July 2000 PRELIMINARY
ML4869 Medium Current Boost Regulator with Load Disconnect
GENERAL DESCRIPTION
The ML4869 is a co...
July 2000 PRELIMINARY
ML4869 Medium Current Boost
Regulator with Load Disconnect
GENERAL DESCRIPTION
The ML4869 is a continuous conduction boost
regulator designed for DC to DC conversion in multiple cell battery power systems. Continuous conduction allows the
regulator to maximize output current for a given inductor. The maximum switching frequency can exceed 200kHz, allowing the use of small, low cost inductors. The ML4869 is capable of start-up with input voltages as low as 1.8V, and is available in 5V and 3.3V output versions with an output voltage accuracy of ±3%. An integrated synchronous rectifier eliminates the need for an external
Schottky diode and provides a lower forward voltage drop, resulting in higher conversion efficiency. In addition, low quiescent current and variable frequency operation result in high efficiency even at light loads. The ML4869 requires only a few external components to build a very small
regulator capable of achieving conversion efficiencies approaching 85%. The SHDN input allows the user to stop the
regulator from switching, and provides complete isolation of the load from the battery.
FEATURES
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Guaranteed full load start-up and operation at 1.8V input Continuous conduction mode for high output current Pulse Frequency Modulation and internal synchronous rectification for high efficiency Isolates the load from the input during shutdown Minimum external components Low ON resistance internal switching FETs Low supply current 5V and 3.3V o...