MAX187BCPA - 12-Bit 75ksps Serial ADC + 5V | Maxim/ADI
部品番号: MAX187BCPA ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $16.55 | $16.55 |
| 10 | $14.95 | $149.50 |
| 100 | $13.2 | $1,320.00 |
| 500 | $11.85 | $5,925.00 |
| 1,000 | $10.5 | $10,500.00 |
MAX187BCPA 概要
A successive-approximation ADC (SAR ADC) is a type of data converter that uses a binary-search algorithm against an internal DAC to determine each digital output code. SAR ADCs are valued for deterministic latency, excellent DC linearity, and low power consumption relative to their throughput, which makes them the dominant choice for multiplexed data-acquisition systems, instrumentation, and process-control front-ends. The MAX187 sits in the product hierarchy of analog-to-digital converter -> data converter -> signal chain IC -> semiconductor.
Key specifications include 12-bit resolution with ±½ LSB integral nonlinearity (MAX187A grade) or ±1 LSB (MAX187B/MAX187C grades), 75 kHz throughput, 8.5 µs successive-approximation conversion time, 1.5 µs acquisition time, single +5V operation, 1.5 mA operating current, 2 µA shutdown current, and 7.5 mW typical power dissipation reducing to 10 µW in shutdown. The 8-pin DIP pinout provides VDD, GND, VREF (4.096 V buffered), AIN, SCLK, DOUT, CS, and SHDN functions, all conveniently on a 0.300 inch (7.62 mm) through-hole lead pitch.
The MAX187BCPA uses a charge-redistribution SAR architecture with an input track/hold and a laser-trimmed internal reference, achieving AC performance (SINAD and THD) suitable for instrumentation-grade measurements. The MAX187 differs from the pin-compatible MAX189 in that MAX187 integrates a 4.096 V buffered reference while MAX189 requires an external reference, so selection between the two depends on absolute-accuracy vs flexible-reference design priorities.
Typical application areas include portable data loggers, industrial process-control analog input modules, weigh scales and strain-gauge digitizers, panel meters, isolated 4-20 mA loop read-back, and battery-powered instrumentation. The 75 ksps throughput and 5V-only operation are well-matched to multiplexing multiple slow analog channels in 12-bit precision systems.
When designing with the MAX187BCPA, ensure the input source impedance is below approximately 1 kΩ to avoid ADC droop errors during the 1.5 µs acquisition window, and tie CS high between conversions to keep the device in shutdown and minimize power. A 0.1 µF decoupling capacitor placed within 5 mm of the VDD pin is required, and the internal reference should be bypassed with at least 4.7 µF at VREF to filter reference noise.
This page consolidates distributor pricing, parametric drop-in alternatives in the same 8-DIP footprint, and practical design notes from the official Maxim datasheet to help engineers evaluate the MAX187BCPA against modern 12-bit ADC alternatives.
ドロップイン代替品: MAX187BCPA — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: MAX187BCPA （同一形状・フットプリント） — 相違点: Operating Current, Package, Sampling Rate, Supply Voltage.
クイック比較ツール — 並列比較する代替部品を選択:
MAX187BCPA+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX187BEPA
✅ ドロップイン✓ 在庫あり
$9.85 / 個
データシートを見る →MAX187ACPA
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX187CCPA+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX187BEPA+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX187BCPA 最大定格＆電気的特性
| 分解能 | 12 bits |
| サンプリングレート | 75 ksps |
| Number of Channels | 1 single-ended input |
| Architecture | SAR (Successive Approximation) |
| 電源電圧 | +5 V single supply |
| Analog Input Range | 0 V to 5 V |
| Conversion Time | 8.5 µs |
| Track/Hold Acquisition Time | 1.5 µs |
| Integral Nonlinearity (MAX187B) | ±1 LSB |
| Integral Nonlinearity (MAX187A) | ±½ LSB |
| Internal Reference (MAX187) | 4.096 V buffered |
| Operating Current | 1.5 mA |
| シャットダウン電流 | 2 µA |
| Power Dissipation | 7.5 mW (operating), 10 µW (shutdown) |
| Serial Interface | 3-wire SPI/QSPI/MICROWIRE compatible |
| パッケージ | 8-PDIP (0.300 inch / 7.62 mm pitch) |
| 実装タイプ | Through-Hole |
MAX187BCPA ピン構成
| ピン 1 | VDD — +5V analog and digital supply |
| ピン 2 | AIN — Analog input (0 V to 5 V) |
| ピン 3 | SHDN — Shutdown input (active high; tie low for normal operation) |
| ピン 4 | GND — Analog and digital ground |
| ピン 5 | DOUT — Serial data output; high-Z when CS is high |
| ピン 6 | CS — Active-low chip select; falling edge initiates conversion |
| ピン 7 | SCLK — Serial clock input (SPI/QSPI/MICROWIRE) |
| ピン 8 | VREF — Buffered 4.096 V reference output; bypass with ≥4.7 µF |
主な用途
MAX187BCPA の用途: 6 件s: Portable Data Logger, Industrial Process-Control Analog Input Module, Weigh Scale and Strain-Gauge Digitizer, Panel Meter and Digital Indicator, Isolated 4-20 mA Loop Read-Back, Battery-Powered Instrumentation Front-End.
Portable Data Logger
The MAX187BCPA is well suited to battery-powered portable data loggers because it operates from a single +5V supply, consumes only 1.5 mA (2 µA in shutdown), and integrates a 4.096 V reference - eliminating an external reference IC and shrinking the BOM. With 12-bit resolution and 75 ksps throughput, the SAR core can digitize thermocouple, RTD, or strain-gauge signals at rates that exceed typical logging rates of 1-100 sps, while the 10 µW shutdown current between samples extends battery life into months.
おすすめ
Industrial Process-Control Analog Input Module
Industrial analog input modules for PLCs and DCS systems digitize 4-20 mA, 0-10 V, or thermocouple signals at 12-bit precision. The MAX187BCPA's SAR architecture offers deterministic latency (no pipeline delay), 0-5 V input range matched to 0-10 V signal conditioning dividers, and 75 ksps throughput that comfortably handles multiplexed 8/16-channel scanning. The internal 4.096 V reference provides absolute accuracy for voltage (not ratiometric) measurements, and the 8-PDIP package suits legacy through-hole backplane designs.
おすすめ
Weigh Scale and Strain-Gauge Digitizer
Load-cell and strain-gauge measurement bridges typically output millivolt-level differential signals requiring precision amplification and digitisation. The MAX187BCPA's ±1 LSB INL (B-grade) and low integral nonlinearity support better than 0.025 %FS digitisation when paired with a low-noise instrumentation amplifier front-end. The internal 4.096 V reference provides a stable, low-drift excitation reference for bridge supply, simplifying the analog chain and reducing calibration complexity in production.
おすすめ
Panel Meter and Digital Indicator
Digital panel meters require a 12-bit (or higher) ADC to display 0.1 %-accurate voltage, current, or temperature readings. The MAX187BCPA integrates an 8.5 µs SAR engine with a 4.096 V internal reference, allowing a 2-digit-trim calibration scheme at the VREF node to compensate for gain error. Through-hole 8-PDIP fits the through-hole PCB layout common in low-volume panel-meter designs, and the 3-wire serial interface connects directly to common 8051/PIC microcontrollers.
おすすめ
Isolated 4-20 mA Loop Read-Back
Reading back the current on an isolated 4-20 mA HART or analog loop requires digitising a 1-5 V sense voltage after burden resistor. The MAX187BCPA's 0-5 V input range matches the post-burden signal directly without signal inversion, and its single +5V supply can be derived from the loop-side DC-DC converter. The MAX187's low 1.5 mA operating current adds negligible error to the loop current measurement, and the SPI/MICROWIRE serial interface enables isolation with only 3 digital signals crossing the barrier.
おすすめ
Battery-Powered Instrumentation Front-End
Hand-held multimeters, portable gas detectors, and field instrumentation require the lowest possible quiescent current to extend battery life. The MAX187BCPA delivers 1.5 mA active and 2 µA in shutdown (10 µW) - among the lowest in its speed class - while providing 12-bit accuracy sufficient for 4-digit meter readouts. The SHDN pin allows power cycling between conversions, with 1.5 µs wake-and-acquisition, suitable for duty-cycled measurement at sub-1 mA average current.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: MAX187BCPA — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | MAX187BCPA+ | MAX187BEPA | MAX187ACPA | MAX187CCPA+ | MAX187BEPA+ |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 8-PDIP | 8-PDIP - same | 8-PDIP - same | 8-PDIP - same | 8-PDIP - same | 8-PDIP - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sampling Rate | 75 ksps | 75 ksps | 75 ksps | 75 ksps | 75 ksps | 75 ksps |
| Integral Nonlinearity | ±1 LSB (B-grade) | ±1 LSB (B-grade) | ±1 LSB (B-grade) | ±½ LSB (A-grade, tighter) | ±2 LSB (C-grade, looser) | ±1 LSB (B-grade) |
| Temperature Range | 0 °C to +70 °C (commercial) | 0 °C to +70 °C | -40 °C to +85 °C (industrial) | 0 °C to +70 °C | 0 °C to +70 °C | -40 °C to +85 °C (industrial) |
| Reference Type | Internal 4.096 V buffered | Internal 4.096 V | Internal 4.096 V | Internal 4.096 V | Internal 4.096 V | Internal 4.096 V |
| Shutdown Current | 2 µA | 2 µA | 2 µA | 2 µA | 2 µA | 2 µA |
| Lead-Free / RoHS | Not specified (commercial part) | Yes (lead-free, RoHS) | No (SnPb finish) | No (SnPb finish) | Yes (lead-free, RoHS) | Yes (lead-free, RoHS) |
主な差別化要因
- B-grade (±1 LSB) INL with internal 4.096 V reference in 8-PDIP （vs MAX187CCPA+)
- Commercial temperature range with non-RoHS finish (legacy part) （vs MAX187BCPA+)
- Internal buffered reference eliminates external REF IC （vs MAX189BCPA)
- 8-PDIP through-hole package with SPI/QSPI/MICROWIRE-compatible interface （vs MAX187BCWE+ (SOIC-16))
設計ノート
Power supply decoupling is critical for the MAX187BCPA's 12-bit resolution. Place a 0.1 µF ceramic capacitor within 5 mm of the VDD pin and a 10 µF bulk electrolytic or tantalum capacitor on the same supply node. Per the Maxim datasheet, VREF requires at least 4.7 µF of bypass capacitance (tantalum or ceramic) to filter internal reference noise - an undersized capacitor degrades SINAD at higher sampling rates.
Per the Maxim datasheet, an input source impedance above approximately 1 kΩ can cause ADC droop errors during the 1.5 µs acquisition window. Either buffer the AIN input with a low-output-impedance amplifier (such as MAX145) or add a 100 pF to 1 nF capacitor directly at the AIN pin to provide transient charge. Route the analog AIN trace away from the digital SCLK and CS signals to minimise digital switching noise coupling into the analog input.
Common pitfalls include: (1) leaving CS high during shutdown, which prevents the device from entering the 2 µA shutdown state - it will continue drawing 1.5 mA; (2) clocking SCLK faster than the rated 2.5 MHz maximum, which causes data corruption; (3) violating the 0-5 V analog input range when negative-going transients appear (e.g., from thermocouple wiring inductance) - clamp with a Schottky diode to GND. The MAX187 also requires the input to be settled to within ±0.5 LSB before CS falls to start conversion.
For best 12-bit AC performance, route the digital DOUT trace as a short point-to-point connection and add a 100 Ω series damping resistor at the receiver end if the cable or trace is longer than 50 mm. Synchronize SCLK with the internal conversion cycle by waiting at least 8.5 µs after CS falling edge before applying the first SCLK pulse, per the Maxim datasheet's timing diagram. Adding a small ferrite bead on the +5V supply near the IC can suppress digital switching noise on the analog reference.
コンプライアンス情報
MAX187BCPA is the legacy through-hole SnPb-finish variant; for RoHS compliance, order MAX187BCPA+ (lead-free finish) per the Maxim datasheet's part-numbering convention. AEC-Q100 not applicable (industrial/commercial temperature range, not automotive qualified). REACH/halogen/conflict-mineral status: [DATA_NEEDED: confirm via Maxim/Analog Devices environmental compliance documentation].
