Overview
The L6924D013TR, produced by STMicroelectronics, is a fully integrated battery charger IC designed for single-cell Li-Ion/Polymer battery packs. It is particularly suited for space-limited applications such as handheld devices and digital cameras. This IC integrates all necessary power elements, including a power MOSFET, reverse blocking diode, sense resistor, and thermal protection, into a compact VFQFPN16 package (3 x 3 mm).
The L6924D operates in both linear and quasi-pulse modes, depending on the type of adapter used. It features closed-loop thermal control to prevent overheating and supports programmable charge currents, pre-charge currents, and end-of-charge currents. The device also includes an NTC or PTC thermistor interface for battery temperature monitoring and protection.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Input Voltage (VIN) | 2.5 | - | 12 | V |
| Start-up Threshold | 4.1 | - | - | V |
| Supply Current (Charging Mode) | 1.8 | 2.5 | - | mA |
| Supply Current (Shutdown Mode) | 60 | 90 | - | µA |
| Battery Regulated Voltage (VOUT) | 4.06 | 4.1 | 4.14 | V |
| Charge Current (ICHG) with RPRG = 24kΩ | 450 | 490 | 525 | mA |
| Pre-Charge Current (IPRECH) with RPRE floating | 41 | 49 | 56 | mA |
| Pre-Charge Voltage Threshold (VPRETH) default | 2.7 | 2.8 | 2.9 | V |
| Maximum Charging Time Accuracy | - | - | 10% | % |
| Thermal Resistance Junction to Ambient | - | - | 75 | °C/W |
Key Features
- Fully integrated solution with power MOSFET, reverse blocking diode, sense resistor, and thermal protection.
- Programmable charge current up to 1 A and programmable pre-charge, end-of-charge currents.
- Supports both linear and quasi-pulse operation modes.
- Closed-loop thermal control to prevent overheating.
- USB BUS-compatible and programmable output voltage at 4.1 V and 4.2 V with ± 1% accuracy.
- NTC or PTC thermistor interface for battery temperature monitoring and protection.
- Flexible charge process termination and gas gauge capability.
- Status outputs to drive LEDs or interface with a host processor.
- Small VFQFPN16 package (3 x 3 mm).
Applications
- Handheld devices.
- Digital cameras.
- Standalone chargers.
- USB-powered chargers.
Q & A
- What is the operating input voltage range of the L6924D?
The operating input voltage range is from 2.5 V to 12 V, with a start-up threshold of 4.1 V.
- What are the different operation modes of the L6924D?
The L6924D operates in both linear and quasi-pulse modes, depending on the type of adapter used.
- How does the L6924D manage thermal protection?
The device features closed-loop thermal control to prevent overheating, reducing the charging current if the junction temperature reaches approximately 120°C.
- Can the charge current be programmed?
- What is the purpose of the NTC or PTC thermistor interface?
The NTC or PTC thermistor interface is used for battery temperature monitoring and protection.
- How does the L6924D indicate the status of the charging process?
The device provides two open collector outputs (ST1 and ST2) for diagnostic purposes, which can drive external LEDs or interface with a host microcontroller.
- What is the package type and size of the L6924D?
The L6924D comes in a VFQFPN16 package, which is 3 x 3 mm in size.
- Can the L6924D be used in USB-powered chargers?
- How does the L6924D handle battery absence detection?
The device includes a mechanism for battery absence detection, where it goes into standby mode if the battery is not detected.
- What is the maximum charging time accuracy of the L6924D?
The maximum charging time accuracy is 10%.
