l9610 STMicroelectronics, l9610 Datasheet - Page 9

• Manufacturer Part Number: l9610
• Description: Pwm Powermos Controller
• Manufacturer: STMicroelectronics

L9610
4.5
4.6
4.7
Short circuit current regulation
The maximum load current in the short circuit condition can be chosen by the value of the
current sensing resistor R
Two identical V
After reaching the lower threshold voltage (typical value V
enables the timer and the gate is driven with the full continuous pump voltage : when the
upper threshold voltage value is reached the second comparator maintains the chosen I
driving the NMOS gate in continuous mode.
This function, showed in
Bandgap voltage reference
The circuit provides a reference voltage which may be used as control input voltage through
a resistive divider. This reference is protected against the short circuit current.
Charge pump
The charge pump circuit holds the N-MOS gate above the supply voltage during the ON
phase. This circuit consists of an RC astable which drives a comparator with a push-pull
output stage. The external charge pump capacitor C
parasitic input capacitance.
For fast gate voltage variation C
The bootstrap capacitor should be at least 10 times greater than the PowerMOS parasitic
capacitance.
The charge pump voltage V
The circuit is disabled if the supply voltage is higher than V
S
compatible comparators are provided to realize the short circuit protection.
Figure
S
according to :
PUMP
V
PUMP
5., speeds up the switch on phase for a lamp as a load.
P
can reach to :
must be increased or the bootstrap function can be used.
=
I
SC
2V
=
S
V
–
SI
V
BE
⁄
R
–
S
P
V
must be at least equal to the NMOS
CESAT
SI
SH
-10 mV), the first comparator
.
9/15
SC