ICL7135CPI+ 4.5-Digit BCD ADC | Maxim Integrated
料号： ICL7135CPI+ ✓ 量产中ICL7135CPI+ 概述
A dual-slope integrating ADC is a signal-conditioning and conversion category that averages an unknown voltage over a fixed integration interval and compares the result with a reference. Within the broader hierarchy, the ICL7135CPI+ is an analog-to-digital converter, an integrated data-conversion circuit, and a semiconductor intended for precision measurement and display instrumentation. Dual-slope conversion is especially useful when resistance, temperature, or slow-changing sensor signals are converted into stable numerical readings.
The principal feature set includes 4.5-digit resolution, multiplexed binary-coded decimal outputs for four digit-drive positions, and high-impedance differential inputs. The ±1-count-in-20,000 accuracy specification provides a useful figure for panel meters and digital voltmeters. Its 2.0000 V full-scale capability lets the designer define the measurable range with an external reference. The multiplexed BCD architecture reduces the number of dedicated output signals required to drive a visual display.
Technically, the converter separates its analog and digital functions. The analog section develops an integrated representation of the differential input, while the digital section contains counters, timing control, input interfaces, output interfaces, and the logic that coordinates each measurement cycle. This integrating approach favors noise rejection and repeatable readings when the input changes slowly, although conversion time is longer than with a high-speed successive-approximation ADC.
Typical uses include digital panel meters, digital voltmeters, laboratory instruments, temperature-measurement panels, process-monitoring displays, and weighing equipment. The ICL7135CPI+ is especially appropriate when a readable decimal display, differential input, and deterministic integration cycle are more important than high conversion throughput. The BCD outputs are intended to interface naturally with digit drivers and display-oriented instrument designs.
Designers should verify reference accuracy, input-common-mode range, integration-cycle timing, digit-driver polarity, and display multiplexing against the manufacturer datasheet before layout release. Because this is a through-hole 28-pin DIP device, its physical package differs from surface-mount display ADC families and should not be treated as a board-level equivalent. The manufacturer datasheet remains the controlling source for pin names, timing, and electrical limits.
This page consolidates the verified distributor price, package information, function description, available drop-in candidates, comparison parameters, and practical design cautions. That engineering-focused context helps buyers distinguish a genuine 28-pin replacement from a merely similar 4.5-digit converter and supports faster qualification without replacing the manufacturer datasheet as the authoritative design reference.
直接替换替代料： ICL7135CPI+ ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： ICL7135CPI+ （相同外形与封装尺寸） ——差异在于 Output Format, Package.
ICL7135CPI
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ICL7135CN
✅ 直接替换 ⚠️ 规格未核验联系询价
查看数据手册 →ICL7135CNG4
✅ 直接替换📋 参考替代料（不在目录中）
ICL7135CPI-2
✅ 直接替换📋 参考替代料（不在目录中）
TLC7135C
✅ 直接替换📋 参考替代料（不在目录中）
ICL7135CPI+ 最大额定值与电气特性
| Converter Type | 4.5-digit dual-slope analog-to-digital converter |
| Output Format | Multiplexed binary-coded decimal (BCD) |
| Conversion Accuracy | ±1 count in 20,000 |
| Full-Scale Range | 2.0000 V |
| Input Architecture | Differential, high impedance |
| 封装 | 28-pin plastic DIP |
| 引脚数量 | 28 pins |
| Digit Drive Outputs | 4 multiplexed digit-drive positions |
| BCD Outputs | Multiplexed B1, B2, B4, and B8 outputs |
| 工作温度 | 0 °C to +70 °C |
| Screening Level | Commercial |
| RoHS 状态 | RoHS compliant |
| Input Voltage | -2 V to +2 V |
| Conversion Method | Dual-slope integrating |
| Display Interfaces | Multiplexed digit drive and BCD outputs |
ICL7135CPI+ 28-pin plastic dip 引脚配置指南
ICL7135CPI+（28-pin plastic dip 封装）的引脚配置。 该模拟元件具有输入、输出和电源引脚。请参阅制造商数据手册以了解失调调零、补偿和使能引脚配置。适用于信号调理和放大器电路。
暂无详细引脚数据： ICL7135CPI+.
请参阅 数据手册 以查看完整引脚配置。
典型应用
ICL7135CPI+ 适用于 6 应用s: Digital Panel Meter, Digital Voltmeter, Laboratory Measurement Instrument, Temperature Measurement Panel, Industrial Process Monitoring, Weighing Scale Display.
Digital Panel Meter
The ICL7135CPI+ fits a digital panel meter because it combines 4.5-digit resolution with multiplexed BCD outputs and four digit-drive positions for a decimal display. Its stated ±1-count-in-20,000 accuracy provides a useful starting point for stable instrument readouts, while the dual-slope method is appropriate for slowly changing panel signals such as pressure, level, or temperature. The 2.0000 V full-scale capability supports scaled analog inputs when paired with suitable front-end conditioning. In implementation, the converter drives the display digit lines and presents the selected BCD digit through its multiplexed outputs. The designer must verify digit polarity and timing in the manufacturer pin table. Because this is a 28-pin DIP device, the meter should be built around a through-hole footprint rather than a compact surface-mount display ADC.
推荐
Digital Voltmeter
The ICL7135CPI+ is well matched to a digital voltmeter requiring a readable decimal result and differential analog measurement. The advertised accuracy of ±1 count in 20,000 can support a precision panel-meter format, while the 2.0000 V full-scale range defines the nominal measurement span. A typical implementation scales the unknown voltage into the differential input range, uses an accurate external reference, and formats the multiplexed BCD result through display drivers. The dual-slope conversion method is useful when the measured voltage is relatively stable because it averages the input during each measurement cycle. Calibration should include reference and front-end offset rather than attributing every error to the converter. Verify the input common-mode range and complete conversion timing from the manufacturer datasheet before finalizing the analog board.
推荐
Laboratory Measurement Instrument
The ICL7135CPI+ can support laboratory instruments that prioritize stable numerical readings over high conversion speed. Its 4.5-digit dual-slope architecture provides a displayed result at a rate suitable for manual or slowly updating laboratory equipment, and the ±1-count-in-20,000 specification provides a useful baseline for instrument accuracy. The high-impedance differential input also suits measurement systems in which the source impedance must not significantly load the signal. In a typical instrument, the input network scales and filters the unknown voltage, the converter completes successive integration cycles, and the multiplexed BCD outputs update the display. Component tolerances, reference stability, leakage, and input settling determine the final uncertainty. The 28-PDIP package supports serviceable and prototype-oriented laboratory hardware, although a modern surface-mount implementation may require a different converter family.
推荐
Temperature Measurement Panel
The ICL7135CPI+ can serve as the display-oriented conversion stage in a temperature measurement panel. A temperature sensor produces a slowly changing analog signal, making the converter's integrating dual-slope process suitable for a stable numerical indication. The 4.5-digit BCD format allows a decimal reading to be displayed directly, while the stated accuracy of ±1 count in 20,000 supports useful resolution after calibration. A practical circuit would condition the sensor signal, apply the appropriate scaling and reference, and use the ICL7135 digit-drive outputs to operate the display. Linearization and cold-junction compensation, if required, must be implemented separately or in surrounding circuitry. The DIP package makes the converter practical for industrial panel prototypes and serviceable instruments, while the final design should verify the temperature coefficient of the reference and the input network.
推荐
Industrial Process Monitoring
The ICL7135CPI+ is appropriate for industrial process monitoring where a plant variable must be presented as a clear local measurement. The differential input can accept a conditioned transmitter or sensor signal, and the multiplexed BCD outputs reduce the connection burden compared with a converter providing separate parallel digits. The stated ±1-count-in-20,000 accuracy helps preserve useful process resolution, but reference drift, electrical noise, grounding, and sensor calibration remain critical in an industrial environment. The converter is typically installed beside the display and connected to a protected analog input network. Use careful grounding and isolation techniques to prevent process transients from disturbing the measurement cycle. Because the ICL7135CPI+ is a 28-pin DIP converter, it is most natural in legacy or serviceable equipment rather than a new compact surface-mount controller. Validate EMC, input protection, and operating-temperature requirements independently.
推荐
Weighing Scale Display
The ICL7135CPI+ can support a weighing-scale display because load-cell signals change slowly and require stable integration before being shown to the operator. The 4.5-digit dual-slope conversion format maps naturally to a decimal mass readout, while the BCD and digit-drive outputs simplify connection to display hardware. The converter's ±1-count-in-20,000 accuracy provides a relevant starting point for scale resolution, although excitation stability, bridge balance, amplifier noise, and calibration determine real scale performance. In a typical design, the bridge signal is amplified and filtered before entering the differential input, and the converter repeatedly integrates the conditioned voltage. Mechanical shock and settling time may require averaging beyond one conversion cycle. The 28-PDIP format suits serviceable commercial and laboratory scales. Engineers should confirm input impedance, reference accuracy, and integration timing before selecting passive and protection components.
推荐
推荐产品汇总
工程参考数据： ICL7135CPI+ ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | ICL7135CPI | ICL7135C | ICL7135CNG4 | ICL7135CPI-2 | TLC7135C |
|---|---|---|---|---|---|---|
| Package | 28-PDIP | 28-PDIP | 28-PDIP | DIP-28 | 28-PDIP | 28-PDIP |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Texas Instruments |
| Resolution | 4.5 digits | 4.5 digits | 4.5 digits | 4.5 digits | 4.5 digits | 4.5 digits |
| Conversion Method | Dual-slope integrating | Dual-slope integrating | Dual-slope integrating | Dual-slope integrating | Dual-slope integrating | Dual-slope integrating |
| Output Format | Multiplexed BCD with 4 digit-drive positions | Multiplexed BCD display output | Multiplexed BCD display output | Multiplexed BCD display output | Multiplexed BCD display output | D1-D4 digit drive and multiplexed B1, B2, B4, B8 |
关键差异点
- Explicitly documented complete-replacement candidate （对比 ICL7135CNG4)
- Exact ordering code with verified commercial distributor availability （对比 TLC7135C)
- Integrated 4.5-digit display conversion （对比 General-purpose flash ADCs)
- Cross-brand design option with matching converter architecture （对比 Maxim Integrated ICL7135CNG4)
设计说明
Treat the 28-pin DIP footprint as a through-hole layout constraint and verify every socket or PCB pad against the manufacturer pin table before fabrication. The verified distributor listings establish the 28-PDIP package but do not supply the complete pin-name sequence in the retrieved snippets. Do not copy a generic 28-pin DIP pinout: analog inputs, reference connections, clock signals, digit drives, and multiplexed BCD outputs have specific assignments. For new boards, preserve the same land pattern only when the candidate part's mechanical drawing and pin functions have both been checked.
Design the analog input path for the converter's high-impedance differential inputs. Keep input traces short, protect them from switching-node radiation, and use guarding where leakage from board contamination or flux residue could disturb the measurement. The verified data specifies differential inputs and a -2 V to +2 V input-voltage range, but it does not provide input impedance or common-mode limits. Those two specifications must be obtained from the manufacturer datasheet before selecting source impedance, protection leakage, and input filter components.
Separate the reference-quality supply path from noisy display and logic currents. The device uses a 2.0000 V full-scale range, so reference stability directly affects measurement accuracy; bypass the reference and analog supply nodes locally with values recommended by the manufacturer datasheet. Because the supplied data does not state the supply-voltage range or quiescent current, do not select a regulator or capacitors from inference. Check decoupling stability, reference ripple, and ground-return paths against the complete application guidance before releasing the schematic.
Do not approve a replacement solely because it is described as a 4.5-digit dual-slope ADC or uses a 28-pin package. The verified cross-reference explicitly calls ICL7135CNG4 completely replaceable, while TLC7135C offers a cross-brand option with a similar display architecture. Even for those candidates, compare pin names, analog and logic supply levels, reference polarity, clock requirements, conversion timing, digit-drive polarity, and BCD output timing. A package-count match does not establish electrical drop-in compatibility.
合规信息
The verified component listing explicitly states RoHS compliant and identifies commercial screening. No verified evidence was supplied for REACH, AEC-Q100, lead-free status, halogen-free status, or conflict-minerals compliance. A listing's RoHS statement does not automatically establish the other declarations.
