MAX1634

19-0480; Rev 3; 4/97 KIT ATION EVALU LE B A IL A AV Multi-Output, Low-Noise Power-Supply Controllers for Notebook Computers ____________________________Features o o o o o o o o o o o o o o o o o 96% Efficiency +4.2V to +30V Input Range 2.5V to 5.5V Dual Adjustable Outputs Selectable 3.3V and 5V Fixed or Adjustable Outputs (Dual Mode™) 12V Linear Regulator Adjustable Secondary Feedback (MAX1631/MAX1634) 5V/50mA Linear Regulator Output Precision 2.5V Reference Output Programmable Power-Up Sequencing Power-Good (RESET) Output Output Overvoltage Protection (MAX1630/MAX1631/MAX1632) Output Undervoltage Shutdown (MAX1630/MAX1631/MAX1632) 200kHz/300kHz Low-Noise, Fixed-Frequency Operation Low-Dropout, 99% Duty-Factor Operation 2.5mW Typical Quiescent Power (+12V input, both SMPSs on) 4µA Typical Shutdown Current 28-Pin SSOP Package ________________General Description The MAX1630–MAX1635 are buck-topology, step-down, switch-mode, power-supply controllers that generate logic-supply voltages in battery-powered systems. These high-performance, dual/triple-output devices include onboard power-up sequencing, power-good signaling with delay, digital soft-start, secondary winding control, lowdropout circuitry, internal frequency-compensation networks, and automatic bootstrapping. Up to 96% efficiency is achieved through synchronous rectification and Maxim’s proprietary Idle Mode™ control scheme. Efficiency is greater than 80% over a 1000:1 load-current range, which extends battery life i...