G5601A Global Mixed-mode Technology Inc. High-Speed Step-Down Controller with LDO Controller for Notebook Computer Features General Description --PWM Controller Ultra-High Efficiency No Current-Sense Resistor (Lossless ILIMIT) Quasi-PWM with 100ns Load-Step Response 1% VOUT Accuracy Over Line and Load 0.75V to 3.6V Adjustable Output Range 4.5V to 24V Battery Input Range OVP & UVP 1.7ms Soft-Start Drives Large Synchronous-Rectifier FETs Power-Good Indicator G5601A PWM controller uses constant on-time control scheme to handle wide input/output voltage ratios with ease and provides 100ns “instant-on” response to load transients while maintaining a relatively constant switching frequency. The G5601A achieves high efficiency at a reduced cost by eliminating the current-sense resistor found in traditional current-mode PWMs. Efficiency is further enhanced by an ability to drive very large synchronous rectifier MOSFETs. Single-stage buck conversion allows these devices to directly step down high-voltage batteries for the highest possible efficiency. Alternatively, two-stage conversion (stepping down the +5V system supply instead of the battery) at a higher switching frequency allows the minimum possible physical size. The G5601A is intended for CPU core, chipset, DRAM, or other low-voltage supplies as low as 0.75V. G5601A LDO controller can drive an external NMOSFET to provide a second output voltage from PWM output or other power source. It is adjusted output from 0.75V. The independent enable input, open-drain power good indicator, under-voltage protection and soft-start are provided for system application. The G5601A is available in 16-pin TQFN (3X3) package. --LDO Controller 1.5% Accuracy Over Line and Load Adjustable Output down to 0.75V Independent Enable and Power Good Indicator Drives N-channel MOSFET within Rail to Rail Controller Voltage MLCC and POSCAP Stable Applications Notebook Computers CPU Core Supply Chipset/RAM Supply as Low as 0.75V 1.8V and 2.5V I/O Supply Networking Power Supply Ordering Information ORDER NUMBER MARKING G5601AR41U 5601A TEMP. RANGE PACKAGE (Green) -40°C to +85°C TQFN3X3-16 Note:R4:TQFN3X3-16 1: Bonding Code U : Tape & Reel TON EN_S KIP LE N BS T 15 14 13 8 4 DL PGOOD 7 3 L DRV FB Thermal Pad 6 2 L FB VCC 17 GND 5 1 LP G OUT 16 Pin Configuration 12 DH 11 LX 10 ILIM 9 VDD G5601A TQFN3X3-16 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.4 Feb 11, 2010 1