LINER LTC1706EMS-61

LTC1706-61
5-Bit VID Voltage
Programmer for AMD
Opteron CPUs
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FEATURES
■
■
■
■
■
DESCRIPTIO
The LTC®1706-61 is a precision, digitally programmed,
resistive ladder which adjusts the output of any 0.6V
referenced regulator. Depending on the state of the five
VID inputs, an output voltage between 0.8V and 1.55V is
programmed in 25mV increments.
Programs Regulator Output Voltage Range from
0.8V to 1.55V in 25mV Steps
Programs a Wide Range of Linear Technology
DC/DC Converters with a 0.6V Reference
±0.35% Accurate Output Voltage
Built-In 40k Pull-Up Resistors on VID Inputs
Available in MSOP-10 Package
The LTC1706-61 is designed specifically to program
an entire family of Linear Technology DC/DC converters
with on board 0.6V references.
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APPLICATIO S
■
■
■
The LTC1706-61 programs the following Linear
Technology DC/DC converter products: LTC1629-6,
LTC3714, LTC3731 and LTC3778. (Consult factory for
additional DC/DC converter products.)
TM
AMD Opteron Processor Power Supply
Workstations and Servers
Large Memory Array Supply
, LTC and LT are registered trademarks of Linear Technology Corporation.
AMD Opteron is a trademark of Advanced Micro Devices, Inc.
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TYPICAL APPLICATIO
5-Bit VID-Controlled High Current Application (Simplified Block Diagram)
VIN
4.5V TO 22V
VIN
LTC1629-6
VID0
FROM
µP
INTVCC
SENSE
VID2 LTC1706-61
VID3
VID4
RSENSE1
VDIFFOUT
+
BG1
VOUT
0.8V TO 1.55V
UP TO 80A
COUT
VIN
PGND
SGND
FB
GND
L1
SW1
VCC
VID1
TG1
TG2
EAIN
L2
RSENSE2
L3
RSENSE3
L4
RSENSE4
SW2
ITH
BG2
VIN
4.5V TO 22V
VIN
LTC1629-6
TG1
SW1
BG1
PGND
VIN
SGND
EAIN
ITH
TG2
SW2
BG2
1706-61 TA01
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LTC1706-61
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PACKAGE/ORDER INFORMATION
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(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 Ambient 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
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ABSOLUTE MAXIMUM RATINGS
ORDER PART
NUMBER
TOP VIEW
VID0
VID1
VID2
VID3
VCC
1
2
3
4
5
10
9
8
7
6
FB
GND
NC
VID4
SENSE
MS PACKAGE
10-LEAD PLASTIC MSOP
TJMAX = 110°C, θJA = 120°C/ W
LTC1706EMS-61
MS
PART MARKING
LTK9
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
2.7V ≤ VCC ≤ 5.5V, VID0 = VID1 = VID2 = VID3 = VID4 = NC unless otherwise specified.
SYMBOL
VCC
IVCC
RFB-SENSE
VOUT Error %
RPULLUP
VIDTH
IVID-LEAK
VPULLUP
PARAMETER
Operating Supply Voltage Range
Supply Current
Resistance Between SENSE and FB
Output Voltage Accuracy
VID Input Pull-Up Resistance
VID Input Voltage Threshold
VID Input Leakage Current
VID Pull-Up Voltage
CONDITIONS
MIN
2.7
(Note 3)
●
●
VDIODE = 0.6V (Note 4)
VIL (2.7V ≤ VCC ≤ 5.5V)
VIH (2.7V ≤ VCC ≤ 5.5V)
VCC < VID < 7V (Note 4)
VCC = 3.3V
VCC = 5V
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC1706EMS-61 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.
6
– 0.35
TYP
0.1
10
MAX
5.5
5
14
+ 0.35
40
0.4
1.6
0.01
2.8
4.5
±1
UNITS
V
µA
kΩ
%
kΩ
V
V
µA
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 VID Input Characteristics section for more
details.)
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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LTC1706-61
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TYPICAL PERFORMANCE CHARACTERISTICS
IVID-PULLUP vs Temperature
1.0
100
80
60
1.5
SUPPLY CURRENT (µA)
120
ALL VID INPUTS OPEN
TA = 25°C
ALL VID INPUTS OPEN
VCC = 5V
VID4 = 0V
VID0 = VID1 = VID2 = VID3 = OPEN
SUPPLY CURRENT (µA)
VID PULL-UP CURRENT (µA)
Supply Current vs Supply Voltage
Supply Current vs Temperature
2.0
140
1.0
VCC = 5V
VCC = 3.3V
0.5
VCC = 2.7V
0.5
40
20
–50
0
50
TEMPERATURE (°C)
0
–50
100
0
50
TEMPERATURE (°C)
VID
0.35
0.25
0.25
0.15
0.15
–0.05
–0.15
–0.25
–0.25
–0.35
0.775
0.975
1.175
1.375
1.575
VCC = 5.5V
10.05
0.05
–0.15
VSENSE = 0.8V
VSENSE = 1.55V
10.00
9.95
–0.35
–60 –40 –20
0
20
40
60
80
100
9.90
–50
TEMPERATURE (°C)
SENSE VOLTAGE (V)
6.0
RFB1 vs Temperature
VSENSE = 1.15V
–0.05
5.5
10.10
RFB1 (kΩ)
VIDACCURACY ( %)
VIDACCURACY ( %)
0.35
VCC = 2.7V
3.5 4.0
4.5 5.0
SUPPLY VOLTAGE (V)
1706-61 G03
VID Sense Accuracy vs
Temperature
VID Sense Accuracy
VCC = 5.5V
3.0
1706-61 G02
1706-61 G01
0.05
0
2.5
100
1706-61 G04
1706-61 G05
0
50
TEMPERATURE (°C)
100
1706-61 G06
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PIN FUNCTIONS
VID0 (Pin 1): LSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID0 adds 25mV
to the 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.
VID3 (Pin 4): 2nd MSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID3 adds 200mV
to the output sense voltage.
VCC (Pin 5): Power Supply Voltage. Range from 2.7V to
5.5V.
SENSE (Pin 6): Regulator Output Voltage. Connect
directly to regulator output sense node.
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 0.6V feedback
pin of a compatible regulator.
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LTC1706-61
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PIN FUNCTIONS
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
0.8
1.55
– 0.3
7
7
VID4
1st MSB Programmable Input
0
VCC
– 0.3
7
8
NC
9
GND
Ground
– 0.3
7
10
FB
0.6V Feedback Input
– 0.3
7
0
0
0.6
1.5
W
BLOCK DIAGRA
VCC
40k
VID0 1
VCC
VCC
5
6
40k
VID1 2
SENSE
RFB1
VCC
10 FB
SWITCH
CONTROL
LOGIC
RFB2
9
40k
GND
VID2 3
1706-61 BD
VCC
VCC
40k
VID3 4
40k
VID4 7
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OPERATIO
The LTC1706-61 is a precision resistive divider designed
specifically for use with an entire family of Linear
Technology Corporation DC/DC switching regulators with
0.6V internal reference and feedback voltage. The
LTC1706-61 produces an output voltage ranging from
0.8V to 1.55V 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.
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LTC1706-61
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OPERATIO
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.
Table 1. VID Inputs and Corresponding Output Voltage
CODE
VID4
VID3
VID2
VID1
VID0
OUTPUT
00000
GND
GND
GND
GND
GND
1.550V
00001
GND
GND
GND
GND
Float
1.525V
00010
GND
GND
GND
Float
GND
1.500V
00011
GND
GND
GND
Float
Float
1.475V
00100
GND
GND
Float
GND
GND
1.450V
00101
GND
GND
Float
GND
Float
1.425V
00110
GND
GND
Float
Float
GND
1.400V
00111
GND
GND
Float
Float
Float
1.375V
01000
GND
Float
GND
GND
GND
1.350V
01001
GND
Float
GND
GND
Float
1.325V
01010
GND
Float
GND
Float
GND
1.300V
01011
GND
Float
GND
Float
Float
1.275V
01100
GND
Float
Float
GND
GND
1.250V
01101
GND
Float
Float
GND
Float
1.225V
01110
GND
Float
Float
Float
GND
1.200V
01111
GND
Float
Float
Float
Float
1.175V
10000
Float
GND
GND
GND
GND
1.150V
10001
Float
GND
GND
GND
Float
1.125V
10010
Float
GND
GND
Float
GND
1.100V
10011
Float
GND
GND
Float
Float
1.075V
10100
Float
GND
Float
GND
GND
1.050V
10101
Float
GND
Float
GND
Float
1.025V
10110
Float
GND
Float
Float
GND
1.000V
10111
Float
GND
Float
Float
Float
0.975V
11000
Float
Float
GND
GND
GND
0.950V
11001
Float
Float
GND
GND
Float
0.925V
11010
Float
Float
GND
Float
GND
0.900V
11011
Float
Float
GND
Float
Float
0.875V
11100
Float
Float
Float
GND
GND
0.850V
11101
Float
Float
Float
GND
Float
0.825V
11110
Float
Float
Float
Float
GND
0.800V
11111
Float
Float
Float
Float
Float
*0.775V
*Represents codes without a defined output (shutdown) voltage as
specified in AMD specifications. The LTC1706-61 interprets these codes
as a valid input and produces an output voltage as follows:
(11111) = 0.775V.
When all five VID inputs are high or floating, such as when
no CPU is present in a system, a regulated 0.775V output
is generated at VSENSE.
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 either be 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 LTC1629-6, the LTC1706-61’s FB,
SENSE, VCC and GND pins should be connected, respectively, with the EAIN, VDIFFOUT, INTVCC and SGND pins of
the LTC1629-6. The result of this application is a precisely
controlled, variable output voltage supply to any low
voltage, high current system such as a powerful personal
computer, workstation or network server.
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 LTC1706-61 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 inputs. This
increase in quiescent current is calculated from:
IQ = N(VCC – VDIODE)/RPULLUP
N is the number of grounded VID inputs. VDIODE is typically
0.6V while RPULLUP has a typical pull-up resistance of
40kΩ.
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LTC1706-61
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OPERATIO
In other words, each VID input has a typical pull-up current
of 68µA for a 3.3V system.
Besides the LTC1629-6, the LTC1706-61 also programs a
whole family of LTC DC/DC converters that have an onboard
0.6V reference. The LTC3714, LTC3778 and LTC3731 are
just a few of the high efficiency step-down switching
regulators that will work equally well with the LTC1706-61.
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TYPICAL APPLICATIO
2-Phase 12V Input, 0.8V to 1.55V/45A Max Power Supply with Adjustable Overvoltage Protection
VCC
VDD_CORE+
LTC1706-61
SENSE
–
OVP
TO SYSTEM
OVERVOLTAGE
PROTECTION
VID0
VID1
VID2
VID3
VID4
LOGIC
FB
OVP
THRESHOLD
FROM
µP
+
COMPARATOR
PWRGD
ENABLE
RUN/SS
D1
BAT54
C3
1nF
C1
0.1µF
TG1
3
SENSE1–
SW1
6
7
C9 4.7nF
R6 2.2k
8
C10 220pF
9
R24
107k
C14 470pF
INTVCC
Q9 (OPT)
2N7002
C17
1nF
VID0
VID1
PGOOD
SENSE1+
5
CLK1
RUN/SS
2
4
R23 48.7k
R1
10Ω
LTC3719
1
10
EAIN
PLLFLTR
PLLIN
BOOST1
VIN
BG1
FCB
EXTVCC
ITH
INTVCC
SGND
VDIFFOUT
PGND
BG2
11
VOS–
BOOST2
12
VOS+
SW2
13
SENSE2 –
TG2
14
SENSE2 +
ATTENIN
15
16
17
18
ATTENOUT
VBIAS
NO_CPU
VID4
VID0
VID3
VID1
VID2
36
35
34
C5
0.47µF
33
32
C7 1µF
31
30
29
28
INTVCC
C11
2.2µF
+
27
D3
BAT54A
C12
10µF
C15
0.47µF
26
25
R12 10Ω
5 6 7 8
Q3
Si7448DP
1 2 3 ×2
C13
0.47µF
L2
0.8µH
C2
0.47µF
10Ω
L1
0.8µH
12VIN
CIN1
10Ω
GND
R5
0.002Ω
D2
B320A
C8
0.47µF
VDD_CORE+
+
COUT1
R7
0.002Ω
R8
50Ω
C16
0.47µF
D4
B320A
10Ω
22
21
5 6 7 8
Q2
Si7448DP
1 2 3 ×3
5 6 7 8
Q4
Si7448DP
1 2 3 ×3
24
23
5 6 7 8
Q1
Si7448DP
1 2 3 ×2
GND
R9
50Ω
COREFB_H
10Ω
C18
0.1µF
20
19
VID2
VID3
VID4
COREFB_L
CIN1: SIX 10µF 16V CERAMIC CAPACITORS
COUT1: TEN 22µF 6.3V CERAMIC CAPACITORS
L1, L2: SUMIDA CEP125-1R0MC-H
1706-61 TA03
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LTC1706-61
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TYPICAL APPLICATIO
0.8V to 1.55V VID Programmable 15A Power Supply
1µF
X5R
CMDSH-3
1
2
100k 3
4
1500pF
20k
5
6
22pF
7
0.01µF
8
9
330k
10
RUN/SS
VON
BOOST
LTC3778
PGOOD
TG
SW
VRNG
SENSE +
ITH
SENSE –
FCB
PGND
SGND
BG
ION
DRVCC
VFB
INTVCC
EXTVCC
VIN
20
19
0.22µF
18
VIN
12V
10µF
16V
X5R
×4
IRF7811
0.68µH
17
16
B320A
15
VOUT
0.8V TO 1.55V
15A
SP
270µF
2V
×3
22µF
6.3V
X5R
IRF7811
14
13 4.7µF
X5R
6.3V
12
1Ω
11
VIN
5V
0.1µF
5
FROM
µP
1
2
3
4
7
VCC
6
VID0
SENSE
VID1
VID2 LTC1706-61
VID3
FB
VID4
GND
10
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1706-61 TA02
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PACKAGE DESCRIPTION
MS Package
10-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1661)
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.889 ± 0.127
(.035 ± .005)
10 9 8 7 6
5.23
(.206)
MIN
3.2 – 3.45
(.126 – .136)
0.254
(.010)
0.50
0.305 ± 0.038
(.0197)
(.0120 ± .0015)
BSC
TYP
RECOMMENDED SOLDER PAD LAYOUT
3.00 ± 0.102
(.118 ± .004)
NOTE 4
4.90 ± 0.15
(1.93 ± .006)
DETAIL “A”
0.497 ± 0.076
(.0196 ± .003)
REF
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)
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
SEATING
PLANE
0.17 – 0.27
(.007 – .011)
TYP
0.50
(.0197)
BSC
0.13 ± 0.076
(.005 ± .003)
MSOP (MS) 0802
170661f
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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LTC1706-61
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TYPICAL APPLICATION
VID Controlled High Current 70A 4-Phase Application
OPTIONAL SYNC
CLOCK IN
0.33µF
RUN/SS
SENSE1+
TG1
3
SENSE1–
SW1
1000pF 4
5
1
2
FROM
µP
3
4
VCC
SENSE
VID2
47k
LTC1706-61
FB
GND
PHASMD
8
ITH
9
LTC1629-6
EXTVCC
INTVCC
10
VOS–
11
VOS+
VOS–
BOOST2
12
VOS+
SW2
SENSE2–
TG2
SENSE2+
AMPMD
VID3
VID4
6800pF
VIN
BG1
100pF
VDIFFOUT
100pF
7
PLLIN
7
6
BOOST1
PLLFLTR
6
0.33µF
VID1
EAIN
5
VID0
CLKOUT
2
10
SGND
VDIFFOUT
1000pF 13
9
14
PGND
BG2
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
0.8V TO
1.55V
70A
COUT
470µF, 6.3V
×3
19
18
D1
MBRS
340T3
M6
15
D2
MBRS
340T3
0.003Ω
L2
75k
1
2
1000pF
3
47pF
4
10k
5
0.01µF
6
RUN/SS
SENSE1+
SENSE1–
EAIN
PLLFLTR
PLLIN
7
47pF
VDIFFOUT
VOS–
VOS+
1000pF
M1 TO M12: FDS7760A
L1 TO L4: 1µH SUMIDA CEPH149-IROMC
D7 TO D10: CENTROI CMDSH-3TR
COUT: KEMET T510X477M006AS
fSW: 200kHz
CLKOUT
TG1
SW1
BOOST1
VIN
BG1
EXTVCC
PHASMD
8
LTC1629-6
INTVCC
ITH
9
PGND
SGND
10
BG2
VDIFFOUT
11
BOOST2
VOS–
12
SW2
VOS+
13
TG2
SENSE2–
14
AMPMD
SENSE2+
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
COUT
470µF, 6.3V
×3
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
1706-61 TA04
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PolyPhase is a registered trademark of Linear Technology Corporation.
170661f
8
Linear Technology Corporation
LT/TP 0603 1K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2002