HA16114P Datasheet, PDF (12/38 Pages) Hitachi Semiconductor – Switching Regulator for Chopper Type DC/DC Converter

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
Bias
circuit
Totem-pole output circuit
OUT
To C_L
R_G
Gate protection
resistor
P.GND
Example:
P-channel power MOSFET
V_O
Figure 4.1 Connection of Output Stage to Power MOS FET
V_IN
R_G
V_O
OUT
GND
D_Z
Example: N-channel power MOSFET
Figure 4.2 Gate Protection by Zener Diodes
V_IN
Base current
limiting resistor
V_O
OUT
GND
Base discharging resistor
Example: NPN power transistor
Figure 4.3 Driving a Bipolar Power Transistor
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