LTC1706-19 VID Voltage Programmer U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ 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.) U APPLICATIONS ■ ■ ■ ■ 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. U 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 U W W W ABSOLUTE AXI U RATI GS U W U 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 U W 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 U U U 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 U 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 U 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. U 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 U 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 U 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 U 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 LTC1174/LTC1174-3.3 High Efficiency Step-Down and Inverting DC/DC Converter Monolithic Switching Regulator, Burst ModeTM Operation LTC1265 1.2A, High Efficiency Step-Down DC/DC Converter Constant Off-Time Monolithic, Burst Mode Operation LT1375/LT1376 1.5A, 500kHz Step-Down Switching Regulator 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