The MAX1652-MAX1655 are high-efficiency, pulse-width-modulated (PWM), step-down DC-DC controllers in small QSOP packages. The MAX1653/MAX1655 also come in 16-pin narrow SO packages that are pin-compatible upgrades to the popular MAX797. Improvements include higher duty-cycle operation for better dropout, lower quiescent supply currents for better light-load efficiency, and an output voltage down to 1V (MAX1655).
The MAX1652-MAX1655 achieve up to 96% efficiency and deliver up to 10A using a unique Idle Mode™ synchronous-rectified PWM control scheme. These devices automatically switch between PWM operation at heavy loads and pulse-frequency-modulated (PFM) operation at light loads to optimize efficiency over the entire output current range. The MAX1653/MAX1655 also feature logic-controlled, forced PWM operation for noise-sensitive applications.
All devices operate with a selectable 150kHz/300kHz switching frequency, which can also be synchronized to an external clock signal. Both external power switches are inexpensive N-channel MOSFETs, which provide low resistance while saving space and reducing cost.
The MAX1652 and MAX1654 have an additional feedback pin that permits regulation of a low-cost second output tapped from a transformer winding. The MAX1652 provides an additional positive output. The MAX1654 provides an additional negative output.
The MAX1652-MAX1655 have a 4.5V to 30V input voltage range. The MAX1652/MAX1653/MAX1654's output range is 2.5V to 5.5V while the MAX1655's output range extends down to 1V. An evaluation kit (MAX1653EVKit) is available to speed designs.
Key Features
Applications/Uses
96% Efficiency
Small, 16-Pin QSOP Package (half the size of a 16-pin narrow SO)
Pin-Compatible with MAX797 (MAX1653/MAX1655)
Output Voltage Down to 1V (MAX1655)
4.5V to 30V Input Range
99% Duty Cycle for Lower Dropout
170µA Quiescent Supply Current
3µA Logic-Controlled Shutdown
Dual, N-Channel, Synchronous-Rectified Control
Fixed 150kHz/300kHz PWM Switching, or Synchronized from 190kHz to 340kHz
Programmable Soft Start
Low-Cost Secondary Outputs (MAX1652/MAX1654)
Synchronous rectifier, secondary output regulation, high efficiency over full IOUT range
Notes: **This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
duties, taxes, fees, and exchange rates. For volume-specific prices
and delivery, please see the price and availability page
or contact an authorized distributor.
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