MAX8741

19-3262; Rev 0; 4/04 www.DataSheet4U.com 500kHz Multi-Output Power-Supply Controllers with High Impedance in Shutdown MAX8741/MAX8742 General Description Features ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ 97% 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 (MAX8741) 5V/50mA Linear-Regulator Output Precision 2.5V Reference Output Programmable Power-Up Sequencing Power-Good (RESET) Output Output Overvoltage Protection Output Undervoltage Shutdown 333kHz/500kHz Low-Noise, Fixed-Frequency Operation Low-Dropout, 98% Duty-Factor Operation 2.5mW Typical Quiescent Power (12V Input, Both SMPSs On) 4µA Typical Shutdown Current The MAX8741/MAX8742 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 97% 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 in system suspend or standby mode. Excellent dynamic response corrects output load transients within five clock cycles. ...