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TS52002

Version 1.2

Specifications subject to change

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FUNCTIONAL DESCRIPTION

The TS52002 is a fully-integrated MPP regulator IC based on a highly-efficient switching topology. It includes a Maximum

Power Point Tracking (MPPT) function to optimize its input voltage to extract the maximum possible power from a

photovoltaic cell. A 1 MHz internal switching frequency facilitates low-cost LC filter combinations.

When the output voltage is below the termination voltage, the device will regulate to the maximum power point. This will

continue as long as the output current is below the current limit and no fault has occurred. In order for the Maximum Power

Point (MPP) regulation to be most effective, the output load needs to not allow high frequency transients in output voltage.

This will cause the device to operate at a non optimal MPP point until the output voltage has remained static for several

milliseconds.

As detailed in the Application Diagram, the external µC pulses the charging current based on a NiMH charging profile. The

battery voltage and/or temperature is monitored to safely charge and ensure the battery is fully charged. One or two NiMH

cells can be configured in series or parallel with a parallel configuration requiring two switches to allow the µC to manage the

charging profile.

INTERNAL PROTECTION DETAILS

Internal Current Limit

The current through the inductor is sensed on a cycle by cycle basis and if current limit is reached, it will abbreviate the cycle.

Current limit is always active when the regulator is enabled.

Thermal Shutdown

If the temperature of the die exceeds 170C (typical), the SW outputs will tri-state to protect the device from damage. The nFLT

and all other protection circuitry will stay active to inform the system of the failure mode. Once the device cools to 160C

(typical), the device will attempt to start up again. If the device reaches 170C, the shutdown/restart sequence will repeat.

VIN Under-Voltage Lockout

The device is held in the off state until VIN reaches 3.15V. There is a 200mV hysteresis on this input, which requires the input

to fall below 2.95V before the device will disable.

VBAT Over-Voltage Protection

The TS52002 has an output protection circuit designed to shutdown the charging profile if the output voltage is greater than

the termination voltage. Shutting down the charging profile puts the TS52002 in a fault condition.