General Description
The DS1858 dual temperature-controlled nonvolatile (NV) variable resistors with three monitors consists of two 50kΩ 256-position linear variable resistors, three analog monitor inputs (MON1, MON2, MON3), and a direct-to-digital temperature sensor. The device pro vides an ideal method for setting and temperature-compensating bias voltages and currents in control applications using minimal circuitry. The variable resistor settings are stored in EEPROM memory and can be accessed over the 2-wire serial bus.

Features
♦ Five Total Monitored Channels (Temperature, VCC, MON1, MON2, MON3)
♦ Three External Analog Inputs (MON1, MON2, MON3)
♦ Internal Direct-to-Digital Temperature Sensor
♦ Two 50kΩ, Linear, 256-Position, Nonvolatile Temperature-Controlled Variable Resistors
♦ Resistor Settings Changeable Every 2°C
♦ Access to Monitoring and ID Information Configurable with Separate Device Addresses
♦ 2-Wire Serial Interface
♦ Two Buffers with TTL/CMOS-Compatible Inputs and Open-Drain Outputs
♦ Operates from a 3.3V or 5V Supply
♦ SFF-8472 Compatible

Applications
Optical Transceivers
Optical Transponders
Instrumentation and Industrial Controls
RF Power Amps
Diagnostic Monitoring