Overview
The ICL7135CN, produced by Texas Instruments, is a high-precision 4.5-digit analog-to-digital (A/D) converter. This monolithic device utilizes dual-slope conversion, offering reliability and accuracy with ±1 in 20,000 count accuracy and a 2.0000V full-scale capability. It features high impedance differential inputs, nearly ideal differential linearity, true ratiometric operation, auto-zero, and auto-polarity. The device is designed for easy interface with external display drivers and microprocessors, making it ideal for use in microprocessor-based data acquisition and control systems.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| Zero Input Reading | -0.0000 | ±0.0000 | +0.0000 | Digital Reading |
| Full Scale Reading | +0.9995 | +0.9999 | +1.0000 | Digital Reading |
| Linearity over ± Full Scale | 0.5 | 1 | - | Digital Count Error |
| Rollover Error | 0.5 | 1 | - | Digital Count Error |
| Input Bias Current | - | 1 pA | 10 pA | pA |
| Zero Drift | - | - | 0.5 µV/°C | µV/°C |
| Voltage Supply | 4 V | - | 6 V | V |
| Operating Temperature | 0°C | - | 70°C | °C |
| Package | - | - | 28-DIP (0.600", 15.24mm) | - |
Key Features
- High precision 4.5-digit A/D conversion with dual-slope integration.
- High impedance differential inputs with nearly ideal differential linearity.
- True ratiometric operation, auto-zero, and auto-polarity.
- Multiplexed BCD outputs and digit drivers for easy interface with external display drivers.
- Control signals for interfacing with UARTs or microprocessors, including STROBE, OVERRANGE, UNDERRANGE, RUN/HOLD, and BUSY lines.
- Low rollover error of ±1 count maximum.
- CMOS buffer with a common mode input voltage range and low quiescent current.
- Integrator amplifier with high linearity and output current capability.
- TTL-compatible outputs.
Applications
- Microprocessor-based data acquisition and control systems.
- Precision digital voltmeters (DVMs) and digital panel meters (DPMs).
- Industrial control and measurement systems.
- Medical and scientific instruments requiring high precision A/D conversion.
- Automated test and measurement equipment.
Q & A
- What is the precision of the ICL7135CN A/D converter?
The ICL7135CN offers ±1 in 20,000 count accuracy and a 2.0000V full-scale capability.
- What type of conversion does the ICL7135CN use?
The ICL7135CN uses dual-slope integration for A/D conversion.
- What are the key features of the ICL7135CN's input stage?
The device features high impedance differential inputs, nearly ideal differential linearity, and true ratiometric operation.
- How does the ICL7135CN interface with external devices?
The ICL7135CN provides multiplexed BCD outputs and digit drivers, along with control signals like STROBE, OVERRANGE, UNDERRANGE, RUN/HOLD, and BUSY lines for easy interface with microprocessors and UARTs.
- What is the typical input bias current of the ICL7135CN?
The typical input bias current is 1 pA, with a maximum of 10 pA.
- What is the operating temperature range of the ICL7135CN?
The operating temperature range is from 0°C to 70°C.
- What is the package type of the ICL7135CN?
The ICL7135CN is packaged in a 28-DIP (0.600", 15.24mm) package.
- What are some common applications of the ICL7135CN?
Common applications include microprocessor-based data acquisition and control systems, precision DVMs and DPMs, industrial control and measurement systems, and medical and scientific instruments.
- Does the ICL7135CN have autoranging capability?
Yes, the ICL7135CN has autoranging capability with over-and under-range signals.
- What is the typical quiescent current of the CMOS buffer in the ICL7135CN?
The CMOS buffer has a quiescent current of approximately 100 µA.
