MAX133CPL+ - 3.75-Digit 50ms DMM ADC | Analog Devices
MPN： MAX133CPL+ ✓ 啟用中MAX133CPL+ 概覽
An integrating ADC is a specialized data-conversion category used where a measured analog input is converted by integrating it over a defined interval. The MAX133 belongs to the broader ADC → data-converter IC → data-acquisition semiconductor hierarchy. Its integration-based measurement method and multi-pin mixed-signal interface are intended for precision panel-meter and multimeter products rather than general-purpose high-speed signal acquisition.
The primary verified characteristics are 3.75-digit resolution, ±40,000-count internal resolution, a 50 ms conversion cycle, and a commercial operating grade of 0°C to +70°C. Distributor listings identify the device as a 40-pin PDIP, through-hole part. The Analog Devices product page lists the MAX133 as a production 3.75-digit DMM circuit and provides the manufacturer datasheet, documentation, tools, and product-selection resources.
The MAX133 family is designed for integrating A/D converters used in 3.75-digit multimeters, data loggers, and weigh scales. The guard-digit feature is particularly useful for measurement systems that compensate offset or residual noise during autozero or tare operations. Because conversion completes in 50 ms, the device is appropriate for slow-changing measurements where stable integration is more useful than high sampling throughput.
A typical implementation places the MAX133 at the center of a digital meter front end, where it digitizes a conditioned differential measurement while supporting zero or tare correction. Its through-hole PDIP-40 package favors leaded, serviceable, and instrument-style assemblies. The package also requires careful routing of the analog input, reference, supply, digital-control, and display-interface signals across 40 pins.
The principal design consideration is that the MAX133 is a dedicated DMM conversion circuit rather than a general-purpose ADC. System designers should follow the manufacturer datasheet for input range, reference requirements, input impedance, excitation behavior, and display-interface timing. PCB layout should preserve a quiet analog signal path, provide stable reference routing, and place bypass and input-network components close to their associated pins.
This page consolidates verified manufacturer and distributor information, same-family replacement guidance, package and sourcing details, and practical selection considerations. It also distinguishes documented facts from electrical data that was not present in the supplied records, helping engineers make a preliminary design decision before reviewing the complete MAX133 datasheet.
直接替換替代品，適用於 MAX133CPL+ — 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。
此系列的變體
與下列產品可直接替換的同系列型號： MAX133CPL+ （相同外形與佔位） — 差異在於 Temperature Grade, Package.
MAX133EPL+
✅ 直接替換📋 參考替代品（不在目錄中）
MAX131EPL+
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →MAX132CPL+
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MAX130CPL+
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MAX134CPL+
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →MAX133CPL+ 最大額定值與電氣特性
| ADC Type | Integrating A/D converter for 3.75-digit multimeters |
| Display Resolution | 3.75 digits |
| Internal Resolution | ±40,000 counts |
| Guard Digit | 1 digit |
| Conversion Time | 50 ms |
| Input Type | Differential |
| 封裝 | 40-pin PDIP |
| 安裝類型 | Through-hole |
| Terminal Count | 40 terminals |
| 工作溫度範圍 | 0°C to +70°C |
| Temperature Grade | Commercial |
MAX133CPL+ 40-pin pdip 腳位配置指南
MAX133CPL+（40-pin pdip 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： MAX133CPL+.
請參閱 資料表 以查看完整腳位配置。
典型應用
MAX133CPL+ 適用於 6 應用s: Digital Multimeter Front End, Industrial Panel Meter, Data Logger and Recorder, Weigh-Scale Instrumentation, Bench Test and Measurement Instrument, Process Monitoring and Control.
Digital Multimeter Front End
The MAX133CPL+ is appropriate for the measurement engine of a digital multimeter because it provides 3.75-digit display resolution, ±40,000-count internal resolution, and a dedicated 50 ms conversion cycle. The guard-digit capability allows autozero or tare correction to one-tenth of a displayed count on a 4000-count reading. It can therefore support stable resistance, voltage, or current measurements when paired with a suitable front-end network, reference, display driver, and keyboard controller. The main design trade-off is its 0°C to +70°C commercial operating range; MAX133EPL+ may be preferable when operation down to −40°C is required.
推薦
Industrial Panel Meter
The MAX133CPL+ can serve as the A/D element in an industrial panel meter when the displayed quantity changes slowly and a stable integrated measurement is more important than high sampling speed. Its ±40,000-count internal resolution provides additional guard-digit resolution beyond the nominal 4000-count display, while the 50 ms conversion interval is practical for continuously refreshed panel indications. The circuit should be paired with an input conditioner and stable reference, and the layout must keep sensitive analog routing away from display and control signals. Its commercial 0°C to +70°C range suits controlled indoor equipment, but an extended-temperature variant may be needed in harsher industrial enclosures.
推薦
Data Logger and Recorder
For a low-speed data logger, the MAX133CPL+ provides a dedicated path for converting conditioned analog measurements into a three-and-three-quarter-digit result. The ±40,000-count internal resolution and one-digit guard function make it useful when offset correction, autozero, or tare must be applied to a 4000-count displayed value. Its 50 ms conversion time supports periodic measurements without imposing the timing demands of a high-speed general-purpose ADC. Design work should verify the complete input and reference ranges from the manufacturer datasheet and account for the through-hole 40-pin package. The 0°C to +70°C rating must also be checked against the logger's enclosure temperature.
推薦
Weigh-Scale Instrumentation
The MAX133CPL+ is suitable for a basic weigh-scale measurement channel when the bridge signal is conditioned into the converter's specified differential input range. The ±40,000-count internal resolution supports a 3.75-digit displayed result and provides guard-digit capacity for zeroing or tare operations, both of which are useful when load-cell offsets must be removed. A 50 ms conversion interval is appropriate for a stable, human-readable weight display rather than a high-speed sorting system. The implementation should follow the manufacturer's excitation, reference, and analog-filtering guidance, and it should include adequate settling time between range or zero changes.
推薦
Bench Test and Measurement Instrument
The MAX133CPL+ can support the measurement channel of a bench instrument that displays calibrated DC values and does not require high-frequency sampling. Its dedicated 3.75-digit DMM architecture, 50 ms conversion time, and guard-digit capability simplify the relationship between the measured value and the displayed count. The through-hole PDIP-40 package is particularly convenient for prototype and instrument-style assemblies where component accessibility and hand rework are useful. Before final selection, engineers should verify the allowable input span, reference behavior, supply requirements, and error specifications because those details were not included in the supplied distributor records.
推薦
Process Monitoring and Control
The MAX133CPL+ is applicable to slow-changing process variables displayed by industrial monitoring equipment, provided its specified input and reference limits match the sensing system. The 50 ms conversion cycle provides frequent updates without requiring a rapid successive-approximation ADC, while the ±40,000-count internal resolution can improve resolution beyond the basic displayed count. Autozero or tare may be used to compensate sensor offset in a controlled measurement path. Because the device is commercial grade from 0°C to +70°C, enclosure heating or an extended-temperature MAX133-family option may be needed where ambient conditions exceed that range.
推薦
推薦產品摘要
工程參考資料，適用於 MAX133CPL+ — 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 | MAX133EPL+ | MAX131EPL+ | MAX132CPL+ | MAX130CPL+ |
|---|---|---|---|---|---|
| Package | 40-pin PDIP | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
主要差異化特點
- Commercial-grade operating range with an extended-temperature family option (對比MAX133EPL+)
- Documented 50 ms conversion time (對比MAX131EPL+)
- Dedicated 3.75-digit DMM conversion architecture (對比MAX134CPL+)
設計說明
Route the differential measurement input, reference, and supply connections using the layout in the official MAX133 datasheet. Keep the input-network components close to their associated MAX133CPL+ pins, avoid sharing high-current paths with sensitive analog traces, and provide a quiet return path. Because the verified records establish a 40-pin PDIP but do not provide the complete pin table, do not finalize the PCB until all pin numbers and exposed functions have been checked against the manufacturer document.
Treat the MAX133 as an integrating measurement converter rather than a high-speed ADC. Its 50 ms conversion time is suited to stable, slowly changing signals, so input filtering should suppress ripple without creating excessive settling delay between readings. Verify that the chosen filter preserves the required measurement bandwidth and that the reference remains stable throughout each conversion interval. Use the manufacturer's input, reference, and grounding guidance when setting the filter and acquisition timing.
Do not treat a shared 40-pin PDIP footprint as proof that every MAX13x or MAX134 variant is electrically interchangeable. The Analog Devices product page states that MAX133 and MAX134 differ functionally, while comparison records indicate differences between MAX131, MAX133, and MAX134. Before substitution, compare input range, supply arrangement, reference, conversion timing, output coding, and control signals directly against the manufacturer datasheets for both devices.
Power bypass placement is especially important in a meter because the analog input, reference, display, and control circuitry may share a board area. Follow the exact supply-pin and component-selection recommendations in the MAX133 datasheet, including the required capacitor types, voltage ratings, and effective capacitance. Place high-frequency bypass capacitors at the relevant pins and keep supply routing away from the differential input and reference nodes to minimize conversion errors and displayed-digit instability.
合規資訊
The supplied verified records do not explicitly state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is recorded as not applicable because the MAX133CPL+ is identified as a commercial-grade DMM circuit rather than an automotive-qualified device.