SMBus battery charger needs no microcontroller

Linear Technology Corp. has introduced the LTC4101, a fast, precision smart battery charger controller that operates with or without a host microcontroller.

According to the press release, LTC4101 is 100 percent compliant with Rev. 1.1 SMBus specifications and meets the requirements of Smart Battery System Level 2 charging functions. It is optimized for 3-5.5V charging voltages, suitable for 1-cell Li-ion and 3- to 4-cell nickel-chemistry batteries. It is capable of fast charging up to 4A with 0.8 percent voltage accuracy and 4 percent current accuracy.

In addition, synchronous switching operation provides high efficiency charging from a wide input supply voltage range of 6-28V. The LTC4101 is housed in a small 24-pin SSOP package and is ideal for use in portable computers and instruments.

For flexibility, the LTC4101 integrates a 10bit DAC for charge current programming and an 11bit DAC for charge voltage programming. Using the charger's input current limit feature, a maximum charge rate is achieved without overloading the input supply, such as a wall adapter. The SMBus interface remains alive when the input power is removed and responds to all SMBus activity directed to it, including SafetySignal status, which in tandem with the IC automatically monitors the battery temperature, connectivity and battery type information.

The LTC4101 is rated for operation from -40°C to 85°C and is available in small 24-pin narrow SSOP package. Pricing starts at $5 each in 1,000-piece quantities.