MAX8893A

The MAX8893A power-management integrated circuits (PMICs) are designed for a variety of portable devices including cellular handsets.The PMICs MAX8893A include a high-efficiency step-down DC-DC converter, five low-dropout linear regulators (LDOs) with programmable output voltages, individual power-on/off control inputs, a load switch, and a USB high-speed switch. These MAX8893A maintain high efficiency with a low no-load supply current, and the small 3.0mm x 2.5mm WLP package makes them ideal for portable devices.

Features of the MAX8893A are:(1)three low-noise LDOs with programmable output voltages; (2)two low supply current LDOs with programmable output voltages; (3)low on-resistance load switch; (4)USB high-speed switch with ±15kV ESD; (5)individual enable control for all regulators and switches; (6)overcurrent and thermal protection for all LDOs; (7)3.0mm x 2.5mm x 0.64mm, 30-bump WLP; (8)guaranteed 500mA output current; (9)up to 4MHz switching frequency; (10)programmable output voltage from 0.8V to 2.4V; (11)dynamic voltage scaling with programmable ramp rate.The step-down DC-DC converter utilizes a proprietary 4MHz hysteretic PWM control scheme that allows for ultra-small external components. Internal synchronous rectification improves efficiency and eliminates the external Schottky diode that is required in conventional stepdown converters.

The absolute maximum ratings of the MAX8893A can be summarized as:(1)PGND to AGND:-0.3V to +0.3V;(2)storage temperature range:-65 to +150;(3)operating temperature range:-40 to +85;(4)junction temperature:+150;(5)continuous power dissipation:1600mW.Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the MAX8893A. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied.Exposure to absolute maximum rating conditions for extended periods may affect device reliability.After the step-down converter is in regulation, its output voltage can dynamically ramp up at the rate set by the BUCKRAMP bits for a positive voltage change. For a negative voltage change, the decay rate of the output voltage of MAX8893A depends on the size of the external load: a small load results in an output-voltage decay that is slower than the specified ramp rate and LX sinks current from the output capacitor to actively ramp down the output voltage; a large load (greater than COUT x Ramp Rate) results in an output-voltage decay with the specified ramp rate.