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I²C USB power manager provides digital control, status readback

Milpitas, Calif.—Linear Technology Corp. has introduced the LTC4099, an autonomous I²C controlled, high efficiency power manager, ideal diode controller and Li-Ion/Polymer battery charger for portable USB powered devices such as media players, digital cameras, PDAs, PNDs and smart phones.

The LTC4099 prevents damage caused by accidental application of high voltage on the USB input with an overvoltage protection (OVP) circuit; protection up to 68V requires only an external NFET/resistor combination. The LTC4099's “instant-ON” operation ensures system load power at plug-in even with a dead battery. Its onboard ideal diode guarantees that ample power is always available to VOUT even if there is insufficient power at the LTC4099's two input pins. The device's ideal diode controller can be used to drive the gate of an optional PFET, reducing the impedance between the load and the battery to 30mOhm or less.

The LTC4099's full-featured single-cell Li-Ion/Polymer battery charger allows the load current to exceed the current drawn from the USB port while conforming to USB load specifications. For fast charging, the IC's switching input stage converts nearly all of the 2.5W available from the USB port to current, enabling up to 600mA charge current or 700mA system load current from a 500mA limited USB port. There is also 1.5A charge current available when wall powered. For improved safety margin, an integrated over-temperature battery conditioning circuit can optionally reduce the battery voltage in case both high battery temperature and high battery voltage occur simultaneously.

The LTC4099 is housed in an ultra-thin (0.55mm) 20-pin 3mm x 4mm QFN package and is guaranteed for operation from -40°C to 85°C.

Pricing: 1,000-pieces at 2.80 each.
Availability: Now.
Datasheet: Click here.

Linear Technology, www.linear.com

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