GENERAL DESCRIPTION

The ADN2850 is a dual-channel, nonvolatile memory1, digitally controlled resistors2 with 1024-step resolution, offering guaranteed maximum low resistor tolerance error of ±8. The device performs the same electronic adjustment function as a mechanical rheostat with enhanced resolution, solid state reliability, and superior low temperature coefficient performance. The versatile programming of the ADN2850 via an SPI?-compatible serial interface allows 16 modes of operation and adjustment including scratchpad programming, memory storing and restoring, increment/decrement, ±6 dB/step log taper adjustment, wiper setting readback, and extra EEMEM1 for user-defined information such as memory data for other components, look-up table, or system identification information.

FEATURES

Dual-channel, 1024-position resolution

25 k?, 250 k? nominal resistance

Maximum ±8 nominal resistor tolerance error

Low temperature coefficient: 35 ppm/°C

2.7 V to 5 V single supply or ±2.5 V dual supply

Current monitoring configurable function

SPI-compatible serial interface

Nonvolatile memory stores wiper settings

Power-on refreshed with EEMEM settings

Permanent memory write protection

Resistance tolerance stored in EEMEM

26 bytes extra nonvolatile memory for user-defined

information

1M programming cycles

100-year typical data retention

APPLICATIONS

SONET, SDH, ATM, Gigabit Ethernet, DWDM laser diode

driver, optical supervisory systems

Mechanical rheostat replacement

Instrumentation gain adjustment

Programmable filters, delays, time constants

Sensor calibration