ADP3198

Rev. A | Page 7 of 32

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

PIN 1

INDICATOR

1

EN

2

PWRGD

3

FBRTN

4

FB

5

COMP

6

SS

7

DELAY

8

VRFAN

9

VRHOT

10

TTSENSE

23

SW3

24

SW2

25

SW1

26

NC

27

PWM4

28

PWM3

29

PWM2

30

PWM1

22

SW4

21

IMON

TOP VIEW

(Not to Scale)

ADP3198

NOTES

1. NC = NO CONNECT.

2. THE EXPOSED EPAD ON BOTTOM SIDE OF PACKAGE IS AN

ELECTRICAL CONNECTION AND SHOULD BE SOLDERED TO GROUND.

Figure 5. Pin Configuration

Table 3. Pin Function Descriptions

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 reference for remote sensing of the output voltage.

4

FB

Feedback Input. Error amplifier input for remote sensing of the output voltage. An external resistor between this

pin and the output voltage sets the no load offset point.

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 latch-

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

8

VRFAN

VR Fan Activation Output. Open-drain output that signals when the temperature at the monitoring point

connected to TTSENSE exceeds the programmed VRFAN temperature threshold.

9

VRHOT

VR Hot Output. Open-drain output that signals when the temperature at the monitoring point connected to

TTSENSE exceeds the programmed VRHOT temperature threshold.

10

TTSENSE

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

ILIMIT

Current-Limit Set Point. An external resistor from this pin to GND sets the current-limit threshold of the converter.

12

RT

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

frequency of the device.

13

RAMPADJ

PWM Ramp Current Input. An external resistor from the converter input voltage to this pin sets the internal PWM ramp.

14

LLSET

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 LLSET 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 average 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

Output Disable Logic Output. This pin is actively pulled low when the EN input is low or when VCC is below its

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

20

IREF