MAX17085B

The MAX17085B is an all-in-one notebook power solution integrating a multichemistry battery charger, dual fixedoutput Quick-PWMK step-down controllers, and dual keep-alive linear regulators.The high-frequency (-1.4MHz) multichemistry battery charger uses a current-mode, fixed inductor current ripple architecture that significantly reduces component size and cost. Low-offset sense amplifiers allow the use of low-value sense resistors for charging and input current limit.

Features of the MAX17085B are:(1)all-in-one charger plus dual main step-down controllers; (2)S 5V/100mA and 3.3V/50mA LDO regulators; (3)dual quick-PWM with fast transient response; (4)and extended on-time; (5)300kHz to 800kHz switching frequency; (6)fixed 5V and 3.3V SMPS outputs; (7)low-noise ultrasonic mode; (8)autoretry fault protection; (9)analog/PWM (100Hz to 500kHz) adjustable charge current setting; (10)AC adapter overvoltage and overcurrent protection; (11)high switching frequency (1.4MHz); (12)selectable 2-, 3-, and 4-cell battery voltage; (13)automatic selection of system power source; (14)internal charge-pump for adapter n-channel MOSFETs drive.

The absolute maximum ratings of the MAX17085B can be summarized as:(1)CSIP to CSIN, CSSP to CSSN:-0.3V to +0.3V;(2)ON3, ON5, PGOOD to GND:-0.3V to +6V;(3)storage temp:-65 to +150;(4)operating temp:-40 to 85;(5)BSTC to LXC:-0.3V to +6V;(6)LDO3 current (internal regulator) continuous:+50mA.Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Separate enable inputs for each SMPS and a combined open-drain power-good output allow flexible power sequencing. Voltage soft-start reduces inrush current, while passive shutdown discharges the output through an internal switch. Fast transient response, with an extended on-time feature reduces output capacitance requirements. Selectable pulseskipping mode and ultrasonic mode improve lightload efficiency. Ultrasonic mode operation maintains a minimum switching frequency at light loads, minimizing audible noise effects.