LTC1753 5-Bit Programmable Synchronous Switching Regulator Controller for Pentium III Processor FEATURES DESCRIPTIO n 5-Bit Digitally Programmable 1.3V to 3.5V Fixed The LTC 1753 is a high power, high efficiency switching Output Voltage, VRM 8.4 Compliant regulator controller optimized for 5V input to a digitally n Fast Transient Response: 0% to 100% Duty Cycle programmable 1.3V-3.5V output. The internal 5-bit DAC n Phase Lead Compensation for Remote Sensing programs the output voltage from 1.3V to 2.05V in 50mV n Overtemperature Protection increments and from 2.1V to 3.5V in 100mV increments. The n Flags for Power Good and Overvoltage Fault precision internal reference and an internal feedback system n 19A Output Current Capability from a 5V Supply provide an output accuracy of 1.5% at room temperature n Dual N-Channel MOSFET Synchronous Driver and typically 2% over temperature, load current and line n Initial Output Accuracy: 1.5% voltage shifts. The LTC1753 uses a synchronous switching n Excellent Output Accuracy: 2% Typ Over Line, architecture with two external N-channel output devices, Load and Temperature Variations providing high efficiency and eliminating the need for a high n High Efficiency: Over 95% Possible power, high cost P-channel device. Additionally, it senses the n Adjustable Current Limit Without External Sense output current across the on-resistance of the upper N- Resistors channel FET, providing an adjustable current limit without an n Available in 2O-Lead SSOP and SW Packages external low value sense resistor. The LTC1753 free-runs at 300kHz and can be synchronized U to a faster external clock if desired. It provides a phase lead APPLICATIO S compensation scheme and under harsh loading conditions, n Power Supply for Pentium III, AMD-K6 -2, SPARC, the PWM duty cycle can be momentarily forced to 0% or ALPHA and PA-RISC Microprocessors 100% to reduce the output voltage recovery time. n High Power 5V to 1.3V-3.5V Regulators , LTC and LT are registered trademarks of Linear Technology Corporation. Pentium is a registered trademark of Intel Corporation. AMD-K6 is a registered trademark of Advanced Micro Devices, Inc. TYPICAL APPLICATIO PV CC V IN 12V 5V + C ** IN 0.1m F 10m F 0.1m F 10m F 1200m F 600 4 5.6k 5.6k Q1A* V I CC MAX PV L CC O PWRGD Q1* G1 1.3m H V OUT 18A 20W FAULT 1.3V TO I FB CPU 5 3.5V VID0 TO VID4 LTC1753 C OUT + 14A Q2A* 2700m F OUTEN 5 G2 Q2* COMP V NC FB SS SGND GND SENSE R C 15k C1 C SS 150pF C C * SILICONIX SUD50N03-10 0.1m F 1m F 4700pF ** SANYO 10MV1200GX PANASONIC ETQP 6FIR3LFA SANYO 6MV2700GX 1753 F01 Figure 1. 5V to 1.3V-3.5V Supply Application 1753fa 1 + + U ULTC1753 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW Supply Voltage ORDER PART V ........................................................................ 7V G2 1 20 G1 CC NUMBER PV ................................................................... 14V PV 2 19 OUTEN CC CC GND 3 18 VID0 Input Voltage LTC1753CG SGND 4 17 VID1 I (Note 2)............................................ PV + 0.3V FB CC LTC1753CSW V 5 16 VID2 CC I ........................................................ 0.3V to 9V MAX SENSE 6 15 VID3 All Other Inputs ...................... 0.3V to (V + 0.3V) CC I 7 14 VID4 MAX Digital Output Voltage ................................. 0.3V to 9V I 8 13 PWRGD FB I Input Current (Notes 2, 3) .......................... 100mA FB SS 9 12 FAULT Junction Temperature.......................................... 125 C COMP 10 11 V FB Operating Temperature Range ..................... 0 C to 70 C G PACKAGE SW PACKAGE Storage Temperature Range ................. 65 C to 150 C 20-LEAD PLASTIC SSOP 20-LEAD PLASTIC SO Lead Temperature (Soldering, 10 sec.)................. 300 C T = 125 C, q = 100 C/ W (G) JMAX JA T = 125 C, q = 100 C/ W (SW) JMAX JA Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. A V = 5V, PV = 12V, unless otherwise noted. (Note 3) CC CC SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Supply Voltage l 4.5 6 V CC PV Supply Voltage for G1, G2 l 13.2 V CC V Internal Feedback Voltage 1.3V Output Voltage 0.5 V FB 2.1V Initial Output Voltage 0.8 V 3.5V Initial Output Voltage 1.34 V V 1.3V Initial Output Voltage With Respect to Rated Output Voltage (Figure 2) 20 ( 1.5%) 20 (+1.5%) mV OUT 1.8V Initial Output Voltage 27 (1.5%) 27 (+1.5%) mV 2.8V Initial Output Voltage 42 (1.5%) 42 (+ 1.5%) mV 3.5V Initial Output Voltage 52 (1.5%) 52 (+1.5%) mV 1.3V Initial Output Voltage l 26 (2%) 26 (+2%) mV 1.8V Initial Output Voltage l 36 (2%) 36 (+2%) mV 2.8V Initial Output Voltage l 56 (2%) 56 (+2%) mV 3.5V Initial Output Voltage l 70 (2%) 70 (+2%) mV D V Output Load Regulation I = 0 to 14A (Figure 2) 5 mV OUT OUT Output Line Regulation V = 4.75V to 5.25V, I = 0 (Figure 2) 1mV IN OUT V Positive Power Good Trip Point % Above Output Voltage (Note 4) (Figure 2) l 3 6 % PWRGD Negative Power Good Trip Point % Below Output Voltage (Note 4) (Figure 2) l 6 3 % V FAULT Trip Point % Above Output Voltage (Note 4) (Figure 2) l 813 18 % FAULT I Operating Supply Current OUTEN = V = 5V (Note 5)(Figure 3) l 800 1200 m A CC CC Shutdown Supply Current OUTEN = 0, VID0 to VID4 Floating (Figure 3) l 130 250 m A I Supply Current PV = 12V, OUTEN = V (Note 6) (Figure 3) 15 mA PVCC CC CC PV = 12V, OUTEN = 0, VID0 to VID4 Floating 1 m A CC f Internal Oscillator Frequency (Figure 4) l 250 300 350 kHz OSC V V at Minimum Duty Cycle (Note 11) 1.8 V SAWL COMP V V at Maximum Duty Cycle (Note 11) 2.8 V SAWH COMP 1753fa 2 U WWW