LTC3832/LTC3832-1 High Power Step-Down Synchronous DC/DC Controllers for Low Voltage Operation FEATURES DESCRIPTIO n The LTC 3832/LTC3832-1 are high power, high effi- V as Low as 0.6V OUT n High Power Switching Regulator Controller ciency switching regulator controllers optimized for for 3.3V-5V to 0.6V-3.xV Step-Down Applications 3.3V-5V to 0.6V-3.xV step-down applications. A preci- n sion internal reference and feedback system provide No Current Sense Resistor Required n Low Input Supply Voltage Range: 3V to 8V 1% output regulation over temperature, load current n Maximum Duty Cycle >91% Over Temperature and line voltage variations. The LTC3832/LTC3832-1 use n a synchronous switching architecture with N-channel All N-Channel External MOSFETs n Excellent Output Regulation: 1% Over Line, Load MOSFETs. Additionally, the chip senses output current and Temperature Variations through the drain-source resistance of the upper n N-channel MOSFET, providing an adjustable current limit High Efficiency: Over 95% Possible n Adjustable or Fixed 2.5V Output (LTC3832) without a current sense resistor. n Programmable Fixed Frequency Operation: 100kHz to The LTC3832/LTC3832-1 operate with an input supply 500kHz voltage as low as 3V and with a maximum duty cycle of n External Clock Synchronization >91% over temperature. They include a fixed frequency n Soft-Start PWM oscillator for low output ripple operation. The 300kHz n Low Shutdown Current: <10m A free-running clock frequency can be externally adjusted or n Overtemperature Protection synchronized with an external signal from 100kHz to 500kHz. n Available in SO-8 and SSOP-16 Packages In shutdown mode, the LTC3832 supply current drops to U <10m A. The LTC3832-1 is the SO-8 version without current APPLICATIO S limit, frequency adjustment and shutdown functions. n CPU Power Supplies , LTC and LT are registered trademarks of Linear Technology Corporation. n Multiple Logic Supply Generator n Distributed Power Applications n High Efficiency Power Conversion TYPICAL APPLICATIO V IN Efficiency 4.7F 3V TO 7V 5.1 100 + V = 2.5V OUT MBR0520T1 90 0.1F LTC3832-1 SS V /PV CC CC2 0.01F 80 V = 1V OUT Si9426DY COMP G1 L1 0.1F 15k 3.2H 70 V OUT GND PV 1V CC1 9A 60 6.49k FB G2 Si9426DY + C OUT 270F 50 2V 4.32k 3832 F01 V = 3.3V IN 680pF L1: SUMIDA CDEP105-3R2MC-88 40 0312456789 10 C : PANASONIC EEFUEOD271R OUT LOAD CURRENT (A) 3832 F01b Figure 1. High Efficiency 3.3V to 1V Power Converter sn3832 3832fs 1 EFFICIENCY (%) U ULTC3832/LTC3832-1 ABSOLUTE AXI U RATI GS (Note 1) Supply Voltage Junction Temperature........................................... 125 C V ....................................................................... 9V Operating Temperature Range (Note 9) .. 40 C to 85 C CC PV ................................................................ 14V Storage Temperature Range ................. 65 C to 150 C CC1,2 Input Voltage Lead Temperature (Soldering, 10 sec).................. 300 C I , I ............................................... 0.3V to 14V FB MAX + SENSE , SENSE , FB, SHDN, FREQSET ....................... 0.3V to V + 0.3V CC UUW PACKAGE/ORDER I FOR ATIO TOP VIEW ORDER PART ORDER PART NUMBER NUMBER G1 1 16 G2 TOP VIEW PV 2 15 PV CC1 CC2 LTC3832EGN LTC3832-1ES8 G1 1 8 G2 PGND 3 14 V CC PV 2 7 V /PV CC1 CC CC2 GND 4 13 I FB GND 3 6 COMP SENSE 5 12 I MAX FB SS FB 6 11 FREQSET 4 5 GN S8 + SENSE 7 10 COMP PART MARKING PART MARKING S8 PACKAGE 8-LEAD PLASTIC SO SHDN 8 9 SS 3832 38321 T = 125 C, q = 130 C/ W JMAX JA GN PACKAGE 16-LEAD PLASTIC SSOP T = 125 C, q = 130 C/ W JMAX JA Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes specifications that apply over the full operating temperature range, otherwise specifications are at T = 25 C. V , PV , PV = 5V, unless otherwise noted. (Note 2) A CC CC1 CC2 SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Supply Voltage l 358 V CC PV PV , PV Voltage (Note 7) l 3 13.2 V CC CC1 CC2 V Undervoltage Lockout Voltage 2.4 2.9 V UVLO V Feedback Voltage V = 1.25V 0.595 0.6 0.605 V FB COMP l 0.593 0.6 0.607 V V Output Voltage V = 1.25V 2.462 2.5 2.538 V OUT COMP l 2.450 2.5 2.550 V D V Output Load Regulation I = 0A to 10A (Note 6) 2 mV OUT OUT Output Line Regulation V = 4.75V to 5.25V 0.1 mV CC sn3832 3832fs 2 U WWW