The ADD5207 is a white LED driver for backlight applications based on high efficiency, current mode, step-up converter technology. It is designed with a 0.15 Ω, 1.5 A internal switch and a pin-adjustable operating frequency between 600 kHz and 1 MHz.
The ADD5207 contains four regulated current sources for uniform LED brightness. Each current source can drive up to 25 mA and the LED-driving current is pin adjustable by an external resistor. The ADD5207 drives up to four parallel strings of multiple series-connected LEDs with a ±1.5% current matching between strings.
The ADD5207 provides phase shift PWM brightness control methods. LED dimming control is achieved through the PWM input. The device includes an 8 kHz LED-dimming oscillator for driving each current source. The ADD5207 operates over an input voltage range of 6 V to 21 V, but the device can function with a voltage as low as 5.6 V.
The ADD5207 also has multiple safety protection features to prevent damage during fault conditions. If any LED is open, the device automatically disables the faulty current source. The internal soft start circuit prevents a high inrush current during startup. Thermal shutdown protection prevents thermal damage.
The ADD5207 is available in a low profile, thermally enhanced, 4 mm × 3 mm × 0.75 mm, 14-lead, RoHS-compliant lead frame chip scale package (LFCSP) and is specified over the industrial temperature range of −25°C to +85°C.
APPLICATIONS
- Notebook PCs UMPCs, and monitor displays
