MP2932 - 6-PHASE PWM CONTROLLER WITH 8-BIT ADC CODE

MP2932 Rev.1.02

www.MonolithicPower.com

10

4/30/2012

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© 2012 MPS. All Rights Reserved.

OPERATION

Multiphase Power Conversion

The MP2932 is a multiphase VR controller for

Intel VR11 or VR10. It can be programmed for 2-,

3-, 4-, 5- or 6 channel operation for micro-

processor core supply power converters with

interleaved switching. The interleaving work of

each phase can help to reduce of ripple current

amplitude in the multiphase circuit and to reduce

input ripple current.

The MP2932 control system is based on Dual-

Edge PWM providing the fastest load response.

Under load transition condition, the MP2932 can

turn on all phase together to improve the load

transient. It can achieve excellent transient

performance and reduce the demand on the

output capacitors.

Number of Phases

The number of operational phases is determined

by internal circuitry that monitors the PWM

outputs. Normally, the MP2932 operates as a 6-

phase controller. The number of active channels

is determined by the state of PWM3, PWM4,

PWM5, and PWM6. For 2-phase operation,

connect PWM3 to VCC; similarly, PWM4 for 3-

phase, PWM5 for 4-phase, and PWM6 for 5-

phase operation. Table 1 shows the phase firing

sequence.

Table 1—Phase firing sequence

Configuration

Phase Sequence

6-Phase

1 - 2 - 3 - 4 - 5 - 6

5-Phase

1 - 2 - 3 - 4 - 5

4-Phase

1 - 3 - 4 - 2

3-Phase

1 - 2 - 3

2-Phase

1 - 2

Switching Frequency

The clock frequency is set by an external resistor

600







SW

10

T

F

10

2.5

R

(1)

phase.

Current Sensing

MP2932 has cycle by cycle current sense for fast

response. MP2932 adopts inductor DCR sensing,

or resistive sensing techniques. The sense

current. The sensed current is used for current

balance, load-line regulation, and overcurrent

protection.

Inductor DCR Sensing

The MP2932 can adopt a lossless current

sensing scheme, commonly referred to as

inductor DCR sensing, as shown in Figure 2.

CURRENT

SENSE

ISEN+(n)

ISEN-(n)

RC

V (s)

V

LDCR

MP2932 INTERNAL CIRCUIT

SW

PWM

Intelli-Phase

Vin

Vin

GND

PWM(n)

I(s)

C

L

L

=I

R

DCR

SEN

I

L

ISEN

In

Figure 2—DCR Sensing Configuration

Equation (2) shows the s-domain equivalent



DCR

L

s

L

I

L

V









(2)

A simple RC network across the inductor extracts

the DCR voltage, as shown in Figure 2.

Equation (3).



RC

s

L

I

DCR

1

DCR

L

s

C

V



























(3)