LINER LTC1706IS8-19 Vid voltage programmer Datasheet

LTC1706-19
VID Voltage Programmer
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DESCRIPTIO
FEATURES
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The LTC®1706-19 is a precision, digitally programmed,
resistive ladder which adjusts the output of any 1.19V
referenced regulator. Depending on the state of the four
VID inputs, an output voltage between 1.3V and 2V is
programmed in 50mV increments.
Programs Regulator Output Voltage from 1.3V to
2V in 50mV Steps
Programs an Entire Family of Linear Technology
DC/DC Converters
Fully Compliant with the Intel Mobile VID
Specification
±0.25% Accurate Output Voltage
Built-In 40k Pull-Up Resistors on VID Inputs
Available in SO-8 Packaging
The LTC1706-19 is designed specifically to program an
entire family of Linear Technology DC/DC converters in full
compliance with the Intel Mobile VID specification.
The LTC1706-19 programs the following Linear Technology DC/DC converter products: LTC1433, LTC1434,
LTC1435, LTC1435A, LTC1436, LTC1437, LTC1438,
LTC1439, LTC1538-AUX, LTC1539, LTC1624 and
LTC1625. (Consult factory for future compatible DC/DC
converter products.)
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APPLICATIONS
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Intel Mobile Pentium® II Processor Power Supply
Notebook and Palmtop Computers, PDAs
Portable Instruments
Battery-Powered Equipment
, LTC and LT are registered trademarks of Linear Technology Corporation.
Pentium is a registered trademark of Intel Corporation.
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TYPICAL APPLICATIO
Intel Mobile Pentium II Processor Power Supply
COSC
47pF
1
2
3
CSS
0.1µF
COSC
VIN
RUN/SS
TG
SW
50pF
INTVCC
5
6
16
M1
Si4410
CIN
10µF
30V
X2
+
CF
0.1µF
CC
1000pF
RC
10k
13
ITH
LTC1435A
CC2
220pF
VIN
4.5V TO 22V
RF
4.7Ω
L1
3.3µH
14
RSENSE
0.015Ω
VOUT
1.3V TO 2V
7A
SENSE
12
VCC
*DB
SGND
0.22µF
BOOST
VOSENSE
BG
PGND
SENSE –
+
15
FB
+
11
10
4.7µF
M2
Si4410
LTC1706-19
COUT
820µF
4V
X2
D1
MBRS140T3
VID
0 1 2 3
GND
SENSE+
7
8
FROM µP
1000pF
*CMDSH-3
1706-19 TA01
1
LTC1706-19
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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
LTC1706C-19 .......................................... 0°C to 70°C
LTC1706I-19 ...................................... – 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
VID2 1
8
VID1
VID3 2
7
VID0
VCC 3
6
SENSE
GND 4
5
FB
LTC1706CS8-19
LTC1706IS8-19
S8 PART
MARKING
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 110°C, θJA = 120°C/W
170619
706I19
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
TA = 25°C, 2.7V ≤ VCC ≤ 5.5V, VID0 = VID1 = VID2 = VID3 = N. C., unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN
VCC
Operating Supply Voltage Range
IVCC
Supply Current
RFB-SENSE
Resistance Between SENSE and FB
VOUT Error %
Output Voltage Accuracy
Programmed From 1.3V to 2V
RPULLUP
VID Input Pull-Up Resistance
VDIODE = 0.6V, VCC = 5V, (Note 3)
VIDT
VID Input Voltage Threshold
VIL (2.7V ≤ VCC ≤ 5.5V)
VIH (2.7V ≤ VCC ≤ 5.5V)
TYP
2.7
(Note 2)
●
8
●
– 0.25
5.5
V
5
µA
15
20
kΩ
0.25
%
40
kΩ
0.4
V
V
±1
µA
1.6
VID Input Leakage Current
VCC < VID < 7V, (Note 3)
0.01
VPULLUP
VID Pull-Up Voltage
VCC = 3.3V
VCC = 5V
2.8
4.5
2
UNITS
0.1
IVID-LEAK
The ● denotes specifications which apply over the full specified
temperature range.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: With all four VID inputs floating, the VCC supply current is simply
the device leakage current. However, the VCC supply current will rise and
MAX
V
V
be approximately equal to the number of grounded VID input pins times
(VCC – 0.6V)/40k. (See the Typical Applications section for more detail.)
Note 3: 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
detail.)
LTC1706-19
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TYPICAL PERFOR A CE CHARACTERISTICS
Typical Error % vs Output Voltage
Typical Error % vs Temperature
0.25
ERROR (%)
ERROR (%)
0.25
0
–0.25
–50
–0.25
1.3
1.5
1.7
OUTPUT VOLTAGE (V)
1.9
VOUT = 1.3V
0
2.0
VOUT = 1.7V
VOUT = 2V
0
50
TEMPERATURE (°C)
100
1706-19 G02
1706-19 G01
RFB1 vs Temperature
IVID-PULLUP vs Temperature
30
120
VID PULL-UP CURRENT (µA)
VCC = 5V
RFB1 (kΩ)
20
10
100
80
60
40
20
0
–50
0
50
TEMPERATURE (°C)
0
–50
100
0
50
TEMPERATURE (°C)
1706-19 G03
100
1706-19 G04
Supply Current vs Supply Voltage
Supply Current vs Temperature
5
2.0
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
4
1.5
1.0
VCC = 5V
VCC = 3.3V
0.5
0
–50
VCC = 2.7V
3
2
1
0
0
50
TEMPERATURE (°C)
100
1706-19 G05
0
2
4
6
SUPPLY VOLTAGE (V)
8
1706-19 G06
3
LTC1706-19
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PI FU CTIO S
VID2 (Pin 1): 2nd MSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID2 adds 200mV to the
output sense voltage.
FB (Pin 5): Feedback Input. Connect to the 1.19V feedback
pin of a compatible regulator.
SENSE (Pin 6): Regulator Output Voltage. Connect directly to regulator output sense node.
VID3 (Pin 2): 1st MSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID3 adds 400mV to the
output sense voltage.
VID0 (Pin 7): LSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID0 adds 50mV to the
output sense voltage.
VCC (Pin 3): Power Supply Voltage. Range from 2.7V to
5.5V.
VID1 (Pin 8): 3rd MSB Programming Input. Low = GND,
High = VCC or Float. Grounding VID1 adds 100mV to the
output sense voltage.
GND (Pin 4): Ground. Connect to regulator signal ground.
MIN
NOMINAL (V)
TYP
MAX
ABSOLUTE MAX (V)
MIN
MAX
PIN
NAME
DESCRIPTION
1
VID2
2nd MSB Programmable Input
2
VID3
1st MSB Programmable Input
3
VCC
Power Supply
4
GND
Ground
5
FB
1.19V Feedback Input
1.5
– 0.3
7
6
SENSE
Regulator Output Voltage
1.3
2
– 0.3
7
7
VID0
LSB Programmable Input
0
VCC
– 0.3
7
8
VID1
3rd MSB Programmable Input
0
VCC
– 0.3
7
0
VCC
0
VCC
– 0.3
7
2.7
5.5
– 0.3
7
0
0
0
0
1.19
W
BLOCK DIAGRA
VCC
VCC
40k
VID0
VCC
SENSE
40k
VID1
RFB1
VCC
FB
SWITCH
CONTROL
LOGIC
40k
RFB2
GND
VID2
VCC
40k
VID3
1706-19 BD
4
– 0.3
7
LTC1706-19
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OPERATIO
The LTC1706-19 is a precision resistive divider designed
specifically for use with an entire family of Linear Technology Corporation DC/DC switching regulators with 1.19V
internal reference and feedback voltages. The LTC1706-19
produces an output voltage ranging from 1.3V to 2V in
50mV steps by closing the loop between the output
voltage sense and the feedback input of the regulator with
the appropriate resistive divider network.
Table 1. VID Inputs and Corresponding Output Voltage
The “top” feedback resistor, RFB1, connected between
SENSE and FB, is typically 15k and is not modified by the
state of the VID program inputs. However, the “bottom”
feedback resistor, RFB2, is modified by the four VID inputs
and is precisely ratioed to RFB1.
VID Programming
Programming is accomplished by applying the proper
voltage (or float condition) on the four digital VID inputs.
VID3 is the most significant bit (MSB), and VID0 is the
least significant bit (LSB). When all four inputs are low, or
grounded, the regulator output voltage is set to 2V. Each
increasing binary count is equivalent to a decrease of
50mv in the output voltage. Therefore, to obtain a 1.3V
output, the three MSBs are left floating, or high, while only
the LSB, VID0, is grounded. A list of programmed inputs
and their corresponding output voltages is shown in
Table 1.
When all four VID inputs are high or floating (1111), such
as when no CPU is present in a system, a regulated 1.25V
output is generated at VSENSE.
CODE
VID3
VID2
VID1
VID0
OUTPUT
0000
GND
GND
0001
GND
GND
GND
GND
2.00V
GND
Float
1.95V
0010
GND
GND
Float
GND
1.90V
0011
0100
GND
GND
Float
Float
1.85V
GND
Float
GND
GND
1.80V
0101
GND
Float
GND
Float
1.75V
0110
GND
Float
Float
GND
1.70V
0111
GND
Float
GND
GND
1.65V
1000
Float
GND
GND
GND
1.60V
1001
Float
GND
GND
Float
1.55V
1010
Float
GND
Float
GND
1.50V
1011
Float
GND
Float
Float
1.45V
1100
Float
Float
GND
GND
1.40V
1101
Float
Float
GND
Float
1.35V
1110
Float
Float
Float
GND
1.30V
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 LTC1435A, the LTC1706-19’s FB,
SENSE, VCC and GND pins should be connected, respectively, with the VOSENSE, VOUT, INTVCC and SGND pins of
the LTC1435A. The result of this application is a precisely
controlled variable voltage supply for any low voltage
system such as a palmtop or a laptop computer.
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 if it is driven higher
than VCC.
5
LTC1706-19
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OPERATIO
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 below VCC. Because of the
diode between VCC and the pull-up resistor, the inputs can
go higher than VCC without being bootstrapped to VCC or
damaging the input. This allows the LTC1706-19 to be
logic compatible and operational over a much 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 the input. This increase in
quiescent current is calculated from
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. In other words, each VID input has a
typical pull-up current of (VCC – 0.6V)/40k, which is
approximately 68µA for a 3.3V system.
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TYPICAL APPLICATIO S
450mA, Low Noise Monolithic Current Mode Step-Down DC/DC Converter
0.1µF
68µF
20V
+
D1*
VOUT
1.3V TO 2V
450mA
2.7V TO 5.5V
3
1
L1**
100µH
2
6
3
SENSE
4
VCC
5
0.1µF
5
+
FB
LTC1706-19
COUT
820µF
4V
×2
6
0.1µF
7
8
SSW
PWRVIN
BSW
SVIN
NC
COSC
LTC1433
RUN/SS
LBO
LBI
INPUT VOLTAGE
3.5V TO 12V
PGND 15
NC
SGND
16
POR
ITH
VOSENSE
VPROG
14
10k
13
12
POWER ON RESET
11
10
5.1k
VID
0 1 2 3
7 8 1 2
6800pF
GND
4
FROM µP
* MOTOROLA MBRS130LT3
** COILCRAFT D03316-104
6
680pF
NC
1706-19 TA02
47pF
LTC1706-19
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TYPICAL APPLICATIO S
High Efficiency Low Noise Synchronous Step-Down Switching Regulator
0.1µF
10k
1
COSC
39pF
24
PLL LPF
2
3
4
COSC
VIN
RUN/SS
TGL
TGS
LTC1436A-PLL
SW
CC
510pF
100pF
18
21
M1
Si4412DY
19
M3
IRLML2803
CIN
22µF
35V
X2
+
L1
3.3µH
20
RSENSE
0.02Ω
VOUT
1.3V TO 2V
5A
6
NC
RC
10k
VIN
4.5V TO 22V
PLLIN
ITH
CSS
0.1µF
EXTERNAL
FREQUENCY
SYNCHRONIZATION
7
VPROG
6
INTVCC
3
17
VCC
*DB
SGND
8
SENSE
0.22µF
BOOST
VOSENSE
BG
PGND
SENSE –
FB
+
16
+
5
22
4.7µF
M2
Si4412DY
D1
MBRS140T3
COUT
100µF
10V
×2
VID
15
0 1 2 3
7 8 1 2
SENSE+
9
LTC1706-19
GND
4
10
FROM µP
1000pF
*CMDSH-3
1706-19 TA03
Ultrafast Transient Response Low Dropout Regulator with Adjustable Output Voltage
VCC
3.3V
0.1µF
7
8
VID0
VIN
12V
3
VCC SENSE 6
2
VID1
LTC1706-19
1
2
1
1µF
VID2
VID3
GND
FB
5
3
4
SHDN
VIN
IPOS
INEG
LT1575-ADJ
GND
FB
GATE
COMP
8
3.3V
+
7
220µF
6
5Ω
IRFZ24
5
ADJUSTABLE
VOUT
1.27V TO 2.03V
(50.8mV STEPS)
4
10pF
7.5k
1000pF
1µF
× 24
1706-19 TA04
Used with the LT1575-ADJ, which has a 1.21V reference,
the LTC1706-19 programs the output voltage of the
ultrafast transient response low dropout regulator that’s
ideal for today’s power-hungry microprocessors. How-
ever, since the LT1575 does not have a 1.19V reference,
the output range will instead be from 1.27V to 2.03V in
steps of 50.8mV.
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.
7
LTC1706-19
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TYPICAL APPLICATIO S
High Efficiency 3A SO-8 N-Channel Switching Regulator with Programmable Output
VIN
4.8V TO 20V
VCC
0.1µF
7
8
3
VCC SENSE 6
VID0
2
VID1
LTC1706-19
1
1
470pF
3
VID2
SENSE –
ITH/RUN
VIN
BOOST
LTC1624
TG
VFB
1000pF
8
RSENSE
0.033Ω
7
6
VID3
GND
FB
4
0.1µF
4
5
GND
SW
CIN
22µF
35V
×2
+
COUT
100µF
10V
×2
Si4412DY
100pF
2
+
10µH
5
6.8k
MBRS340T3
VOUT
1.3V TO 2V
3A
1706-19 TA05
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PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
0.010 – 0.020
× 45°
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
0.053 – 0.069
(1.346 – 1.752)
0.004 – 0.010
(0.101 – 0.254)
8
7
6
5
0°– 8° TYP
0.016 – 0.050
0.406 – 1.270
0.014 – 0.019
(0.355 – 0.483)
0.050
(1.270)
TYP
0.150 – 0.157**
(3.810 – 3.988)
0.228 – 0.244
(5.791 – 6.197)
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
SO8 0996
1
2
3
4
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
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LT1375/LT1376
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High Frequency, Small Inductor, High Efficiency
LTC1435/LTC1435A
High Efficiency, Low Noise, Synchronous Step-Down Converter
16-Pin Narrow SO and SSOP
LTC1436/LTC1436-PLL
High Efficiency, Low Noise, Synchronous Step-Down Converter
24-Pin Narrow and 24-Pin SSOP
LTC1438/LTC1439
Dual, Low Noise, Synchronous Step-Down Converter
Multiple Output Capability
LTC1538-AUX
Dual, Low Noise, Synchronous Step-Down Converter
5V Standby Regulator in Shutdown
Burst Mode is a trademark of Linear Technlology Corporation.
8
Linear Technology Corporation
170619f LT/TP 0299 4K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 1999
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