LTC1699 Series
SMBus VID
Voltage Programmers
FEATURES
s
DESCRIPTIO
s
s
s
s
s
s
Fully Compliant with Intel 5-Bit Mobile
(LTC1699-80) and Desktop VRM8.4 (LTC1699-81)
and VRM9.0 (LTC1699-82) VID Specifications
Precision
±0.35%
Programmable Resistor Divider
for Use with 0.8V Referenced DC/DC Converters
Two Different Divider Settings Can Be Stored Using a
2-Wire SMBus Serial Interface (Rev 1.1)
Built-In Safeguards Minimize Misprogramming Due
to Bus Conflicts
Three Open-Drain Pins (CPU_ON, IO_ON, CLK_ON)
and a Global Control Pin (VRON)to Shutdown or
Soft-Start 3 DC/DC Converters Simultaneously
PGOOD Pin and 50µs PGOOD Timer
Available in MSOP-8 and SSOP-16 Package
The LTC
®
1699-80, LTC1699-81 and LTC1699-82 are pre-
cision (±0.35% max), digitally programmed resistor di-
viders that comply with Intel 5-bit mobile (LTC1699-80),
desktop VRM8.4 (LTC1699-81) and VRM9.0 (LTC1699-82)
VID specifications. Each IC can switch the output of a
DC/DC converter between two set voltages. A digital input
pin, SEL, selects one of two divider settings stored into
registers via a 2-wire SMBus interface.
The SMBus interface uses Write Word protocol to setup
the registers and to turn the DC/DC converters on or off.
Read Word protocol is used to verify register contents and
to return the On/Off status of the converters. The
LTC1699-80, LTC1699-81 and LTC1699-82 incorporate
safeguards against errors due to bus conflicts.
Three open-drain N-channel outputs (CPU_ON, IO_ON
and CLK_ON) are provided to turn DC/DC converter sup-
plies on or off via their RUN/SS inputs. A global control pin,
VRON is used to turn the converters on or off simulta-
neously. An internal timer pulls the PGOOD pin low for
50µs if the divider setting changes or the converters are
turned on via the SMBus and the VRON pin.
, LTC and LT are registered trademarks of Linear Technology Corporation.
AMD Athlon is a trademark of Advanced Micro Devices, Inc.
Pentium is a registered trademark of Intel Corporation.
Intel SpeedStep is a trademark of Intel Corporation.
APPLICATIO S
s
s
s
s
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Intel Desktop Pentium
®
III Power Supply
Intel Mobile Pentium
®
Power Supply with Intel
SpeedStep
TM
Technology
Desktop AMD Athlon
TM
Power Supply
Software Programmable Remote Power Supply
Power Supplies with Voltage Margining
TYPICAL APPLICATIO
R9
100k
U1
LTC1699-81
VRON
SDA
SCL
SEL
5
3
4
1
2
7
11
14
15
VRON
SDA
SCL
SEL
NC
NC
NC
GND
GND
CPU_ON
FB
IO_ON
CLK_ON
PGOOD
8
13
9
10
6
12
SENSE 16
V
CC
PGOOD
SMBus Controlled High Efficiency DC/DC Converter
5V
R1
39k
C6
0.01µF
1
2
3
4
5
6
7
8
U2
LTC1778
16
RUN/SS BOOST
15
PGOOD
TG
14
V
RNG
SW
13
FCB
PGND
12
I
TH
BG
11
SGND
INTV
CC
10
I
ON
V
IN
9
V
FB
EXTV
CC
R5
715k, 1%
C19, 0.01µF
V
IN
D1
M1
C7
0.22µF
C1
10µF
25V
C2
10µF
25V
C3
10µF
25V
C4
10µF
25V
C8, 0.01µF
R2, 11k
L1, 1µH
C9
22µF
6.3V
M2
C13
4.7µF
6.3V
C15
220pF
C18
2200pF
R4
10k
R3
1Ω
C12
0.1µF
5VDC
C14, 0.1µF
U
+
C5
10µF
35V
ALUM
GND
V
IN
5V
TO 20V
U
U
+
D2
C10
180µF
4V
+
C11
180µF
4V
V
OUT
2.5V
AT 10A
GND
C1, C2, C3, C4, C9: TAIYO YUDAN
C5: SANYO
C10, C11: PANASONIC, SPCL. POLY.
D1: CMDSH-3
D2: DIODES INC., B340A
L1: TOKO, 919AS-1RON
M1: Si4884DY
M2: Si4874DY
1699 TA05
1
LINER [ LINEAR TECHNOLOGY ]
