Maxim MAX840ESA+

充电泵，手机发射器2.5V ~ 10V-2V，-0.5V ~ -9.4V

Overview

The MAX840/MAX843/MAX844 low-noise, inverting charge-pump power supplies are ideal for biasing GaAsFETs in cellular telephone transmitter amplifiers. They operate with inputs down to 2.5V. The MAX840ESA offers both a -2V preset output and a -0.5V to -9.4V adjustable output. The MAX843/MAX844 use an external positive control voltage to set the negative output voltage. Input voltage range for all the devices is 2.5V to 10V, and output current is 4mA with VIN > 2.7V. These circuits can operate with small capacitors, as low as 0.22μF. An internal linear regulator reduces the MAX840's output voltage ripple to 1mVp-p. With a well-filtered control voltage (VCTRL), the MAX843/MAX844 also achieve less than 1mVp-p typical output ripple. Supply current is 750μA, and reduces to less than 1μA in shutdown (MAX840/MAX843). The MAX844's unregulated output is active in shutdown, with the charge pump switching at 20kHz. It provides a low-power LCD supply.

Features

Tube Package
Widely used in Charge Pump, Cellular Telephone Transmitter applications
SWITCHED CAPACITOR REGULATOR analog IC

Surface Mount Mounting Type

Applications

There are a lot of Maxim Integrated
MAX840ESA+ Specialized Voltage Regulators applications.

• LCD-TV/PDP-TV
• Copier/Printer
• Set-Top Box
• DDR Vooo and Vπ Voltage Generation
• PC Dual Power Supply
• Server DDR Power
• Desktop Computer
• Graphics Cards
• Cell Phones
• Wireless Modems