Diodes Incorporated ZXLD1322 | Demoboard ZXLD1322EV2

Description

The ZXLD1322 is an inductive DC-DC converter, with an internal switch, designed for driving single or multiple LEDs in series up to a total of 700mA output current.Applications cover input voltages ranging from 2.5V to 15V. Depending upon supply voltage and external components, this can provide up to 12W of output power.The device employs a variable ‘on’ and ‘off’ time control scheme with adjustable peak switch current limiting and operates in Buck/Boost modes, offering higher power efficiency and lower system cost than conventional PFM buck/boost circuitry.The device includes the DC-DC converter, a high-side current monitor and an NPN switching transistor to provide an integrated solution offering small PCB size, competitive cost/performance, highpower efficiency of DC-DC conversion and maximum LED brightness/reliability. More importantly, it retains design flexibility to add customer specific features.The feedback control circuitry inside theZXLD1322 provides excellent load and current regulation, resulting in very stable LED current over the useful life of the battery and over the full operatingtemperature range.The LED current can be adjusted from 100% down to 10% of the set value by applying a dc voltage to theADJ pin and down to 1% by applying a PWM signal.An on-chip LED protection circuit also allows output current to be reduced linearly above a predeterminedthreshold temperature using an external thermistor at the TADJ pin.External resistors set nominal average LED current and coil peak current independently.The device can be shut down by applying a continuous low level dc voltage to the ADJ pin.

Features

• 2.5V to 15V Input Voltage Range
• Up to 700mA output current
• Typical efficiency (*) : >80%
• User-defined thermal control of LED output currentusing external thermistor
• 12μA typical standby current
• LED current adjustable from 100% down to 1%
• Adjustable Soft-Start
• Capable of driving 3 LEDs in series (Total LED dropVF+VIN <= 18V)

Typical applications

• High Power LED flashlights
• General LED lighting
• LED back-up lighting

More information

• Datasheet
• IC product information