Dual, Temperature-Controlled Resistors with Internally Calibrated Monitors and Password Protection

The DS1856 dual, temperature-controlled, nonvolatile (NV) variable resistors with three monitors consists of two 256-position, linear, variable resistors; three analog monitor inputs (MON1, MON2, MON3); and a direct-to-digital temperature sensor. The device provides 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.

Relative to other members of the family, the DS1856 is essentially a DS1859 with a DS1852-friendly memory map. In particular, the DS1856 can be configured so the 128 bytes of internal Auxiliary EEPROM memory is mapped into Main Device Table 00h and Table 01h, maintaining compatibility between both the DS1858/DS1859 and the DS1852. The DS1856 also features password protection equivalent to the DS1852, further enhancing compatibility between the two.

Applications

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

* SFF-8472 Compatible

* Five Monitored Channels (Temperature, VCC, MON1, MON2, MON3)

* Three External Analog Inputs (MON1, MON2, MON3) That Support Internal and External Calibration

* Scalable Dynamic Range for External Analog Inputs

* Internal Direct-to-Digital Temperature Sensor

* Alarm and Warning Flags for All Monitored Channels

* Two Linear, 256-Position, Nonvolatile Temperature-Controlled Variable Resistors

* Resistor Settings Changeable Every 2°C

* Three Levels of Security

* 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

* -40°C to +95°C Operating Temperature Range