5

FN3976.4

September 17, 2015

Application

The HIP4020 is designed to detect load current feedback

from sampling resistors of low value in the source

(See Figure 1). When the sink or source current at OUTA or

OUTB exceeds the preset OC (Overcurrent) limiting value of

550mA typical, the current is held at the limiting value. If the

OT (Over-Temperature) Shutdown Protection limit is

exceeded, temperature sensing BiMOS circuits limit the

junction temperature to 150°C typical.

The circuit of Figure 1 shows the Full H-Switch in a small motor-

drive application. The left (A) and right (B) H-Switch’s are

controlled from the A and B inputs via the A and B CONTROL

LOGIC to the MOS output transistors Q1, Q2, Q3 and Q4. The

circuit is intended to safely start, stop, and control rotational

direction for a motor requiring no more than 0.5A of supply

current. The stop function includes a Dynamic Braking feature.

With the ENABLE Inputs Low, the MOS transistors Q1 and Q3

are OFF; which cuts-off supply current to OUTA and OUTB.

With the BRAKE terminal Low and ENABLE Inputs High, either

Q1 and Q4 or Q3 and Q2 will be driven into conduction by the

FIGURE 1. TYPICAL MOTOR CONTROL APPLICATION CIRCUIT SHOWING DIRECTIONAL AND BRAKING CONTROL

B1

B2

ENB

A1

A2

ENA

V+

OUTA

OUTB

BRAKE

ON

OFF

DIRECTION

ENABLE

(LOGIC

GROUND)

LOAD

ILF

Q1

Q3

Q2

Q4

D1

D3

D4

D2

CONTROL

LOGIC A

V-

CONTROL

LOGIC B

SWITCHING WAVEFORMS

FIGURE 2.

TRUTH TABLE

SWITCH DRIVER A

SWITCH DRIVER B

INPUTS

OUTPUT

INPUTS

OUTPUT

A1 A2 ENA

OUTA

B1 B2 ENB

OUTB

HL

H

OH

L

L

H

OH

LL

H

OL

H

L

H

OL

HH

H

OL

L

H

H

OL

LH

H

OL

H

H

H

OL

XX

L

Z

XX

L

Z

L = Low logic level; H = High logic level

Z = High Impedance (off state)

OH = Output High (sourcing current to the output terminal)

OL = Output Low (sinking current from the output terminal)

X = Don’t Care

50%

50%

50%

50%

10%

90%

10%

90%

HIP4020