Advanced Monolithic Systems, Inc.

www.advanced-monolithic.com

Phone (925) 443-0722 Fax (925) 443-0723

AMS4122

PIN DESCRIPTION

Pin Number

NAME

DESCRIPTION

1

SW2

This connects the inductor the Internal Switch2

2

P2VIN

Input Power Pin for SW2 from unregulated power supply

3

GND

Ground Pin connected to PCB ground plane. This pin is also the ground for internal

voltage reference.

4

F/B2

Feedback2. A resistor network of two resistors is used to set-up the output voltage

connected between Output2 to GND. The node between the two resistors is connected to

Feedback2 pin. In Two Phase Mode F/B2 should be connected to a voltage 2.5V or

higher

5

F/B1

Feedback1. A resistor network of two resistors is used to set-up the output voltage

connected between Output1 to GND. The node between the two resistors is connected to

Feedback1 pin.

6

EN

Enable. A voltage greater than 2.5V at this pin enables both devices operation.

7

P1+AVIN

Input Power Pin for SW1 and Analog Input Voltage that powers up the chip

8

SW1

This connects the inductor the Internal Switch1

RECOMMANDED OPERATING CONDITIONS: The minimum input voltage should be 4.5V, however the device will

function as low as 4.0V. The maximum operating voltage should be 20V, the device will work at 22V but the switching loss is

higher. The best performance is at 1.5A output load per channel; however it works well with 2A load per channel. The minimum

supply voltage is Vout +1Vfor 1A load and Vout +1.1V for 2A load but must be higher than 4.2V. There is an internal UVLO

that will turn off the device if the input voltage is below 4.0V. When the input voltage exceeds 12V the output load current

should be maintain below 1.5A, due to switching loss the device will have lower performance.