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LTC1706-19 VID Voltage Programmer
FEATURES
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DESCRIPTIO
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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 LTC(R)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. 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.)
, LTC and LT are registered trademarks of Linear Technology Corporation. Pentium is a registered trademark of Intel Corporation.
APPLICATIONS
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Intel Mobile Pentium(R) II Processor Power Supply Notebook and Palmtop Computers, PDAs Portable Instruments Battery-Powered Equipment
TYPICAL APPLICATIO
COSC 47pF 1 2 3 CSS 0.1F COSC RUN/SS ITH LTC1435A CC 1000pF CC2 220pF RC 10k 50pF
Intel Mobile Pentium II Processor Power Supply
RF 4.7 VIN 4.5V TO 22V
VIN TG
13 16
M1 Si4410 CF 0.1F
+
CIN 10F 30V X2 RSENSE 0.015 VOUT 1.3V TO 2V 7A
SW
14
L1 3.3H
INTVCC 5 6 SGND VOSENSE BOOST BG PGND SENSE - 7 SENSE+ 8
12 *DB 0.22F 15
+
11 10 4.7F M2 Si4410 D1 MBRS140T3
1000pF *CMDSH-3
1706-19 TA01
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SENSE VCC
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FB LTC1706-19
COUT 820F 4V X2
VID 0123 GND
FROM P
1
LTC1706-19
ABSOLUTE
(Note 1)
AXI U RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW VID2 1 VID3 2 VCC 3 GND 4 8 7 6 5 VID1 VID0 SENSE FB
(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 .......................................... 0C to 70C LTC1706I-19 ...................................... - 40C to 85C Junction Temperature ........................................... 110C Storage Temperature Range ................. - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C
ORDER PART NUMBER LTC1706CS8-19 LTC1706IS8-19 S8 PART MARKING 170619 706I19
S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 110C, JA = 120C/W
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
TA = 25C, 2.7V VCC 5.5V, VID0 = VID1 = VID2 = VID3 = N. C., unless otherwise specified.
SYMBOL VCC IVCC RFB-SENSE VOUT Error % RPULLUP VIDT 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 Programmed From 1.3V to 2V VDIODE = 0.6V, VCC = 5V, (Note 3) VIL (2.7V VCC 5.5V) VIH (2.7V VCC 5.5V) VCC < VID < 7V, (Note 3) VCC = 3.3V VCC = 5V 1.6 0.01 2.8 4.5 1 (Note 2)
q q
CONDITIONS
MIN 2.7
TYP 0.1
MAX 5.5 5 20 0.25
UNITS V A k % k V V A V V
8 - 0.25
15 40
0.4
The q 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
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.)
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LTC1706-19 TYPICAL PERFOR A CE CHARACTERISTICS
Typical Error % vs Output Voltage
0.25 0.25
ERROR (%)
ERROR (%)
0
-0.25 1.3 1.5 1.7 OUTPUT VOLTAGE (V) 1.9 2.0
RFB1 vs Temperature
30 120
20
VID PULL-UP CURRENT (A)
RFB1 (k)
10
0 -50
0 50 TEMPERATURE (C)
Supply Current vs Temperature
2.0 5
SUPPLY CURRENT (A)
SUPPLY CURRENT (A)
1.5
1.0 VCC = 5V 0.5 VCC = 3.3V
0 -50
0 50 TEMPERATURE (C)
UW
Typical Error % vs Temperature
0
VOUT = 1.3V
VOUT = 1.7V
VOUT = 2V
-0.25 -50
0 50 TEMPERATURE (C)
100
1706-19 G02
1706-19 G01
IVID-PULLUP vs Temperature
VCC = 5V 100 80 60 40 20 0 -50
100
1706-19 G03
0 50 TEMPERATURE (C)
100
1706-19 G04
Supply Current vs Supply Voltage
4
3
2
VCC = 2.7V
1
0 100
1706-19 G05
0
2 4 6 SUPPLY VOLTAGE (V)
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1706-19 G06
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LTC1706-19
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. VID3 (Pin 2): 1st MSB Programming Input. Low = GND, High = VCC or Float. Grounding VID3 adds 400mV to the output sense voltage. VCC (Pin 3): Power Supply Voltage. Range from 2.7V to 5.5V. GND (Pin 4): Ground. Connect to regulator signal ground. 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. VID0 (Pin 7): LSB Programming Input. Low = GND, High = VCC or Float. Grounding VID0 adds 50mV to the output sense voltage. VID1 (Pin 8): 3rd MSB Programming Input. Low = GND, High = VCC or Float. Grounding VID1 adds 100mV to the output sense voltage.
NOMINAL (V) TYP MAX VCC VCC 5.5 0 0 1.3 0 0 1.19 1.5 2 VCC VCC ABSOLUTE MAX (V) MIN MAX - 0.3 - 0.3 - 0.3 0 - 0.3 - 0.3 - 0.3 - 0.3 7 7 7 0 7 7 7 7
PIN 1 2 3 4 5 6 7 8
NAME VID2 VID3 VCC GND FB SENSE VID0 VID1
BLOCK DIAGRA
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DESCRIPTION 2nd MSB Programmable Input 1st MSB Programmable Input Power Supply Ground 1.19V Feedback Input Regulator Output Voltage LSB Programmable Input 3rd MSB Programmable Input
MIN 0 0 2.7
VCC
VCC
40k VID0 VCC
40k VID1 VCC SWITCH CONTROL LOGIC 40k VID2 VCC RFB2 RFB1
SENSE
FB
GND
40k VID3
1706-19 BD
LTC1706-19
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. 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. 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.
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Table 1. VID Inputs and Corresponding Output Voltage
CODE 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 VID3 GND GND GND GND GND GND GND GND Float Float Float Float Float Float Float VID2 GND GND GND GND Float Float Float Float GND GND GND GND Float Float Float VID1 GND GND Float Float GND GND Float GND GND GND Float Float GND GND Float VID0 GND Float GND Float GND Float GND GND GND Float GND Float GND Float GND OUTPUT 2.00V 1.95V 1.90V 1.85V 1.80V 1.75V 1.70V 1.65V 1.60V 1.55V 1.50V 1.45V 1.40V 1.35V 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.
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LTC1706-19
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).
TYPICAL APPLICATIO S
450mA, Low Noise Monolithic Current Mode Step-Down DC/DC Converter
0.1F
VOUT 1.3V TO 2V 450mA 2.7V TO 5.5V 0.1F 5 3 VCC
6 SENSE
FB
LTC1706-19
VID 0123 7812 FROM P * MOTOROLA MBRS130LT3 ** COILCRAFT D03316-104 GND 4
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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 40k. In other words, each VID input has a typical pull-up current of (VCC - 0.6V)/40k, which is approximately 68A for a 3.3V system.
68F 20V
+
D1* L1** 100H
1 2 3 4 5
SSW NC BSW NC LTC1433 SGND RUN/SS LBO LBI
PWRVIN
16
PGND 15 SVIN COSC POR ITH VOSENSE VPROG 14 13 12 11 10 NC 10k
INPUT VOLTAGE 3.5V TO 12V
POWER ON RESET
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COUT 820F 4V x2
6 0.1F 7 8
5.1k
680pF
47pF
6800pF
1706-19 TA02
LTC1706-19
TYPICAL APPLICATIO S
High Efficiency Low Noise Synchronous Step-Down Switching Regulator
10k 0.1F EXTERNAL FREQUENCY SYNCHRONIZATION VIN 4.5V TO 22V 18 21 19 M3 IRLML2803 M1 Si4412DY
COSC 39pF 2 3 4 CSS 0.1F
1 PLL LPF COSC RUN/SS ITH LTC1436A-PLL
24 PLLIN VIN TGL TGS
CC 510pF NC RC 10k 100pF 7 VPROG
SW
INTVCC
6 8
SGND VOSENSE BOOST BG PGND SENSE - 9 SENSE+ 10 22
1000pF *CMDSH-3
1706-19 TA03
Ultrafast Transient Response Low Dropout Regulator with Adjustable Output Voltage
VCC 3.3V VIN 12V
0.1F 7 8 1 2 VID0 VID1
3 VCC SENSE 6
LTC1706-19 VID2 VID3 FB 5
GND 4
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-
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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CIN 22F 35V X2 RSENSE 0.02 6
20
L1 3.3H
VOUT 1.3V TO 2V 5A
17
3
SENSE VCC
*DB 0.22F 5 FB 4.7F M2 Si4412DY D1 MBRS140T3 VID 0123 7812 FROM P GND 4 LTC1706-19
+
+
16 15
COUT 100F 10V x2
1 2 1F 3 4
SHDN VIN
IPOS
8 7 6 5 5 IRFZ24
3.3V
INEG LT1575-ADJ GATE COMP
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220F
GND FB
10pF
7.5k 1000pF
1F x 24
1706-19 TA04
ADJUSTABLE VOUT 1.27V TO 2.03V (50.8mV STEPS)
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.
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LTC1706-19
TYPICAL APPLICATIO S
High Efficiency 3A SO-8 N-Channel Switching Regulator with Programmable Output
VCC 0.1F 7 8 1 2 3 VCC SENSE 6 1 2 LTC1706-19 VID2 100pF VID3 GND 4 FB 5 6.8k 4 GND SW 5 470pF 3 8 7 6 0.1F 1000pF RSENSE 0.033 VIN 4.8V TO 20V
VID0 VID1
PACKAGE DESCRIPTIO
0.010 - 0.020 x 45 (0.254 - 0.508) 0.008 - 0.010 (0.203 - 0.254) 0- 8 TYP
0.016 - 0.050 0.406 - 1.270
*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
RELATED PARTS
PART NUMBER LTC1174/LTC1174-3.3 LTC1265 LT1375/LT1376 LTC1435/LTC1435A LTC1436/LTC1436-PLL LTC1438/LTC1439 LTC1538-AUX DESCRIPTION High Efficiency Step-Down and Inverting DC/DC Converter 1.2A, High Efficiency Step-Down DC/DC Converter 1.5A, 500kHz Step-Down Switching Regulator High Efficiency, Low Noise, Synchronous Step-Down Converter High Efficiency, Low Noise, Synchronous Step-Down Converter Dual, Low Noise, Synchronous Step-Down Converter Dual, Low Noise, Synchronous Step-Down Converter COMMENTS Monolithic Switching Regulator, Burst ModeTM Operation Constant Off-Time Monolithic, Burst Mode Operation High Frequency, Small Inductor, High Efficiency 16-Pin Narrow SO and SSOP 24-Pin Narrow and 24-Pin SSOP Multiple Output Capability 5V Standby Regulator in Shutdown
Burst Mode is a trademark of Linear Technlology Corporation.
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Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 q FAX: (408) 434-0507 q www.linear-tech.com
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SENSE - ITH/RUN VFB
VIN BOOST TG
+
CIN 22F 35V x2
LTC1624
Si4412DY 10H VOUT 1.3V TO 2V 3A
+
MBRS340T3
COUT 100F 10V x2
1706-19 TA05
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)
0.053 - 0.069 (1.346 - 1.752)
0.004 - 0.010 (0.101 - 0.254)
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7
6
5
0.014 - 0.019 (0.355 - 0.483)
0.050 (1.270) TYP
0.228 - 0.244 (5.791 - 6.197)
0.150 - 0.157** (3.810 - 3.988)
SO8 0996
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2
3
4
170619f LT/TP 0299 4K * PRINTED IN USA
(c) LINEAR TECHNOLOGY CORPORATION 1999

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