ICL7135CAI+ - 4.5-Digit Dual-Slope ADC | Analog Devices
MPN： ICL7135CAI+ ✓ 啟用中ICL7135CAI+ 概覽
A dual-slope ADC is an integrating analog-to-digital converter that measures input voltage by comparing a controlled integration period with a reference-driven de-integration period. This technique belongs to the wider ADC, data-converter, and semiconductor hierarchies. It is especially useful when low-frequency measurements require good noise rejection and predictable behavior with slow-changing sensor signals.
The ICL7135CAI+ provides a 4.5-digit measurement range, a 2.0000 V full-scale capability, and ±1 count in 20,000 accuracy. Its high-impedance differential input structure supports source impedances that would otherwise degrade simple resistive divider measurements. Multiplexed BCD outputs reduce the number of connections required when driving a seven-segment display, while the 28-SSOP format supports compact panel-meter and laboratory-instrument layouts.
The manufacturer describes the ICL7135 as a monolithic converter designed around a dual-slope conversion architecture. Differential input handling is central to its measurement behavior because it permits a sensor signal to be measured relative to a return or reference node. The 4.5-digit result format supports a maximum reading of 19,999 counts, while the stated ±1-count-in-20,000 accuracy establishes the conversion-error target for the product family.
Typical uses include digital panel meters, temperature measurement instruments, laboratory readouts, process monitoring, portable meters, and industrial measurement equipment. The device is particularly appropriate when a regulated reference, controlled input excitation, and a dedicated display interface are available. It is less suitable for high-speed waveform acquisition, communications, or applications requiring many conversions per second.
For implementation, follow the manufacturer pin-description and application tables when assigning the reference, integrator, input, clock, and display signals. Stable reference and input components are central to repeatable dual-slope measurements, while correct grounding and protection are necessary when external sensors connect to the measurement terminals.
This product record combines the official ICL7135 product information with distributor package, ordering, and availability details. It also distinguishes the closely related ICL7135CAI- temperature-grade variant from the ICL7135CMH-D, which uses a different 44-pin package, so engineers can assess replacement options without treating package-incompatible parts as drop-in substitutes.
直接替換替代品，適用於 ICL7135CAI+ — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
ICL7135CAI-
✅ 直接替換📋 參考替代品（不在目錄中）
ICL7135CAI+ 最大額定值與電氣特性
| Converter Type | Dual-slope A/D converter |
| 解析度 | 4.5 digits, 0.5-count increment |
| Maximum Reading | 19,999 counts |
| Conversion Accuracy | ±1 count in 20,000 |
| Full-Scale Voltage | 2.0000 V |
| Input Configuration | High-impedance differential input |
| Output Format | Multiplexed BCD |
| Display Compatibility | 7-segment display driver |
| 封裝 | 28-SSOP, 5.30 mm width |
| 安裝類型 | Surface mount |
| RoHS 狀態 | unknown |
| REACH Status | unknown |
| AEC-Q100 Qualification | unknown |
ICL7135CAI+ 28-ssop, 5.30 mm width 腳位配置指南
ICL7135CAI+（28-ssop, 5.30 mm width 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： ICL7135CAI+.
請參閱 資料表 以查看完整腳位配置。
典型應用
ICL7135CAI+ 適用於 6 應用s: Digital Panel Meters, Temperature Measurement Instruments, Laboratory Digital Readouts, Industrial Process Monitoring, Portable Metering, Precision Resistance Measurement.
Digital Panel Meters
The ICL7135CAI+ fits digital panel meters because its 4.5-digit format, multiplexed BCD outputs, and 19,999-count maximum reading are directly suited to seven-segment display readouts. The converter measures a differential input and presents a stable decimal display without requiring a separate display-control microcontroller. Its ±1 count in 20,000 accuracy gives the instrument a clear precision target, while the 2.0000 V full-scale capability provides a defined conversion range. In a production design, follow the manufacturer reference and display-driver tables so the converter clock, integrator, display multiplexing, and bypass connections follow the intended timing.
推薦
Temperature Measurement Instruments
The ICL7135CAI+ is appropriate for thermometers and temperature-monitoring instruments that measure slow-changing analog temperatures. Its high-impedance differential input can support a resistive sensor or conditioned bridge signal, while the 4.5-digit resolution and ±1 count in 20,000 accuracy provide useful display precision. A regulated reference and stable sensor excitation remain necessary to preserve the converter’s stated performance. The part is better suited to a readable laboratory or industrial temperature readout than to a thermal waveform system requiring rapid sampling, and the complete measurement chain should be calibrated as a single system.
推薦
Laboratory Digital Readouts
The ICL7135CAI+ can form the measurement core of a laboratory digital readout when the instrument needs a stable 4.5-digit result and a direct display interface. Its dual-slope conversion method, differential input, and multiplexed BCD output simplify a display-oriented instrument without requiring a separate digital interface. The 2.0000 V full-scale range is well suited to normalized sensor outputs, but engineers should account for the complete signal path, including input filtering, reference accuracy, and integrator components. For bench equipment, printed calibration instructions and clearly identified input terminals improve usability alongside the converter’s high measurement precision.
推薦
Industrial Process Monitoring
The ICL7135CAI+ is well matched to industrial process monitoring points where a slowly changing pressure, level, or resistance signal must be shown locally. The differential input reduces sensitivity to shared return-path disturbance, and the 4.5-digit readout can resolve one count in 20,000. Its multiplexed BCD outputs support a direct seven-segment display for panel-mounted equipment. The converter is not the right choice for fast process transients, so the input path should provide sufficient filtering and the design should verify that the measured bandwidth is appropriate. Robust grounding, surge protection, and stable references are especially important in industrial environments.
推薦
Portable Metering
The ICL7135CAI+ can support portable, battery-powered meter designs when a low-noise digital readout is more important than conversion speed. Its dual-slope architecture and differential measurement are useful for stable readings from resistive probes, and the multiplexed BCD output directly serves a compact display. The product’s 4.5-digit resolution and ±1 count in 20,000 accuracy help distinguish small measurement changes in field equipment. Designers should use the manufacturer’s power, reference, and clock guidance to manage energy use and start-up behavior, and should add suitable input protection for handheld probes or external sensor connections.
推薦
Precision Resistance Measurement
The ICL7135CAI+ is suitable for a precision ohmmeter or resistance-measurement front end when the test current and reference network are carefully designed. The high-impedance differential input helps accommodate the source impedance of a resistive probe, and the 4.5-digit conversion format is appropriate for laboratory resistance readings. Its stated accuracy must be treated as converter accuracy rather than complete instrument accuracy because lead resistance, excitation drift, contact quality, and reference stability also affect the result. A four-wire arrangement, guarded traces, and calibrated current source can extend practical measurement performance without changing the converter package.
推薦
推薦產品摘要
工程參考資料，適用於 ICL7135CAI+ — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ICL7135CAI- |
|---|---|---|
| Package | 28-SSOP | 28-SSOP |
| Brand | Analog Devices | Analog Devices |
| Converter Type | Dual-slope A/D converter | Dual-slope A/D converter |
| Resolution | 4.5 digits | 4.5 digits |
| Maximum Reading | 19,999 counts | 19,999 counts |
| Conversion Accuracy | ±1 count in 20,000 | ±1 count in 20,000 |
| Full-Scale Voltage | 2.0000 V | 2.0000 V |
| Input Configuration | High-impedance differential input | High-impedance differential input |
| Output Format | Multiplexed BCD | Multiplexed BCD |
主要差異化特點
- Direct multiplexed display interface (對比ICL7135CMH-D)
- Defined precision for display-oriented measurement (對比ICL7135CAI-)
- High-impedance differential measurement (對比ICL7135CMH-D)
設計說明
Do not substitute the ICL7135CMH-D for the ICL7135CAI+ on an existing board. The former uses a 44-pin QFP package while the target uses a 28-SSOP package, so the land pattern, pin numbering, and PCB outline are incompatible. For a no-redesign replacement, verify the complete ICL7135CAI- ordering information and operating grade against the schematic and assembly drawings.
Assign the reference, integrator, input, clock, control, and multiplexed display nets strictly from the manufacturer pin-description table. The 28-SSOP footprint provides little package spacing, so route sensitive input and reference connections away from display multiplex lines and switching-node areas. Use a stable ground reference for the converter and connect bypass capacitors close to their specified pins to reduce supply disturbance and digital coupling.
Design the reference and supply network around the manufacturer’s application guidance because measurement accuracy depends on stable reference and integrator behavior. Confirm the exact supply limits, capacitor values, and clock requirements from the current datasheet before release. Avoid adding series impedance to the reference path or placing long, high-impedance routes beside the analog input and integrator nets.
合規資訊
The manufacturer product page and distributor results do not provide extractable RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations for the exact ICL7135CAI+ orderable suffix.
