STMicroelectronics AN2507 Application Note for STCF03 Flash LED Driver

About this manual

The document provides a detailed guide on designing an application circuit for the STCF03, a high-frequency (1.8 MHz) Buck-Boost current mode converter designed to drive single LEDs with forward voltages between 2.7 V and 5 V. It covers three device versions (A, B, and C), which differ in their support for NTC thermal protection features.

The note includes instructions on selecting external components such as input/output capacitors, inductors, resistors, and LEDs. It also details PCB layout rules for both QFN and BGA packages across different layer counts. Furthermore, it describes the internal registers, operation modes (Shutdown, Ready, Torch, Flash), and provides specific I2C data packets and register settings for various use cases like red-eye reduction and long-duration flashes.

What's inside

• Schematic description
• Selection of external components
• PCB design rules
• Internal registers access
• Operation modes (Shutdown, Ready, Torch, Flash)
• STATUS register bits
• I2C bus communication examples

Specifications

Frequently asked questions

What is the forward voltage range for the LED this driver is designed for?

The device is designed for driving a single LED with a forward voltage range from 2.7 to 5 V.

What is the maximum LED current in FLASH mode for the VQFPN version?

The maximum LED current in FLASH mode is 800 mA for a battery voltage ranging from 2.7 V to 5.5 V.

What is the maximum LED current in TORCH mode for the device?

The maximum LED current in TORCH mode is 200 mA for a battery voltage ranging from 2.7 V to 5.5 V.