VNH5180A-E Application information
Doc ID 17074 Rev 6 19/31
3 Application information
In normal operating conditions the DIAG
X
/EN
X
pin is considered as an input pin by the
device. This pin must be externally pulled high.
PWM pin usage: In all cases, a “0” on the PWM pin turns off both LS
A
and LS
B
switches.
When PWM rises back to “1”, LS
A
or LS
B
turn on again depending on the input pin state.
Figure 11. Typical application circuit for DC to 20 kHz PWM operation short circuit
protection
Note: The value of the blocking capacitor (C) depends on the application conditions and defines
voltage and current ripple on supply line at PWM operation. Stored energy of the motor
inductance may fly back into the blocking capacitor, if the bridge driver goes into 3-state.
This causes a hazardous overvoltage if the capacitor is not big enough. As basic orientation,
500 µF per 10 A load current is recommended.
In case of a fault condition the DIAG
X
/EN
X
pin is considered as an output pin by the device.
The fault conditions are:
– Overtemperature on one or both high-sides
– Short to battery condition on the output (overcurrent detection on the low-side
Power MOSFET)
Possible origins of fault conditions may be:
OUT
A
is shorted to ground
→
overtemperature detection on high-side A
OUT
A
is shorted to V
CC
→
low-side Power MOSFET overcurrent detection
When a fault condition is detected, the user can identify which power element is in fault by
monitoring the IN
A
, IN
B
, DIAG
A
/EN
A
and DIAG
B
/EN
B
pins.
M
μC
Reg 5V
+ 5V
HS
A
HS
B
LS
A
LS
B
V
CC
DIAG
A
/EN
A
DIAG
A
/EN
A
CS
IN
A
PWM
OUT
A
OUT
B
D
S
G
b) N MOSFET
3.3K
1K
1K
1K
10K
33nF
1.5K
V
CC
DIAG
B
/EN
B
+5V
1K
3.3K
IN
B
1K
GND
GND
Vcc
CS_DIS
1k
100K
