A2557KB, A2557KEB, A2557KLB have been specifically designed provide co

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2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
A2557KB, A2557KEB, A2557KLB have been specifically designed provide cost-effective solutions relay-driving applications with drive current channel. They also used driving incandescent lamps applications where turn-on time concern. Each four outputs will sink state. outputs have minimum breakdown voltage sustaining voltage low-power Sleep Mode activated with either ENABLE inputs low. this mode, supply current drops below Over-current protection each channel been designed into these devices activated nominal protects each output from short circuits with supply voltages When output experiences short circuit, output current limited current clamp. addition, foldback circuitry decreases current limit excessive voltage present across output assists keeping device within (safe operating area). exclusive-OR circuit compares input output state each driver. either short open load condition detected, single FAULT output turned (active low). Similar devices, operation available UDx2547B/EB. Continuous multiple overload conditions causing channel temperature reach approximately 165°C will result additional linear decrease output current affected driver. fault condition corrected, output stage will return normal saturated condition. suffix devices 16-pin power DIPs; suffix `EB' devices 28-lead power PLCCs suffix `LB' 16-lead power SOICs surfacemount applications. packages batwing construction provide maximum package power dissipation.
Data Sheet 29317.16
PROTECTED QUAD LOW-SIDE DRIVER WITH FAULT DETECTION SLEEP MODE
A2557KLB
OUT1 OUT2 GROUND GROUND OUT3 FAULT OUT4 ENABLE GROUND GROUND
Dwg. PP-017-4
Note that A2557KB (DIP) A2557KLB (SOIC) electrically identical share common terminal number assignment.
ABSOLUTE MAXIMUM RATINGS
Output Voltage, Over-Current Protected Output Voltage, Output Current, FAULT Output Voltage, VFLT Logic Supply Voltage, Input Voltage, Package Power Dissipation, Graph Operating Temperature Range, -40°C +125°C Junction Temperature, +150°C* Storage Temperature Range, -55°C +150°C
*Outputs current limited approximately driver junction temperature limited higher current attempted.
FEATURES Output Current Channel Independent Over-Current Protection &Thermal Limiting Each Driver Output Voltage Output Protection Fault-Detection Circuitry Open Shorted Load Quiescent Current Sleep Mode Integral Output Flyback/Clamp Diodes TTL- CMOS-Compatible Inputs
Complete part number includes suffix identify operating temperature range (K-) package type (-B, -EB, -LB). Always order complete part number, e.g., A2557KLB
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
FUNCTIONAL BLOCK DIAGRAM
FAULT ENABLE SLEEP CONTROL
COMMON CONTROL FOUR DRIVERS
OUTN
THERMAL LIMIT CURRENT LIMIT
Dwg. FP-007-2
A2557KEB
CONNECTION
ENABLE
ALLOWABLE PACKAGE POWER DISSIPATION WATTS
OUT2
OUT1
SUFFIX 'EB', 36°C/W
6°C/W
GROUND GROUND GROUND GROUND
SUFFIX 'B', 43°C/W
SUFFIX 'LB', 63°C/W
TEMPERATURE
CONNECTION
FAULT
SUPPLY
Dwg. GP-004-2A
Dwg. PP-019-2
Northeast Cutoff, 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright 1998, Allegro MicroSystems, Inc.
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
ELECTRICAL CHARACTERISTICS over operating temperature range, 4.75 5.25
Characteristic
Output Leakage Current
Symbol
ICEX
Test Conditions
Min.
Limits Typ. Max.
<1.0 <1.0
Units
Output Sustaining Voltage Output Saturation Voltage
VO(SUS) VO(SAT)
Open
Over-Current Limit Input Voltage
PulseTest, ENABLE ENABLE ENABLE, ENABLE, VFLT VFLT
Input Current
Fault Output Leakage Current
IFLT
Fault Output Current Fault Output Saturation Voltage Clamp Diode Forward Voltage
IFLT VFLT(SAT)
VFLT Driver Output Open, IFLT
Clamp Diode Leakage Current Turn-ON Delay
tPHL
From Sleep,
Turn-OFF Delay
tPLH
Total Supply Current
Outputs Output Outputs Three Outputs Outputs
Thermal Limit
Typical Data +25°C design information only. *Measurement includes input current other elements.
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
TYPICAL OPERATING CHARACTERISTICS
+25°C
OUTPUT CURRENT LIMIT MILLIAMPERES
Dwg. GP-064
OUTPUT SATURATION VOLTAGE VOLTS
Dwg. GP-065
OUTPUT CURRENT MILLIAMPERES
OUTPUT VOLTAGE VOLTS
SWITCHING (FROM SLEEP)
TURN-OFF DELAY MICROSECONDS
TURN-ON DELAY MICROSECONDS
+25°C
+25°C
ENABLE SWITCHING
SWITCHING (AWAKE)
Dwg. GP-066
Dwg. GP-066-1
OUTPUT CURRENT MILLIAMPERES
OUTPUT CURRENT MILLIAMPERES
Northeast Cutoff, 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
CIRCUIT DESCRIPTION APPLICATION
A2557 low-current quad power drivers provide same protected output driver function (and compatible with) UDx2543/49/59 devices, combined with fault diagnostic scheme similar UDx2547, plus automatic low-current Sleep-Mode function. These devices monitor their outputs fault (open shorted) conditions. each channel input output levels compared. these different from expected levels then fault condition flagged pulling common FAULT output low. Status Normal Load Sleep Mode Over-Current Short Supply Open Load Short Ground ENABLE FAULT power dissipation output device increases local junction temperature above 165°C (nominal), limit power dissipation (and hence local junction temperature). each channel thermal limit circuitry this provides some independence between output channels, i.e., channel operating thermally reduced current limit, while others provide full drive capability. function output voltage. Full current limit (nominal) available approximately above this limit reduced linearly about This helps improve immediately reducing peak power pulse into shorted load high logic ENABLE input causes outputs switched regardless state terminals. addition, device into quiescent current `sleep' mode, reducing below ENABLE taken high inputs high, circuit will `auto-wake-up'. However, device enabled, inputs stay low, then circuit remains `sleep' mode. outputs have internal flyback diodes, with commoncathode connection terminal. Incandescent lamp driver High incandescent lamp turn-ON (in-rush currents) contribute poor lamp reliability destroy semiconductor lamp drivers. When incandescent lamp initially turned cold filament minimum resistance would normally allow in-rush current. Warming (parallel) current-limiting (series) resistors protect both driver lamp significant power either when lamp when lamp respectively. Lamps with steady-state current ratings driven without need warming current-limiting resistors, lamp turn-ON time concern (10's ms). With these drivers, during turn-ON, high in-rush current sensed internal sense resistor, drive current output stage reduced, output operates linear mode with load current limited approximately During lamp warmup, filament resistance increases maximum value, output driver goes into saturation applies maximum rated voltage lamp.
Thermal Fault Linear drive, current limited.
FAULT output operational only ENABLE high. output state detected monitoring OUTn terminal using comparator whose threshold typically order detect open-circuit outputs, current sink pulls output below comparator threshold. ensure correct fault operation, minimum load approximately required. fault function disabled when `sleep' mode, i.e., FAULT goes high output sinks turned OFF. FAULT output switched current sink typically Each channel consists TTL/CMOS-compatible logic input gated with common ENABLE input. logic high input will provide drive turn output switch. Each output current-limit circuit that limits output current detecting voltage drop across low-value internal resistor emitter output switch. this drop reaches threshold, then base drive output switch reduced maintain constant current output. keep device within safe operating area (SOA) this output current limit further reduced
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
CIRCUIT DESCRIPTION APPLICATION (continued)
Fault diagnostics
NORMAL LAMP IN-RUSH CURRENT
SCALE
LAMP CURRENT
pull-up resistor current source required FAULT output. This connected whatever supply level following circuitry requires (within specification constraints). supply (i.e., Vcc) greater should used. fault diagnostic function indicate when output state different from input state channel, FAULT output waveform will obviously produce pulse waveform following combined duty-cycle channels showing fault condition. There therefore basic approaches using function application: interrupt controller-based system. system microcontroller then FAULT causes interrupt, which then initiates diagnostic sequence find culprit channel. This sequence usually consists cycling through each channel time, while monitoring FAULT output. then easy determine which channel faulty output failing (i.e., short supply, opencircuit short ground). system then take whatever action required, could continue with operation remaining `good' channels while disabling signals faulty channel. simple `common' fault indication. there controller system then FAULT output give indication (via lamp LED, etc.) fault condition which might anywhere four channels. Because FAULT output dependent states input output (four possibilities) will only indicate them, duty cycle FAULT output will reflect duty cycle faulty channel's input inverse, depending upon fault type). typical applications (50% duty cycles) simple solution make pull-up current FAULT output much less than pull-down current µA), capacitor give time constant longer than period operation. typical values, device will produce continuous output level. Component values will need adjusted cope with different conditions.
THERMAL GRADIENT SENSING CURRENT LIMIT ITRIP
TIME
Dwg. WP-008
Inductive load driver Bifilar (unipolar) stepper motors (and other inductive loads) driven directly. internal diodes prevent damage output transistors suppressing high-voltage spikes that occur when turning inductive load. rapid current decay (fast turn-OFF speeds), Zener diodes will raise flyback voltage improve performance. However, peak voltage must exceed specified minimum sustaining voltage (VSUPPLY VO(SUS)). Over-current conditions event shorted load, stalled motor, load current will attempt increase. described above, drive current affected output stage linearly reduced, causing output linear (limiting load current about mA). junction temperature output stage increases, thermal-shutdown circuit will shut affected output. fault condition corrected, output driver will return normal saturated condition.
Northeast Cutoff, 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
CIRCUIT DESCRIPTION APPLICATION (continued)
SCALE
FAULT
(SHORTED LOAD)
WITH OUTPUT CAPACITOR
FAULT
(OPEN LOAD)
Dwg. WP-035
OUTPUT CURRENT
SHORT CIRCUIT
NORMAL LOAD CURRENT LIMIT SUPPLY)
Under some conditions possible spurious glitches FAULT output load turn-ON turn-OFF transitions: Light load turn-OFF. Under light loading conditions turn-OFF delay (see characteristics above) output stage increases result spurious fault output (the duration being proportional turn-OFF delay). difficult define this over operating conditions, particular application would sensitive this type glitch, then generally recommended include small (about 0.01 smoothing/storage capacitor FAULT output. Incandescent lamp turn-ON. described above, driving incandescent filament results driver operating current limit period after turn-ON. During this period "fault" condition will indicated (over current). discussed above this period 10's avoid this indication, capacitor FAULT output would need increased provide appropriate time constant. Alternatively, microcontroller-based system, code could written ignore FAULT condition appropriate period after lamp turn Correct FAULT operation cannot guaranteed with unconnected output unused outputs should turned unused outputs should pulled high >2.5 and/or associated inputs tied low.
CURRENT LIMIT SUPPLY)
TIME
Dwg. WP-013-1
Thermal considerations Device power dissipation calculated as:PD (VO1 duty cycle1) (VO4 duty cycle4) (VCC ICC) Note also modulated duty cycle, this reasonable approximation most purposes. This then compared against permitted package power dissipation, using: Permitted (150 TA)/RJA where given 28-lead PLCC (part number suffix `EB') 36°C/W 16-pin PDIP (part number suffix `B') 43°C/W 16-lead SOIC (part number suffix `LB') 60°C/W thermal resistance from junction power (RJT) about 6°C/W three package types, therefore power dissipation improved adding area printed wiring board copper (typically square centimetres) connected power-tab GROUND terminals device.
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
A2557KB
Dimensions Inches (controlling dimensions)
0.020 0.008
NOTE
0.430 0.280 0.240
0.300
0.070 0.045
0.100 0.775 0.735
0.005
0.210
0.015
0.150 0.115 0.022 0.014
Dwg. MA-001-17A
Dimensions Millimeters (for reference only)
NOTE
0.508 0.204
10.92 7.11 6.10
7.62
1.77 1.15
2.54 19.68 18.67
0.13
5.33
0.39
3.81 2.93 0.558 0.356
Dwg. MA-001-17A
NOTES:1.
Exact body lead configuration vendor's option within limits shown. Lead spacing tolerance non-cumulative Lead thickness measured seating plane below. Webbed lead frame. Leads internally piece.
Northeast Cutoff, 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
A2557KLB
Dimensions Inches (for reference only)
0.0125 0.0091
0.2992 0.2914
0.419 0.394
0.050 0.016 0.020 0.013
0.4133 0.3977
0.050
0.0926 0.1043 0.0040 MIN.
Dwg. MA-008-17A
Dimensions Millimeters (controlling dimensions)
0.32 0.23
7.60 7.40
10.65 10.00
1.27 0.40 0.51 0.33
10.50 10.10
1.27
2.65 2.35 0.10 MIN.
Dwg. MA-008-17A
NOTES:1.
Exact body lead configuration vendor's option within limits shown. Lead spacing tolerance non-cumulative Lead thickness measured seating plane below. Webbed lead frame. Leads internally piece.
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
A2557KEB
Dimensions Inches (controlling dimensions)
0.013 0.021 0.219 0.191
0.050
0.026 0.032 0.456 0.450 0.495 0.485
INDEX AREA
0.219 0.191
0.020
0.165 0.180
0.456 0.450 0.495 0.485
Dwg. MA-005-28A
Dimensions Millimeters (for reference only)
0.331 0.533 5.56 4.85
1.27
0.812 0.661 11.58 11.43 12.57 12.32
INDEX AREA
5.56 4.85
0.51
4.57 4.20
11.582 11.430 12.57 12.32
Dwg. MA-005-28A
NOTES:1. Exact body lead configuration vendor's option within limits shown. Lead spacing tolerance non-cumulative Webbed lead frame. Leads through through internally piece.
Northeast Cutoff, 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
Allegro MicroSystems, Inc. reserves right make, from time time, such departures from detail specifications required permit improvements design products. information included herein believed accurate reliable. However, Allegro MicroSystems, Inc. assumes responsibility use; infringements patents other rights third parties which result from use.
2557 PROTECTED QUAD DRIVER WITH FAULT DETECTION SLEEP MODE
POWER SINK DRIVERS SELECTION GUIDE
ORDER OUTPUT CURRENT, OUTPUT VOLTAGE, NUMBER DRIVERS
Output Ratings
Serial Latched
Features
Diode Saturated Internal Protection Input Drivers Clamp Outputs Hall Sensor/Driver Hall Sensor/Driver Dual 14-Line Decoder/Driver Hall Sensor/Driver Hall Sensor/Driver Stepper Motor Controller/Driver Microstepping Controller/Driver Stepper Motor Translator/Driver Stepper Motor Controller/Driver
Part Number
2595 5833 5832 7003 5140 2003 2803 2596 5275 2557 2023 2823 5800 2004 2804 5801 5821 5822 5841 5842 2024 2824 6817 2547 2549 2543 2559 2597 3625 3626 7024 7029 7042 5804 2064 2068 2065 2069 5829 2544 2540 7026 2878 2879
1000 1200 1250 1500 1600 1800 3000 4000
Current maximum specified test condition, voltage maximum rating. specification sustaining voltage limits over-current protection voltage limits. Complete part number includes additional characters indicate operating temperature range package style.
Northeast Cutoff, 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000

A2557KB, A2557KEB, A2557KLB have been specifically designed provide co

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