MAX187CEPA - 12-Bit Serial ADC, +5V, 75ksps, DIP-8 | Maxim
Артикул: MAX187CEPA ✓ Активен| Кол-во | Цена за ед. | Итого |
|---|---|---|
| 1 | $16.55 | $16,55 |
| 10 | $14.2 | $142,00 |
| 100 | $12.05 | $1.205,00 |
| 500 | $10.5 | $5.250,00 |
| 1.000 | $9.45 | $9.450,00 |
MAX187CEPA Обзор
An ADC (analog-to-digital converter) is a mixed-signal data-acquisition component that samples a continuous analog voltage and quantizes it into a discrete digital code. Within the power management and signal-chain hierarchy, ADCs sit downstream of analog signal conditioning (op-amps, filters) and upstream of microcontrollers, DSPs, or FPGAs. The MAX187 family belongs to the successive-approximation register (SAR) ADC category, which trades conversion speed for excellent static accuracy and low power consumption, making it a workhorse for industrial process control, instrumentation, and portable data-logger designs.
Key specifications include 12-bit resolution, +/-0.5 LSB integral nonlinearity (INL) for the MAX187A grade, 75kHz (75ksps) sampling rate, 1.5mA operating supply current, and a 2uA shutdown current that lets battery-powered systems gate power between conversions. The MAX187 variant includes the internal 4.096V reference; the pin-compatible MAX189 leaves REF open for an external reference. Internal calibration circuitry holds linearity over the full operating temperature range.
Typical applications include portable instrumentation, data loggers, process-control analog front ends, weigh scales, isolated sensor digitizers, and pen-digitizer / tablet digitizing systems. The wide analog input range (0 to 5V) plus internal reference make it a single-chip solution for many industrial 4-20mA loop and thermocouple-amplifier digitizing tasks.
When designing with the MAX187CEPA, place 0.1uF decoupling close to VDD and follow the recommended REF bypass (4.7uF) to keep the internal reference quiet. Use the SHDN pin aggressively in battery systems - the 2uA quiescent current drops total system standby power dramatically versus always-on operation.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives (MAX187BEPA, MAX187ACPA+, MAX187CCPA+), and practical design notes not consolidated in the manufacturer datasheet, enabling faster engineering decisions.
Аналоги без доработки для MAX187CEPA — тот же корпус, pin-to-pin совместимость. Компоненты в других корпусах, требующие переработки PCB, исключены.
Варианты в этой серии
Модели той же серии, совместимые без доработки с MAX187CEPA (тот же форм-фактор и посадочное место) — отличается по Package, Sampling Rate, Resolution, Integral Nonlinearity (INL), Internal Reference.
Инструмент быстрого сравнения — выберите альтернативные компоненты для сравнения бок о бок:
MAX187BEPA
✅ Прямая замена✓ В наличии
$9.85 / шт.
Открыть даташит →MAX187AEPA+
✅ Прямая замена ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
MAX187CCPA+
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
MAX187CEPA+
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
MAX187BCPA+
✅ Прямая замена ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
MAX187BEPA+
✅ Прямая замена ⚠️ Характеристики не проверены📋 Справочный аналог (нет в каталоге)
MAX187CEPA Максимальные параметры и электрические характеристики
| Разрешение | 12 bits |
| Частота дискретизации | 75 ksps |
| Conversion Time | 8.5 us (successive approximation) |
| Track/Hold Acquisition | 1.5 us |
| Integral Nonlinearity (INL) | +/-0.5 LSB (MAX187A/MAX189A grade) |
| Analog Input Range | 0 V to 5 V |
| Напряжение питания | +5 V single supply (4.75 V to 5.25 V) |
| Operating Supply Current | 1.5 mA (operating) |
| Ток выключения | 2 uA |
| Internal Reference | 4.096 V buffered (MAX187 only; MAX189 requires external) |
| Serial Interface | 3-wire SPI/QSPI/MICROWIRE-compatible |
| Корпус | 8-pin PDIP (DIP-8) |
| Тип монтажа | Through-Hole |
| Temperature Grade | Industrial (C grade) |
| Power Consumption | 7.5 mW (operating); 10 uW (shutdown) |
| Статус RoHS | Compliant (MAX187CEPA+ version); non-compliant for original CEPA suffix |
Конфигурация выводов MAX187CEPA
| Контакт 1 | VIN — Analog input positive |
| Контакт 2 | AIN — Analog input (0 to 5V range) |
| Контакт 3 | GND — Ground |
| Контакт 4 | REF — Reference input/output (internal 4.096V reference on MAX187; external reference on MAX189) |
| Контакт 5 | SHDN — Shutdown input (active-high; tie low for always-on operation) |
| Контакт 6 | DOUT — Serial data output (SPI MISO) |
| Контакт 7 | CS — Chip select input (active-low) |
| Контакт 8 | VDD — +5V positive supply |
Типичное применение
MAX187CEPA подходит для 6 применениеs: Portable Battery-Powered Data Loggers, Industrial Process Control Analog Front Ends, Precision Weigh Scales and Load-Cell Digitizers, Thermocouple and Temperature Sensor Digitizing, Isolated Sensor Digitizers and Field Instrumentation, Pen Digitizer and Tablet Input Digitizing Systems.
Portable Battery-Powered Data Loggers
The MAX187CEPA's 2uA shutdown current and 1.5 mA operating current make it a strong fit for 32-bit microcontrollers and ultra-low-power data loggers. The 12-bit resolution at 75 ksps captures temperature, pressure, and battery voltage with 1 mV/LSB granularity using the internal 4.096V reference - no external reference IC needed, reducing BOM count. The 3-wire SPI interface connects directly to most low-power MCUs without glue logic. In a typical logger, the host MCU holds SHDN high only during the 8.5us conversion window, dropping quiescent drain to microamps between samples and extending coin-cell or Li-ion battery life by 10-100x versus always-on designs.
Рекомендуется
Industrial Process Control Analog Front Ends
The MAX187CEPA's 0-5V input range maps directly to industrial 4-20mA current loop shunts (250 ohm) and 0-5V transducer outputs without signal conditioning. Its +/-0.5 LSB INL (A-grade variants) and 75 ksps sampling rate deliver 12-bit accuracy for pressure, flow, and level transmitters at update rates above 1 kHz. The internal 4.096V reference simplifies isolation barrier design - the host MCU sits on the digital side and reads conversions through optocouplers, while the analog side needs only the MAX187CEPA, bypass caps, and a precision op-amp front end. This combination is widely deployed in PLC analog input modules and distributed I/O systems.
Рекомендуется
Precision Weigh Scales and Load-Cell Digitizers
Weigh scales demand 12-bit-plus resolution, low integral nonlinearity, and excellent gain stability - exactly the niche the MAX187CEPA family addresses. The internal 4.096V reference drives a load-cell bridge excited at 5V, producing a ratiometric measurement where reference drift cancels out. Combined with a low-noise instrumentation amplifier such as the MAX174AEPI, the MAX187CEPA achieves 0.05% full-scale accuracy suitable for commercial bench scales. The 75 ksps throughput oversamples mechanically slow load changes, enabling digital filtering for stable readings and tare-zero calibration in firmware.
Рекомендуется
Thermocouple and Temperature Sensor Digitizing
The MAX187CEPA accepts the 0-5V output of thermocouple amplifier chains with cold-junction compensation, digitizing type K, J, and T thermocouple readings with 1 mV/LSB resolution at the reference. For type K thermocouples spanning -200 to +1250C at 41uV/C, the MAX187CEPA's noise floor (about 0.5 LSB rms at 75 ksps) translates to roughly 0.1-0.2 C rms temperature resolution - more than adequate for HVAC, appliance, and process-temperature monitoring. The 8.5us conversion time supports multiplexed thermocouple scanning across 4-8 channels with sub-millisecond cycle times.
Рекомендуется
Isolated Sensor Digitizers and Field Instrumentation
Field-mounted instrumentation requires galvanic isolation between the sensor analog side and the 4-20mA loop or digital bus. The MAX187CEPA's 3-wire SPI interface crosses isolation barriers using three standard digital isolators (one each for CS, SCLK, DOUT), with the analog side powered by an isolated DC-DC converter. The 2uA shutdown current is critical here because the isolated side typically has only milliwatts of available power. This architecture is the canonical pattern for IEC 61508 SIL-rated safety instrumentation, where the MAX187CEPA digitizes near the sensor and only digital bits cross the barrier, eliminating analog isolation errors.
Рекомендуется
Pen Digitizer and Tablet Input Digitizing Systems
The MAX187CEPA's combination of 75 ksps sampling and 1.5us track/hold acquisition supports digitizer tablets that scan a pen position across an XY resistive or capacitive matrix. With 12-bit resolution over a 5V input range, position sensing resolution reaches 1 mV/LSB which maps to roughly 0.025 mm position accuracy on a typical 10x15 cm tablet. The SHDN pin lets the host MCU power the ADC only during active pen strokes, reducing power consumption in battery-powered stylus tablets by 90%+ versus always-on architectures. This application was one of Maxim's original target markets for the MAX187 family in the 1990s.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для MAX187CEPA — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | MAX187BEPA | MAX187AEPA+ | MAX187CCPA+ | MAX187CEPA+ | MAX187BCPA+ | MAX187BEPA+ |
|---|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | PDIP-8 (DIP-8) | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same |
| Resolution | 12 bits | 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 | 75 ksps |
| INL (max) | +/-2 LSB | +/-1 LSB (B-grade, tighter) | +/-0.5 LSB (A-grade, tightest) | +/-2 LSB (C-grade, same) | +/-2 LSB (same) | +/-1 LSB (B-grade, tighter) | +/-1 LSB (B-grade, tighter) |
| Operating Temperature Range | -40C to +85C (industrial) | -40C to +85C | -40C to +85C | 0C to +70C (commercial) | -40C to +85C | 0C to +70C (commercial) | -40C to +85C |
| Supply Current (operating) | 1.5 mA | 1.5 mA | 1.5 mA | 1.5 mA | 1.5 mA | 1.5 mA | 1.5 mA |
| Shutdown Current | 2 uA | 2 uA | 2 uA | 2 uA | 2 uA | 2 uA | 2 uA |
| Internal Reference | 4.096V (yes) | 4.096V (yes) | 4.096V (yes) | 4.096V (yes) | 4.096V (yes) | 4.096V (yes) | 4.096V (yes) |
Ключевые отличия
- Industrial temperature grade with +/-2 LSB INL at lower cost than A-grade (против MAX187AEPA+)
- Internal 4.096V reference integrated (против MAX189CEPA)
- Wide -40C to +85C industrial temperature range (против MAX187CCPA+)
Заметки по проектированию
The MAX187CEPA's 2uA shutdown current is the key power-saving feature for battery systems. Drive the SHDN pin (pin 5) high only during the 8.5us conversion + 1.5us acquisition window - typically 20-30us total per conversion - then return it low. According to the Maxim datasheet, total power drops from 7.5 mW operating to 10 uW in shutdown, a 750x reduction. Do not tie SHDN to a noisy MCU output without a 100kohm pull-down to keep the ADC enabled (default-on) during MCU reset.
Place a 0.1uF ceramic decoupling capacitor within 5mm of the VDD pin (pin 8) and a 4.7uF tantalum or ceramic bypass on the REF pin (pin 4). The internal 4.096V reference is sensitive to load transients; without proper REF bypassing the conversion noise floor can degrade by 1-2 LSB. Route analog ground (AGND) and digital ground (DGND) separately and join them at a single point at the chip's GND pin (pin 3) to avoid digital-noise coupling into the analog input.
Do not apply analog input voltages exceeding VDD (5V) or going below GND by more than 0.3V - the ESD diodes will forward-conduct and corrupt the conversion. For signals exceeding 5V, add an external resistor divider or a unity-gain buffer such as the MAX174AEPI. Also note that the SPI interface requires the host MCU to provide SCLK edges during the conversion - read the datasheet timing diagram carefully; a CS transition without the correct SCLK count produces invalid output codes.
Информация о соответствии
Original MAX187CEPA (without + suffix) is not lead-free / not RoHS compliant per Maxim legacy product designation. The MAX187CEPA+ variant (with plus suffix) is the RoHS-compliant lead-free version. Neither variant is AEC-Q100 qualified; these are commercial/industrial-grade parts not intended for automotive safety-critical applications.
