BTM7745G Datasheet, PDF (20/24 Pages) Infineon Technologies AG – High Current H-Bridge Trilith IC 3G

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.
Microcontroller
XC866
I/O
Reset
Vdd
I/O I/O I/O I/O I/O I/O ^Vss
C_Q
22µF
C_D
47nF
Voltage Regulator
WO
TLE
I
RO _4278G
Q
D
GND
Reverse Polarity
Protection
D_Z1
V_S
10V
R₁
e.g.
10kΩ
IPD50P03P4L-11
R_ST
4.7kΩ
BTM7745G VS
VS
R_INH
4.7kΩ
R_IN1
4.7kΩ
R_IN2
4.7kΩ
INH
HS1
IN1
IN2
ST
LS1
HS2
OUT1
OUT2
LS2
GND
GND
C_Sc
C_S
R_D1
R_D2
M
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_s of at least 100 µF from VS to GND is recommended. This prevents destructive voltage
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_sc from VS to GND close to each device is recommended to provide current for
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.
Data Sheet
20
Rev. 1.0, 2010-05-28