LIN D O C #: 1670 LX1670 5 - B I T P R O G R A M M A B L E V O L TA G E R E F E R E N C E T H E I P N F I N I T E O W E R O F I P N N O VA T I O N R O D U C T I O N DESCRIPTION The LX1670 is a complete precision reference and voltage monitor circuit for the Intel Pentium® Pro Processor and other high-end microprocessor supplies. It is designed for use in conjunction with the LX1660/1661 PWM controller. The LX1670 reads a 5-bit voltage identification (VID) code from the microprocessor and sets the output voltage reference to be used by the LX1660/61 controller. Together, they convert +5 or 12V input power to an adjustable output ranging from 1.8VDC to 3.5VDC in 100mV steps (50mV steps below 2.1V) with 1% DC system accuracy. OF THE BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 Enable Blank Enable S H E E T p p p p p 1% TOTAL OUTPUT ERROR POWER GOOD, UV, 0V COMPARATORS 0V COMPARATOR HAS SCR DRIVE UNDER-VOLTAGE LOCKOUT CAPABILITY 5-BIT INPUT FOR ADVANCED PENTIUM PRO PROCESSOR APPLICATIONS (5 TH BIT IS FOR AUTOMATIC GAIN AND OFFSET SCALING) p IMPLEMENTS 1% DC ACCURATE CONTROL SYSTEM p 14-PIN NARROW BODY SOIC PACKAGE A P P L I C AT I O N S LX1670 ■ PENTIUM II & PENTIUM PRO VOLTAGE REGULATOR MODULES ■ PROGRAMMABLE POWER SUPPLIES ■ VOLTAGE REFERENCE ■ ADVANCED MICROPROCESSOR SUPPLIES VCC 5-Bit Digital Input Word A T A K E Y F E AT U R E S PRODUCT HIGHLIGHT T Y P I C A L A P P L I C AT I O N D VCC D0 D1 D2 D3 D4 LX1670 ENABLE BLKEN GND VIDO To PWM Error Amplifier OVOUT SCR Drive PGOOD Power Good VSENSE System Output Voltage PA C K A G E O R D E R I N F O TA (°C) SOIC D Plastic 14-pin 0 to 70 LX1670CD Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. LX1670CDT) F O R F U R T H E R I N F O R M AT I O N C A L L ( 7 1 4 ) 8 9 8 - 8 1 2 1 Copyright © 1997 Rev. 1.0 7/97 11861 WESTERN A VENUE , G ARDEN G ROVE , CA. 92841 1 PRODUCT DATABOOK 1996/1997 LX1670 5 - B I T P R O G R A M M A B L E V O L TA G E R E F E R E N C E P R O D U C T I O N A B S O L U T E M A X I M U M R AT I N G S D A T A S H E E T PACKAGE PIN OUTS (Note 1) Supply Voltage (VCC) .................................................................................... -0.3V to +15V PGOOD, D0-D3, D4, ENABLE, BLKEN ....................................................... -0.3V to VCC+0.3 VIDO, OVOUT, V SENSE ....................................................................................... -0.3V to +5V OVOUT ........................................................................................................................ -35mA VIDO ........................................................................................................................... -5mA Operating Junction Temperature Plastic (D Package) ............................................................................................... 150°C Storage Temperature Range .................................................................... -65°C to +150°C Lead Temperature (Soldering, 10 Seconds) ............................................................. 300°C VIDO VSENSE PGOOD OV OUT ENABLE BLKEN GND 1 14 2 13 3 12 4 11 5 10 6 9 7 8 VCC D4B D4 D3 D2 D1 D0 D PACKAGE (Top View) Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. Pin numbers refer to DIL packages only. T H E R M A L D ATA D PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA 120°C/W Junction Temperature Calculation: TJ = TA + (PD x θJA). The θ JA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow 2 Copyright © 1997 Rev. 1.0 7/97 PRODUCT DATABOOK 1996/1997 LX1670 5 - B I T P R O G R A M M A B L E V O L TA G E R E F E R E N C E P R O D U C T I O N ELECTRICAL D A T A S H E E T CHARACTERISTICS (Unless otherwise specified, these specifications apply over the operating ambient temperatures for LX1670C with 0°C ≤ TA ≤ 70°C ; 10.8V < VCC < 13.2V, D0-D3 = Open, D4 = Open, ENABLE = 1, BLKEN = 1. Nominal conditions: VCC = 12.0V, T = 25°C. Currents flowing into chip are positive. Current maximums are currents with the highest possible value.) Parameter Symbol Test Conditions Min. LX1670 Typ. Max. Units Power Supply Current and Power Section Positive 12V Supply Current ICC Digital-to-Analog Converter Section (Includes DAC, I-V Converter and output scaling amplifier. RLOAD > 1k, CLOAD < 100pF) Voltage Set Point Accuracy VSPA LSB VSTP Coding All outputs, inputs unloaded D0-D3 = X, D4 = Open, 2.00 ≤ VIDO ≤ 3.50V D0-D3 = X, D4 = GND, 1.80 ≤ VIDO ≤ 2.05V D4 = Open D4 = GND Binary, D0 = LSB, D3 = MSB 5 -1.0 -1.5 mA 1.0 1.5 % % mV mV 1.0 4.47 V V mV 100 50 Under-Voltage Lockout Section Power-up Reset Threshold Hysteresis VRES UVLOT UVLOH IGOOD = 5mA VCC = 5V, Supply ramping down VCC = 5V, Supply ramping up 4.27 4.37 50 ±5.5 ±7 0.2 ±8.5 0.4 % V 10 -20 15 20 % mA mV Under/Over-Voltage Comparator Section Percent of VIDO Threshold PGOOD Low Voltage UOVTH VLG IGOOD = 5mA Over-Voltage Protection Comparator Section Percent of VIDO Threshold OVP Sourcing Current OVP Output Low OVPTH IOVP VLOVP OVP = 3.0V IOVP = 100µA 100 TTL Inputs Section Input Low Voltage Input High Voltage Input Low Current Input High Current Open Drain Inputs Section Input Low Current Input High Voltage Copyright © 1997 Rev. 1.0 7/97 VIL VIH IIL IIH 0.8 -10 0 V V µA µA -37.5 2.0 µA V 2.0 VIL = 0.8V VIH = 2.0V (D0-D3, D4) IIL VIH Pin Ground Pin Open 3 PRODUCT DATABOOK 1996/1997 LX1670 5 - B I T P R O G R A M M A B L E V O L TA G E R E F E R E N C E P R O D U C T I O N D A T A S H E E T F U N C T I O N TA B L E S Table 1 - Input vs. Output Functions VCC VCC < 1.0 1.0 < VCC < UVLOT VCC > UVLOT VCC > UVLOT VCC > UVLOT VCC > UVLOT VCC > UVLOT VCC > UVLOT VCC > UVLOT VCC > UVLOT VCC > UVLOT D4-D0 ENABLE BLKEN X X X VIDO Table VIDO Table VIDO Table VIDO Table VIDO Table VIDO Table VIDO Table VIDO Table X X 0 1 1 1 1 1 1 1 1 X X X 0 0 0 0 1 1 1 1 VSENSE (VS) VIDO (VO) X X X VS < 0.93VO 0.93VO < VS < 1.07VO 1.07VO < VS < 1.15VO VS > 1.15VO VS < 0.93VO 0.93VO < VS < 1.07VO 1.07VO < VS < 1.15VO VS > 1.15VO PGOOD Undefined LOW LOW VIDO Table 3 VIDO Table 3 VIDO Table 3 VIDO Table 3 VIDO Table 2 VIDO Table 2 VIDO Table 2 VIDO Table 2 Undefined LOW LOW LOW HIGH LOW LOW LOW HIGH LOW LOW OVOUT Undefined LOW LOW LOW LOW LOW HIGH LOW LOW LOW HIGH Table 2 - VIDO Output (BLKEN pulled high or left open) D4 D3 D2 D1 D0 VIDO D4 D3 D2 D1 D0 VIDO 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 1.800 1.850 1.900 1.950 2.000 2.050 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 2.00 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90 3.00 3.10 3.20 3.30 3.40 3.50 D4 D3 D2 D1 D0 VIDO D4 D3 D2 D1 D0 VIDO 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1.300 1.350 1.400 1.450 1.500 1.550 1.600 1.650 1.700 1.750 1.800 1.850 1.900 1.950 2.000 2.050 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 2.00 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90 3.00 3.10 3.20 3.30 3.40 3.50 Table 3 - VIDO Output (BLKEN pulled low) Table 4 - Mode Control 4 D4 ENABLE BLKEN Mode X 0 X Disable VIDO is pulled low through 10k State 0 1 1 1 0 0 Low Normal VIDO is scaled. Output 1.3V to 2.05V Normal Output 2.0 to 3.5V 0 1 1 1 1 1 Low Normal VIDO is scaled. Output 1.8V to 2.05V Normal output 2.0 to 3.5V Copyright © 1997 Rev. 1.0 7/97 PRODUCT DATABOOK 1996/1997 LX1670 5 - B I T P R O G R A M M A B L E V O L TA G E R E F E R E N C E P R O D U C T I O N D A T A S H E E T BLOCK DIAGRAM BLKEN 6 2V REF 14 VCC 5 ENABLE 4 OVOUT 3 PGOOD 2 VSENSE BLOCK < 1.8V D0 8 4.67/4.47V 10.6/10.1V D1 9 DAC D2 10 D3 11 VCC D4B 13 0.87 * VS 1 S D4 12 0 2X1 MUX OUT 0.935 * VS 0.93 * VE GND 7 VE VS 1 VIDO FUNCTIONAL PIN DESCRIPTION Pin Name VIDO VSENSE PGOOD OV OUT ENABLE BLKEN GND D0 D1 D2 D3 D4 D4B VCC Copyright © 1997 Rev. 1.0 7/97 Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Description Output reference voltage used by PWM controller to set system voltage. Connected directly to system output voltage. Open collector output pulls low when the processor's supply is not good. SCR Driver goes high when processor supply is over voltage. TTL compatible chip enable. Internally pulled high. Enables or disables blocking of codes with voltage blow 1.8V for CPU protection. Internally pulled high. Analog ground return. LSB DAC logic control. Internally pulled high. 2nd LSB DAC logic control. Internally pulled high. 3rd LSB DAC logic control. Internally pulled high. MSB DAC logic control. Internally pulled high. Scales VIDO output when low. Internally pulled high. Inverting output of D4. Analog power supply. 5 PRODUCT DATABOOK 1996/1997 LX1670 5 - B I T P R O G R A M M A B L E V O L TA G E R E F E R E N C E P R O D U C T I O N D A T A S H E E T THEORY OF OPERATION UNDER-VOLTAGE LOCKOUT OVER- / UNDER-VOLTAGE COMPARATORS This function keeps order to the IC until the power supply voltage reaches 85% of its nominal value. The output voltage is pulled low and PGOOD and OVOUT are pulled low. Once the power supply voltage crosses 85%, the output voltage, VIDO, is released, and P GOOD continues to be pulled low. When V SENSE (the microprocessor's power supply) is within ±7% of VIDO, PGOOD is released. The comparator has hysteresis to prevent transient oscillation. This function generates an open collector Power Good signal when VSENSE is within ±7% of VIDO. This function generates an OVOUT voltage signal when VSENSE is 15% higher than VIDO. This voltage can be used to drive an external SCR. CHIP ENABLE 4-BIT DAC and 5th-BIT SCALER This function generates a precise voltage from a binary, 5-bit digital word VID [0:4]. It uses a 4-bit, binary weighted current DAC, driving a precise current to voltage converter. This voltage is then op-amp buffered and sent out. The scaling is accomplished by multiplexing the buffer op-amp. The resulting transfer function is: VIDO (D0,D1,D2,D3) = (2.00 + 0.1 * (1*D0 + 2*D1 + 4*D2 + 8*D3)) OVER-VOLTAGE PROTECTION This function disables the chip when low. VIDO, PGOOD and OVOUT are all pulled low. When ENABLE is high, the chip's state is then determined by the other functions. BLANK ENABLE This function will disable VIDO for codes with voltages below 1.80V when this pin is high. When pulled low, this function will allow VIDO to accept codes for voltages of 1.30 to 3.50V. for D4 = 1 VIDO (D0,D1,D2,D3) = (2.00 + 0.6 + 0.1 * (1*D0 + 2*D1 + 4*D2 + 8*D3)) * 0.5 for D4 = 0 for the code VIDO < 1.8V will be blocked and VIDO = 0. The zero-scale output voltage, full-scale output voltage and the scale factor are all trimmed on-chip using fusable links. 6 Copyright © 1997 Rev. 1.0 7/97 PRODUCT DATABOOK 1996/1997 LX1670 5 - B I T P R O G R A M M A B L E V O L TA G E R E F E R E N C E P R O D U C T I O N D S A T A H E E T A P P L I C AT I O N I N F O R M AT I O N See Note 1 JP1 D1 1N4148 F1 D2 1N4148 C20 0.1µF JP4 JP3 2 3 LX1670 1 2 3 PWRGD 4 5 OUTEN 6 7 VIDO VSENSE PGOOD OVOUT ENABLE BLKEN GND VCC D4B D4 D3 D2 D1 D0 14 13 12 11 10 9 8 R2 R3 10K 1K C4 390µF 4 5 6 7 8 VID4 VID3 VID2 VID1 VID0 C3 0.1µF C7 0.1µF C8 680pF VC1 TDRV PGND BDRV VCC SYNCEN CS+ 16 15 See Note 1 C19 0.1µF R7 10 14 13 12 Q2 IRL3103 R8 10 11 10 CS- 9 LX1661 C1 390pF L1 R1 TOROID 5µH 5mΩ C5 C12 C13 1500µF 6.3V C10 0.1µF EN OTADJ SGND VVREF INV NINV/SS HICCUP CT 1500µF 6.3V 1 C11 1500µF 6.3V Q1 IRL3103 C9 1µF VRM CONTROLLER C2 1500µF 6.3V 1500µF 6.3V R4 1K 5VIN 16A 32V R13 10 See Note 1 12VIN JP2 R5 1K R6 1K Q3 2N6504 SUPPLY OUTPUT CLAMP Note 1. Setup shown is for 5V application. For 12V input change the following: - Close JP1 and JP4 - Open JP2 and JP3 - For C2 and C11, use 16V/850µF capacitors instead - Inductor L1 = 10µH FIGURE 1 — LX1660/61 CONTROLLER USED WITH THE LX1670 PROGRAMMABLE REFERENCE/DAC CHIP FOR PENTIUM PRO PROCESSOR OR PENTIUM II PROCESSOR APPLICATIONS. GUARANTEED TO MEET INTEL SPECIFICATIONS. Pentium is a registered trademark of Intel Corporation. PRODUCTION DATA - Information contained in this document is proprietary to Linfinity, and is current as of publication date. This document may not be modified in any way without the express written consent of Linfinity. Product processing does not necessarily include testing of all parameters. Linfinity reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright © 1997 Rev. 1.0 7/97 7