Overview
The DDC118IRTCTG4, produced by Texas Instruments, is a 20-bit, octal channel, current-input analog-to-digital (A/D) converter. This device is designed to integrate both current-to-voltage and A/D conversion, allowing it to directly connect to low-level current output devices such as photodiodes. The DDC118 features dual-switched integrator front-ends for each of the eight inputs, enabling continuous current integration. It operates in two modes: Low-Power and High-Speed, with adjustable full-scale ranges and integration times, making it versatile for various precision measurement applications.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| Analog Input Range | 12 | - | 350 | pC |
| Resolution | - | - | 20 bits (FORMAT = 1), 16 bits (FORMAT = 0) | - |
| Data Rate | 2.5 | - | 3.125 | kSPS |
| Integration Time (TINT) | 50 | - | 1,000,000 | µs |
| System Clock Input (CLK) | 4 | - | 19.2 | MHz |
| Analog Power-Supply Voltage (AVDD) | 4.75 | - | 5.25 | V |
| Digital Power-Supply Voltage (DVDD) | 2.7 | - | 5.25 | V |
| Total Power Dissipation per Channel | 13.5 | - | 25 | mW |
| Operating Temperature Range | -40 | - | 85 | °C |
Key Features
- Dual-switched integrator front-end for continuous current integration.
- Adjustable full-scale ranges from 12 pC to 350 pC.
- Adjustable integration times from 50 µs to 1 s.
- Low-Power mode with 13.5 mW per channel and High-Speed mode with 18 mW per channel.
- Serial interface for daisy-chaining in multi-device systems.
- Single-supply operation with +5V analog supply and +2.7V to +5.25V digital supply.
- Operating temperature range of -40°C to +85°C.
- Available in a QFN-48 package.
Applications
- CT Scanners
- Photodiode Sensors
- Infrared Pyrometers
- Liquid/Gas Chromatography
Q & A
- What is the resolution of the DDC118? The DDC118 has a resolution of 20 bits in FORMAT = 1 and 16 bits in FORMAT = 0.
- What are the adjustable full-scale ranges of the DDC118? The adjustable full-scale ranges are from 12 pC to 350 pC.
- What are the operating modes of the DDC118? The DDC118 operates in Low-Power and High-Speed modes.
- What is the power dissipation per channel in Low-Power mode? The power dissipation per channel in Low-Power mode is 13.5 mW.
- How does the DDC118 handle integration and A/D conversion? The DDC118 uses dual-switched integrators to allow continuous current integration while one set of integrators is being digitized by the onboard A/D converter.
- What is the operating temperature range of the DDC118? The operating temperature range is -40°C to +85°C.
- What package type is the DDC118 available in? The DDC118 is available in a QFN-48 package.
- Can the DDC118 be daisy-chained? Yes, the DDC118 has a serial interface designed for daisy-chaining in multi-device systems.
- What are some common applications of the DDC118? Common applications include CT scanners, photodiode sensors, infrared pyrometers, and liquid/gas chromatography.
- How does the test mode function in the DDC118? In test mode, the inputs are disconnected from the integrators, allowing for the measurement of a zero input signal or the transfer of packets of charge to the integrators.
