XR75100 Datasheet, PDF (5/15 Pages) Exar Corporation – 40V Synchronous Step Down COT Controller

XR75100
Pin Configuration
Pin Assignments
PGND VCC
16 15
VIN AGND
14 13
GL 1
12 AGND
NC 2
SW 3
EXPOSED PAD
11 FB
10 PGOOD
GH 4
9 SS
5
6
7
8
BST ILIM EN TON
Pin No.
Pin Name
1
GL
2
NC
3
SW
4
GH
5
BST
6
ILIM
7
EN/MODE
8
TON
9
SS
10
PGOOD
11
FB
12, 13
14
15
16
AGND
VIN
VCC
PGND
Exposed Pad
Type
O
A
O
A
A
I
A
A
OD
A
A
PWR
PWR
PWR
A
Description
Driver output for Low-side N-channel synchronous MOSFET.
Internally not connected. Leave this pin floating.
Lower supply rail for high-side gate driver GH. Connect this pin to the junction between the two
external N-channel MOSFETs.
Driver output for high-side N-channel switching MOSFET.
High-side driver supply pin. Connect a 0.1uF bootstrap capacitor between BST and SW.
Over-current protection programming. Connect with a resistor to the drain of the low-side MOS-
FET.
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.
Constant on-time programming pin. Connect with a resistor to AGND.
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 VOUT is outside the regulation.
Feedback input to feedback comparator. Connect with a set of resistors to VOUT and GND in
order to program VOUT.
Analog ground. Control circuitry of the IC is referenced to this pin.
IC supply input. Provides power to internal LDO.
The output of LDO. For operation using a 5V rail, VCC should be shorted to VIN.
Low side driver ground
Thermal pad for heat dissipation. Connect to AGND with a short trace.
Type: A = Analog, I = Input, O = Output, I/O = Input/Output, PWR = Power, OD = Open-Drain
© 2016 Exar Corporation
5 / 15
exar.com/XR75100
Rev 1C