LTC1699 Datasheet, PDF (1/20 Pages) Linear Technology – SMBus VID Voltage Programmers

LTC1699 Series
SMBus VID
Voltage Programmers
FEATURES
s _{Fully Compliant with Intel 5-Bit Mobile}
(LTC1699-80) and Desktop VRM8.4 (LTC1699-81)
and VRM9.0 (LTC1699-82) VID Specifications
s _{Precision ±0.35% Programmable Resistor Divider}
for Use with 0.8V Referenced DC/DC Converters
s _{Two Different Divider Settings Can Be Stored Using a}
2-Wire SMBus Serial Interface (Rev 1.1)
s _{Built-In Safeguards Minimize Misprogramming Due}
to Bus Conflicts
s _{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
s _{PGOOD Pin and 50µs PGOOD Timer}
s _{Available in MSOP-8 and SSOP-16 Package}
U
APPLICATIO S
s _{Intel Desktop Pentium}^® _{III Power Supply}
s _{Intel Mobile Pentium}^® _{Power Supply with Intel}
SpeedStep^TM Technology
s _{Desktop AMD Athlon}^TM _{Power Supply}
s _{Software Programmable Remote Power Supply}
s _{Power Supplies with Voltage Margining}
DESCRIPTIO
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.
TYPICAL APPLICATIO
SMBus Controlled High Efficiency DC/DC Converter
U1
LTC1699-81
5
VRON ₃ VRON
SDA ₄ SDA
SCL ₁ SCL
SEL ₂ SEL
7 ^NC
11 ^NC
14 ^NC
15 ^GND
GND
8
CPU_ON ₁₃
FB ₉
IO_ON ₁₀
CLK_ON ₆
PGOOD ₁₂
SENSE ₁₆
V_CC
5VDC
R9
5V
100k
C6
PGOOD
R1 _0.01µF
39k
U2
LTC1778
C8, 0.01µF
R2, 11k
C15 R4
220pF 10k
C18
1
16
2 ^{RUN/SS BOOST} 15
3 ^PGOOD
TG ₁₄
4 ^VRNG
SW ₁₃
5 ^FCB
PGND ₁₂
6 ^ITH
BG ₁₁
7 ^{SGND INTVCC} 10
8 ^ION
V_{IN 9}
V_FB
EXTV_CC
2200pF
R5
715k, 1%
V_IN
D1
C7
0.22µF
C13
4.7µF
C12
6.3V
R3
0.1µF
1Ω
C14, 0.1µF
C19, 0.01µF
C1
C2
C3
C4 +
M1
10µF
10µF
10µF
10µF
25V
25V
25V
25V
L1, 1µH
M2
D2
C9 +
22µF
6.3V
C10 +
180µF
4V
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
V_IN
5V
C5 _{TO 20V}
10µF
35V
ALUM
GND
V_OUT
2.5V
C11 ^{AT 10A}
180µF
4V
GND
1699 TA05
1