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L6917B
September 2002
■
2 PHASE OPERATION WITH
SYNCRHONOUS RECTIFIER CONTROL
■
ULTRA FAST LOAD TRANSIENT RESPONSE
■
INTEGRATED HIGH CURRENT GATE
DRIVERS: UP TO 2A GATE CURRENT
■
TTL-COMPATIBLE 5 BIT PROGRAMMABLE
OUTPUT COMPLIANT WITH VRM 9.0
■
0.8% INTERNAL REFERENCE ACCURACY
■
10% ACTIVE CURRENT SHARING
ACCURACY
■
DIGITAL 2048 STEP SOFT-START
■
OVERVOLTAGE PROTECTION
■
OVERCURRENT PROTECTION REALIZED
USING THE LOWER MOSFET'S R
dsON
OR A
SENSE RESISTOR
■
300 kHz INTERNAL OSCILLATOR
■
OSCILLATOR EXTERNALLY ADJUSTABLE
UP TO 600kHz
■
POWER GOOD OUTPUT AND INHIBIT
FUNCTION
■
REMOTE SENSE BUFFER
■
PACKAGE: SO-28
APPLICATIONS
■
POWER SUPPLY FOR SERVERS AND
WORKSTATIONS
■
POWER SUPPLY FOR HIGH CURRENT
MICROPROCESSORS
■
DISTRIBUTED DC-DC CONVERTERS
DESCRIPTION
The device is a power supply controller specifically
designed to provide a high performance DC/DC con-
version for high current microprocessors.
The device implements a dual-phase step-down con-
troller with a 180° phase-shift between each phase.
A precise 5-bit digital to analog converter (DAC) al-
lows adjusting the output voltage from 1.100V to
1.850V with 25mV binary steps.
The high precision internal reference assures the se-
lected output voltage to be within ±0.8%. The high
peak current gate drive affords to have fast switching
to the external power mos providing low switching
losses.
The device assures a fast protection against load
over current and load over/under voltage. An internal
crowbar is provided turning on the low side mosfet if
an over-voltage is detected. In case of over-current,
the system works in Constant Current mode.
SO-28
ORDERING NUMBERS:L6917BD
L6917BDTR (Tape & Reel)
5 BIT PROGRAMMABLE DUAL-PHASE CONTROLLER
BLOCK DIAGRAM
CURRENT
READING
CURRENT
READING
IFB
TOTAL
CURRENT
AVG
CURRENT
CH 1 OVER
CURRENT
CH 2 OVER
CURRENT
DAC
DIGITAL
SOFT START
L
OGI
C
P
W
M
AD
AP
T
IVE AN
T
I
CRO
S
S
-C
O
NDUCT
IO
N
L
OGI
C
P
W
M
AD
AP
T
IVE AN
T
I
CRO
S
S
-C
O
NDUCT
IO
N
CH1 OVER
CURRENT
CH2 OVER
CURRENT
LOGIC
AND
PROTECTIONS
2 PHASE
OSCILLATOR
PWM1
CU
RR
E
N
T
CO
R
R
E
C
T
IO
N
PWM2
CU
RR
E
N
T
CO
R
R
E
C
T
IO
N
ERROR
AMPLIFIER
REMOTE
BUFFER
10k
10k
10k
LS
LS
HS
Vcc
HS
BOOT1
UGATE1
PHASE1
LGATE1
ISEN1
PGNDS1
PGND
PGNDS2
ISEN2
LGATE2
PHASE2
UGATE2
BOOT2
Vcc
COMP
FB
VSEN
FBG
FBR
VID0
VID1
VID2
VID3
VID4
PGOOD
ROSC / INH
SGND
VCCDR
10k
< >
+
-
+
+
-
VCCDR
VCC
Obsolete Product(s) - Obsolete Product(s)
Obsolete Product(s) - Obsolete Product(s)
