LINER LTC1706EMS-82

LTC1706-82
VID Voltage Programmer
for Intel VRM9.0/9.1
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DESCRIPTIO
FEATURES
■
■
■
■
■
■
The LTC®1706-82 is a precision, digitally programmed,
resistive ladder which adjusts the output of any 0.8V
referenced regulator. Depending on the state of the five
VID inputs, an output voltage between 1.10V and 1.85V is
programmed in 25mV increments.
Fully Compliant with the Intel VRM9.0/9.1 VID
Specification
Programs Regulator Output Voltage from 1.10V to
1.85V in 25mV Steps
Programs an Entire Family of Linear Technology
DC/DC Converters
±0.25% Accurate Voltage Divider
Built-In 40k Pull-Up Resistors on Program Inputs
Available in MSOP-10 Packaging
The LTC1706-82 is designed specifically to program an
entire family of Linear Technology DC/DC converters in full
compliance with the Intel VRM9.0/9.1 specifications.
The LTC1706-82 programs the following Linear Technology DC/DC converters: LTC1628, LTC1629, LTC1702,
LTC1735, LTC1735-1, LTC1929 and LTC3729.
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APPLICATIO S
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Intel Pentium® III Processor Power Supply
Multiprocessor Workstations and Servers
Multiphase Processor Power Supply
AMD AthlonTM Processor Power Supply
For a compact VRM9.0/9.1 solution with up to 60A capability, see the LTC3732, a 3-phase synchronous controller
with integrated 5-bit VID and MOSFET drivers.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Pentium is a registered trademark of Intel Corporation.
AMD Athlon is a trademark of Advanced Micro Devices, Inc.
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TYPICAL APPLICATIO
VID Controlled High Current 4-Phase DC/DC Converter (Simplified Block Diagram)
VIN
4.5V TO 22V
VIN
TG1
INTVCC
VID0
VCC
VID1
FROM
µP
LTC1629
SENSE
VID2 LTC1706-82
VID3
VID4
L1
RSENSE1
SW1
VDIFFOUT
+
BG1
VOUT
1.10V TO 1.85V
UP TO 70A
COUT
VIN
PGND
SGND
FB
TG2
EAIN
L2
RSENSE2
L3
RSENSE3
L4
RSENSE4
SW2
GND
BG2
VIN
4.5V TO 22V
VIN
LTC1629
TG1
SW1
BG1
PGND
VIN
SGND
EAIN
TG2
SW2
NOTE: UP TO SIX LTC1629s CAN BE PARALLELED
TO DELIVER AS MUCH AS 200A
BG2
1706-82 TA01
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LTC1706-82
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ABSOLUTE
AXI U RATI GS
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PACKAGE/ORDER I FOR ATIO
(Note 1)
(Voltages Referred to GND Pin)
Input Supply Voltage (VCC) ..........................– 0.3V to 7V
VID Input Pins .............................................– 0.3V to 7V
SENSE Pin ...................................................– 0.3V to 7V
FB Pin ..........................................................– 0.3V to 7V
Operating Temperature Range (Note 2) .. – 40°C to 85°C
Junction Temperature ........................................... 110°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
TOP VIEW
1
2
3
4
5
VID0
VID1
VID2
VID3
VCC
10
9
8
7
6
FB
GND
NC
VID4
SENSE
LTC1706EMS-82
MS PACKAGE
10-LEAD PLASTIC MSOP
MS PART MARKING
TJMAX = 110°C, θJA = 200°C/W
LTMJ
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
2.7V ≤ VCC ≤ 5.5V, VID0 = VID1 = VID2 = VID3 = VID4 = NC unless otherwise specified.
SYMBOL
PARAMETER
VCC
Operating Supply Voltage Range
IVCC
Supply Current
CONDITIONS
MIN
TYP
2.7
(Note 3)
0.1
RFB-SENSE
Resistance Between SENSE and FB
VOUT Error %
Output Voltage Accuracy
Programmed From 1.10V to 1.85V
RPULLUP
VID Input Pull-Up Resistance
VDIODE = 0.6V, (Note 4)
VIDT
VID Input Voltage Threshold
VIL (2.7V < VCC < 5.5V)
VIH (2.7V < VCC < 5.5V)
●
6
●
– 0.25
10
UNITS
5.5
V
5.0
µA
14
kΩ
0.25
%
40
kΩ
0.4
V
V
±1.00
µA
1.6
IVID-LEAK
VID Input Leakage Current
VCC < VID < 7V, (Note 4)
0.01
VPULLUP
VID Pull-Up Voltage
VCC = 3.3V
VCC = 5V
2.8
4.5
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC1706-82 is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the – 40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
MAX
V
V
Note 3: With all five VID inputs floating, the VCC supply current is simply
the device leakage current. However, the VCC supply current will rise and
be approximately equal to the number of grounded VID input pins times
(VCC – 0.6V)/40k. (See the Applications Information section for more
detail.)
Note 4: Each built-in pull-up resistor attached to the VID inputs also has a
series diode connected to VCC to allow input voltages higher than the VCC
supply without damage or clamping. (See Operation section for further
details.)
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LTC1706-82
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TYPICAL PERFOR A CE CHARACTERISTICS
Typical Error % vs Output Voltage
Typical Error % vs Temperature
0.25
0.25
TA = 25°C
ERROR (%)
ERROR (%)
VOUT = 1.1V
0
–0.25
1.1
1.2
1.3 1.4 1.5 1.6 1.7
OUTPUT VOLTAGE (V)
1.8
VOUT = 1.5V
VOUT = 1.85V
0
–0.25
–50
0
50
TEMPERATURE (°C)
1706-82 G01
100
1706-82 G02
RFB1 vs Temperature
IVID-PULLUP vs Temperature
150
VID PULL-UP CURRENT (µA)
30
RFB1 (kΩ)
20
10
VCC = 5V
VID4 = 0V
VID0 = VID1 = VID2 = VID3 = OPEN
130
110
90
70
50
0
–50
0
50
TEMPERATURE (°C)
30
–50
100
0
50
TEMPERATURE (°C)
1706-82 G04
1706-82 G03
Supply Current vs Temperature
Supply Current vs Supply Voltage
5
ALL VID INPUTS OPEN
ALL VID INPUTS OPEN
TA = 25°C
4
1.5
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
2.0
100
1.0
VCC = 5V
VCC = 3.3V
0.5
VCC = 2.7V
3
2
1
0
–50
0
50
TEMPERATURE (°C)
100
1706-82 G05
0
0
2
4
6
SUPPLY VOLTAGE (V)
8
1706-82 G06
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LTC1706-82
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PI FU CTIO S
VID0 (Pin 1): LSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID0 adds 25mV to the
output sense voltage.
SENSE (Pin 6): Regulator Output Voltage. Connect directly to regulator output sense node or VDIFFOUT when
used with the LTC1629 and LTC1929.
VID1 (Pin 2): 4th MSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID1 adds 50mV to the
output sense voltage.
VID4 (Pin 7): MSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID4 adds 400mV to the
output sense voltage.
VID2 (Pin 3): 3rd MSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID2 adds 100mV to the
output sense voltage.
NC (PIN 8): No Connect.
VID3 (Pin 4): 2nd MSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID3 adds 200mV to the
output sense voltage.
GND (Pin 9): Ground. Connect to regulator signal ground.
FB (Pin 10): Feedback Input. Connect to the 0.8V feedback
pin of a compatible regulator or the EAIN pin of the
LTC1629, LTC1929 and LTC3729.
VCC (Pin 5): Power Supply Voltage. Range from 2.7V to
5.5V.
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PI TABLE
MIN
NOMINAL (V)
TYP
MAX
ABSOLUTE MAX (V)
MIN
MAX
PIN
NAME
DESCRIPTION
1
VID0
LSB Programmable Input
0
VCC
– 0.3
7
2
VID1
4th MSB Programmable Input
0
VCC
– 0.3
7
3
VID2
3rd MSB Programmable Input
0
VCC
– 0.3
7
4
VID3
2nd MSB Programmable Input
0
VCC
– 0.3
7
5
VCC
Power Supply
2.7
5.5
– 0.3
7
6
SENSE
Regulator Output Voltage
1.075
1.85
– 0.3
7
7
VID4
MSB Programmable Input
0
VCC
– 0.3
7
8
NC
9
GND
Ground
– 0.3
7
10
FB
0.8V Feedback Input
– 0.3
7
0
0
0.8
1.075
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LTC1706-82
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BLOCK DIAGRA
VCC
40k
VID0 1
VCC
VCC
5
6
40k
SENSE
RFB1
10k
VID1 2
VCC
10 FB
SWITCH
CONTROL
LOGIC
RFB2
9
40k
GND
VID2 3
1706-82 BD
VCC
VCC
40k
VID3 4
40k
VID4 7
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OPERATIO
The LTC1706-82 is a precision resistive divider designed
specifically for use with an entire family of Linear Technology Corporation DC/DC switching regulators with 0.8V
internal reference and feedback voltages. The LTC1706-82
produces an output voltage ranging from 1.10V to 1.85V
in 25mV steps by closing the loop between the output
voltage sense and the feedback input of the regulator with
the appropriate resistive divider network.
The “top” feedback resistor, RFB1, connected between
SENSE and FB, is typically 10k and is not modified by the
state of the VID program inputs.
The “bottom” feedback resistor, RFB2, however, is modified by the five VID inputs and is precisely ratioed to RFB1.
VID Programming
A list of programmed inputs and their corresponding
output voltages is shown in Table 1. Programming is
accomplished by applying the proper voltage (or float
condition) on the five digital VID inputs. VID4 is the most
significant bit (MSB) and VID0 is the least significant bit
(LSB).
When the five VID inputs are low, or grounded, the
regulator output voltage is set to 1.85V. Each increasing
binary count is equivalent to a decrease of 25mV in the
output voltage. Therefore, to obtain a 1.10V output, only
VID0 is grounded while the other four VID inputs are tied
high or floating.
When all five VID inputs are high or floating, such as when
no CPU is present in a system, a regulated 1.075V output
is generated at VSENSE.
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LTC1706-82
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OPERATIO
Each VID input pin is pulled up by a 40k resistor in series
with a diode connected to VCC. Therefore, it should be
grounded (or driven low) to produce a digital low input. It
can be either floated or connected to VCC to get a digital high
input. The series diode is included to prevent the input from
being damaged or clamped when it is driven higher than VCC.
Table 1. VID Inputs and Corresponding Output Voltage
CODE
VID4
VID3
VID2
VID1
VID0
OUTPUT
00000
GND
GND
GND
GND
GND
1.850
00001
GND
GND
GND
GND
Float
1.825
00010
GND
GND
GND
Float
GND
1.800
00011
GND
GND
GND
Float
Float
1.775V
00100
GND
GND
Float
GND
GND
1.750V
00101
GND
GND
Float
GND
Float
1.725V
The FB pin is a high impedance node that requires minimum layout distance to reduce extra loading and unwanted stray pickup.
00110
GND
GND
Float
Float
GND
1.700V
00111
GND
GND
Float
Float
Float
1.675V
01000
GND
Float
GND
GND
GND
1.650V
When used with the LTC1629, the LTC1706-82’s FB,
SENSE, VCC and GND pins should be connected, respectively, with the EAIN, VDIFFOUT, INTVCC, and SGND pins of
the LTC1629. The result of this application is a precisely
controlled, multiphase, variable output voltage supply to
any low voltage, high current system such as a powerful
personal computer, workstation or network server. True
remote sense capability of the LTC1629 is also retained in
this case.
01001
GND
Float
GND
GND
Float
1.625V
01010
GND
Float
GND
Float
GND
1.600V
Voltage Sensing and Feedback Pins
01011
GND
Float
GND
Float
Float
1.575V
01100
GND
Float
Float
GND
GND
1.550V
01101
GND
Float
Float
GND
Float
1.525V
01110
GND
Float
Float
Float
GND
1.500V
01111
GND
Float
Float
Float
Float
1.475V
10000
Float
GND
GND
GND
GND
1.450V
10001
Float
GND
GND
GND
Float
1.425V
10010
Float
GND
GND
Float
GND
1.400V
10011
Float
GND
GND
Float
Float
1.375V
The VID inputs should be driven with a maximum VIL of
0.4V and a minimum VIH of 1.6V. However, the VID input
range is not limited to values less than VCC. Because of the
internal diode between VCC and the pull-up resistor, the
inputs can go higher than VCC without being clamped to
VCC or damaging the input.
10100
Float
GND
Float
GND
GND
1.350V
10101
Float
GND
Float
GND
Float
1.325V
10110
Float
GND
Float
Float
GND
1.300V
This allows the LTC1706-82 to be fully logic compatible
and operational over a higher input voltage range (less
than the 7V absolute maximum rating).
VID Input Characteristics
When a VID input is grounded, there will be a higher
quiescent current flow from Vcc because of a resistor from
Vcc through a series diode to each one of the VID inputs.
This increase in quiescent current is calculated from
10111
Float
GND
Float
Float
Float
1.275V
11000
Float
Float
GND
GND
GND
1.250V
11001
Float
Float
GND
GND
Float
1.225V
11010
Float
Float
GND
Float
GND
1.200V
11011
Float
Float
GND
Float
Float
1.175V
11100
Float
Float
Float
GND
GND
1.150V
11101
Float
Float
Float
GND
Float
1.125V
11110
Float
Float
Float
Float
GND
1.100V
11111
Float
Float
Float
Float
Float
NO_CPU
(1.075V)
IQ = N(VCC – VDIODE)/RPULLUP
N is the number of grounded VID inputs. VDIODE is typically
0.6V while RPULLUP has a typical pullup resistance of 40k.
In other words, each VID input has a typical pull up current
of (VCC – 0.6)/40K, which is approximately 68µA for a 3.3V
system.
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APPLICATIO S I FOR ATIO
Besides the LTC1629, the LTC1706-82 also programs a
whole family of LTC DC/DC converters that have an onboard
0.8V reference. The LTC1628, LTC1735, LTC1702,
LTC1772, LTC1929 and LTC3729 are just a few of the high
efficiency step-down switching regulators that will work
equally well with the LTC1706-82.
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PACKAGE DESCRIPTIO
MS Package
10-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1661)
0.889 ± 0.127
(.035 ± .005)
5.23
(.206)
MIN
3.2 – 3.45
(.126 – .136)
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.50
0.305 ± 0.038
(.0197)
(.0120 ± .0015)
BSC
TYP
RECOMMENDED SOLDER PAD LAYOUT
0.254
(.010)
0.497 ± 0.076
(.0196 ± .003)
REF
10 9 8 7 6
3.00 ± 0.102
(.118 ± .004)
NOTE 4
4.90 ± 0.15
(1.93 ± .006)
DETAIL “A”
0° – 6° TYP
GAUGE PLANE
1 2 3 4 5
0.53 ± 0.01
(.021 ± .006)
DETAIL “A”
0.86
(.034)
REF
1.10
(.043)
MAX
0.18
(.007)
SEATING
PLANE
0.17 – 0.27
(.007 – .011)
TYP
0.50
(.0197)
BSC
0.13 ± 0.076
(.005 ± .003)
MSOP (MS) 0802
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
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Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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LTC1706-82
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TYPICAL APPLICATIO
VID Controlled High Current 70A 4-Phase Power Supply
OPTIONAL SYNC
CLOCK IN
2
0.33µF
3
1000pF 4
5
1
2
FROM
µP
3
4
7
5
VCC
6
VID0
SENSE
VID1
VID2
6
FB
7
100pF
8
SENSE1
EAIN
ITH
VOS–
12
+
1000pF 13
14
EXTVCC
LTC1629
11
9
BG1
PHASMD
VOS–
GND
VIN
PLLIN
9
VID4
SW1
BOOST1
PLLFLTR
10
VOS+
TG1
SENSE1–
VDIFFOUT
10
CLKOUT
+
6800pF
47k
LTC1706-82
VID3
0.33µF
RUN/SS
INTVCC
SGND
PGND
VDIFFOUT
BG2
BOOST2
VOS
SW2
SENSE2–
TG2
SENSE2+
AMPMD
L1
28
27
5V
0.003Ω
26
0.47µF
25
M1
10Ω
24
M2
1µF
23
22
21
D7
20
D8
1µF
25V
+
1
22µF
6.3V
M3
150µF, 16V
×2
+
+
GND
M4
0.47µF
17
M5
16
VOUT
1.10V TO
1.85V
70A
×3
470µF, 6.3V
KEMET CAP
19
18
D1
MBRS
340T3
M6
15
D2
MBRS
340T3
0.003Ω
L2
75k
1
2
3
47pF
1000pF 4
10k
5
0.01µF
6
1nF
47k
7
6800pF
100pF
VIN: 12V
VOUT: 1.1V TO 1.85, 70A
M1 TO M12: FDS7760A
L1 TO L4: 1µH SUMIDA CEPH149-IROMC
D7 TO D10: CENTROL CMDSH-3TR
COUT: KEMET T510X477M006AS
8
9
VDIFFOUT
10
–
VOS
11
VOS+
12
1000pF 13
14
CLKOUT
RUN/SS
SENSE1+
TG1
SENSE1–
SW1
BOOST1
EAIN
VIN
PLLFLTR
BG1
PLLIN
EXTVCC
PHASMD
LTC1629
ITH
SGND
INTVCC
PGND
BG2
VDIFFOUT
VOS–
BOOST2
VOS
+
SW2
SENSE2–
TG2
SENSE2+
AMPMD
L3
28
27
5V
0.003Ω
26
25
0.47µF
10Ω
24
M7
22
21
D9
20
D10
1µF
25V
M9
M8
1µF
23
+
24k
×3
470µF, 6.3V
KEMET CAP
150µF, 16V
×2
22µF
6.3V
+
D3
MBRS
340T3
+
GND
VIN
12V
19
18
17
0.47µF
M10
M12
M11
16
15
D4
MBRS
340T3
0.003Ω
L4
1706-82 TA02
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Burst Mode and PolyPhase are registered trademarks of Linear Technoogy Corporation. No RSENSE is a trademark of Linear Technology Corporation.
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Linear Technology Corporation
LT/TP 1002 1K REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2000