The ICL7126 is a high performance, very low power 31/2-digit, A/D converter from Intersil. All the necessary active devices are contained on a single CMOS IC, including seven segment decoders, display drivers, reference, and clock. The ICL7126 is designed to interface with a liquid crystal display (LCD) and includes a backplane drive. The supply current of 100µA is ideally suited for 9V battery operation. The ICL7126 brings together an unprecedented combination of high accuracy, versatility, and true economy. It features auto-zero to less than 10µV, zero drift of less than 1µV/oC, input bias current of 10pA maximum, and rollover error of less than one count. The versatility of true differential input and reference is useful in all systems, but gives the designer an uncommon advantage when measuring load cells, strain gauges and other bridge-type transducers. And finally the true economy of single power operation allows a high performance panel meter or multi-meter to be built with the addition of only 10 passive components and a display. The ICL7126 can be used as a plug-in
The ICL7126 is a 3½‑digit, low‑power, single‑chip A/D converter designed for battery‑operated panel meters and multimeters. It integrates segment decoders, display drivers, reference, and clock on a single CMOS IC and can directly drive an LCD backplane.
The datasheet includes detailed electrical specifications, pinout diagrams, typical application schematics, and design guidelines such as auto‑zero performance, noise levels, and package dimensions. It also outlines operating temperature ranges, supply current, and recommended oscillator frequencies for 50/60 Hz rejection.
| Typical Input Bias Current | 1 pA (typical) |
|---|---|
| Low Power Dissipation | < 1 mW |
| Rollover Error | < 1 count |
| Noise | < 15 µV p‑p |
| Battery Life (9 V) | 8,000 hours typical |
| Operating Temperature Range | 0 °C to 70 °C |
The datasheet lists a typical input bias current of 1 pA.
Each conversion cycle consists of 4,000 counts (1,000 counts for auto‑zero, 1,000 for signal integrate, up to 2,000 for de‑integrate).
The device is designed for 9 V battery operation with a supply current of 100 µA.