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STCC2540

Functional description

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Functional description

The STCC2540 device integrates, in one package, a complete solution to charge portable

devices through USB ports, including:

•

Charger emulator compatible with USB battery charging BC1.2 standard, Chinese

•

3 control pins, CTL1, CTL2, CTL3 allowing the host to select the emulation profile.

These pins may be controlled directly from the host USB controller or from the

embedded controller.

•

USB data switch with wide bandwidth up to 1100 MHz compliant with USB 2.0

resistance, allowing signals to pass with minimum edge and phase distortion.

•

accuracy and high current output capability, 2.5 A typ. The current limit threshold can

be adjusted with a good accuracy by an external resistor in the range 500 mA to 2.8 A

(max.).

Constant current mode protection is used to protect the device and the host system

against overcurrent or short-circuit. Other protection includes reverse current and

reverse voltage protection, undervoltage lockout and thermal shutdown.

•

A deglitched output (FAULT) reporting the failure events of overcurrent, thermal

•

Charging current sensing circuit. The output CHARGING is asserted if charging current

is above 20 mA in CDP and DCP modes.

In CDP mode the charging flag is s asserted only if the CDP handshaking between the

portable device and the host is performed before the current is above threshold.

After the current drops below threshold, the output CHARGING is deasserted. The host

system can then disable the high power DC-DC converter and thus reduce the power

consumption. This is crucial when the host is battery supplied.

•

An enable input (EN) to enable/disable the device.

The device is offered in a small, RoHS compliant VFQFPN 16L (3 x 3 x 0.8 mm) package

with an exposed pad for effective cooling.