L6710

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REFERENCE SCHEMATIC

DEVICE DESCRIPTION

The device is an integrated circuit realized in BCD technology. It provides complete control logic and pro-

tections for a high performance dual-phase step-down DC-DC converter optimized for microprocessor

power supply. It is designed to drive N Channel MOSFETs in a two-phase synchronous-rectified buck to-

pology. A 180 deg phase shift is provided between the two phases allowing reduction in the input capacitor

current ripple, reducing also the size and the losses.

The output voltage of the converter can be precisely regulated, programming the VID pins, from 0.8375 to

1.6000V with 12.5mV binary steps, with a maximum tolerance on the output regulated voltage of ±0.5%

over temperature and line voltage variations. Since the VID pins program the maximum output voltage,

the device automatically regulates to a voltage VID*=VID-25mV avoiding use of any external component

to lower the regulated voltage. Dynamic VID Code changes are managed stepping to the new configura-

tion following the VID table with no need for external components. The device provides an average cur-

rent-mode control with fast transient response. It includes a 150kHz oscillator externally adjustable

through a resistor. The error amplifier features a 15V/

µs slew rate that permits high converter bandwidth

for fast transient performances.

the LS mos in fully differential mode. The current information corrects the PWM output in order to equalize

the average current carried by each phase. Current sharing between the two phases is then limited at

±10% over static and dynamic conditions unless considering the sensing element spread.

The device protects against Over-Current, with an OC threshold for each phase, entering in constant cur-

rent mode. Since the current is read across the low side mosfets, the device keeps constant the bottom

of the inductors current triangular waveform. When an under voltage is detected the device latches and

the FAULT pin is driven high. The device performs also Over-Voltage protection that disables immediately

the device turning ON the lower driver and driving high the FAULT pin.

L6710

PGOOD

PGND

PGNDS

ISEN2

LGATE2

VSEN

FB

PHASE2

HGATE2

BOOT2

VCC

COMP

SGND

REF_OUT

VID0

VID1

VID2

VID3

VID4

To PGNDS

ISEN1

LGATE1

PHASE1

HGATE1

BOOT1

VCCDR

5

31

35

36

38

21

20

41

3

43

42

40

19

28

27

26

24

25

6, 7

39

30

13

9

8

14

18

OUTEN

FBG

12

Rg

Rg

LS2

HS2

L2

S1

S0

S3

S2

S4

Rg

LS1

L1

HS1

Vin

GNDin

PGOOD

CPU

Rg

VID5

29

S5

OSC / FAULT

22

17

FBR

VID_Pgood

To VCC