A3974SED-T

A3974SED-T Datasheet

A3974 DMOS Dual Full-Bridge PWM Motor Driver

Part	Datasheet
A3974SED-T	A3974SED-T (pdf)

Related Parts	Information
A3974SEDTR-T	A3974SEDTR-T
A3974SEDTR	A3974SEDTR
A3974SED	A3974SED

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A3974 DMOS Dual Full-Bridge PWM Motor Driver Last Time Buy These parts are in production but have been determined to be LAST TIME BUY. This classification indicates that the product is obsolete and notice has been given. Sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because of obsolescence in the near future. Samples are no longer available. Date of status change November 2, 2009 Deadline for receipt of LAST TIME BUY orders April 30, 2010 Recommended Substitutions: For existing customer transition, and for new customers or new applications, refer to the A3992. NOTE For detailed information on purchasing options, contact your local Allegro field applications engineer or sales representative. A3974 DMOS Dual Full-Bridge PWM Motor Driver A, 50 V continuous output rating Low rDS on DMOS output drivers Programmable slow, fast, and mixed current-decay modes Serial-interface controls chip functions Synchronous rectification for low power dissipation Internal UVLO and thermal shutdown circuitry Crossover-current protection Sleep and idle modes Package 44-pin PLCC with internally fused pins suffix ED Not to scale Designed for pulse width modulated PWM current control of two DC motors, the A3974 is capable of output currents to A and operating voltages to 50 V. Internal fixed off-time PWM current-control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed currentdecay modes. Independent ENABLE input terminals are provided for use in controlling the speed and torque of each DC motor with externally applied PWM control signals. Synchronous rectification circuitry allows the load current to flow through the low rDS on of the DMOS output driver during the current decay. This feature will eliminate the need for external clamp diodes in most applications, saving cost and external component count, while minimizing power dissipation. Internal circuit protection includes thermal shutdown with hysteresis, undervoltage monitoring of VDD and the charge pump, and crossover-current protection. Special power-up sequencing is not required. TheA3974 is supplied in a 44-pin plastic PLCC with 3 internally fused pins on each side, for maximum heat dissipation. The fused pins are at ground potential and need no electrical isolation. Pin-out Diagram 6 OUT1A 5 NC 4 NC 3 SENSE1 2 GND 1 GND 44 GND LOAD 43 SUPPLY1 42 ENABLE1 41 NC 40 OUT1B 29319.35C OUT2A 18 NC 19 NC 20 SENSE2 21 GND 22 GND 23 GND 24 LOAD SUPPLY2 25 ENABLE2 26 NC 27 OUT2B 28 NC 7 STROBE 8 CLOCK 9 DATA 10 GND 11 GND 12 GND 13 REF1 14 REF2 15 LOGIC SUPPLY 16 VDD NC 17 SERIAL PORT CHARGE PUMP VBB1 PROGRAM PWM TIMER LOGIC PROGRAM PWM TIMER LOGIC VBB2 39 NC 38 CP2 37 CP1 36 CP 35 GND 34 GND 33 GND 32 OSC 31 SLEEP 30 VREG 29 NC Dwg. PP-073 A3974 DMOS Dual Full-Bridge PWM Motor Driver Selection Guide Part Number A3974SED-T A3974SEDTR-T

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A3974 DMOS Dual Full-Bridge PWM Motor Driver

Last Time Buy

These parts are in production but have been determined to be LAST TIME BUY. This classification indicates that the product is obsolete and notice has been given. Sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because of obsolescence in the near future. Samples are no longer available. Date of status change November 2, 2009 Deadline for receipt of LAST TIME BUY orders April 30, 2010

Recommended Substitutions:

For existing customer transition, and for new customers or new applications, refer to the A3992.

NOTE For detailed information on purchasing options, contact your local Allegro field applications engineer or sales representative.

A3974 DMOS Dual Full-Bridge PWM Motor Driver

A, 50 V continuous output rating Low rDS on DMOS output drivers Programmable slow, fast, and mixed current-decay modes Serial-interface controls chip functions Synchronous rectification for low power dissipation Internal UVLO and thermal shutdown circuitry Crossover-current protection Sleep and idle modes

Package 44-pin PLCC with internally fused pins suffix ED

Not to scale

Designed for pulse width modulated PWM current control of two DC motors, the A3974 is capable of output currents to A and operating voltages to 50 V. Internal fixed off-time PWM current-control timing circuitry can be programmed via a serial interface to operate in slow, fast, and mixed currentdecay modes.

Independent ENABLE input terminals are provided for use in controlling the speed and torque of each DC motor with externally applied PWM control signals.

Synchronous rectification circuitry allows the load current
to flow through the low rDS on of the DMOS output driver
during the current decay. This feature will eliminate the need for external clamp diodes in most applications, saving cost and external component count, while minimizing power dissipation.

Internal circuit protection includes thermal shutdown with hysteresis, undervoltage monitoring of VDD and the charge pump, and crossover-current protection. Special power-up sequencing is not required.

TheA3974 is supplied in a 44-pin plastic PLCC with 3 internally fused pins on each side, for maximum heat dissipation. The fused pins are at ground potential and need no electrical isolation.

Pin-out Diagram
6 OUT1A 5 NC 4 NC 3 SENSE1 2 GND 1 GND 44 GND

LOAD 43 SUPPLY1 42 ENABLE1 41 NC 40 OUT1B
29319.35C

OUT2A 18 NC 19 NC 20

SENSE2 21 GND 22 GND 23 GND 24

LOAD SUPPLY2 25 ENABLE2 26

NC 27 OUT2B 28

NC 7 STROBE 8

CLOCK 9 DATA 10 GND 11 GND 12 GND 13 REF1 14 REF2 15 LOGIC

SUPPLY 16 VDD NC 17

SERIAL PORT CHARGE PUMP

VBB1

PROGRAM PWM TIMER

LOGIC

PROGRAM PWM TIMER

LOGIC

VBB2
39 NC 38 CP2 37 CP1 36 CP 35 GND 34 GND 33 GND 32 OSC 31 SLEEP 30 VREG 29 NC

Dwg. PP-073

A3974

DMOS Dual Full-Bridge PWM Motor Driver

Selection Guide Part Number

A3974SED-T A3974SEDTR-T

More datasheets: 277200095300002 | 277200095302001 | 277200095302101 | 277200095303002 | 677200262300675 | 277200095302002 | AT25DF081-SSHN-B | A3974SEDTR-T | A3974SEDTR | A3974SED

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Datasheet ID: A3974SED-T 516032