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FEATURES

LTC2910 Octal Positive/Negative Voltage Monitor DESCRIPTION
The LTC(R)2910 is an octal input voltage monitor intended for monitoring multiple voltages in a variety of applications. Each input has a nominal 0.5V threshold, featuring 1.5% tight threshold accuracy over the entire operating temperature range. Glitch filtering ensures reliable reset operation without false or noisy triggering. Polarity selection and a buffered reference allow monitoring up to two separate negative voltages. A three state input pin allows setting the polarity of two inputs without requiring any external components. The LTC2910 provides a precise, versatile, space-conscious, micropower solution for voltage monitoring.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

8 Low Voltage Adjustable Inputs (0.5V) Guaranteed Threshold Accuracy: 1.5V Input Glitch Rejection Pin Selectable Input Polarity Allows Negative and OV Monitoring Buffered 1V Reference Output Adjustable Reset Timeout with Timeout Disable 70A Quiescent Current Open Drain RST and RST Outputs Guaranteed RST and RST for VCC 1V Available in 16-Lead SSOP and 16-Lead (5mm x 3mm) DFN Packages
APPLICATIONS

Desktop and Notebook Computers Network Servers Core, I/O Voltage Monitors
TYPICAL APPLICATION
Octal Supply Monitor, 10% Tolerance, 12V, 5V (x2), 3.3V (x2), 2.5V, 1.8V, 1.2V
12V 5V TYPICAL TRANSIENT DURATION (s) 3.3V 2.5V POWER SUPPLIES 1.8V 1.2V 5V 3.3V 54.9k 11k 11k 88.7k 11k 12.7k 11k 24.9k 11k 39.2k 11k 54.9k 11k 88.7k 11k 226k SYSTEM 600 500 400 300 200 VCC = 6V 100 VCC = 2.3V 700
Typical Transient Duration vs Comparator Overdrive
RESET OCCURS ABOVE CURVE
V8
V7
V6
V5
V4
V3
V2
V1 VCC 0.1F
0 1 10 100 0.1 COMPARATOR OVERDRIVE PAST THRESHOLD (%)
2910 TD01b
LTC2910 GND TMR 1nF TIMEOUT = 8.5ms DIS RST RST
SEL
2910 TA01
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LTC2910 ABSOLUTE MAXIMUM RATINGS
(Note 1, 2)
Terminal Voltages VCC (Note 3)............................................. -0.3V to 6V RST, RST ............................................... -0.3V to 16V TMR ..........................................-0.3V to (VCC + 0.3V) Vn, DIS, SEL ......................................... -0.3V to 7.5V Terminal Current IVCC ....................................................................10mA Reference Load Current (IREF) ...........................1mA IRST/RST..............................................................10mA
Operating Temperature Range LTC2910C ................................................ 0C to 70C LTC2910I ............................................. -40C to 85C Storage Temperature Range SSOP, DFN ......................................... -65C to 150C Lead Temperature (Soldering, 10 sec) SSOP ................................................................ 300C
PACKAGE/ORDER INFORMATION
TOP VIEW V1 V2 V3 V4 V5 V6 V7 V8 1 2 3 4 5 6 7 8 17 16 VCC 15 TMR 14 SEL 13 DIS 12 RST 11 RST 10 REF 9 GND V1 V2 V3 V4 V5 V6 V7 V8 1 2 3 4 5 6 7 8 TOP VIEW 16 VCC 15 TMR 14 SEL 13 DIS 12 RST 11 RST 10 REF 9 GND
DHC16 PACKAGE 16-LEAD (5mm x 3mm) PLASTIC DFN TJMAX = 150C, JA = 43.5C/W EXPOSED PAD (PIN 17) PCB GND CONNECTION OPTIONAL
GN16 PACKAGE 16-LEAD PLASTIC SSOP TJMAX = 150C, JA = 110C/W
ORDER PART NUMBER LTC2910CDHC LTC2910IDHC
DHC16 PART MARKING* 2910 2910
ORDER PART NUMBER LTC2910CGN LTC2910IGN
GN16 PART MARKING 2910 2910I
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL VSHUNT VSHUNT VCC VCC(MIN) PARAMETER VCC Shunt Regulator Voltage VCC Shunt Regulator Load Regulation Supply Voltage Minimum VCC Output Valid
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 3.3V, Vn = 0.55V, SEL = VCC, DIS = OPEN unless otherwise noted. (Note 2)
CONDITIONS ICC = 5mA ICC = 2mA to 10mA DIS = 0V

MIN 6.2 2.3
TYP 6.6 200
MAX 6.9 300 VSHUNT 1
UNITS V mV V V
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LTC2910 ELECTRICAL CHARACTERISTICS
SYMBOL VCC(UVLO) VCC(UVHYST) ICC VREF VRT tPROP IVN tRST VDIS(VIH) VDIS(VIL) IDIS ITMR(UP) ITMR(DOWN) VTMR(DIS) VOH VOL PARAMETER Supply Undervoltage Lockout Supply Current Reference Output Voltage Vn Input Voltage Threshold Vn Input Threshold to Output Delay Vn Input Current Reset Timeout Period DIS Input Threshold Voltage High DIS Input Threshold Voltage Low DIS Input Current TMR Pull-Up Current TMR Pull-Down Current Timer Disable Voltage Output Voltage High RST/RST Output Voltage Low RST/RST VDIS > 0.5V VTMR = 0V VTMR = 1.6V Referenced to VCC VCC = 2.3V, IRST/RST = -1A VCC = 2.3V, IRST/RST = 2.5mA VCC = 1V, IRST = 100A CTMR = 1nF Vn = VRT - 5mV
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VCC = 3.3V, Vn = 0.55V, SEL = VCC, DIS = OPEN unless otherwise noted. (Note 2)
CONDITIONS VCC Rising, DIS = 0V VCC = 2.3V to 6V IVREF = 1mA

MIN 1.9 5 0.985 492 50 6 1.2
TYP 2 25 70 1 500 125 8.5
MAX 2.1 50 100 1.015 508 500 15 12.5 0.8
UNITS V mV A V mV s nA ms V V A A A mV V
Supply Undervoltage Lockout Hysteresis DIS = 0V
1 -1.3 1.3 -180 1
2 -2.1 2.1 -270 0.1 0.01
3 -2.8 2.8
0.3 0.15 0.4
V V V V V A A
Three-State Input SEL VIL VIH VZ ISEL ISEL(MAX) Low Level Input Voltage High Level Input Voltage Pin Voltage when Left in Hi-Z State SEL High, Low Input Current Maximum SEL Input Current SEL tied to either VCC or GND ISEL = 10A

1.4 0.7 0.9 1.1 25 30
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: All currents into pins are positive; all voltages are referenced to GND unless otherwise noted.
Note 3: VCC maximum pin voltage is limited by input current. Since the VCC pin has an internal 6.5V shunt regulator, a low impedance supply that exceeds 6V may exceed the rated terminal current. Operation from higher voltage supplies requires a series dropping resistor. See Applications Information.
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LTC2910 TIMING DIAGRAM
Vn Positive Monitor Timing
Vn VRT tPROP RST 1V tRST
RST
1V
2285 TD01
Vn Positive Monitor Timing (TMR strapped to VCC)
Vn VRT tPROP RST 1V tPROP
RST
1V
2285 TD03
Vn Negative Monitor Timing
Vn VRT tPROP RST 1V tRST
RST
1V
2285 TD02
Vn Negative Monitor Timing (TMR strapped to VCC)
Vn VRT tPROP RST 1V tPROP
RST
1V
2285 TD04
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LTC2910 TYPICAL PERFORMANCE CHARACTERISTICS
unless otherwise noted. (Note 2) Input Threshold Voltage vs Temperature
0.505 0.504 THRESHOLD VOLTAGE, VRT (V) 0.503 0.502 ICC (A) 0.501 0.500 0.499 0.498 0.497 0.496 0.495 -50 -25 0 25 50 TEMPERATURE (C) 75 100
2910 G01
Specifications are at TA = 25C and VCC = 3.3V VCC Shunt Voltage vs Temperature
6.8 10mA
Supply Current vs Temperature
105 100 95 90 85 80 75 70 65 60 55 50 -50 -25 0 25 50 TEMPERATURE (C) 75 100
2910 G02
VCC = 6V VCC = 3.3V VCC (V)
6.7 6.6 6.5 6.4 6.3 6.2 -50
5mA 2mA 1mA 200A
VCC = 2.3V
-25
0 25 50 TEMPERATURE (C)
75
100
2910 G03
VCC Shunt Voltage vs ICC
6.75 REFERENCE VOLTAGE, VREF (V) 1.005 1.004 6.65 1.003 1.002 1.001 1.000 0.999 0.998 0.997 0.996 6.25 -2 0 2 4 6 ICC (mA) 8 10 12
Buffered Reference Voltage vs Temperature
700 TYPICAL TRANSIENT DURATION (s) 600 500 400 300 200
Transient Duration vs Comparator Overdrive
VCC (V)
6.55 25C -40C 85C 6.35
RESET OCCURS ABOVE CURVE
6.45
VCC = 6V 100 VCC = 2.3V
0.995 -50
-25
0 25 50 TEMPERATURE (C)
75
100
2910 G05
0 0.1 1 10 100 COMPARATOR OVERDRIVE PAST THRESHOLD (%)
2910 G06
2910 G04
Reset Time-Out Period vs Temperature
12 RST/RST TIMEOUT PERIOD, tRST (ms) 11 0.6 RST VOLTAGE (V) 10 9 8 7 6 -50 0 -25 0 25 50 TEMPERATURE (C) 75 100
2910 G07
RST Output Voltage vs VCC
0.8 5 VCC 4 RST VOLTAGE (V) 1.0
2910 G08
RST Output Voltage vs VCC
Vn = 0.55V SEL = VCC
CTMR = 1nF
3
0.4 RST WITH 10k PULL-UP 0.2 RST WITHOUT 10k PULL-UP 0 0.2 0.4 0.6 0.8 SUPPLY VOLTAGE, VCC (V)
2
1
0 0 1 2 3 4 SUPPLY VOLTAGE, VCC (V) 5
2910 G09
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LTC2910 TYPICAL PERFORMANCE CHARACTERISTICS
unless otherwise noted. (Note 2) RST, ISINK vs VCC
5 PULL-DOWN CURRENT, IRST (mA) Vn = 0.45V SEL = VCC 1.0 125C 0.8 RST/RST, VOL (V) RST AT 150mV 3 25C -40C 0.6
Specifications are at TA = 25C and VCC = 3.3V Reset Timeout Period vs Capacitance
10000 RST/RST TIMEOUT PERIOD, tRST (ms) 25 30
2910 G11
RST/RST Voltage Output Low vs Output Sink Current
4
1000
100
2 RST AT 50mV 1
0.4
10
0.2
0 0 1 2 3 4 SUPPLY VOLTAGE, VCC (V) 5
2910 G10
0 0 5 10 15 20 IRST/RST (mA)
1 0.1
1 10 100 TMR PIN CAPACITANCE, CTMR (nF)
1000
2910 G12
PIN FUNCTIONS
DIS (Pin 13): Output Disable Input. Disables the RST and RST output pins. When DIS is pulled high, the RST and RST pins are not asserted except during a UVLO condition. Pin has a weak (2A) internal pull-down to GND. Leave pin open if unused. Exposed Pad (Pin 17, DFN Package): Exposed pad may be left open or connected to device ground. GND (Pin 9): Device Ground REF (Pin 10): Buffered Reference Output. 1V reference used for the offset of negative-monitoring applications. The buffered reference sources and sinks up to 1mA. The reference drives capacitive loads up to 1nF. Larger capacitive loads may cause instability. Leave pin open if unused. RST (Pin 11): Open-Drain Reset Logic Output. Asserts high when any positive polarity input voltage is below threshold or any negative polarity input voltage is above threshold. Held high for an adjustable delay time after all voltage inputs are valid. Pin has a weak pull-up to VCC and may be pulled above VCC using an external pull-up. Leave pin open if unused. RST (Pin 12): Open-Drain Inverted Reset Logic Output. Asserts low when any positive polarity input voltage is below threshold or any negative polarity input voltage is above threshold. Held low for an adjustable delay time after all voltage inputs are valid. Pin has a weak pull-up to VCC and may be pulled above VCC using an external pull-up. Leave pin open if unused. SEL (Pin 14): Input Polarity Select Three-State Input. Connect to VCC, GND or leave unconnected in open state to select one of three possible input polarity combinations (refer to Table 1). TMR (Pin 15): Reset Delay Timer. Attach an external capacitor (CTMR) of at least 10pF to GND to set a reset delay time of 9ms/nF. A 1nF capacitor will generate an 8.5ms reset delay time. Tie pin to VCC to bypass timer. V1-V6 (Pin 1, 2, 3, 4, 5 & 6): Voltage Inputs 1 through 6. When the voltage on this pin is below 0.5V, a reset condition is triggered. Tie pin to VCC if unused. V7-V8 (Pin 7 & 8): Voltage Inputs 7 and 8. The polarity of the input is selected by the state of the SEL pin (refer
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LTC2910 PIN FUNCTIONS
to Table 1). When the monitored input is configured as a positive voltage, a reset condition is triggered when the pin is below 0.5V. When the monitored input is configured as a negative voltage, a reset condition is triggered when the pin is above 0.5V. Tie pin to VCC if unused and configured as a positive supply. Tie pin to GND if unused and configured as a negative supply. VCC (Pin 16): Supply Voltage. Bypass this pin to GND with a 0.1F (or greater) capacitor. Operates as a direct supply input for voltages up to 6V. Operates as a shunt regulator for supply voltages greater than 6V and must have a resistance between the pin and the supply to limit input current to no greater than 10mA. When used without a current-limiting resistance, pin voltage must not exceed 6V.
BLOCK DIAGRAM
VCC 16 V1 TMR 15 VCC OSCILLATOR 400k
1
V2 2 + - RESET DELAY TIMER DISABLE
V4 + - 4
V5 + - 5
V6 + - 6
V7 7 + - + - - 1V 2A DIS 13
V8 8 +
10
REF
+
-
3
V3
+ + UVLO - 2V VCC 0.5V THREE-STATE POLARITY DECODER 1V BUFFER 14 SEL
-
RST
12
VCC 400k
RST
11
GND
9
2910 BD
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LTC2910 APPLICATIONS INFORMATION
Voltage Monitoring The LTC2910 is a low power octal voltage monitoring circuit with eight individual undervoltage monitor inputs. A timeout period that holds a reset after all faults have cleared is adjustable using an external capacitor and is disabled, by tying TMR to VCC. Each voltage monitor is compared to a fixed 0.5V reference for detecting undervoltage conditions. When configured to monitor a positive voltage Vm, the application is connected as shown in Figure 1. For negative inputs Vm is connected as shown in Figure 2. RA is now connected to the REF pin and RB remains connected to the monitored voltage Vm. Using the configurations in Figures 1 and 2, a UV condition will result when the magnitude of the voltage at Vm is less than its designed threshold. Polarity Selection The three-state polarity-select pin (SEL) selects one of three possible polarity combinations for the input thresholds, as described in Table 1. When an input is configured for negative supply monitoring, a reset condition occurs when the supply voltage is less negative than the configured threshold. The three-state input pin SEL is connected to GND, VCC, or left unconnected during normal operation. When the pin is left unconnected, the maximum leakage allowed from the pin is 10A to ensure it remains in the open state. Table 1 shows the three possible selections of polarity based on the SEL pin connection.
Vm RB Vn + - UVn RA RA Vn + - UVn RB 0.5V Vm
2910 F01 2910 F02
Table 1. Voltage Polarity Programming (VRT = 0.5V Typical)
SEL VCC Open GND V7 INPUT Positive V7 < VRT UV Positive V7 < VRT UV Negative V7 > VRT UV V8 INPUT Positive V8 < VRT UV Negative V8 > VRT UV Negative V8 > VRT UV
2-Step Design Procedure The following 2-step design procedure allows selecting appropriate resistances to obtain the desired UV trip point for the positive voltage monitor circuit in Figure 1 and the negative voltage monitor circuit in Figure 2. For positive supply monitoring, Vm is the desired nominal operating voltage, Im is the desired nominal current through the resistive divider, and VUV is the desired undervoltage trip point. For negative supply monitoring, to compensate for the 1V reference, 1V must be subtracted from Vm and VUV before using each in the following equations. 1. Choose RA to obtain the desired UV trip point RA is chosen to set the desired trip point for the undervoltage monitor. RA = 0.5V Vm * Im VUV
LTC2910 REF + -
(1)
+ -
1V
LTC2910
+ -
+ -
0.5V
Figure 1. Positive UV Monitoring Configuration
Figure 2. Negative UV Monitoring Configuration
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LTC2910 APPLICATIONS INFORMATION
2. Choose RB to complete the design Once RA is known, RB is determined by: V RB = m - RA Im (2) current in the resistive divider is 10A. For the negative case, 1V is subtracted from Vm and VUV. 1. Find RA to set the UV trip point of the monitor. RA = 0.5V -5V - 1V * 54.9k 10A -4.5V - 1V
If any of the variables Vm, Im, or VUV change, then both steps must be recalculated. Positive Voltage Monitor Example A positive voltage monitor application is shown in Figure 3. The monitored voltage is a 5V 10% supply. Nominal current in the resistive divider is 10A. 1. Find RA to set the UV trip point of the monitor. RA = 0.5V 5V * 56.2k 10A 4.5V
2. Determine RB to complete the design. RB = -5V - 1V - 57.6k 549k 10A
Power-Up/Down As soon as VCC reaches 1V during power up, the RST output asserts low and the RST output weakly pulls to VCC. The LTC2910 is guaranteed to assert RST low and RST high under conditions of low VCC, down to VCC = 1V. Above VCC = 2V (2.1V maximum) the Vn inputs take control. Once all inputs and VCC become valid, an internal timer is started. After an adjustable delay time, RST pulls low and RST weakly pulls high. Threshold Accuracy Reset threshold accuracy is important in a supply sensitive system. Ideally, such a system would reset only if supply
5V VCC
2. Determine RB to complete the design. RB = 5V - 56.2k 499k 10A
Negative Voltage Monitor Example A negative voltage monitor application is shown in Figure 4. The monitored voltage is a -5V 10% supply. Nominal
5V VCC 5V 10% RST
REF
RST
RB 449k V7 RA 56.2k
RST LTC2910
RA 54.9k V7
RST LTC2910
SEL
RB 549k -5V 10% GND
SEL
GND
2910 F02
2910 F04
Figure 3. Positive Supply Monitor
Figure 4. Negative Supply Monitor
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LTC2910 APPLICATIONS INFORMATION
voltages fell below the exact threshold for a specified margin. All LTC2910 inputs have a relative threshold accuracy of 1.5% over the full operating temperature range. For example, when the LTC2910 is programmed to monitor a 5V input with a 10% tolerance, the desired UV trip point is 4.5V. Because of the 1.5% relative accuracy of the LTC2910, the UV trip point is between 4.433V and 4.567V which is 4.5V 1.5%. The accuracy of the resistances chosen for RA and RB affect the UV trip point as well. Using the example just given, if the resistances used to set the UV trip point have 1% accuracy, the UV trip range is between 4.354V and 4.650V. This is illustrated in the following calculations. The UV trip point is given as R VUV = 0.5V * 1+ B RA The two extreme conditions, with a relative accuracy of 1.5% and resistance accuracy of 1%, result in R * 0.99 VUV(MIN) = 0.5V * 0.985 * 1+ B RA * 1.01 and R * 1.01 VUV(MAX ) = 0.5V * 1.015 * 1+ B RA * 0.99 For a desired trip po int of 4.5V, Therefore, 0.99 = 4.354V VUV(MIN) = 0.5V * 0.985 * 1+ 8 * 1.01 and 1.01 = 4.650 V VUV(MAX ) = 0.5V * 1.015 * 1+ 8 * 0.99 RB =8 RA Glitch Immunity In any supervisory application, noise riding on the monitored DC voltage causes spurious resets. To solve this problem without adding hysteresis, which causes a new error term in the trip voltage, the LTC2910 lowpass filters the output of the first stage comparator at each input. This filter integrates the output of the comparator before asserting the reset output logic. A transient at the input of the comparator of sufficient magnitude and duration triggers the output logic. The Typical Performance Characteristics section shows a graph of the Transient Duration vs. Comparator Overdrive. RST/RST Timing The LTC2910 has an adjustable timeout period (tRST) that holds RST and RST asserted after all faults have cleared. This assures a minimum reset pulse width allowing a settling time delay for the monitored voltage after it has entered the valid region of operation. When any input drops below its designed threshold, the RST pin asserts low and the RST pin asserts high. When all inputs recover above their designed thresholds, the reset delay timer starts. If all inputs remain above their designed thresholds when the timer finishes, the RST pin weakly pulls high and the RST pin strongly pulls low. However, if any input falls below its designed threshold during this timeout period, the timer resets and restarts when all inputs are above the designed thresholds. Selecting the Reset Timing Capacitor The reset timeout period (tRST) for the LTC2910 is adjustable to accommodate a variety of applications. Connecting a capacitor, CTMR, between the TMR pin and ground sets the timeout period. The value of capacitor needed for a particular timeout period is: CTMR = tRST * 115 * 10-9 (F/s) The Reset Timeout Period vs. Capacitance graph found in the Typical Performance Characteristics section shows
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LTC2910 APPLICATIONS INFORMATION
the desired delay time as a function of the value of the timer capacitor. The TMR pin must have a minimum of 10pF or be tied to VCC. For long timeout periods, the only limitation is the availability of a large value capacitor with low leakage. Capacitor leakage current must not exceed the minimum TMR charging current of 1.3A. Tying the TMR pin to VCC bypasses the timeout period. Undervoltage Lockout When VCC falls below 2V, the LTC2910 asserts an undervoltage lockout (UVLO) condition. During UVLO, RST is asserted and pulled low and RST is pulled high. When VCC rises above 2V, RST and RST follow the same timing procedure as an undervoltage condition on any input. Shunt Regulator The LTC2910 has an internal shunt regulator. The VCC pin operates as a direct supply input for voltages up to 6V. In this range, the quiescent current of the device remains below a maximum of 100A. For VCC voltages higher than 6V, the pin functions as a shunt regulator and must have a resistance RZ between the supply and the VCC pin to limit the current to no greater than 10mA. When selecting this resistance value, choose an appropriate location on the I-V curve shown in the Typical Performance Characteristics to accommodate any variations in VCC due to changes in current through RZ. RST/RST Output Characteristics The DC characteristics of the RST and RST pull-up and pull-down strength are shown in the Typical Performance Characteristics. Each has a weak internal pull-up to VCC and a strong pull-down to ground. This arrangement allows each pin to have open-drain behavior while possessing several other beneficial characteristics. The weak pull-up eliminates the need for an external pull-up resistor when the rise time on this pin is not critical. On the other hand, the open drain configuration allows for wired-OR connections and is useful when more than one signal needs to pull down on the RST or RST lines. VCC of 1V guarantees a maximum VOL = 0.15V. At VCC = 1V, the weak pull-up current on RST is barely turned on. Therefore, an external pull-up resistor of no more than 100k is recommended on the RST pin if the state and pull-up strength of the RST pin is crucial at very low VCC. Note however, by adding an external pull-up resistor, the pull-up strength on the RST pin is increased. Therefore, if it is connected in a wired-OR connection, the pull-down strength of any single device must accommodate this additional pull-up strength. Output Rise and Fall Time Estimation The RST and RST outputs have strong pull-down capability. The following formula estimates the output fall time (90% to 10%) for a particular external load capacitance (CLOAD): tFALL 2.2 * RPD * CLOAD where RPD is the on-resistance of the internal pull-down transistor, typically 50 at VCC > 1V, and at room temperature (25C). CLOAD is the external load capacitance on the pin. Assuming a 150pF load capacitance, the fall time is 16.5ns. The rise time on the RST and RST pins is limited by a 400k internal pull-up resistance to VCC. A similar formula estimates the output rise time (10% to 90%) at the RST and RST pins: tRISE 2.2 * RPU * CLOAD where RPU is the pull-up resistance. Disable The LTC2910 allows disabling the RST and RST outputs via the DIS pin. Pulling DIS high forces both outputs to remain unasserted, regardless of any faults that occur on the inputs. However, if a UVLO condition occurs, RST asserts and pulls low, RST asserts and pulls high, but the timeout function is bypassed. RST pulls high and RST pulls low as soon as the UVLO condition is cleared. DIS has a weak 2A (typical) internal pull-down current guaranteeing normal operation with the pin left open.
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LTC2910 TYPICAL APPLICATIONS
Eight UV Supply Monitor, 10% Tolerance, 12V, 5V (x2), 3.3V (x2), 2.5V, 1.8V, 1.2V
12V 5V 3.3V 2.5V POWER SUPPLIES 1.8V 1.2V 5V 3.3V RB8 54.9k RA8 11k RA7 11k RB7 88.7k RA6 11k RB6 12.7k RA5 11k RB5 24.9k RA4 11k RB4 39.2k RA3 11k RB3 54.9k RA2 11k RB2 88.7k RA1 11k RB1 226k
SYSTEM
8 V8
7 V7
6 V6
5 V5
4 V4
3 V3
2 V2
1 V1 VCC 16
LTC2910 GND 9 TMR 15 CTMR 1nF TIMEOUT = 8.5ms DIS 13 RST 12 RST 11
CBYP 0.1F
SEL 14
2910 TA02
Six Positive and Two Negative UV Supply Monitor, 10% Tolerance, 12V, 5V, 3.3V, 2.5V, 1.8V, 1.2V, -5V, -3.3V
12V 5V 3.3V POWER SUPPLIES 2.5V 1.8V 1.2V RB8 54.9k RA8 107k RA7 11k RB7 11k RA6 11k RB6 12.7k RA5 11k RB5 24.9k RA4 11k RB4 39.2k RA3 11k RB3 54.9k RA2 11k RB2 88.7k RA1 11k SYSTEM 8 V8 7 V7 10 REF 6 V6 5 V5 LTC2910 GND 9 TMR 15 CTMR 22nF TIMEOUT = 200ms DIS 13 RST 12 RST 11 4 V4 3 V3 2 V2 1 V1 VCC SEL 14 16 CBYP 0.1F RB1 226k
-3.3V -5V
2910 TA03
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LTC2910 TYPICAL APPLICATIONS
Six UV and One OV/UV Supply Monitor, 10% Tolerance, 12V, 5V, 3.3V (x2), 2.5V, 1.8V, 1.2V
12V 5V 3.3V POWER 2.5V SUPPLIES 1.8V 1.2V 3.3V RB7 27.4k RA8 4.53k RA7 1k RA6 11k RB6 12.7k RA5 11k RB5 24.9k RA4 11k RB4 39.2k RA3 11k RB3 54.9k RA2 11k RB2 88.7k RA1 11k RB1 226k SYSTEM
8 V8
7 V7
6 V6
5 V5
4 V4
3 V3
2 V2
1 V1 VCC 16 CBYP 0.1F
LTC2910 GND 9 TMR 15 CTMR 1nF TIMEOUT = 8.5ms DIS 13 RST 12 RST 11
SEL 14
2910 TA04
Six UV Supply Monitor Powered from 48V, 10% Tolerance, 48V, 5V, 3.3V, 2.5V, 1.8V, 1.2V
48V 5V 3.3V POWER 2.5V SUPPLIES 1.8V 1.2V RB6 12.7k RA6 11k RA5 11k RB5 24.9k RA4 11k RB4 39.2k RA3 11k RB3 54.9k RA2 11k RB2 88.7k RA1 11k RZ 8.25k 8 V8 7 V7 6 V6 5 V5 4 V4 3 V3 2 V2 1 V1 VCC RST 12 RST 11 SEL 14 16 CBYP 0.1F SYSTEM RB1 953k
LTC2910 GND 9 TMR 15 VCC DIS 13
2910 TA05
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LTC2910 TYPICAL APPLICATIONS
Eight UV Supply Monitor with Manual Reset Button, 10% Tolerance, 12V, 5V (x2), 3.3V (x2), 2.5V, 1.8V, 1.2V
12V 5V 3.3V 2.5V POWER 1.8V SUPPLIES 1.2V 5V 3.3V RPB 10k RA8 110k RB8 549k RB7 88.7k RB6 12.7k RB5 24.9k RB4 39.2k RB3 54.9k RB2 88.7k RB1 226k SYSTEM RA7 11k RA6 11k RA5 11k RA4 11k RA3 11k RA2 11k RA1 11k
MANUAL RESET BUTTON (NORMALLY OPEN)
8 V8
7 V7
6 V6
5 V5
4 V4
3 V3
2 V2
1 V1 VCC 16
LTC2910 GND 9 TMR 15 CTMR 22nF TIMEOUT = 200ms DIS 13 RST 12 RST 11
CBYP 0.1F
SEL 14
2910 TA06
2910fb
14
LTC2910 PACKAGE DESCRIPTION
DHC Package 16-Lead Plastic DFN (5mm x 3mm)
(Reference LTC DWG # 05-08-1706)
5.00 0.10 (2 SIDES) 0.65 0.05 3.50 0.05 3.00 0.10 (2 SIDES) 1.65 0.05 (2 SIDES) PACKAGE OUTLINE 1.65 0.10 (2 SIDES) PIN 1 NOTCH
(DHC16) DFN 1103
R = 0.115 TYP R = 0.20 TYP 9 16
0.40 0.10
2.20 0.05
PIN 1 TOP MARK (SEE NOTE 6) 8 0.200 REF 0.75 0.05 4.40 0.10 (2 SIDES) BOTTOM VIEW--EXPOSED PAD 1 0.25 0.05 0.50 BSC
0.25 0.05 0.50 BSC 4.40 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
0.00 - 0.05
NOTE: 1. DRAWING PROPOSED TO BE MADE VARIATION OF VERSION (WJED-1) IN JEDEC PACKAGE OUTLINE MO-229 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE
GN Package 16-Lead Plastic SSOP (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1641)
.189 - .196* (4.801 - 4.978) .015 .004 x 45 (0.38 0.10) .007 - .0098 (0.178 - 0.249) .016 - .050 (0.406 - 1.270)
.0532 - .0688 (1.35 - 1.75) .004 - .0098 (0.102 - 0.249) .009 (0.229) REF
16 15 14 13 12 11 10 9
.045 .005
0 - 8 TYP
.008 - .012 (0.203 - 0.305) TYP
.0250 (0.635) BSC
.229 - .244 (5.817 - 6.198)
.150 - .157** (3.810 - 3.988)
.254 MIN
.150 - .165
NOTE: 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS)
3. DRAWING NOT TO SCALE *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
1
23
4
56
7
8
.0165 .0015
.0250 BSC
RECOMMENDED SOLDER PAD LAYOUT
GN16 (SSOP) 0204
2910fb
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LTC2910 TYPICAL APPLICATION
Eight UV Supply Monitor with LED Indicator, 10% Tolerance, 12V, 5V (x2), 3.3V (x2), 2.5V, 1.8V, 1.2V
12V 5V 3.3V 2.5V POWER 1.8V SUPPLIES 1.2V 5V 3.3V 54.9k 11k 11k 88.7k 11k 12.7k 11k 24.9k 11k 39.2k 11k 54.9k 11k 88.7k 11k 226k SYSTEM
8 V8
7 V7
6 V6
5 V5
4 V4
3 V3
2 V2
1 V1 VCC 16 0.1F
LTC2910 GND 9 TMR 15 1nF TIMEOUT = 8.5ms DIS 13 RST 12 RST 11
SEL 14
2910 TA07
510 VCC
RELATED PARTS
PART NUMBER LTC690 LTC694-3.3 LTC2900 LTC2901 LTC2902 LTC2903 LTC2904 LTC2905 LTC2906 LTC2907 LTC2908 LTC2909 LTC2914 DESCRIPTION 5V Supply Monitor, Watchdog Timer and Battery Backup 3.3V Supply Monitor, Watchdog Timer and Battery Backup Programmable Quad Supply Monitor Programmable Quad Supply Monitor Programmable Quad Supply Monitor Precision Qual Supply Monitor 3-State Programmable Precision Dual Supply Monitor 3-State Programmable Precision Dual Supply Monitor Precision Dual Supply Monitor One Selectable and One Adjustable Precision Dual Supply Monitor One Selectable and One Adjustable Precision Six Supply Monitor (Four Fixed and Two Adjustable) Prevision Dual Input UV, OV and Negative Voltage Monitor Quad UV/OV Positive/Negative Voltage Monitor COMMENTS 4.65V Threshold 2.9V Threshold Adjustable RESET , 10-Lead MSOP and 3mm x 3mm 10-Lead DFN Package Adjustable RESET and Watchdog Timer, 16-Lead SSOP Package Adjustable RESET and Tolerance, 16-Lead SSOP Package, Margining Functions 6-Lead SOT-23 Package, Ultra Low Voltage Reset Adjustable Tolerance, 8-Lead SOT-23 Package Adjustable RESET and Tolerance, 8-Lead SOT-23 Package Separate VCC Pin, RST/RST Outputs Separate VCC, Adjustable Reset Timer 8-Lead SOT-23 and DDB Packages Separate VCC Pin, Adjustable Reset Timer, 8-Lead SOT-23 and DDB Packages Separate VCC Pin, Four Inputs, Up to Two Negative Monitors, Adjustable Reset Timer, 16-Lead SSOP and DFN Packages
2910fb LT 1106 REV B * PRINTED IN USA
16 Linear Technology Corporation
(408) 432-1900 FAX: (408) 434-0507
1630 McCarthy Blvd., Milpitas, CA 95035-7417
www.linear.com
(c) LINEAR TECHNOLOGY CORPORATION 2006

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