ZXLD1321:Low Voltage DC-DC LED Drivers

Part NumberData SheetSPICE ModelTopologies (Buck)Topologies (Buck-Boost)Topologies (Boost)MinimumInput Voltage (V)MaximumInput Voltage (V)Maximum Output Voltage (V)LED Current (A)Switching Frequency (kHz)Efficiency (%)OperatingTemperatureRange (°C)QuiescentCurrentTyp (mA)
ZXLD1321ZXLD1321.pdf---Yes1.21218160085-40 to +851.5
Description

The ZXLD1321 is an inductive DC-DC converter, with an internal switch, designed for driving single or multiple °Cs in series up to a total of 1A output current. Applications cover commercial environments with input voltages ranging from 1.2V to 12V. The device employs a variable 'on' and 'off' time control scheme with adjustable peak switch current limiting and supports step-up (Boost) mode and self-powering Bootstrap operating modes, offering higher power efficiency and lower system cost than conventional PFM 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, high power efficiency of DC-DC conversion and maximum °C brightness/reliability. More importantly, it retains design flexibility to add customer specific features. The feedback control circuitry inside the ZXLD1321 provides excellent load and current regulation, resulting in very stable °C current over the useful life of the battery and over the full operating temperature range. The °C current can be adjusted from 100% down to 10% of the set value by applying a dc voltage to the ADJ pin and down to 1% by applying a PWM signal to the ADJ pin. An onchip °C protection circuit also allows output current to be reduced linearly above a predetermined threshold temperature using an external thermistor at the TADJ pin. External resistors set nominal average °C current and coil peak current independently. The device can be shut down by applying a continuous low level dc voltage to the ADJ pin.

Application
  • High power LED flashlights
  • LED back-up lighting
  • General LED lighting
  • Emergency lighting
Features
  • 1.2V to 12V Input voltage range
  • Up to 1A output current
  • Typical efficiency >85%
  • Bootstrap operation enables input voltage down to 1V
  • User-defined thermal control of °C output current using external thermistor
  • High output current stability over input voltage and temperature
  • 12μA typical standby current
  • °C current adjustable from 100% down to 2%
  • Adjustable soft-start
  • Drives up to 5 white °Cs in series
Ordering Information
  • ZXLD1321DCATC
DFN4030-14
ZXLD1321.pdf ZXLD1321
ZXLD1322 buck/boost mode dc-dc converter for led driving with 700ma output and current control ZXLD1322
ZXLD1322 buck/boost mode dc-dc converter for led driving with 700ma output and current control ZXLD1322