ZXLD1352 (Obsolete)

Description

The ZXLD1352 is a continuous mode inductive step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the LED voltage. The device operates from an input supply between 7V and 30V and provides an externally adjustable output current of up to 350mA. Depending upon supply voltage and external components, this can provide up to 8 watts of output power. The ZXLD1352 includes the output switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current. Output current can be adjusted above, or below the set value, by applying an external control signal to the 'ADJ' pin. The ADJ pin will accept either a DC voltage or a PWM waveform. DC voltages between 0.3V and 2.5V allow adjustment of output current from 25% to 200% of nominal. 1000:1 adjustment of output current is possible using PWM control. Applying a voltage of 0.2V or lower to the ADJ pin turns the output off and switches the device into a low current standby state. The device is assembled in a TSOT25 pin package.

Feature(s)

• Simple low parts count
• Internal 30V NDMOS switch
• 350mA output current
• Single pin on/off and brightness control using DC voltage or PWM
• 1000:1 PWM dimming range
• Soft-start
• High efficiency (up to 95%)
• Wide input voltage range: 7V to 30V
• 40V transient capability
• Output shutdown
• Up to 1MHz switching frequency
• Inherent open-circuit LED protection
• Typical 4% output current accuracy

Application(s)

• Low voltage halogen replacement LEDs
• Automotive lighting
• Low voltage industrial lighting
• LED back-up lighting
• Illuminated signs