Data Sheet

20

Rev. 1.0, 2010-05-28

High Current H-Bridge

BTM7745G

Application Information

7

Application Information

Note: The following information is given as a hint for the implementation of the device only and shall not be

regarded as a description or warranty of a certain functionality, condition or quality of the device.

XC866

TLE

4278G

V

S

Reset

Vss

WO

RO

Q

D

GND

I

Microcontroller

Reverse Polarity

Protection

Voltage Regulator

I/O

I/O

I/O

I/O

C

D

47nF

C

Q

22µF

R

1

10k

Ω

e.g.

IPD50P03P4L-11

VS

OUT1

GND

BTM7745G

C

Sc

VS

OUT2

GND

LS2

LS1

HS2

HS1

M

R

D1

R

D2

C

S

D

Z1

10V

I/O

I/O

I/O

Vdd

R

ST

4.7k

Ω

R

IN1

4.7k

Ω

R

IN2

4.7k

Ω

R

INH

4.7k

Ω

INH

IN2

ST

IN1

Figure 13

Application Diagram

Note: This is a very simplified example of an application circuit. The function must be verified in the real application.

7.1

Application and Layout Considerations

Due to the fast switching times for high currents, special care has to be taken during the PCB layout. Stray

inductances have to be minimized in the power bridge design as it is necessary in all switched high power bridges.

The BTM7745G has no separate pin for power ground and logic ground. Therefore it is recommended to assure

that the offset between power ground and logic ground pins of the device is minimized. It is also

necessary to ensure that all VS pins are at the same voltage level. Therefore the VS pins need to be

shorted together. Voltage differences between the VS pins may cause parameter deviations (such as reduced

current limits) up to a latched shutdown of the device with error signal on the ST pin, similar to overtemperature

shutdown.

Due to the fast switching behavior of the device in current limitation mode or overvoltage lock out a low ESR

electrolytic capacitor

C

peaks and drops on VS. This is recommended for both PWM and non PWM controlled applications. The value of

the capacitor must be verified in the real application.

In addition a ceramic capacitor

C

the switching phase via a low inductance path and therefore reducing noise and ground bounce. A reasonable

value for this capacitor would be about 470 nF.