L9610C STMicroelectronics, L9610C Datasheet - Page 7

• Manufacturer Part Number: L9610C
• Description: Switching Converters, Regulators & Controllers Power MOS Controller
• Manufacturer: STMicroelectronics

Specifications of L9610C

• Mounting Style: SMD/SMT
• Package / Case: SO-16
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

L9610
4
4.1
4.2
4.3
4.4
Functional description
Pulse width comparator
A ground compatible comparator generates the PWM signal which controls the gate of the
external PowerMOS. The slopes of the leading and trailing edges of the gate driving signal
are defined by the external capacitor C
This feature allows to optimize the switching speed for the power and RFI performance best
suited for the application.
The lower limit of the duty cycle is fixed at 15 % of the ratio between the input and the
reference voltage (see
oscillator signal and therefore the gate driver.
Ground compatible triangle oscillator
The triangle oscillator provides the switching frequency f
according to:
If the pin PWL (power limitation) is connected to ground and Vs is higher than the PWL
threshold voltage, the duty cycle and the f
costant power to the load (see
Timer and protection latch
When an overcurrent occurs, the device starts charging the external capacitor C
protection time is set according to :
After the overcurrent protection time is reached, the PowerMOS is switched-off ; this
condition is latched by setting an internal flip-flop and is externally monitored by the low
state of the MON pin.
To reset the latch the supply voltage has to fall below V
Under and overvoltage sense with load dump protection
The undervoltage detection feature resets the timer and switches off the output driving
signal when the supply voltage is less than V
If the supply voltage exceeds the max operating supply voltage value, an internal
comparator disables the charge pump, the oscillator and the external PowerMOS.
In both cases the thresholds are provided with suitable hysteresis values.
overvoltages. It consists of an active clamping diode which limits the circuit supply voltage to
The load dump protection function allows the device to withstand, for a limited time, high
Figure
3.). Input voltages lower than this value disable the internal
Figure
dV
4.).
t
G
prot
S
f
0
⁄
according to :
( )
o
dt
=
frequency are reduced: this allows to transfer a
=
K
SL
K
=
F
.
T
⁄
K
C
⋅
S
C
F
⁄
T
C
SL
S
o
or the device must be switched off.
set by the external capacitor C
T
; the
7/15
F