Write Access - Level 2 Fast-Trip Temperature Relationships Byte 2 Byte 3 Byte 4 bits<7-0> bits<7-0> bits<7-0> [8 to 24) [24 to 40) [40 to 56) [40 to 72) [40 to 72) 72 72
Fast Trip * B-in * P-in * R-in
Byte 0 bits<7-0> < -8 <8 <8
Byte 1 bits<7-0> [-8 to 8) [8 to 40) [8 to 40)
Byte 5 bits<7-0> [56 to 72)
Byte 6 bits<7-0> [72 to 88)
Byte 7 bits<7-0> 88
* There is one degree of hysteresis at transitions only (e.g., for B-in, if temp increases to +8.0C then byte 2 is active. It will remain active until temp reaches +24.0C or falls below +7.0C.). Byte Name Chip address X-ad scale MSB* X-ad scale LSB* config/O-ride Bit 7 b
7
Bit 6 b
6
Bit 5 b
5
Table 03h (Expanded) Bit 4 Bit 3 b
4
Bit 2 b
2
Bit 1 b
1
Bit 0 X 28 20 reserved
b
3
215 27 reserved
214 26 reserved
213 25 manual AD alarm
212 24 EE Bar
211 23 SW-POR
210 22 A/D Enable
29 21 Manual fast alarm
* V-, B-, P- or R- as appropriate
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DS1852
Memory Location (Table 3) 80h - 81h 88h - 89h 90h - 91h 98h - 99h A0h - A1h 82h - 83h 8Ah - 8Bh 92h - 93h 9Ah - 9Bh A2h - A3h 84h - 85h 8Ch - 8Dh 94h - 95h 9Ch - 9Dh A4h - A5h 86h - 87h 8Eh - 8Fh 96h - 97h 9Eh - 9Fh A6h - A7h B2h, Bah, C5h - C7h C8h - C9h CAh - CBh CCh - CDh CEh - CFh D0h D3h - D6h
Name of Location Temperature High Alarm VCC High Alarm Bin High Alarm Pin High Alarm Rin High Alarm Temperature Low Alarm VCC Low Alarm Bin Low Alarm Pin Low Alarm Rin Low Alarm Temp High Warning VCC High Warning Bin High Warning Pin High Warning Rin High Warning Temperature Low Warning VCC Low Warning Bin Low Warning Pin Low Warning Rin Low Warning Logic State Control VCC - A/D Scale Bin - A/D Scale Pin - A/D Scale Rin - A/D Scale Chip Address PW1 Byte 3 (D3h) MSB PW1 Byte 2 (D4h) PW1 Byte 1 (D5h) PW1 Byte 0 (D6h) LSB Bin Fast Trip Pin Fast Trip Rin Fast Trip Configuration Override Byte
Table 03h Function of Location The value written to this location serves as the high alarm limit. Data format is the same as the corresponding value (temperature, VCC, Bin, Pin, Rin). The value written to this location serves as the low alarm limit. Data format is the same as the corresponding value (temperature, VCC, Bin, Pin, Rin). The value written to this location serves as the high warning limit. Data format is the same as the corresponding value (temperature, VCC, Bin, Pin, Rin). The value written to this location serves as the low warning limit. Data format is the same as the corresponding value (temperature, VCC, Bin, Pin, Rin). These should be left at the factory default values as shown in the table to allow reading of the digital inputs from address 6Eh in Table 00h. 16 bits of gain adjustment for corresponding A/D conversion values.
This is the chip address used when pin ASEL is high (A2h default). The four bytes are used for password 1 entry. The password entered here will allow Level 1 access. Factory default is 00h. These bytes define the fast-trip comparison over temperature. These bytes define the fast-trip comparison over temperature. These bytes define the fast-trip comparison over temperature. Location of the bits is defined in Table 03h expanded.
D8h - DFh E0h - E3h E4h - E7h E8h
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DS1852
ABSOLUTE MAXIMUM RATINGS*
Voltage on Any Pin Relative to Ground Operating Temperature Range Programming Temperature Range Storage Temperature Range Soldering Temperature -0.3V to +6.0V -40C to +125C 0C to +70C -55C to +125C See J-STD-020A specification
*This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.
RECOMMENDED DC OPERATING CONDITIONS
PARAMETER Supply Voltage SYMBOL VCC MIN +2.7 TYP MAX +5.5
(-40C to +100C)
UNITS V NOTES 1
DC ELECTRICAL CHARACTERISTICS
PARAMETER Supply Current Digital Power-On RESET Analog Power-On RESET Input Leakage (SDA, SCL) Input Logic 1 (SDA, SCL, ASEL) Input Logic 0 (SDA, SCL, ASEL) Input Logic 1 (RSin, Din, Fin, Lin) Input Logic 0 (RSin, Din, Fin, Lin) Low Level Output Current (SDA) I/O Capacitance Input Resistance (RSin, Din, Fin, Lin) Input Resistance (ASEL) SYMBOL ICC Vpod Vpoa IIL VIH VIL VIH VIL IOL1 IOL2 CI/O Ripu Ripd to VCC to GND 0.4V 0.6V
(-40C to +100C; VCC = 2.7V to 5.5V)
MIN TYP MAX 1.0 2.0 2.0 -1 0.7VCC GND 0.3 1.5 GND 0.3 3 6 10 25 25 40 40 55 55 2.5 +1 VCC + 0.3 0.3 VCC VCC + 0.3 0.9 UNITS NOTES mA V V mA V V V V mA mA pF kW kW 12 4
CONDITIONS
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DS1852
A/D CONVERTERS
PARAMETER Thermometer Error Conversion Time Voltage A/D input Voltage A/D Offset Absolute Voltage A/D Error Differential Voltage A/D Nonlinearity SYMBOL TERR tCONVT VADin VADoff VADerr VADDNL
(-40C to +100C; VCC = 2.7V to 5.5V)
CONDITIONS -40C to +100C 12-bit conversion 10 0.0 MIN MAX 3.0 20 VCC + 0.3 0.25 0.5 0.25 UNITS C ms V % FSR % FSR % FSR 3 NOTES
COMPARATORS
PARAMETER Sample Time Fast-Trip Input Range Fast-Trip Absolute Error Fast-Trip Nonlinearity SYMBOL tsamp FTrange FTerr FTDNL
(-40C to +100C; VCC = 2.7V to 5.5V)
CONDITIONS MIN 8 0 MAX 10 VCC + 0.3 1.0 2.0 UNITS s V % FSR LSB NOTES 2
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DS1852
AC ELECTRICAL CHARACTERISTICS
PARAMETER SCL Clock Frequency Bus Free Time Between STOP and START Condition Hold Time (Repeated) START Condition Low Period of SCL Clock High Period of SCL Clock Data Hold Time Data Setup Time Start Setup Time Rise Time of Both SDA and SCL Signals Fall Time of Both SDA and SCL Signals Setup Time for STOP Condition Capacitive Load for Each Bus Line Startup Time VCC Power-Up Rate EEPROM Write Time SYMBOL CONDITIONS fSCL Fast Mode Standard Mode tBUF Fast Mode Standard Mode tHD:STA tLOW tHIGH tHD:DAT tSU:DAT tSU:STA tR tF Fast Mode Standard Mode Fast Mode Standard Mode Fast Mode Standard Mode Fast Mode Standard Mode Fast Mode Standard Mode Fast Mode Standard Mode Fast Mode Standard Mode Fast Mode Standard Mode Fast Mode Standard Mode
(-40C to +100C, VCC = 2.7V to 5.5V)
MIN 0 0 1.3 4.7 0.6 4.0 1.3 4.7 0.6 4.0 0 0 100 250 0.6 4.7 20+0.1CB 20+0.1CB 0.6 4.0 400 2 1 10 20 TYP MAX 400 100 UNITS kHz s s s s 0.9 s ns s 300 1000 300 300 ns ns s pF ms V/s ms 11 5 6 NOTES 7 7 7, 8 7 7 7, 9, 10 7 7 11 11
tSU:STO CB tST tW
NONVOLATILE MEMORY CHARACTERISTICS
PARAMETER Writes SYMBOL CONDITIONS +85C MIN 50,000 TYP MAX UNITS NOTES
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DS1852
NOTES
All voltages are referenced to ground. This is the time for one comparison. The complete cycle is this value multiplied by 3. Absolute voltage error for Bin, Pin, and Rin are valid from 0% to 98%. ASEL = GND, SDA = SCL = Din = Fin = Lin = RSin = VCC. The time to begin monitoring operations after VCC has risen above the analog minimum voltage. After STOP command has been received. No acknowledges will be issued during this interval. A fast mode device can be used in a standard mode system, but the requirement tSU:DAT > 250ns must then be met. This will automatically be the case if the device does not stretch the low period of the SCL signal. If such a device does stretch the low period of the SCL signal, it must output the next data bit to the SDA line tRMAX + tSU:DAT = 1000 + 250 = 1250ns before the SCL line is released. 8) After this period, the first clock pulse is generated. 9) The maximum tHD:DAT has only to be met if the device does not stretch the low period (tLOW) of the SCL signal. 10) A device must internally provide a hold time of at least 300ns for the SDA signal (see the VIH MIN of the SCL signal) in order to bridge the undefined region of the falling edge of SCL. 11) CB-- total capacitance of one bus line in picofarads, timing referenced to 0.9VCC and 0.1VCC. 12) Input levels equal either VCC or GND. 1) 2) 3) 4) 5) 6) 7)
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DS1852
SCALING THE ADC
procedure writeTrimValue(trim :integer); (* write trim to part *) procedure forceReference(Vin: real); (* applies reference voltage to input pin*) procedure waitForNewConversion(); (* writes update byte to zero and waits for of new conversion with present trim *) function readValue():integer; (* reads converted digital answer *) procedure ProgramTrim(trim :integer);(*enables EE for table3 & programs trim*) Procedure calVad(maxInput :real) var Bit :integer; (* counter - represents bininary bit 15-0*) trim :integer; (* present trim values *) lsb :real; (* the lsb value of the voltage reading *) Vin :real; (* the reference input voltage *) Dec_in :integer; (* decimal representation of voltage input *) Dec_out :integer; (* voltage reading in decimal *) delta :integer; (* present error of voltage reading *) bestDelta :integer; (* the error closest to zero *) bestTrim :integer; (* the trim that gave the best delta *) Begin bestDelta := 1000000; bestTrim := 0; trim := 4095; (* 0FFFh *) lsb := maxInput / 65535; Dec_in := 63888; (* input is ~97.5% of full scale *) Vin := lsb * Dec_in; forceReference(Vin); (*Use SAR approach to trim course adjust on VAD scale bits 15-12*) for Bit := 15 downto 11 do (* must go 1 bit too far so that zero is possible solution *) begin if (Bit > 11) then begin trim := trim + lshft(1,Bit); end; writeTrimValue(trim); waitForNewConversion; Dec_out := readVoltage; delta := Dec_out - Dec_in; if ( delta >= 0 ) then 23 of 25
update
DS1852 begin bestTrim := trim; if (Bit > 11) then Begin trim := trim - lshft(1,trimBit); end; end; end; (* The upper 4 bits of bestTrim contains the answer for the course adjustment.*) (* It is the smallest value that allows full scale trim with the lower 12 bits*) (* zero out the lower 12 bits of bestTrim *) trim := land(bestTrim,61440(*F000h*)); (*land() is logical AND function*) (*Use SAR approach to trim resolution on VAD scale bits 11-0*) for Bit := 11 downto -1 do (* must go 1 bit too far so that zero is possible solution *) begin if (Bit > 0) then begin trim := trim + lshft(1,Bit); end; writeTrimValue(trim); waitForNewConversion; Dec_out := readVoltage; delta := Dec_out - Dec_in; if ( abs(delta) <= abs(bestDelta) ) then begin bestTrim := trim; bestDelta := delta; end; if ( delta > 0 ) then begin if (Bit > 0) then Begin trim := trim - lshft(1,trimBit); end; end; end; (* bestTrim now contains the trim that gives the lowest delta*) ProgramTrim(bestTrim); end;
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DS1852
MECHANICAL DRAWING
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