This document introduces the features of LT1186F DAC programmable CCFL switching regulator (Bits-to-NitsTM), including wide battery input range (4.5V to 30V), grounded lamp or floating lamp configurations, open lamp protection, precision 50µA full-scale DAC programming current, standard SPI mode or pulse mode, DAC setting is retained in shutdown.
The LT1186F is a fixed frequency, current mode, switching regulator that provides control functions for Cold Cathode Fluorescent Lighting (CCFL). The IC includes an efficient high current switch, an oscillator, output drive logic, and a micropower 8-bit full-scale current output DAC. This device allows for simple 'bits-to-lamp current control' via Standard SPI Mode or Pulse Mode interfaces.
The regulator operates from a logic supply voltage of 3.3V or 5V and features a battery supply voltage pin operating from 4.5V to 30V. It utilizes a 200kHz switching frequency to minimize magnetic component size and includes open lamp protection, grounded or floating lamp configurations, and active low shutdown functionality.
| Wide Battery Input Range | 4.5V to 30V |
|---|---|
| Switching Frequency | 200kHz typical |
| DAC Resolution | 8 Bits |
| Supply Current (Typical) | 6mA |
| Shutdown Supply Current | 35nA |
| Package Type | 16-pin narrow SO |
The control circuitry operates from a logic supply voltage of 3.3V or 5V.
The operating ambient temperature range is 0°C to 100°C.
The LT1186F draws 6mA typical quiescent current.