The DDC112 is a dual input, wide dynamic range, charge-digitizing analog-to-digital (A/D) converter with 20-bit resolution. Low-level current output devices, such as photosensors, can be directly connected to its inputs. Charge integration is continuous as each input uses two integrators; while one is being digitized, the other is integrating. For each of its two inputs, the DDC112 combines current-to-voltage conversion, continuous integration, programmable full-scale range, A/D conversion, and digital filtering to achieve a precision, wide dynamic range digital result. In addition to the internal programmable full-scale ranges, external integrating capacitors allow an additional user-settable full-scale range of up to 1000pC. To provide single-supply operation, the internal A/D converter utilizes a differential input, with the positive input tied to VREF. When the integration capacitor is reset at the beginning of each integration cycle, the capacitor charges to VREF. This charge is removed.
The DDC112 provides dual current inputs, 20‑bit resolution, and a programmable full‑scale range up to 1000 pC. It integrates charge measurement, digital filtering, and a serial output interface for cascading multiple devices.
The device is offered in SO‑28 and TQFP‑32 packages, supports single‑supply operation, and includes detailed electrical, mechanical, and absolute‑maximum specifications for designers.
| Resolution | 20‑bit |
|---|---|
| Conversion Rate | 2‑3 kHz |
| Supply Voltage | 4.75 V to 5.25 V |
| Package Options | SO‑28 or TQFP‑32 |
The DDC112 can convert at a rate of 2 to 3 kHz.
The device is offered in SO‑28 and TQFP‑32 surface‑mount packages.
The DDC112 operates from a single supply of 4.75 V to 5.25 V.