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 kΩ, 250 kΩ 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
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