Overview
The ICL7117CQH is a 3½ digit monolithic analog-to-digital converter (ADC) produced by Analog Devices Inc./Maxim Integrated. This device is part of the ICL7116 and ICL7117 series, which are known for their high accuracy and versatility in various measurement applications. The ICL7117CQH integrates all necessary components for analog-to-digital conversion, including display drive capability, voltage reference, and clock circuit, making it a comprehensive solution for digital panel meters and other measurement devices.
Key Specifications
| Parameter | Value |
|---|---|
| Number of Digits | 3½ |
| Input Type | True Differential |
| Input Impedance | High Impedance CMOS |
| Noise (Pk-Pk Value Not Exceeded 95% of Time) | < 15µV |
| Zero Reading Drift | < 1µV/°C |
| Scale Factor Temperature Coefficient | 1-5 ppm/°C |
| V+ Supply Current | 0.8-1.8 mA |
| Package Type | Plastic Leaded Chip Carrier (PLCC) |
| Pin Count | 44 |
Key Features
- On-board display drive capability—no external circuitry required.
- High-impedance CMOS differential inputs.
- Low noise (< 15µV P-P) without hysteresis or overrange hangover.
- True differential reference and input.
- True polarity indication for precision null applications.
- Monolithic CMOS design.
- Guaranteed first reading recovery from overrange.
- Display hold feature.
Applications
The ICL7117CQH is widely used in digital panel meter applications, including the measurement and display of analog data such as voltage, current, resistance, and temperature. It is particularly useful in industrial environments due to its ability to reject interference signals and provide accurate ratiometric measurements.
Q & A
- What is the primary function of the ICL7117CQH?
The primary function of the ICL7117CQH is to convert analog signals to digital signals for display and measurement purposes. - What type of display does the ICL7117CQH support?
The ICL7117CQH can directly drive a display, but the specific type (e.g., LED or LCD) depends on the model variant; however, the ICL7117 generally supports common anode LED displays. - What is the input impedance of the ICL7117CQH?
The input impedance of the ICL7117CQH is high, using CMOS differential inputs. - How does the ICL7117CQH handle noise and interference?
The ICL7117CQH uses a dual-slope conversion technique that automatically rejects interference signals common in industrial environments. - What is the significance of the true differential input and reference in the ICL7117CQH?
The true differential input and reference are particularly useful for making ratiometric measurements (e.g., ohms or bridge transducers). - Does the ICL7117CQH require external display drive circuitry?
No, the ICL7117CQH has on-board display drive capability and does not require external circuitry. - What is the typical supply current for the ICL7117CQH?
The typical V+ supply current for the ICL7117CQH is between 0.8 and 1.8 mA. - What is the package type of the ICL7117CQH?
The ICL7117CQH comes in a Plastic Leaded Chip Carrier (PLCC) package. - How many pins does the ICL7117CQH have?
The ICL7117CQH has 44 pins. - What are some common applications of the ICL7117CQH?
The ICL7117CQH is commonly used in digital panel meters for measuring voltage, current, resistance, and temperature.
