MP2953B – DIGITAL PWM CONTROLLER WITH PMBUS FOR VR12.5

MP2953B Rev. 1.01

www.MonolithicPower.com

12

10/9/2015

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PIN FUNCTIONS

Pin #

Name

I/O

Description

24

VRFLT#

O

VR Fault. VRFLT# is an open-drain output. When Vin or Vout OVP occurs,

VRFLT# is asserted to shut down the input power supply.

25

VRHOT#

O

Voltage Regulator Thermal Throttling Logic Output. VRHOT# is an open-

drain output. VRHOT# pulls low actively if the monitored temperature exceeds

the programmed VRHOT# temperature threshold.

26

VRRDY

O

VR Ready Output. VRRDY is an open-drain output that signals when the output

voltage is outside of the proper operating range. A VTT rail is expected for pull

up; however, some systems may pull up to a maximum voltage of 3.3V with an

external pull-up circuit.

27

DGND

I/O

Digital Ground.

28

ALT_P#

O

Open-Drain Output that Asserts Low when a Warning has Occurred.

29

SDA_P

I/O

Data Signal between the PMBus Controller and the VID Controller.

30

SCL_P

I

Source Synchronous Clock from the PMBus Controller.

31

CCM

O

Forced CCM Operations Enable. CCM stays high in power state 0 and 1. It

pulls low actively during PS2/3 to enable DCM operation.

32

PWM6

O

33

PWM5

O

34

PWM4

O

35

PWM3

O

36

PWM2

O

37

PWM1

O

Tri-State Logic-Level PWM Outputs. Each output is connected to the input of

Intelli-Phase’s PWM pin.

The logic levels are 0V for low logic and 3.3V for high logic.

The output is set to tri-state (High-Z) to shut down both the high-side MOSFET

and the low-side MOSFET of Intelli-Phase.

38

VDD33

O

3.3V LDO Output for the Internal Digital Power Supply. Connect a 1µF

bypass capacitor to digital ground.

39

EN

I

Enable Control for the Controller.

40

CS6

I

Phase 6 Current Sense Inputs. Float CS of the unused phase.

PAD

AGND

I/O

Analog Ground.