FEATURES • Electrically Programmable Analog Device CMOS Technology • Operates from 2V, 3V, 5V to 10V • Flexible basic circuit building block and design element • Very high resolution -- average e-trim voltage resolution of 0.1mV • Wide dynamic range -- current levels from 0.1mA to 3000mA • Voltage adjustment range from 1.000V to 3.000V in 0.1mV steps • Proven, non-volatile CMOS technology • Typical 10 years drift of less than 2mV • Usable in voltage mode or current mode • High input impedance -- 1012W • Very high DC current gain -- greater than 109 • Device operating current has positive temperature coefficient range and negative temperature coefficient range with cross-over zero temperature coefficient current level at 68mA • Tight matching and tracking of on-resistance between different devices with e-trim • Wide dynamic resistance matching range • Very low input currents and leakage currents • Low cost, monolithic technology • Application-specific or in-system programming modes • Optional user software-controlled automation • Optional e-trim of any standard/custom configuration • Micropower operation • Available in standard PDIP, SOIC and hermetic CDIP packages • Suitable for matched-pair balanced circuit configuration • Suitable for both coarse and fine trimming as well as matched MOSFET array applications APPLICATIONS • Precision PC-based electronic calibration • Automated voltage trimming or setting • Remote voltage or current adjustment of inaccessible nodes • PCMCIA based instrumentation trimming • Electrically adjusted resistive load • Temperature compensated current sources and current mirrors • Electrically trimmed/calibrated current sources • Permanent precision preset voltage level shifter • Low temperature coefficient voltage and/or current bias circuits • Multiple preset voltage bias circuits • Multiple channel resistor pull-up or pull-down circuits • Microprocessor based process control systems • Portable data acquisition systems • Battery operated terminals and instruments • Remote telemetry systems • E-trim gain amplifiers • Low level signal conditioning • Sensor and transducer bias currents • Neural networks GENERAL DESCRIPTION ALD1123E/ALD1121E are monolithic quad/dual EPAD® (Electrically Programmable Analog Device) N-channel MOSFETs with electrically adjustable threshold (turn-on) voltage. The ALD1123E/ALD1121E are precision matched and adjusted (e-trimmed) at the factory resulting in quad/dual MOSFETs that are highly matched in electrical characteristics. The ALD1123E has four (4) separate source pins. SN1, SN2 share a common substrate pin V-1 which has to be connected to the most negative voltage potential. Likewise, SN3, SN4 share a common substrate pin V-2 which has to be connected to the negative voltage potential for SN3, SN4. The ALD1121E has two (2) separate source pins (SN1, SN2). Both SN1, SN2 share a common substrate pin 4 which has to be connected to the most negative voltage potential. Using an ALD1123E/ALD1121E MOSFET array is simple and straight forward. The MOSFETs function in electrical characteristics as n-channel MOSFETs except that all the devices have exceptional matching to each other. For a given input voltage, the threshold voltage of a MOSFET device determines its drain on-current, resulting in an on-resistance characteristic that can be precisely preset and then controlled by the input voltage very accurately. Since these devices are on the same monolithic chip, they also exhibit excellent tempco matching characteristics. These MOSFET devices have very low input currents, and as a result a very high input impedance (>10 12 Ohm). The gate voltage from a control source can drive many MOSFET inputs with practically no loading effects. Used in precision current mirror or current multiplier applications, they can be used to provide a current source over a 100 nA to 3 mA range, and with either a positive, negative or zero tempco.
