MAX840ESA

The MAX840ESA is a low-noise, inverting charge-pump power supply designed by Analog Devices / Maxim Integrated. It is suitable for biasing GaAsFETs in cellular telephone transmitter amplifiers and operates with input voltages as low as 2.5V, up to 10V. The MAX840ESA offers a fixed -2V preset output and can deliver up to 4mA of output current when the input voltage is above 2.7V. It is designed to operate with small capacitors, as low as 0.22µF, and achieves a low output voltage ripple of 1mVp-p. The device has a supply current of 750µA, which reduces to less than 1µA in shutdown mode for the MAX840/MAX843 variants. The MAX844 variant provides a low-power LCD supply with its unregulated output active in shutdown. This component is available in a small 8-pin SO package and is ideal for applications such as cellular phones, GaAsFET power amplifier modules, personal communicators, and LCD-bias contrast control.

The MAX840ESA operates within a temperature range of -40°C to +85°C. Its charge-pump switching frequency is 100kHz in normal operation. The device is designed for surface mount applications and is compatible with small external capacitors, contributing to a compact solution.