IR3843WM_15 Datasheet, PDF (4/34 Pages) International Rectifier – HIGHLY EFFICIENT INTEGRATED 2A SYNCHRONOUS BUCK REGULATOR

PD-97507
IR3843WMPbF
Pin Description
Pin Name
Description
1
Seq
Sequence pin. Use two external resistors to set Simultaneous Power up
sequencing. If this pin is not used connect to Vcc.
Inverting input to the error amplifier. This pin is connected directly to the
2
Fb
output of the regulator via resistor divider to set the output voltage and
provide feedback to the error amplifier.
Output of error amplifier. An external resistor and capacitor network is
3 Comp typically connected from this pin to Fb pin to provide loop
compensation.
4
Gnd Signal ground for internal reference and control circuitry.
5
Rt
Set the switching frequency. Connect an external resistor from this pin
to Gnd to set the switching frequency.
Soft start / shutdown. This pin provides user programmable soft-start
6
SS/S¯D¯
function. Connect an external capacitor from this pin to Gnd to set the
start up time of the output voltage. The converter can be shutdown by
pulling this pin below 0.3V.
7
OCSet
Current limit set point. A resistor from this pin to SW pin will set the
current limit threshold.
8
PGood
Power Good status pin. Output is open drain. Connect a pull up resistor
from this pin to Vcc. If unused, it can be left open.
This pin powers the internal IC and the drivers. A minimum of 1uF high
9
V_CC
frequency capacitor must be connected from this pin to the power
ground (PGnd).
10
PGnd
Power Ground. This pin serves as a separated ground for the MOSFET
drivers and should be connected to the system’s power ground plane.
11
SW
Switch node. This pin is connected to the output inductor.
12
V_IN
Input voltage connection pin.
13
Boot
Supply voltage for high side driver. A 0.1uF capacitor must be
connected from this pin to SW.
Enable pin to turn on and off the device. Use two external resistors to
14 Enable set the turn on threshold (see Enable section). Connect this pin to Vcc if
it is not used.
15 Gnd Signal ground for internal reference and control circuitry.
4
Rev 13.0