A3974SED Datasheet A3974SED, A3974SEDTR-T, A3974SED-T | P4-P6

DMOS Dual Full-Bridge PWM Motor Driver

A3974

3

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

FUNCTIONAL BLOCK DIAGRAM

CHARGE PUMP

BANDGAP

V

DD

C

REG

TSD

UNDER-

VOLTAGE &

FAULT DETECT

CHARGE

PUMP

BANDGAP

REGULATOR

V

DD

V

BB1

+

LOGIC

SUPPLY

V

REG

CP1

CP

CP2

LOAD

SUPPLY

1

GATE DRIVE

SLEEP

MODE

CONTROL LOGIC

PHASE

SYNC RECT MODE

SYNC RECT DISABLE

MODE

PROGRAMMABLE

PWM TIMER

SENSE

1

R

S1

FIXED OFF

BLANK

DECAY

ENABLE

1

OSC

CLOCK

DATA

STROBE

REFERENCE

BUFFER &

DIVIDER

OUT

1A

OUT

1B

REF

1

V

REF

C

S1

PROGRAMMABLE

PWM TIMER

FIXED OFF

BLANK

DECAY

GATE DRIVE

Dwg. FP-048-1

CONTROL LOGIC

PHASE

ENABLE

SYNC RECT MODE

SYNC RECT DISABLE

PWM MODE INT

PWM MODE EXT

SENSE

2

R

S2

ENABLE

2

REFERENCE

BUFFER &

DIVIDER

OUT

2A

OUT

2B

REF

2

V

REF2

C

S2

V

BB2

LOAD

SUPPLY

2

+

SERIAL

PORT

CHARGE

PUMP

TO PWM TIMER

ZERO CURRENT DETECT

CURRENT SENSE

ZERO CURRENT DETECT

CURRENT SENSE

DMOS Dual Full-Bridge PWM Motor Driver

A3974

4

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

ELECTRICAL CHARACTERISTICS at T

A

= +25°C, V

BB

= 50 V, V

DD

= 5.0 V, f

PWM

< 50 kHz (unless

otherwise noted).

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Output Drivers

Load Supply Voltage Range V

BB

Operating 15 — 50 V

During sleep mode 0 — 50 V

Output Leakage Current I

DSS

V

OUT

= V

BB

— <1.0 20 μA

V

OUT

= 0 V — <-1.0 -20 μA

Output ON Resistance r

DS(on)

Source driver, I

OUT

= -1.5 A — 0.5 0.55 Ω

Sink driver, I

OUT

= 1.5 A — 0.315 0.35 Ω

Body Diode Forward Voltage V

F

Source diode, I

F

= 1.5 A — — 1.2 V

Sink diode, I

F

= 1.5 A — — 1.2 V

Load Supply Current I

BB

f

PWM

< 50 kHz — 4.0 7.0 mA

Charge pump on, outputs disabled — 2.0 5.0 mA

Sleep or idle mode — — 20 μA

Control Logic

Logic Supply Voltage Range V

DD

Operating 4.5 5.0 5.5 V

Logic Input Voltage V

IN(1)

2.0 — — V

V

IN(0)

— — 0.8 V

Logic Input Current I

IN(1)

V

IN

= 2.0 V — <1.0 ±20 μA

(except ENABLE) I

IN(0)

V

IN

= 0.8 V — <1.0 ±20 μA

ENABLE Input Current I

EN(1)

V

EN

= 2.0 V — 40 100 μA

I

EN(0)

V

EN

= 0.8 V — 16 30 μA

OSC Input Frequency f

OSC

2.9 — 6.1 MHz

OSC Input Duty Cycle — 40 — 60 %

OSC Input Hysterisis ΔV

IN

200 — 400 mV

Reference Input Voltage Range V

REF

Operating 0 — 2.6 V

continued next page ...

DMOS Dual Full-Bridge PWM Motor Driver

A3974

5

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Limits

Characteristic Symbol Test Conditions Min. Typ. Max. Units

Control Logic (continued)

Reference Input Current I

REF

V

REF

= 2.6 V — — ±1.0 μA

Reference Input Offset Voltage V

IO

— ±10 — mV

Reference Divider Ratio V

REF

/V

S

D16 = 1 — 10 — —

D16 = 0 — 5.0 — —

Gain (G

m

) Error (note 3) E

G

V

REF

= 2.6 V, D16 = 0 — 0 ±4.0 %

V

REF

= 0.5 V, D16 = 0 — 0 ±14 %

V

REF

= 2.6 V, D16 = 1 — 0 ±4.0 %

V

REF

= 0.5 V, D16 = 1 — 0 ±10 %

Propagation Delay Time t

pd

50% TO 90%:

PWM change to source on 600 750 1000 ns

PWM change to source off 50 150 350 ns

PWM change to sink on 600 750 1000 ns

PWM change to sink off 50 150 350 ns

Crossover Delay Time t

COD

SR enabled 300 600 1000 ns

Thermal Shutdown Temperature T

J

— 165 — °C

Thermal Shutdown Hysteresis ΔT

J

— 15 — °C

UVLO Enable Threshold V

UVLO

Increasing V

DD

3.9 4.2 4.45 V

UVLO Hysteresis ΔV

UVLO

0.05 0.10 — V

Logic Supply Current I

DD

f

PWM

< 50 kHz — — 10 mA

Outputs off — — 8.0 mA

Idle mode (D18 = 1, D19 = 0) — — 1.5 mA

Sleep mode (inputs below 0.5 V) — — 100 μA

NOTES: 1. Typical Data is for design information only.

2. Negative current is deﬁ ned as coming out of (sourcing) the speciﬁ ed device terminal.

3. E

G

= [(V

REF

/Range) - V

S

]/(V

REF

/Range).

ELECTRICAL CHARACTERISTICS at T

A

= +25°C, V

BB

= 50 V, V

DD

= 5.0 V, f

PWM

< 50 kHz (unless

otherwise noted), continued.

A3974SED

A3974SED

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