Semtech announced the SC805 and SC806 battery charger devices designed for cable chargers, personal media devices, mobile phones and others. Both devices charge lithium-ion or lithium-polymer batteries and are packaged in 3mm x 3mm, thermally optimized MLP packages. The chargers produce up to 1A when operating in continuous charge mode, and during high power-dissipation periods they behave like pulse chargers that regulate the internal die temperature to a safe level.

Safe and accurate charging profile

SC805 and SC806 chargers feature an input voltage range of 3V to 6V for seamless charging from a current-limited adapter. This feature assures that for high output current designs, the power dissipation can occur in a less-sensitive wall plug adapter rather than in the system's internal charging circuitry itself. The SC805 and SC806 are designed with three programmable charge states, including a trickle-charge phase for deeply discharged batteries, a fast-charge phase, and a constant-voltage (CV) phase. In addition, the SC805 offers a programmable one- to 10-hour charge timer that protects a system from faulty batteries. All aspects can be programmed to facilitate a safe and accurate charging profile.

Precise line and load regulation

The devices feature precise line and load regulation, enabling the devices to control battery voltage to 1% accuracy. Once the charger reaches CV mode, it gradually reduces battery output voltage until the termination voltage is reached and then monitors battery voltage levels and initiates a new charge cycle if the battery voltage drops by more than 100mV. The tho ICs are fully integrated devices, including charger, FET pass transistor, reverse-blocking diode, sense resistor, and thermal protection. In addition to charging lithium-ion or lithium-polymer batteries, the devices can work as general-purpose current sources or as current sources for charging Nickel-Cadmium (NiCd) and Nickel-Metal-Hydride (NiMH) batteries.

"Bed-of-nails" system testing

The chargers can monitor a negative temperature coefficient pin to detect that the battery is not connected. The SC805 can work with or without a battery, functioning as a low dropout (LDO) regulator when the battery is removed. This LDO feature is helpful for "bed-of-nails" system testing where a portable device, such as a cell phone, is assembly tested without a battery. The lead-free package design complies with the European Union's Restriction on Hazardous Substances in Electrical and Electronic Equipment (RoHS) directive to meet worldwide environmental and regulatory requirements.

Pricing and Availability

The SC805, ordering code SC805IMLTRT, is available immediately in production quantities and is priced at $1.05 each in 10,000-piece lots. The SC806 is available immediately in production quantities and is priced at $1.01 each in 10,000-piece lots. Semtech offers design assistance, including field- and factory-based support.