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2022-09-24 23:16:53
MAX1534 - High-efficiency, triple-output, keep-alive, notebook power supply
The MAX1534 is a high-efficiency, triple-output power supply that maintains an active (normally-on) voltage rail. This 500mA buck regulator features an internal current-limited 0.5Ω PMOS step-down, battery or AC adapter power rail to a fixed 5V or adjustable output voltage. Two integrated low-voltage linear regulators follow this output and provide two independent preset output voltages at 3.3V and 1.8V, or an adjustable output voltage. The buck regulator utilizes peak current limiting, pulsefrequency modulation (PFM) architecture for maximum light load efficiency, extending battery life. High switching frequencies (up to 200kHz) allow the use of tiny surface mount inductors and output capacitors. operate with reduced voltage drop at 100% duty cycle (250mV at 500mA). This low dropout linear regulator uses internal P-channel metal oxide (PMOS) transistors to reduce supply current to 160mA and deliver up to 160mA per continuous current. The MAX1534 includes a power-good (thin) signal to show that all outputs are in regulation. An accurate 4% SHDN input threshold allows its use as a lowbattery detector. The MAX1534 is housed in a small 16-pin thin QFN (4mm ✕ 4mm) package that takes up 33% more board space than discrete solutions.