ADN2850

The ADN2850 provides dual channel, digitally controlled programmable resistors²with resolution of 1024 positions. These devices perform the same electronic adjustment function as a mechanical rheostat. The ADN2850's versatile programming via a standard serial interface allows sixteen mode of operations and adjustment including scratch pad programming, memory storing and retrieving, increment/decrement, log taper adjustment, wiper setting readback, and extra user defined EEMEM.

In the scratch pad programming mode, a specific setting can be programmed directly to the RDAC²register, which sets the resistance between terminals W-and-B. The RDAC register can also be loaded with a value previously stored in the EEMEM1 register. The value in the EEMEM can be changed or protected. When changes are made to the RDAC register, the value of the new setting can be saved into the EEMEM. Thereafter, such value will be transferred automatically to the RDAC register during system power ON. It is enabled by the internal preset strobe. EEMEM can also be retrieved through direct programming and external preset pin control. Other key mode of operations include linear step increment and decrement commands such that the setting in the RDAC register can be moved UP or DOWN, one step at a time. For logarithmic changes in wiper setting, a left/right bit shift command adjusts the level in ±6dB steps. The ADN2850 is available in the 5mm x 5mm LFCSP-16 Lead Frame Chip Scale and thin TSSOP-16 packages. All parts of ADN2850 are guaranteed to operate over the extended industrial temperature range of -40°C to +85°C.