Analog Devices Inc./Maxim Integrated

The MAX8804V/MAX8804W/MAX8804Y/MAX8804Z intelligent, dual-input, stand-alone, constant-current, constant-voltage (CCCV), thermally regulated linear chargers are designed for a single-cell lithium-ion (Li+) battery. They integrate the current-sense circuit, MOS pass element, thermal-regulation circuitry, and overvoltage protection (OVP), and eliminate the reverse-blocking Schottky diode.The MAX8804V/MAX8804W/MAX8804Z function as stand-alone chargers to control the charging sequence from the prequalification state through fast-charge, topoff charge, and full-charge indication. The MAX8804Y eliminates the prequalification state to allow startup into a load without a battery. Proprietary thermal-regulation circuitry limits the die temperature when fast-charging or while exposed to high ambient temperatures, allowing maximum charging current without damaging the IC.The MAX8804V/MAX8804W/MAX8804Y/MAX8804Z achieve high flexibility by providing an adjustable DC/USB fast-charge current through a simple single-wire interface (SET input). The chargers automatically select between either a USB or AC adapter input source. The AC adapter charge current is programmable from 400mA to 700mA in 50mA steps through a serial interface. The USB charge current is programmable to 95mA, 380mA, or 475mA through the same interface. Other features include an active-low battery charging-status indicator (active-low CHG), an active-low power-OK indicator (active-low POK), an active-low USB input detection output (active-low USBPWR) on the MAX8804Y/MAX8804Z, and battery pack detection (DETBAT) on the MAX8804V/MAX8804W.The MAX8804V has 120mA, 140mA, 180mA, and 200mA active-low CHG top-off threshold settings, while the MAX8804W/MAX8804Y/MAX8804Z have 70mA, 80mA, 90mA, and 100mA. The MAX8804V/MAX8804W/MAX8804Y/MAX8804Z accept a 4.15V to 30V DC source voltage or a 4.15V to 16V USB input voltage, but disable charging when either input voltage exceeds 7.5V to protect against unqualified or faulty input sources. The MAX8804V/MAX8804W/MAX8804Y/MAX8804Z operate over the extended temperature range (-40°C to +85°C) and are available in a tiny 8-pin thermally enhanced 2mm x 3mm TDFN package.ApplicationsCell Phones/SmartphonesDigital CamerasMP3 PlayersOther Handheld DevicesPortable Media Players

The MAX881R low-noise, inverting power supply is designed for biasing GaAsFET power amplifiers in portable wireless applications. This device is a chargepump inverter followed by a negative linear regulator. The input voltage range is 2.5V to 5.5V. The output is preset at -2.0V or can be set, using two resistors, to any voltage from -0.5V to (-VIN+ 0.6V). It can deliver up to 4mA. The internal linear regulator also filters the output to 1mVP-Pripple and noise.Other features include a power-OK (active-low POK) output that signals when the negative voltage is within 7.5% of its set point. It protects the GaAsFET by not allowing power to be applied to the GaAsFET's drain until it is properly biased. The signal can be routed either to a microcontroller or directly to a switch at the GaAsFET drain. The MAX881R is available in a 10-pin µMAX® package.ApplicationsCell Phones Wireless ModemsPCS Phones Two-Way PagersPHS Phones Mobile RadiosWireless Handsets Wireless Computers