XR79110_17 Datasheet, PDF (6/19 Pages) Exar Corporation – 22V, 10A Synchronous Step Down COT Power Module

XR79110
Pin Assignments
Pin No.
Pin Name
Type
Description
1
SS
2
PGOOD
3
FB
4, 5, 69, 70,
AGND Pad
6
7
AGND
VIN
VCC
8
PGND
13-23, 51-
56, PGND
pads
9-12, 24-30,
SW Pad
31-50,
VOUT Pad
58-65, PVIN
Pad
66, 67, BST
Pad
68
71
PGND
SW
VOUT
PVIN
BST
ILIM
EN/MODE
72
TON
A
OD, O
A
A
Soft-start pin. Connect an external capacitor between SS and AGND to program the soft-start
rate based on the 10uA internal source current.
Power-good output. This open-drain output is pulled low when V_OUT is outside the regulation.
Feedback input to feedback comparator. Connect with a set of resistors to VOUT and AGND in
order to program VOUT.
Analog ground. Control circuitry of the IC is referenced to this pin.
PWR
PWR
PWR
PWR
IC supply input. Provides power to internal LDO.
The output of LDO. Bypass with a 4.7uF capacitor to AGND. For operation from a 5V_IN rail,
VCC should be tied to VIN.
Controller low-side driver ground. Connect with a short trace to closest PGND pins or PGND
pad.
Ground of the power stage. Should be connected to the system’s power ground plane.
PWR
PWR
Switching node. It is internally connected. Use thermal vias and/or sufficient PCB land area in
order to heatsink the low-side FET and the inductor.
Output of the power stage. Place the output filter capacitors as close as possible to these pins.
PWR
Power stage input voltage. Place the input filter capacitors as close as possible to these pins.
A
Controller high-side driver supply pin. It is internally connected to SW via a 0.1uF bootstrap
capacitor. Leave these pins floating.
A
Over-current protection programming. Connect with a short trace to SW pins.
I
Precision enable pin. Pulling this pin above 1.9V will turn the IC on and it will operate in Forced
CCM. If the voltage is raised above 3.0V, then the IC will operate in DCM or CCM depending
on load.
A
Constant on-time programming pin. Connect with a resistor to AGND.
Type: A = Analog, I = Input, O = Output, I/O = Input/Output, PWR = Power, OD = Open-Drain
© 2015-2017 Exar Corporation
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exar.com/XR79110
Rev 2B