Datasheet LTC1706-82 Datasheet (Linear Technology)

LTC1706-82

Final Electrical Specifications

VID Voltage Programmer

for Intel VRM 9.0

FEATURES

■

Fully Compliant with the Intel VRM 9.0 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

U

APPLICATIO S

■

Intel Pentium® III Processor Power Supply

■

Multiprocessor Workstations and Servers

■

Multiphase Processor Power Supply

■

AMD AthlonTM Processor Power Supply

U

January 2000

DESCRIPTIO

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.

The LTC1706-82 is designed specifically to program an
entire family of Linear Technology DC/DC converters in full
compliance with the Intel Desktop VID specification.

The LTC1706-82 programs the following Linear Technol­ogy DC/DC converter products: LTC1622, LTC1628,
LTC1629, LTC1702, LTC1735, LTC1735-1, LTC1772 and
LTC1929.

Consult factory for future compatible DC/DC converter
products.

, 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.

TYPICAL APPLICATIO

VID Controlled High Current 4-Phase DC/DC Converter (Simplified Block Diagram)

V

CC

VID0

FROM

µP

VID1

VID2

LTC1706-82
VID3

VID4

GND

UP TO SIX LTC1629s CAN BE PARALLELED
TO DELIVER AS MUCH AS 200A

SENSE

U

V

IN

4.5V TO 22V

V

IN

INTV

CC

LTC1629

V

DIFFOUT

SGND

FB

EAIN

LTC1629

SGND

EAIN

TG1

SW1

BG1

PGND

TG2

SW2

BG2

V

TG1

SW1

BG1

PGND

TG2

SW2

BG2

IN

V

IN

4.5V TO 22V

L1 R

SENSE1

V

IN

R

L2

SENSE2

R

L3

SENSE3

V

IN

R

L4

SENSE4

1706-82 TA01

+

V

OUT

1.10V TO 1.85V
UP TO 70A

C

OUT

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.

1

LTC1706-82

WW

W

ABSOLUTE AXI U RATI GS

U

UUW

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

TOP VIEW

1

VID0

2

VID1

3

VID2

4

VID3

5

V

CC

MS10 PACKAGE

10-LEAD PLASTIC MSOP

10

FB

9

GND

8

NC

7

VID4

6

SENSE

ORDER PART

NUMBER

LTC1706EMS-82

MS10

PART MARKING

Junction Temperature........................................... 110°C

Storage Temperature Range ................. –65°C to 150°C

T

= 110°C, θJA = 120°C/W

JMAX

LTMJ

Lead Temperature (Soldering, 10 sec).................. 300°C

Consult factory for Industrial and Military grade parts.

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, VIDO = VID1 = VID2 = VID3 = VID4 = NC unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

CC

I

VCC

R

FB-SENSE

V

Error % Output Voltage Accuracy Programmed From 1.10V to 1.85V ● –0.25 0.25 %

OUT

R

PULLUP

VID

T

I

VID-LEAK

V

PULLUP

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.

Operating Supply Voltage Range 2.7 5.5 V
Supply Current (Note 3) 0.1 5.0 µA
Resistance Between SENSE and FB ● 61014 kΩ

VID Input Pull-Up Resistance V
VID Input Voltage Threshold V

VID Input Leakage Current VCC < VID < 7V, (Note 4) 0.01 ±1.00 µA
VID Pull-Up Voltage VCC = 3.3V 2.8 V

= 0.6V, (Note 4) 40 kΩ

DIODE

(2.7V < VCC < 5.5V) 0.4 V

IL

V

(2.7V < VCC < 5.5V) 1.6 V

IH

V

= 5V 4.5 V

CC

Note 3: With all five VID inputs floating, the VCC supply current is simply
the device leakage current. However, the V
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 V
supply without damage or clamping. (See Operation section for further
details.)

to allow input voltages higher than the V

CC

supply current will rise and

CC

CC

2

UW

TEMPERATURE (°C)

–50 0 50 100

ERROR (%)

1706-82 G02

0.25

0

–0.25

V

OUT

= 1.85V

V

OUT

= 1.5V

V

OUT

= 1.1V

TEMPERATURE (°C)

–50 0 50 100

VID PULL-UP CURRENT (µA)

1706-82 G04

120

100

80

60

40

20

0

VCC = 5V
VID4 = 0V
VID0 = VID1 = VID2 = VID3 = OPEN

SUPPLY VOLTAGE (V)

02468

SUPPLY CURRENT (µA)

1706-82 G06

5

4

3

2

1

0

ALL VID INPUTS OPEN

T

A

= 25°C

TYPICAL PERFOR A CE CHARACTERISTICS

Typical Error % vs Output Voltage Typical Error % vs Temperature

0.25

TA = 25°C

0

ERROR (%)

LTC1706-82

(kΩ)
R

FB1

–0.25

1.2 1.3 1.4 1.5 1.6 1.7 1.8

1.1

R

FB1

30

20

10

0

–50 0 50 100

OUTPUT VOLTAGE (V)

1706-82 G01

vs Temperature I

TEMPERATURE (°C)

1706-82 G03

VID-PULLUP

vs Temperature

Supply Current vs Temperature Supply Current vs Supply Voltage

2.0
ALL VID INPUTS OPEN

1.5

1.0

SUPPLY CURRENT (µA)

VCC = 5V

0.5

0

–50 0 50 100

VCC = 3.3V

TEMPERATURE (°C)

VCC = 2.7V

1706-82 G05

3

LTC1706-82

UUU

PI FU CTIO S

VID0 (Pin 1): LSB Programming Input. Low = GND,
High = V

or Float. Grounding VID0 adds 25mV to the

CC

output sense voltage.
VID1 (Pin 2): 4th MSB Programming Input. Low = GND,

High = VCC or Float. Grounding VID1 adds 50mV 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.

SENSE (Pin 6): Regulator Output Voltage. Connect di­rectly to regulator output sense node or V

DIFFOUT

used with the LTC1629 and LTC1929.
VID4 (Pin 7): MSB Programming Input. Low = GND,

High = VCC or Float. Grounding VID4 adds 400mV to the
output sense voltage.

NC (PIN 8): No Connect.
GND (Pin 9): Ground. Connect to regulator signal ground.
FB (Pin 10): Feedback Input. Connect to the 0.8V feedback

VID3 (Pin 4): 2nd MSB Programming Input. Low = GND,

High = VCC or Float. Grounding VID3 adds 200mV to the
output sense voltage.

pin of a compatible regulator or the EAIN pin of the
LTC1629 and LTC1929.

VCC (Pin 5): Power Supply Voltage. Range from 2.7V to

5.5V.

PIUTABLE

NOMINAL (V) ABSOLUTE MAX (V)

PIN NAME DESCRIPTION MIN TYP MAX MIN MAX

1 VID0 LSB Programmable Input 0 V
2 VID1 3rd MSB Programmable Input 0 V
3 VID2 2nd MSB Programmable Input 0 V
4 VID3 1st MSB Programmable Input 0 V
5V
6 SENSE Regulator Output Voltage 1.075 1.85 –0.3 7
7 VID4 MSB Programmable Input 0 V
8NC
9 GND Ground 0 –0.3 7
10 FB 0.8V Feedback Input 0 0.8 1.5 –0.3 7

CC

Power Supply 2.7 5.5 –0.3 7

CC

CC

CC

CC

CC

–0.3 7
–0.3 7
–0.3 7
–0.3 7

–0.3 7

when

4

BLOCK DIAGRA

V

CC

40k

VID0

1

V

CC

40k

VID1

2

V

CC

40k

VID2

3

V

CC

W

LTC1706-82

V

CC

5

6

SENSE

R

FB1

10k

10

FB

SWITCH

CONTROL

LOGIC

V

CC

R

FB2

9

GND

1706-82 BD

VID3

40k

4

VID4

7

40k

U

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, R
SENSE and FB, is typically 10k and is not modified by the
state of the VID program inputs.

The “bottom” feedback resistor, R
fied by the five VID inputs and is precisely ratioed to R

, connected between

FB1

, however is modi-

FB2

FB1

.

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 V

SENSE

.

5

LTC1706-82

U

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.

Voltage Sensing and Feedback Pins

The FB pin is a high impedance node that requires mini­mum layout distance to reduce extra loading and un­wanted stray pickup.

When used with the LTC1629, the LTC1706-82’s FB,
SENSE, VCC and GND pins should be connected, respec­tively, with the EAIN, V

DIFFOUT

, 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.

VID Input Characteristics

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.

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).

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

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
00110 GND GND Float Float GND 1.700V
00111 GND GND Float Float Float 1.675V
01000 GND Float GND GND GND 1.650V
01001 GND Float GND GND Float 1.625V
01010 GND Float GND Float GND 1.600V
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
10100 Float GND Float GND GND 1.350V
10101 Float GND Float GND Float 1.325V
10110 Float GND Float Float GND 1.300V
10111 Float GND Float Float Float 1.275V
11000 Float Float GND GND GND 1.250V
11001 Float Float GND GND Float 1.250V
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 – V

N is the number of grounded VID inputs. V

0.6V while R

PULLUP

)/R

DIODE

PULLUP

DIODE

is typically

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.

6

LTC1706-82

U

WUU

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, LTC1622,
LTC1702, LTC1772 and LTC1929 are just a few of the high
efficiency step-down switching regulators that will work
equally well with the LTC1706-82.

U

PACKAGE DESCRIPTIO

0.007
(0.18)

0.021

± 0.006

(0.53 ± 0.015)

* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH,

PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.

INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

° – 6° TYP

0

Dimensions in inches (millimeters) unless otherwise noted.

MS10 Package

10-Lead Plastic MSOP

(LTC DWG # 05-08-1661)

0.040

± 0.006

(1.02 ± 0.15)

SEATING

PLANE

0.009

(0.228)

0.0197

REF

(0.50)

BSC

0.034 ± 0.004
(0.86 ± 0.102)

0.006 ± 0.004

(0.15 ± 0.102)

0.118 ± 0.004*
(3.00 ± 0.102)

0.193 ± 0.006

(4.90 ± 0.15)

12

8910

3

7

6

45

0.118 ± 0.004**
(3.00 ± 0.102)

MSOP (MS10) 1098

7

LTC1706-82

TYPICAL APPLICATIO

OPTIONAL SYNC

CLOCK IN

5

V

VID0

VID1

VID2

VID3

VID4

CC

SENSE

LTC1706-82

GND

9

6

10

FB

FROM

1

2

3

µP

4

7

U

VID Controlled High Current 70A 4-Phase Power Supply

0.33µF

47k

24k

0.33µF

100pF

75k

1000pF

6800pF

1000pF

10
11
12
13
14

1
2
3
4
5
6
7
8
9

RUN/SS
SENSE1
SENSE1
EAIN
PLLFLTR
PLLIN
PHASMD
I

TH

SGND
V

DIFFOUT

–

V

OS

+

V

OS

SENSE2
SENSE2

+

–

LTC1629

–

+

CLKOUT

TG1

SW1

BOOST1

BG1

EXTV

INTV

PGND

BG2

BOOST2

SW2

TG2

AMPMD

28

5V

27
26
25
24

V

IN

23
22

CC

21

CC

20
19
18
17
16
15

0.47µF

D7

D8

0.47µF

1µF

1µF
25V

10Ω

+

22µF

6.3V

M1

150µF, 16V

× 2

+

M4

GND

L1

0.003Ω

D1
MBRS

M3

M6

340T3

× 3

470µF, 6.3V
KEMET CAP

D2
MBRS
340T3

0.003Ω

+

V

OUT

1.10V TO

1.85V
70A

M2

M5

L2

GND

M8

M11

L3

0.003Ω

D3
MBRS
340T3

M9

× 3

470µF, 6.3V
KEMET CAP

+

V

IN

12V

D4
MBRS

M12

340T3

0.003Ω

L4

1706-82 TA02

: 12V

V

IN

V

: 1.1V TO 1.85, 70A

OUT

M1 TO M12: FDS7760A
L1 TO L4: 1µH SUMIDA CEPH149-IROMC
D7 TO D10: CENTROL CMDSH-3TR

: KEMET T510X477M006AS

C

OUT

47pF

0.01µF

10k

100pF

1nF

1000pF

NC

1000pF

10
11
12
13
14

1
2
3
4
5
6
7
8
9

RUN/SS
SENSE1
SENSE1
EAIN
PLLFLTR
PLLIN
PHASMD
I

TH

SGND
V

DIFFOUT

–

V

OS

+

V

OS

SENSE2
SENSE2

+

–

LTC1629

–

+

CLKOUT

TG1

SW1

BOOST1

BG1

EXTV

INTV

PGND

BG2

BOOST2

SW2

TG2

AMPMD

28

5V

27
26
25
24

V

IN

23
22

CC

21

CC

20
19
18
17
16
15

0.47µF

D9

D10

0.47µF

1µF

1µF
25V

22µF

6.3V

M7

150µF, 16V

× 2

+

M10

10Ω

+

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PART NUMBER DESCRIPTION COMMENTS

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OUT

LTC1709 2-Phase Synchronous Step-Down Controller with 5-Bit Desktop VID 4V ≤ VIN ≤ 36V, PLL, 36-Pin SSOP, Current Mode Operation
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3.5V ≤ V

≤ 36V

IN

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Burst Mode, PolyPhase and No R

are trademarks of Linear Technology Corporation.

SENSE

Linear Technology Corporation

8

1630 McCarthy Blvd., Milpitas, CA 95035-7417

[phone] ● FAX: [phone]

●

www.linear-tech.com

TM

, 2.7V ≤ VIN ≤ 7V

SENSE

Range: 1.3V to 3.5V

Up to 40A, 3.5V ≤ VIN ≤ 36V

OUT

170682i LT/TP 0100 4K • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 2000