L6917B
PIN FUNCTION
N
1
2
3
4
5
Name
LGATE1
VCCDR
Channel 1 low side gate driver output.
Mosfet driver supply. It can be varied from 5V to 12V.
Description
PHASE1 This pin is connected to the source of the upper mosfet and provides the return path for the high
side driver of channel 1.
UGATE1 Channel 1 high side gate driver output.
BOOT1
Channel 1 bootstrap capacitor pin. Through this pin is supplied the high side driver and the upper
mosfet. Connect through a capacitor to the PHASE1 pin and through a diode to Vcc (cathode vs.
boot).
Device supply voltage. The operative supply voltage is 12V.
All the internal references are referred to this pin. Connect it to the PCB signal ground.
This pin is connected to the error amplifier output and is used to compensate the control
feedback loop.
This pin is connected to the error amplifier inverting input and is used to compensate the voltage
control feedback loop.
A current proportional to the sum of the current sensed in both channel is sourced from this pin
(50µA at full load, 70µA at the Over Current threshold). Connecting a resistor between this pin
and VSEN pin allows programming the droop effect.
Connected to the output voltage it is able to manage Over & Under-voltage conditions and the
PGOOD signal. It is internally connected with the output of the Remote Sense Buffer for Remote
Sense of the regulated voltage.
If no Remote Sense is implemented, connect it directly to the regulated voltage in order to
manage OVP, UVP and PGOOD.
Remote sense buffer non-inverting input. It has to be connected to the positive side of the load to
perform a remote sense.
If no remote sense is implemented, connect directly to the output voltage (in this case connect
also the VSEN pin directly to the output regulated voltage).
Remote sense buffer inverting input. It has to be connected to the negative side of the load to
perform a remote sense.
Pull-down to ground if no remote sense is implemented.
Channel 1 current sense pin. The output current may be sensed across a sense resistor or
across the low-side mosfet Rds
ON.
This pin has to be connected to the low-side mosfet drain or
to the sense resistor through a resistor Rg in order to program the positive current limit at 140%
as follow:
35
µA ⋅
R
g
I
MA X
= --------------------------
R
se nse
Where 35µA is the current offset information relative to the Over Current condition (offset at OC
threshold minus offset at zero load).
The net connecting the pin to the sense point must be routed as close as possible to the
PGNDS1 net in order to couple in common mode any picked-up noise.
6
7
8
9
VCC
GND
COMP
FB
10
VSEN
11
FBR
12
FBG
13
ISEN1
14
PGNDS1 Channel 1 Power Ground sense pin. The net connecting the pin to the sense point (*) must be
routed as close as possible to the ISEN1 net in order to couple in common mode any picked-up
noise.
PGNDS2 Channel 2 Power Ground sense pin. The net connecting the pin to the sense point (*) must be
routed as close as possible to the ISEN2 net in order to couple in common mode any picked-up
noise.
15
(*) Through a resistor Rg.
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