数据手册：MAX1705, MAX1706 低噪声、双输出转换器，为蜂窝电话中的PA、无线基带和逻辑电路供电 .pdf [英文Rev.1(PDF,268kB)]
The MAX1705/MAX1706 are high-efficiency, low-noise, step-up DC-DC converters with an auxiliary linear-regulator output. These devices are intended for use in battery-powered wireless applications. They use a synchronous rectifier pulse-width-modulation (PWM) boost topology to generate 2.5V to 5.5V outputs from battery inputs, such as 1 to 3 NiCd/NiMH cells or 1 Li-Ion cell. The MAX1705 has an internal 1A n-channel MOSFET switch. The MAX1706 has a 0.5A switch. Both devices also have a built-in low-dropout linear regulator that
delivers up to 200mA.
With an internal synchronous rectifier, the MAX1705/MAX1706 deliver 5% better efficiency than similar non-synchronous converters. They also feature a pulse-frequency-modulation (PFM) standby mode to improve efficiency at light loads, and a 1µA shutdown mode. An efficiency-enhancing track mode reduces the step-up DC-DC converter output to 300mV above the linear-regulator
Both devices come in a 16-pin QSOP package, which occupies the same space as an 8-pin SO. Other features include two shutdown-control inputs for push-on/push-off control, and an uncommitted comparator for use as a voltage monitor.
- Up to 96% Efficiency
- 1.1VIN Guaranteed Startup
- Up to 850mA Output (MAX1705)
- Step-Up Output (2.5V to 5.5V Adjustable)
- Linear Regulator (1.25V to 5.0V Adjustable)
- PWM/PFM Synchronous-Rectified Topology
- 300kHz PWM Mode or Synchronizable
- 1µA Shutdown Mode
- Voltage Monitor
- Pushbutton On/Off Control