STCF02
New buck / boost converter for high-power camera-flash LEDs

An advanced power-supply IC known as STCF02 has been specifically designed to drive the high-current white LEDs used for flash illumination in the latest generation of mobile imaging equipment such as cameras for mobile phones, digital still cameras, and PDAs. The device is able to support the higher flash illumination powers required by the latest high resolution image sensors. Furthermore it extends battery life thanks to the extremely low standby current of less than 1µA drawn during shutdown mode. The STCF02 is a high-efficiency (85%, typical) buck-boost converter that is able to deliver a controlled current to a single high-power flash white LED.
Accurate current control over the range of battery voltages is essential as the white LED's light output is proportional to the current flowing through it. Based on the battery voltage level the device automatically changes the operating mode between buck (step down) and boost (step up) to accommodate the forward voltage of the white LED.

Buck-boost DC/DC converter
Drives one power flash LED up to 600mA between 2.7 and 5.5 Vin
Output current control
Synchronous rectification, high efficiency
Operating switching frequency: 1.8MHz
Peak inductor limited to 2.3A typ.
LED disconnected from the battery in shutdown mode
LED temperature protection or safety time-out supported
Output over-voltage protection 5.3V
Package: DFN20L 4x4mm

Application flexibility is guaranteed by three input logic signals. They allow the selection of four different operating modes: full flash, medium flash, torch, and shutdown.
The flash-mode current ranges from 200mA to 600mA and the torch-mode current is adjustable from 25mA to 250mA, while the medium flash mode-current is set at a level between the torch-mode and full flash-mode currents.
The STCF02 can also be connected to an external negative temperature coefficient (NTC) to sense the LED temperature and to turn it off in case a failure occurs. The device integrates all the protection to ensure reliable operation. Thanks to its buck-boost smart control mode and the high output power capability, as well as its outstanding conversion efficiency, the STCF02 is an optimum fully integrated solution to drive the high power white LED used in the new generation of high-resolution camera sensors.


Typical application circuit

Ordering Codes

Type (T&R)	Package
STCF02PNR	DFN20L 4x4mm

STCF02 demo board