LTC3734 Single-Phase, High Efficiency DC/DC Controller for Intel Mobile CPUs FEATURES DESCRIPTION n Wide Input Voltage Range: 4V to 30V The LTC 3734 is a single-phase synchronous step-down 1% Output Voltage Accuracy switching regulator controller that drives all N-channel 6-Bit IMVP-IV VID Code: V = 0.7V to 1.708V power MOSFETs in a constant frequency architecture. The OUT Intel Compatible Power Saving Mode (PSIB) output voltage is programmable by six VID bits during Power Good Output with Adaptive Masking normal operation and by external resistors during initial Lossless Voltage Positioning boot-up and deeper sleep state. The LTC3734 drives its Resistor Programmable V at Boot-Up and output stage at frequencies up to 550kHz. Powerful on- OUT Deeper Sleep State chip gate drivers eliminate the need for external gate driver Resistor Programmable Deep Sleep Offset ICs, thus simplifying the design. Programmable Fixed Frequency: 210kHz to 550kHz An Intel compatible PSIB input is provided to select between Adjustable Soft-Start Current Ramping two modes of operation. Fully enhanced synchronous Foldback Output Current Limit mode achieves a very small output ripple and very fast Short-Circuit Shutdown Timer with Defeat Option transient response while power saving mode realizes Overvoltage Protection very high efficiency. OPTI-LOOP compensation allows Available in 32-Lead 5mm 5mm 0.8mm (Profile) the transient response to be optimized for a wide range QFN Package of output capacitance and ESR values. APPLICATIONS The LTC3734 is available in a small 5mm 5mm QFN package. For 2-phase applications refer to the LTC3735. n Mobile and Desktop Computers L, LT, LTC, LTM, OPTI-LOOP, Burst Mode, Linear Technology and the Linear logo are registered Internet Servers trademarks and Stage Shedding is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION V IN 5V TO 24V C IN MCH PG TG M1 10F 0.8H 0.002 35V DPRSLPVR SW 4 STP CPUB BG M2 D1 PSIB PGND V OUT FREQSET + 0.7V TO 1.708V SENSE C OUT 20A + VID5-VID0 6-BIT VID 270F SENSE 2V PGOOD 3 12.7k 13.3k LTC3734 RBOOT I TH 56.2k R RDPRSLP C RUN/SS 3k 1.27M 100pF RDPSLP C C 0.1F 680pF + V OA SGND 13.3k 1.27M OAOUT V 4.5V TO 7V PV OA CC BAT54A 4.7F BOOST SV 4.5V TO 7V CC 0.47F 0.1F 3734 F01 SW Figure 1. High Current Step-Down Converter 3734fa 1LTC3734 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) Input Supply Voltage (PV , SV ) ............. 7V to 0.3V CC CC Topside Driver Voltages (BOOST) .............. 38V to 0.3V Switch Voltage (SW) ..................................... 32V to 5V 32 31 30 29 28 27 26 25 + Boosted Driver Voltages (BOOST-SW) ......... 7V to 0.3V V 1 24 TG OA DPRSLPVR, STP CPUB, MCH PG, PGOOD, V 2 23 SW OA OAOUT 3 22 PV CC RDPRSLP, RDPSLP, RBOOT Voltages ......... 5V to 0.3V STP CPUB 4 21 BG RUN/SS, FREQSET, PSIB Voltages ..............7V to 0.3V 33 SGND 5 20 PGND VID0-VID5 Voltages ....................................5V to 0.3V + SENSE 6 19 VID5 V Voltage ................................................. 2V to 0.3V FB SENSE 7 18 VID4 + V , V Voltage .................................... 3.6V to 0.3V OA OA RDPRSLP 8 17 VID3 Peak Gate Drive Current <1s (TG, BG) ......................5A 9 10 11 12 13 14 15 16 Operating Ambient Temperature Range (Note 2) ...................................................40C to 85C UH PACKAGE Junction Temperature (Note 3) ............................. 125C 32-LEAD (5mm 5mm) PLASTIC QFN Storage Temperature Range ................... 65C to 125C T = 125C, = 34C/W JMAX JA EXPOSED PAD (PIN 33) IS GND, MUST BE SOLDERED TO PCB Reflow Peak Body Temperature ............................ 245C ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3734EUH PBF LTC3734EUH TRPBF 3734 40C to 85C 32-Lead Plastic (5mm 5mm) QFN Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: