ADI LTC1428CS8-50#TRPBF

The LTC1428-50 is a micropower 8-bit current sink output D/A converter (DAC) with an output range of 0µA to 50µA. In 3.3V or 5V systems, the DAC IOUT pin can be biased from 2V to 10V. Supply current is only 130µA. Shutdown mode drops the supply current to 0.2µA.

The LTC1428-50 communicates with external circuitry by using one of three interface modes: standard 3-wire serial mode or one of two pulse modes. Upon power-up, the internal counter resets to 10000000B, the DAC output assumes midrange and the chip configures to 3-wire or pulse mode depending on the CS signal level.

In 3-wire mode, the system MPU can serially transfer 8-bit data to and from the LTC1428-50. In pulse mode, the upper six bits of the DAC output program for incrementonly (1-wire interface) or increment/decrement (2-wire interface) operation depending on the D|N signal level. In increment-only mode, the counter rolls over and sets the DAC to zero if the counter increases beyond full scale. In increment/decrement mode, the counter stops incrementing at full scale, stops decrementing at zero scale and does not roll over.

LTC1428-50 is available in an 8-pin SO package.

• Precision Full-Scale DAC Output Current at 25°C: 50µA ±3%
• Wide Output Voltage DC Compliance: 2V to 10V
• Wide Supply Range: 3V ≤ VCC ≤ 6.5V
• Supply Current in Shutdown: 0.2µA
• Low Supply Current: 130µA
• Available in 8-Pin SO
• Triple ModeTM Interface
  1. Standard 3-Wire Mode
  2. 1-Wire Pulse Mode Interface: Increment-Only
  3. 2-Wire Pulse Mode Interface: Increment/Decrement
• DAC Value Read Back Capability in 3-Wire Mode
• DAC Powers Up at Midrange
• DAC Contents Are Retained in Shutdown

• LCD Contrast Control
• Backlight Brightness Control
• Power Supply Voltage Adjustment
• Battery Charger Voltage/Current Adjustment
• GaAs FET Bias Adjustment
• Trimmer Pot Elimination