The ISL9214A is a fully integrated low-cost single-cell Li-ion
or Li-polymer battery charger. The charger accepts two
power inputs, normally one from a USB (Universal Serial
Bus) port and the other from a desktop cradle. The
ISL9214A is an ideal charger for smart handheld devices
that need to communicate with a personal computer via
USB.
The ISL9214A features 28V maximum voltages for both the
cradle and the USB inputs. Due to the 28V rated inputs,
low-cost, large output tolerance adapters can be used safely.
When both inputs are powered, the cradle input is used to
charge the battery. The charge current is programmable for
the cradle input with a small resistor. The end-of-charge
current is also programmable by another external resistor.
The charger incorporates Thermaguard™ which protects the
IC against over-temperature. If the die temperature rises
above a typical value of +125°C, a thermal foldback function
reduces the charge current automatically to prevent further
temperature rise. The charger has two indication pins. The
PPR (power present) pin outputs an open-drain logic LOW
when either the cradle or the USB input power is attached.
The CHG (charge) pin is also an open-drain output that
indicates a logic LOW when the charge current is above a
minimum current level. When the charge current is below the
preset minimum current, the CHG pin will indicate a logic
HIGH signal. This status is latched and will be reset under
one of the following events:

Features
• Complete Charger for Single-Cell Li-ion/Polymer Batteries
• Dual Input Power Sources for Cradle and USB
• Low Component Count
• Integrated Pass Elements
• Fixed 380mA USB Charge Current
• Programmable Cradle Charge Current
• Charge Current Thermaguard™ for Thermal
Protection
• 28V Maximum Voltages for Cradle and USB Inputs
• Adapter Presence and Charge Indications
• Less than 0.5µA Leakage Current Off the Battery When
No Input Power Attached
• Programmable End-of-Charge Current
• Ambient Temperature Range: -40°C to +85°C
• No External Blocking Diode Required

Applications
• Smart Handheld Devices
• Cell Phones, PDAs, MP3 Players
• Digital Still Cameras
• Handheld Test Equipment