HA16114P/PJ/FP/FPJ, HA16120FP/FPJ
4. PWM Output Circuit and Power MOSFET Driving Method
These ICs have built-in totem-pole push-pull drive circuits that can drive a power MOS FET as shown in
figure 4.1. The power MOS FET can be driven directly through a gate protection resistor.
If V
IN
exceeds the gate breakdown voltage of the power MOS FET additional protective measures should be
taken, e.g. by adding Zener diodes as shown in figure 4.2.
To drive a bipolar power transistor, the base should be protected by voltage and current dividing resistors as
shown in figure 4.3.
V
IN
To C
L
Bias
circuit
OUT
R
G
Gate protection
resistor
Totem-pole output circuit
P.GND
Example:
P-channel power MOSFET
V
O
Figure 4.1 Connection of Output Stage to Power MOS FET
V
IN
R
G
OUT
GND
D
Z
V
O
Example: N-channel power MOSFET
Figure 4.2 Gate Protection by Zener Diodes
V
IN
OUT
GND
Base current
limiting resistor
V
O
Base discharging resistor
Example: NPN power transistor
Figure 4.3 Driving a Bipolar Power Transistor
Rev.2.0, Sep.18.2003, page 12 of 37
RENESAS [ RENESAS TECHNOLOGY CORP ]
