View MAX562_126759.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

19-0144; Rev. 0; 9/93
Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers
_______________General Description
The MAX562 is designed specifically for notebook and palmtop computers that need to transfer data quickly. It runs at data rates up to 230kbps, and has a guaranteed 4V/s slew rate. This device meets the new EIA/TIA-562 standard that guarantees compatibility with RS-232 interfaces. The MAX562 has low-power shutdown and keep-awake modes. In keep-awake mode, the transmitters are disabled but all receivers are active, allowing unidirectional communication. In shutdown mode, the entire chip is disabled and all outputs are in a high-impedance state. The MAX562 is available in a standard 28-pin SO package, and in a smaller footprint shrink small-outline package (SSOP).
____________________________Features
o 230kbps Data Rate, LapLinkTM Compatible o Operates from a 2.7V to 5.25V Supply o Designed for EIA/TIA-562 and EIA/TIA-232 Applications o Guaranteed 4.0V/s Slew Rate o 3 Drivers, 5 Receivers o Flow Through Pinout o Low-Power Shutdown and Keep-Awake Modes o Low-Cost, Surface-Mount External Capacitors
MAX562
______________Ordering Information
PART MAX562CWI MAX562CAI MAX562C/D MAX562EWI MAX562EAI TEMP. RANGE 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C PIN-PACKAGE 28 SO 28 SSOP Dice* 28 SO 28 SSOP
________________________Applications
Palmtop, Notebook, and Subnotebook Computers Peripherals Battery-Powered Equipment
__________Typical Operating Circuit
0.33F +2.7V TO +5.25V 0.33F
* Contact factory for dice specifications.
__________________Pin Configuration
TOP VIEW
V CC 1 C1A+ 2 C1B+ 3 EIA/TIA -562 OUTPUTS C1B- 4 C1A- 5 R1 OUT 6 R2 OUT 7 R3 OUT 8 R4 OUT 9 EIA/TIA -562 INPUTS R5 OUT 10 T1 IN 11 T2 IN 12 T3 IN 13
MAX562 2 C1A 5 3 C1B 4 C1B+ C1B- 28 1 C1A+ C1AVOLTAGE VCC V+ 0.33F C3 0.68F DOUBLER/TRIPLER INPUT 25 C2+ VOLTAGE 26 C2 VINVERTER 24 C20.33F C4 0.33F
T1IN CMOS INPUTS T2IN T3IN R1OUT R2OUT CMOS OUTPUTS R3OUT R4OUT R5OUT EN 11 12 13 6 7 8 9 10 14 T1 T2 T3 R1 5k R2 5k R3 R4 5k R5 5k GND 27 19 15 21 5k 20 22 R2IN R3IN R4IN R5IN SHDN 18 17 16 23 T1OUT T2OUT T3OUT R1IN
28 V+ 27 GND 26 V25 C2+
MAX562
24 C223 R1 IN 22 R2 IN 21 R3 IN 20 R4 IN 19 R5 IN 18 T1 OUT 17 T2 OUT 16 T3 OUT 15 SHDN
EN 14
SO/SSOP
TM LapLink is a registered trademark of Traveling Software, Inc.
________________________________________________________________ Maxim Integrated Products 1
Call toll free 1-800-998-8800 for free samples or literature.
Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers MAX562
ABSOLUTE MAXIMUM RATINGS
VCC ......................................................................... -0.3V to +6V V+ ................................................................ (VCC - 0.3V) to +6V V- ............................................................................ +0.3V to -6V C1A+, C1B+.................................................. -6V to (V+ + 0.3V) C1A-, C1B-, C2+ ........................................ -0.3V to (V+ + 0.3V) C2- .................................................................. (V- - 0.3V) to +6V Input Voltages TIN, EN, SHDN ........................................ -0.3V to (VCC + 0.3V) RIN ....................................................................................25V Output Voltages TOUT ............................................................................... 15V ROUT ...................................................... -0.3V to (VCC + 0.3V) Short-Circuit Duration TOUT to GND ........................................................ Continuous ROUT to GND, VCC ................................................ Continuous Continuous Power Dissipation (TA = +70C) SO (derate 12.50mW/C above +70C) .................. 1000mW SSOP (derate 9.52mW/C above +70C) ................. 762mW Operating Temperature Ranges: MAX562C_ _ ..................................................... 0C to +70C MAX562E_ _ .................................................. -40C to +85C Storage Temperature Range ........................... -65C to +160C Lead Temperature (soldering, 10sec) ........................... +300C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = 2.7V to 5.25V, C1A = C1B = C2 = C4 = 0.33F, C3 = 0.68F, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER EIA/TIA-562 TRANSMITTERS Output Voltage Swing Input Logic Threshold Low Input Logic Threshold High Output Leakage Current Output Resistance Output Short-Circuit Current EIA/TIA-562 RECEIVERS Input Voltage Operating Range Input Threshold Low Input Threshold High Input Hysteresis Input Resistance Output Voltage Low Output Voltage High Output Leakage Current POWER SUPPLY Operating Supply Voltage VCC Power-Supply Current Shutdown Supply Current with Receivers Active Shutdown Supply Current VCC = 3.3V No load All outputs loaded 3k 2.7 20 24 45 1 130 50 5.25 33 V mA A A No hysteresis when SHDN = 0V -15V < VIN < 15V IOUT = 1.6mA IOUT = -1.0mA EN = GND, 0V ROUT VCC VCC -0.5 0.05 10 3 0.3 5 7 0.4 0.8 2.4 25 V V V V k V V A VCC = V+ = V- = 0V, VOUT = 2V VOUT = 0V 300 60 All transmitter outputs loaded with 3k to GND TIN, EN, SHDN TIN, EN, SHDN VCC = 2.7V to 3.6V VCC = 5.0V +5%, -10% VCC = 2.7V to 3.6V VCC = 5.0V +5%, -10% 1.8 3.0 10 3.7 4.5 6.0 0.6 0.8 V V V A mA CONDITIONS MIN TYP MAX UNITS
EN = VCC, SHDN = GND, TA = +25C SHDN = EN = GND, TA = +25C
2
_______________________________________________________________________________________
Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers
AC CHARACTERISTICS
PARAMETER Data Rate Transmitter Slew Rate CONDITIONS 1000pF || 3k load each transmitter output, 150pF load each receiver output CL = 50pF to 2500pF, RL = 3k to 7k. Measured from +3V to -3V, or -3V to +3V RL = 3k measured from +3.3V to -3.3V or -3.3V to +3.3V 2500pF || 3k load, Figure 1 Figure 3 CL = 150pF, SHDN = VCC Figure 2 CL = 150pF, SHDN = GND Figure 2 Figure 4 Figure 4 CL = 2500pF CL = 1000pF tPHLT tPLHT tET tDT tPHLR tPLHR tPHLS tPLHS tER tDR MIN 230.4 4 0.22 0.22 900 1000 100 600 100 250 3000 2000 100 250 250 ns 500 4000 ns 3000 250 500 ns ns TYP 280.0 6 30 3.1 s 2.1 1700 1700 ns s ns MAX UNITS kbits/sec V/s
MAX562
Transmitter Rise/Fall Time
Transmitter Propagation Delay Transmitter-Output Enable Time Transmitter-Output Disable Time Receiver Propagation Delay, Normal Operation Receiver Propagation Delay, Keep-Awake Mode Receiver-Output Enable Time Receiver-Output Disable Time
_______________________________________________________________________________________
3
Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers MAX562
__________________________________________Typical Operating Characteristics
(VCC = 3.3V, C1A = C1B = C2 = C4 = 0.33F, C3 = 0.68F, TA=+25C, unless otherwise noted.) TRANSMITTER SLEW RATE vs. LOAD CAPACITANCE
8.0 TRANSMITTER OUTPUT VOLTAGE (V-, V+) 7.5 7.0 SLEW RATE (V/s) 6.5 6.0 5.5 5.0 4.5 4.0 0 1000 2000 3000 4000 5000 SLEWSLEW+ ALL OUTPUTS LOADED 3k II CL 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6
TRANSMITTER OUTPUT VOLTAGE vs. TEMPERATURE
T_OUT+ +3.7V EIA/TIA-562 TRANSMITTER OUTPUT VOLTAGE (V-, V+)
TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE, TO 231kbps
6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 T_OUT+ ALL TRANSMITTERS LOADED 3k II CL
.....
ALL TRANSMITTERS LOADED 3k
-3.7V EIA/TIA-562 T_OUT-40 0 40 80
.....
T_OUT-
0
1000
2000
3000
4000
5000
CL(pF)
TEMPERATURE (C)
CL (pF)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
38 36 34 SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) 32 30 28 26 24 22 20 2.5 3.0 3.5 4.0 VCC (V) 4.5 5.0 5.5 ALL TRANSMITTERS LOADED 3k 38 36
SUPPLY CURRENT vs. TEMPERATURE
55 50 SUPPLY CURRENT (mA) VCC = +2.7V 45 40 35 30 25 20 -40 0 40 80 0
SUPPLY CURRENT vs. TRANSMITTER DATA RATE
34 32 30 28 26 24 22
3 OUTPUTS LOADED 3k II 2500pF
ALL TRANSMITTERS LOADED 3k
2 OUTPUTS LOADED 3k II 2500pF 1 OUTPUT LOADED 3k II 2500pF 50 100 150 200 250 DATA RATE (kbps)
VCC = +3.3V
TEMPERATURE (C)
SUPPLY CURRENT vs. TEMPERATURE
60 SHDN = 0, EN = 1 ALL TRANSMITTERS LOADED 3k 55 SUPPLY CURRENT (A)
50 VCC = +3.3V VCC = +2.7V 40
45
35
-40
0
40
80
TEMPERATURE (C)
4
_______________________________________________________________________________________
Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers
______________________________________________________________Pin Description
PIN NAME V+ C1A+, C1AC1B+, C1BR_OUT T_IN EN SHDN T_OUT R_IN C2+, C2VGND VCC FUNCTION Positive charge-pump output, typically 5.8V Terminals for positive charge-pump capacitor Terminals for positive charge-pump capacitor TTL/CMOS Receiver Outputs. TTL/CMOS Driver Inputs Receiver Enable, see Shutdown and Enable Control section. Shutdown Control, see Shutdown and Enable Control section. EIA/TIA-562 Driver Outputs EIA/TIA-562 Receiver Inputs Terminals for negative charge-pump capacitor Negative charge-pump output, typically -5.2V Ground +2.7V to +5.25V Supply Voltage
MAX562
28
2, 5 3, 4 6, 7, 8, 9, 10 11, 12, 13 14 15 16, 17, 18 19, 20, 21, 22, 23 24, 25 26 27 1
+3V INPUT 0V INPUT
+3V 50% 50% 0V VCC 50% 50% GND tPLHR tPLHS
OUTPUT
VOH 0V VOL tPHLT
OUTPUT
tPLHT
tPHLR tPHLS
Figure 1. Transmitter Propagation Delay Timing
Figure 2. Receiver Propagation Delay Timing
_______________________________________________________________________________________
5
Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers MAX562
EN R_OUT SHDN +3V 0V OUTPUT DISABLE TIME (tDT) VOH +3V TRANSMITTER OUTPUTS -3V VOL 0V VOH RECEIVER OUTPUTS VOL A. TIMING DIAGRAM B. ENABLE TIMING R_IN A. TEST CIRCUIT 150pF EN INPUT +3V 0V EN OUTPUT ENABLE TIME (tER) R_ 1k VOH -1V, VOL +1.6V
+3V 1 OR 0 TX 3k 50pF EN INPUT VOH 0V
EN
OUTPUT DISABLE TIME (tDR) VOH -0.5V RECEIVER OUTPUTS VOL +0.5V VOL C. DISABLE TIMING
B. TEST CIRCUIT
Figure 3. Transmitter-Output Disable Timing
Figure 4. Receiver-Output Enable and Disable Timing
_______________Detailed Description
The MAX562 has three sections: the charge-pump voltage converter, the drivers (transmitters), and the receivers.
EIA/TIA-562 Drivers
The driver output voltage is guaranteed to meet the 3.7V EIA/TIA-562 specification over the full range of operating temperatures and voltages, when each transmitter is loaded with up to 3k and operated up to 230kbps (see Typical Operating Characteristics). The typical driver output voltage swing exceeds 4V with a 3k load on all transmitter outputs. The open-circuit output voltage swing is typically from (V+ - 0.7V) to (V- + 0.7V). Output swing is not significantly dependent on VCC since the charge pumps are regulated. Input thresholds are CMOS and TTL compatible. Connect unused inputs to VCC or to GND. When SHDN is low, the driver outputs are off and their leakage currents are less than 10A, even if the transmitter outputs are back-driven between -7V and +15V. Taking SHDN low does not disable the receivers. When SHDN and EN are both low, the entire chip is disabled and all outputs are high impedance. Power consumption is lowest in this condition. Exiting shutdown takes about 100s, but depends on VCC. Figure 5 shows
Charge-Pump Voltage Converter
The charge-pump voltage converter is used to produce a positive and a negative supply to drive the transmitters. The positive voltage (V+) is generated by a regulated charge pump working as either a doubler or a tripler (depending on the VCC level) and using capacitors C1A, C1B and C3 (see Typical Operating Circuit). The negative voltage (V-) derives from V+ using a simple charge-pump inverter that employs capacitors C2 and C4. These charge-pump converters are regulated to give output voltages of +5.8V and -5.2V. Having regulated supplies generated on-chip makes the MAX562's performance insensitive to variations in VCC from 2.7V to 5.25V, transmitter loading changes, and operating temperature changes. When SHDN is low, the charge pumps are disabled, V+ is internally connected to VCC, and V- is internally connected to GND.
6
_______________________________________________________________________________________
Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers
5 0 6 4 VOLTS (V) 2 VCC = +2.2V V CC = +2.7V 0 -2 -4 0 100 TIME (s) 200 300 V CC = +3.3V V CC = +5.0V SHDN
The guaranteed 0.8V and 2.4V receiver input thresholds are significantly tighter than the 3.0V thresholds required by the EIA/TIA-562 specification. This allows the receiver inputs to respond to TTL/CMOS logic levels as well as EIA/TIA-562/232 levels. Also, the MAX562's guaranteed 0.8V lower threshold ensures that receivers shorted to ground will have a logic 1 output. The 5k input resistance to ground ensures that a receiver with its input left open will also have a logic 1 output. The receiver inputs have approximately 0.3V hysteresis when SHDN is high. This provides clean output transitions, even with slowly moving input signals with moderate noise and ringing. The receivers are active when EN is high. When EN is low, the receiver outputs are high impedance. This allows wire-OR connection of two EIA/TIA-562 ports (or ports of different types) at the UART. The receivers are always active,when EN is high, irrespective of SHDN's state. When SHDN is high, the receivers have hysteresis and experience the shortest propagation delays (typically 100ns falling, 250ns rising). When SHDN is low, the receivers have longer propagation delays (typically 3s falling, 2s rising) and have no hysteresis. The receiver outputs are not valid for 50s after SHDN goes low.
MAX562
Figure 5. Time for Transmitters to Exit Shutdown
the MAX562 transmitter outputs when SHDN rises. Two transmitter outputs are shown going to opposite EIA/TIA562 levels (one transmitter input is high, the other is low). Each transmitter is loaded with 3k in parallel with 2500pF. The transmitter outputs are well behaved, with no ringing or undesirable transients as they come out of shutdown.
Driving Multiple Receivers Each transmitter is designed to drive a single receiver. Transmitters can be paralleled to drive multiple receivers.
Shutdown and Enable Control
SHDN and EN determine the operation of the MAX562 as shown in Table 1.
EIA/TIA-562 Receivers
All 5 receivers are identical and accept EIA/TIA-562 or EIA/TIA-232 signals. The CMOS receiver outputs swing between VCC and GND. They are inverting, maintaining compatibility with the driver outputs.
__________Applications Information
Capacitor Selection
The capacitor type is not critical for proper MAX562 operation. Any low cost ceramic capacitor (e.g., Z5U, Y5V) is acceptable for operating at room temperature,
Table 1. MAX562 Control Pin Configurations
SHDN
0 0 1 1
EN
CHARGE-PUMP OPERATION STATUS
TRANSMITTERS T1-T3
RECEIVERS R1-R5
SUPPLY CURRENT TYP (A)
0 1 0 1
Shutdown Shutdown Normal Operation Normal Operation
High-Z High-Z Active Active
High-Z Active* High-Z Active
1 45 24m 24m
* Active, but with reduced performance (see EIA/TIA-562 Receivers section). This is "keep-awake" mode.
_______________________________________________________________________________________
7
Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers MAX562
Table 2. Summary of EIA/TIA-232E/V.28 and EIA/TIA-562 Specifications
PARAMETER Driver Output Voltage 0 Level 1 Level Maximum Output Level Signal Rate (3k RL 7k) No load CL = 2500pF CL = 1000pF CONDITION EIA/TIA-232E/V.28 SPECIFICATION 5.0V to 15.0V 3k to 7k load -5.0V to -15.0V 25V Up to 20kbps Not defined -3.7V to -13.2V 13.2V Up to 20kbps Up to 64kbps EIA/TIA-562 SPECIFICATION 3.7V to 13.2V
and X7R ceramic capacitors are recommended for operation over the full temperature range. Larger capacitors may be used for C2 and C4 (see Typical Operating Circuit) to reduce ripple on the transmitter output voltages.
___________________Chip Topography
C1B+ C1A+
3 2 1
V CC
V+
GND V-
C2+
25
28 27 26
Power-Supply Decoupling
In applications that are sensitive to power-supply noise, decouple V CC to ground with a capacitor similar in value to that of the C1A and C1B charge-pump capacitors. Connect the bypass capacitor as close as possible to the VCC and GND pins.
24 C1BC1A4 5 23 R1 OUT R2 OUT R3 OUT R4 OUT R5 OUT 6 7 8 9 10 20 R4 IN 19 R5 IN 0.164" (4.166mm) R1 IN C2-
V+ and V- as Power Supplies
A small amount of power can be drawn from V+ and V-. Excessive loads will cause V+ and V- to fall out of regulation. When V+ or V- are loaded, check for good regulation over the intended operating temperature range.
22 R2 IN 21 R3 IN
11 12 13 14 15 16 17 18 T2 IN EN T3 OUT T1 OUT T1 IN T3 IN SHDN T2 OUT 0.135" (3.429mm)
Substrate connected to V+ Transistor count: 1892
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
8 ___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 (c) 1993 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

▲Up To Search▲

Price & Availability of MAX562

	To Download MAX562 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .