UNITRODE UC3770A, UC3770B Technical data

UNITRODE UC3770A, UC3770B Technical data

UC3770

UC3770A

UC3770B

High Performance Stepper Motor Drive Circuit

FEATURES

Full-Step, Half-Step and Micro-Step Capability.

Bipolar Output Current up to 2A.

Wide Range of Motor Supply Voltage: 10–50V

Low Saturation Voltage

Wide Range of Current Control: 5mA–2A.

Current Levels Selected in Steps or Varied Continuously.

Thermal Protection and Soft Intervention.

DESCRIPTION

The UC3770A and UC3770B are high-performance full bridge drivers that offer higher current and lower saturation voltage than the UC3717 and the UC3770. Included in these devices are LS-TTL compatible logic inputs, current sense, monostable, thermal shutdown, and a power H-bridge output stage. Two UC3770As or UC3770Bs and a few external components form a complete micro- processor-controllable stepper motor power system.

Unlike the UC3717, the UC3770A and the UC3770B require external high-side clamp diodes. The UC3770A and UC3770B are identical in all regards except for the current sense thresholds. Thresholds for the UC3770A are identical to those of the older UC3717 permitting drop-in replacement in applications where high-side diodes are not required. Thresholds for the UC3770B are tailored for half stepping applications where 50%, 71%, and 100% current levels are desirable.

The UC3770A and UC3770B are specified for operation from 0° C to 70° C ambient.

BLOCK DIAGRAM

UDG-92039-1

SLUS403A - FEBRUARY 2000

UC3770A

UC3770B

ABSOLUTE MAXIMUM RATINGS

Logic Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V

Output Supply Voltage, VMM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50V

Logic Input Voltage (Pins 7, 8, 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6V

Analog Input Voltage (Pin 10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VCC

Reference Input Voltage (Pin 11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15V Logic Input Current (Pins 7, 8, 9) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –10mA Analog Input Current (Pins 10, 11) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –10mA Output Current (Pins 1, 15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 2A Junction Temperature, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150° C

Note 1: All voltages are with respect to Gnd (DIL Pins 4, 5, 12, 13); all currents are positive into, negative out of the specified terminal.

Note 2: Consult Unitrode Integrated Circuits databook for thermal limitations and considerations of packages.

CONNECTION DIAGRAMS

DIL-16 (Top View)

PLCC-28 (Top View)

PACKAGE PIN FUNCTION

FUNCTION

PIN

J Or N Package

Q Package

Gnd

1-3

 

 

VM

4

 

 

N/C

5

 

 

AOUT

6

 

 

N/C

7

 

 

Emitters

8

 

 

Gnd

9

 

 

BOUT

10

 

 

Timing

11

 

 

VM

12

 

 

Gnd

13-17

 

 

VCC

18

 

 

I1

19

 

 

Phase

20

 

 

I0

21

 

 

N/C

22

 

 

Current

23

 

 

VR

24

 

 

N/C

25-27

 

 

Gnd

28

ELECTRICAL CHARACTERISTICS: (All tests apply with VM = 36V, VCC = 5V, VR = 5V, No Load, and 0° C<TA<70° C, unless otherwise stated, TA = TJ.)

 

 

 

UC3770A

 

 

UC3770B

 

 

PARAMETER

TEST CONDITIONS

MIN

 

TYP

 

MAX

MIN

 

TYP

 

MAX

UNITS

Supply Voltage VM (Pins 3, 14)

 

10

 

 

 

45

10

 

 

 

45

V

Logic Supply Voltage VCC (Pin 6)

 

4.75

 

5

 

5.3

4.75

 

5

 

5.3

V

Logic Supply Current ICC (Pin 6)

IO = I1 = H, IM = 0

 

 

15

 

25

 

 

15

 

25

mA

 

IO = I1 = L, IM = 0

 

 

18

 

28

 

 

18

 

28

mA

 

IO = I1 = H, IM = 1.3A

 

 

33

 

40

 

 

33

 

40

mA

Thermal Shutdown Temperature

 

 

 

+170

 

 

 

 

+170

 

 

° C

Logic Threshold (Pins 7, 8, 9)

 

0.8

 

 

 

2.0

0.8

 

 

 

2.0

V

Input Current Low (Pin 8)

VI = 0.4V

 

 

 

 

-100

 

 

 

 

-100

A

Input Current Low (Pins 7, 9)

VI = 0.4V

 

 

 

 

-400

 

 

 

 

-400

A

Input Current High (Pins 7, 8, 9)

VI = 2.4V

 

 

 

 

10

 

 

 

 

10

A

Comparator Threshold (Pin 10)

VR = 5V, I0 = L, I1 = L

400

 

415

 

430

400

 

415

 

430

mV

 

VR = 5V, I0 = H, I1 = L

240

 

255

 

265

290

 

300

 

315

mV

 

VR = 5V, I0 = L, I1 = H

70

 

80

 

90

195

 

210

 

225

mV

Comparator Input Current (Pin 10)

 

 

 

 

 

± 20

 

 

 

 

± 20

A

Off Time

RT = 56k, CT = 820pF

25

 

30

 

35

25

 

30

 

35

ms

2

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