XR76115 Datasheet, PDF (6/16 Pages) Exar Corporation – 15A Synchronous Step Down COT Regulator

XR76115
Pin Description
Name
NC
ILIM
EN/MODE
TON
SS
PGOOD
FB
AGND
VIN
VCC
SW
PGND
PVIN
BST
Pin Number
Description
1,9
Not connected.
2
Over-current protection programming. Connect with a resistor to SW.
Precision enable pin. Pulling this pin above 1.9V will turn the regulator on and it will
3
operate in CCM. If the voltage is raised above 3.0V then the regulator will operate in
DCM/CCM depending on load.
4
Constant on-time programming pin. Connect with a resistor to AGND.
5
Soft-Start pin. Connect an external capacitor between SS and AGND to program the
soft-start rate based on the 10uA internal source current.
6
Power-good output. This open-drain output is pulled low when VOUT is outside the
regulation.
7
8, 12,
AGND Pad
10
Feedback input to feedback comparator. Connect with a set of resistors to VOUT and
AGND in order to program VOUT.
Signal ground for control circuitry. Connect AGND Pad with a short trace to pins 8 and
12.
Supply input for the regulator’s LDO. Normally it is connected to PVIN.
11
13-18, 25, 36,
SW Pad
19-24,
PGND Pad
26-35,
PVIN Pad
37
The output of regulator’s LDO. For operation using a 5V rail, VCC should be shorted to
VIN.
Switch node. Drain of the low-side N-channel MOSFET. Source of the high-side MOSFET
is wire-bonded to the SW Pad.
Ground of the power stage. Should be connected to the system’s power ground plane.
Source of the low-side MOSFET is wire-bonded to PGND Pad.
Input voltage for power stage. Drain of the high-side N-channel MOSFET.
High-side driver supply pin. Connect a 1uF bootstrap capacitor between BST and SW.
© 2015 Exar Corporation
6/16
www.exar.com
Rev. 1B