AP3595

Document number: DS36749 Rev. 1 - 2

3 of 23

www.diodes.com

January 2014

© Diodes Incorporated

AP3595

A Product Line of

Diodes Incorporated

Pin Descriptions

Pin Number

Pin Name

Function

1

REFIN

External Reference Input. This is the input pin of external reference voltage. Connect a voltage

divider from VREF to REFIN and FBRTN to set the reference voltage

2

VREF

Output for Reference Voltage. This is the output pin of high precision 2V reference voltage.

Bypass this pin with a 1

F ceramic capacitor to FBRTN

3

RT/EN

Operation Frequency Setting. Connecting a resistor between this pin and GND to set the

operation frequency. Pull this pin to ground to shut down the AP3595

4

IOFS

Current Balance Adjustment. Connect a resistor from this pin to VREF or GND to adjust the

current sharing

5

COMP

Error Amplifier Output. This is the output of the error amplifier (EA) and the non-inverting input

of the PWM comparators. Use this pin in combination with the FB pin to compensate the

voltage control feedback loop of the converter

6

FB

Feedback Voltage. This pin is the inverting input to the error amplifier. Use this pin in

combination with the COMP pin to compensate the voltage control feedback loop of the

converter

7

FBRTN

Feedback Return. Connect this pin to the ground where the output voltage is to be regulated

8

EAP

Non-inverting Input of Error Amplifier. Connect a resistor from this pin to SS pin to set the

droop slope

9

SS

Soft Start Output. Connect a capacitor to FBRTN to set the soft start interval

10

CSN

Negative Input for Current Sensing Amplifier

11

CSP

Positive Input for Current Sensing Amplifier

12

PSI

Power Saving Mode. Connect this pin to VREF for always two phase operation. Short this pin

to ground for always single phase operation

13

BOOT1

Bootstrap Supply for the Floating Upper Gate Driver of Channel 1. Connect a bootstrap

capacitor between BOOT1 pin and the PHASE1 pin to form a bootstrap circuit

14

HG1

Upper Gate Driver Output for Channel 1. Connect this pin to the gate of upper MOSFET. This

pin is monitored by the adaptive shoot-through protection circuitry to determine when the upper

MOSFET has turned off

15

PHASE1

Switch Node for Channel 1. Connect this pin to the source of the upper MOSFET and the drain

of the lower MOSFET. This pin is used as the sink for the Upper GATE driver. It is also

monitored by the adaptive shoot-through protection circuitry to determine when the upper

MOSFET has turned off

16

LG1

Lower Gate Driver Output for Channel 1. Connect this pin to the gate of lower MOSFET. This

pin is monitored by the adaptive shoot-through protection circuitry to determine when the lower

MOSFET has turned off

17

PVCC

Supply Voltage for Gate Driver. This pin is the output of internal 9V LDO. This pin provides

current for gate drivers. Bypass this pin with a minimum 1

F ceramic capacitor

18

VCC

Supply Voltage. This pin provides current for internal control circuit and 9V LDO. Bypass this

pin with a minimum 1

F ceramic capacitor next to the IC

19

LG2

Lower Gate Driver Output for Channel 2. Connect this pin to the gate of lower MOSFET. This

pin is monitored by the adaptive shoot-through protection circuitry to determine when the lower

MOSFET has turned off

20

PHASE2

Switch Node for Channel 2. Connect this pin to the source of the upper MOSFET and the drain

of the lower MOSFET. This pin is used as the sink for the HG2 driver. It is also monitored by

the adaptive shoot-through protection circuitry to determine when the upper MOSFET has

turned off

21

HG2

Upper Gate Driver Output for Channel 2. Connect this pin to the gate of upper MOSFET. This

pin is monitored by the adaptive shoot-through protection circuitry to determine when the upper

MOSFET has turned off

22

BOOT2

Bootstrap Supply for the Floating Upper Gate Driver of Channel 2. Connect a bootstrap

capacitor between BOOT2 pin and the PHASE2 pin to form a bootstrap circuit

23

VID

VID Input. This pin is used to adjust the reference voltage. Logic high enables the internal

MOSFET connected to RSET pin

24

RSET

Reference Voltage Setting. This pin is an open drain output that is pulled low when VID sets to

high. Connect a resistor from this pin to REFIN pin to set the reference voltage

Exposed Pad

GND

Power Ground. Tie this pin to the ground island/plane through the lowest available impedance

connection