The ZLED7720 continuous-mode inductive step-down converter is part of our ZLED7x20 family of LED-control ICs. It is designed for applications requiring high brightness and high current. It can efficiently drive a single LED or multiple series-connected LEDs from a voltage input higher than the LED forward voltage: Vin = 6 to 40 VDC. It provides an adjustable output current ≤0.35A, which is set via an external resistor and controlled by the ZLED7720's integrated high-side output current-sensing circuit and high-speed internal 40V power switch. An external control signal on the ADJ pin, which can be a DC voltage, PWM, or microcontroller-generated waveform, can also be used to linearly adjust a continuous output current or to control a gated output current. The output can be turned off by applying a voltage lower than 0.2V to the ADJ pin, which puts the ZLED7720 in a low-current standby state. The ZLED7720 enables diverse industrial and consumer lighting applications requiring high driving currents, wide operating voltage range, high efficiency, and variable brightness control. It offers over-temperature and LED open-circuit protection. The ZLED7720 can also minimize bill-of-material costs because very few external components are required for most applications. Only a resistor, a diode, an inductor, and three capacitors are needed for a typical basic application.
- Up to 0.35A output current
- Internal 40V power switch
- Wide DC input voltage range: 6 to 40 VDC
- Output current accuracy: 3% (typical)
- Dimming ratio: 1200:1
- LED open-circuit protection
- Thermal shutdown protection