LP4070
Li-ion battery charger with integrated over-voltage protection for USB applications
Product Overview
Description
The LP4070 is a highly integrated Li-ion battery charger designed specifically for USB-powered applications. It includes built-in over-voltage protection (OVP) up to 28V, protecting the device from faulty USB adapters and voltage spikes.
The charger operates from 4.5V to 6.5V input and provides a regulated 4.2V charge voltage with ±1% accuracy. It supports up to 800mA charge current, programmable via external resistor. The device is USB-compliant with 100mA and 500mA input current limiting.
The LP4070 includes comprehensive protection features: over-voltage protection, thermal regulation, reverse current blocking, and short-circuit protection. The charge status output indicates charging and completion states. Available in a compact SOT-23-6 package, it is ideal for smartphones, Bluetooth devices, and other USB-powered portable electronics.
Product Series
LP
Primary Application
Smartphones
Key Features
- Integrated over-voltage protection (28V)
- USB-compliant input current limiting
- Up to 800mA programmable charge current
- ±1% charge voltage accuracy
- Automatic charging with C/10 termination
- Thermal regulation protection
- Reverse current blocking
- Compact SOT-23-6 package
Specifications
| Input Voltage Range | 4.5V - 6.5V |
|---|---|
| Charge Voltage | 4.2V (±1% accuracy) |
| Charge Current | Up to 800mA (programmable) |
| Trickle Charge Current | 10% of fast charge |
| Charge Termination | C/10 threshold |
| Sleep Mode Current | <2μA |
| Thermal Regulation | 120°C junction temperature |
| Charge Status Output | Open-drain indicator |
| Operating Temperature | -40°C to +85°C |
| Package | SOT-23-6 |
| Input Current Limit | 100mA/500mA USB compliant |
Applications
Smartphones
Electronic system design
Bluetooth headsets
Electronic system design
Portable media players
Electronic system design
USB-powered devices
Electronic system design
Wearable electronics
Electronic system design
FAE Expert Insights
"The LP4070 is my recommended charger for USB-powered applications due to its integrated over-voltage protection. I've seen too many devices damaged by faulty USB chargers that output 12V or higher instead of 5V. The LP4070's 28V OVP rating provides excellent protection. The USB-compliant current limiting is important - it prevents overloading USB ports during enumeration. The 800mA charge current is sufficient for most single-cell applications. One implementation tip: the OVP feature is automatic and requires no external components, but you should still use a quality USB cable to minimize voltage drops. The SOT-23-6 package is compact but can handle the power dissipation for 500mA charging. I've used this charger in numerous smartphone accessory designs with excellent reliability. The charge status pin is useful for LED indicators. Overall, a well-protected USB charger solution."
USB charger with integrated over-voltage protection for robust portable applications
— Li Wei, BeiLuo
Frequently Asked Questions
What over-voltage protection does LP4070 provide?
The LP4070 includes integrated over-voltage protection that can withstand input voltages up to 28V. If the input voltage exceeds approximately 6.8V, the charger shuts down to protect the battery and internal circuitry. This protects against faulty USB chargers and voltage transients.
28V OVP rating protects against faulty chargers; automatic shutdown above 6.8V.