MC3479

http://onsemi.com

4

5

Phase A

+ 12 V

MC3479P

CW / CCW

F / HS

OIC

Clk

Bias/Set

56 k

6

7

8

9

10

412 13

15

14

3

2

16

1.0 k

1.0 k

1.0 k

1.0 k

1.0 k

1.0 k

4.0 k

11

L3

L4

L1

L2

0.1

mF

+ 12 V

Figure 2. AC Test Circuit

input signals are

p 25 ns.

Figure 3. Bias/Set Timing (Refer to Figure 2)

Bias/Set

Input

(High Impedance)

0

L1 − L4

Outputs

PIN FUNCTION DESCRIPTION

Pin #

Function

Symbol

Description

16

Power Supply

Power supply pin for both the logic circuit and the motor coil current. Voltage range is

+ 7.2 to + 16.5 V.

4, 5,

12, 13

Ground

GND

Ground pins for the logic circuit and the motor coil current. The physical configuration of

the pins aids in dissipating heat from within the IC package.

1

Clamp Diode Voltage

This pin is used to protect the outputs where large voltage spikes may occur as the

motor coils are switched. Typically a diode is connected between this pin and Pin 16.

See Figure 12.

2, 3,

14, 15

Driver Outputs

L1, L2 L3,

L4

High current outputs for the motor coils. L1 and L2 are connected to one coil, and L3 and

L4 to the other coil.

6

Bias/Set

B/S

the outputs assume a high impedance condition, while the internal logic presets to a

Phase A condition.

7

Clock

Clk

The positive edge of the clock input switches the outputs to the next position. This input

has no effect if Pin 6 is open.

9

Full/Half Step

F/HS

When low (Logic “0”), each clock input pulse will cause the motor to rotate one full step.

When high, each clock pulse will cause the motor to rotate one−half step. See Figure 7

for sequence.

10

Clockwise/

Counterclockwise

CW/CCW

This input allows reversing the rotation of the motor. See Figure 7 for sequence.

8

Output Impedance

Control

OIC

This input is relevant only in the half step mode (Pin 9 > 2.0 V). When low (Logic “0”),

the two driver outputs of the non−energized coil will be in a high impedance condition.

Figure 7.

11

Phase A

Ph A

This open−collector output indicates (when low) that the driver outputs are in the Phase