The MAX722 and MAX723 CMOS power-supply ICs create dual regulated DC outputs for small, battery-operated microprocessor systems. Each device generates a main output (3V or 5V, selectable) and a negative auxiliary output that is adjustable for LCDs. Each device accepts two input voltages. Power can come from a main battery (two or three alkaline or NiCAD), or an unregulated DC source such as an AC-DC wall adapter.
The MAX722/MAX723 provide three improvements over prior-art devices. Physical size is reduced; the high switching frequencies (up to 0.5MHz), made possible by MOSFET power transistors, allow for tiny (< 5mm diameter) surface-mount magnetics. Efficiency is also improved to 87% (10% better than with low-voltage regulators made in bipolar technology). And supply current is reduced to 60µA by CMOS construction and a unique constant-off-time pulse-frequency modulation (PFM) control scheme.
The MAX722 and MAX723 differ only in the lower fixed output voltage of the main regulator, with a 3.3V output for the MAX722 and a 3.0V output for the MAX723.
For flash memory or PCMCIA applications that require a +12V output voltage, refer to the MAX717–721 data sheet.
关键特性
应用/使用
Low 0.9V to 5.5V Battery Input Range
Unregulated 7V to 20V DC Input Range
Dual Regulated Outputs
Main Output: 3.3V/5V
Auxiliary Output: 0V to -100V
87% Efficiency at 200mA
Efficient PRAM Keep-Alive: 80% at 1mA
8W/in³ Power Density
60µA Quiescent Current
20µA Shutdown Mode with VREF Alive
500kHz Maximum Switching Frequency
±1.5% VREF Tolerance (Over Temp.)
Detect Output Power Failures
16-Pin Narrow SO Packages
条码扫描仪
LCD对比度调节
医疗仪表
掌上电脑
便携式数据通信
便携式数据收集设备
Key Specifications:
Switch-Mode DC-DC Power Supplies
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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