ADP3430

http://onsemi.com

4

PIN ASSIGNMENT

Pin No.

Mnemonic

Description

1

EN

Power Supply Enable Input. Pulling this pin to GND disables the PWM outputs and pulls the PWRGD output low.

2

PWRGD

Power−Good Output. Open−drain output that signals when the output voltage is outside of the proper operating range.

3

FBRTN

Feedback Return. VID DAC and error amplifier input for remote sensing of the output voltage.

4

FB

Feedback Input. Error amplifier reference for remote sensing of the output voltage.

5

COMP

Error Amplifier Output and Compensation Point.

6

SS

Soft−Start Delay Setting Input. An external capacitor connected between this pin and GND sets the soft−start

ramp−up time.

7

DELAY

Delay Timer Setting Input. An external capacitor connected between this pin and GND sets the overcurrent

latchoff delay time, boot voltage hold time, EN delay time, and PWRGD delay time.

8

TRDET

Transient Detection Output. This pin is pulled low when a load release transient is detected.

9

VRHOT

VR Hot Output. Active high open−drain output that signals when the temperature of the temperature sensor

connected to TTSNS exceeds the programmed VRHOT temperature threshold.

10

TTSNS

VR Hot Thermal Throttling Sense Input. An NTC thermistor between this pin and GND is used to remotely

sense the temperature at the desired thermal monitoring point.

11

ILIM

Current Sense and Limit Pin. Connecting a resistor from this pin to CSCOMP sets the internal current sensing

signal for current limit and IMON.

12

RT

Frequency Setting Resistor Input. An external resistor connected between this pin and GND sets the PWM

oscillator frequency. The switching frequency for each phase is up to 800 KHz.

13

RAMP

PWM Ramp Slope Setting Input. An external resistor from the converter input voltage to this pin sets the slope

of the internal PWM ramp.

14

LLINE

Output Load Line Programming Input. This pin can be directly connected to CSCOMP, or it can be connected to

the center point of a resistor divider between CSCOMP and CSREF. Connecting LLINE to CSREF disables

positioning.

15

CSREF

Current Sense Reference Voltage Input. The voltage on this pin is used as the reference for the current sense

amplifier and the power−good and crowbar functions. This pin should be connected to the common point of the

output inductors.

16

CSSUM

Current Sense Summing Node. External resistors from each switch node to this pin sum the inductor currents

together to measure the total output current.

17

CSCOMP

Current Sense Compensation Point. A resistor and capacitor from this pin to CSSUM determines the gain of the

current sense amplifier and the positioning loop response time.

18

GND

Ground. All internal biasing and the logic output signals of the device are referenced to this ground.

19

OD

below its UVLO threshold to signal to the Driver IC that the driver high−side and low−side outputs should go low.

This pin needs to connect to both 1st and 2nd phase gate drivers.

20

IREF

Current Reference Input. An external resistor from this pin to ground sets the internal reference current used to

21

IMON

IMON Total Current Output Pin. A resistor/capacitor from this pin to FBRTN/VSS Sense sets the IMON signal.

22

NC

No Connection

23 to 25

SW3 to

SW1

Current Balance Inputs. Inputs for measuring the current level in each phase. The SW pins of unused phases

should be left open.

26

ODN

Output Disable Logic output for PSI Operation. This pin is pulled low when PSI is low, otherwise it functions the

same as OD. This pin needs to connect to the 3rd phase gate driver.

27

NC

No Connection

28 to 30

PWM3 to

PMW1

Logic−Level PWM Outputs. Each output is connected to the input of an external MOSFET driver such as the

ADP3430 to operate as a 2− or 3−phase controller.

31

32 to 39

VID7 to

VID0

Voltage Identification DAC Inputs. These eight pins are pulled down to GND, providing a Logic 0 if left open.

When in normal operation mode, the DAC output programs the FB regulation voltage from 0.5 V to 1.6 V.

40

PSI

Power State Indicator Input. Pulling this pin low places controller in lower power state operation. PSI = Low

demands 2−phase operation, PSI = High for 3−phase. While PSI is an input signal which supports OTF change.