Dual 300mA Pin-Programmable Low-Dropout Linear Regulators with Reset or Low-Noise Output in a Tiny 2mm x 2mm µDFN Package

The MAX8633–MAX8636 offer low-dropout (LDO) voltage and ultra-low-power regulation in a subminiaturized 2mm x 2mm µDFN package. The devices operate from a 2.7V to 5.5V supply and deliver up to 300mA from each output, with a typical dropout voltage of 90mV at 100mA load current. Each device is designed with internal p-channel MOSFET pass transistors to ensure a low-quiescent supply current of 54µA (typical, both LDOs on). Other features include low-noise operation (MAX8634/MAX8636), output current limiting, and thermal shutdown.

The MAX8633 features an open-drain, active-low RESET output to monitor OUT2, eliminating external components and adjustments. The MAX8633 asserts an active-low RESET signal (120ms minimum timeout) when VOUT2 drops below 87% of the nominal output voltage. The MAX8634/MAX8636 feature a noise bypass input to the internal reference for low output noise (45µVRMS typ). The MAX8634/MAX8635 provide independent active-low SHDN inputs for disabling the regulators, while the MAX8633/MAX8636 provide a single active-low SHDN input for disabling both regulators.

The MAX8633/MAX8635/MAX8636 have two logic inputs that select one of nine preset output-voltage combinations, eliminating external 1% resistors, as well as inventory burden. The MAX8634 has one logic input to select three output-voltage options.

The MAX8633–MAX8636 are available in an 8-pin, 2mm x 2mm µDFN package for minimizing footprint, and an 8-pin, 3mm x 3mm TDFN package for higher power dissipation. The devices are specified over the extended temperature range (-40°C to +85°C). All packages are lead free.

Applications

* Cellular and Cordless Phones * Handheld Instruments * Notebook Computers * PDAs and Digital Cameras * Small LCD Displays * Wireless LAN Cards

* Pin-Programmable Output Voltages

* 300mA Output Current

* Low 90mV Dropout at 100mA Load

* Open-Drain, Active-Low RESET (MAX8633)

* Low 45µVRMS Output Noise (MAX8634/MAX8636)

* Low 54µA Quiescent Supply Current

* Low < 1µA Maximum Shutdown Current

* Output Current Limit

* Thermal Shutdown