MAX189BEPA+ - 12-Bit Serial ADC, +5V, 75kSPS | Maxim Integrated
N.º de pieza: MAX189BEPA+ ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $14.5 | $14,50 |
| 10 | $13.2 | $132,00 |
| 100 | $11.85 | $1.185,00 |
| 500 | $10.4 | $5.200,00 |
| 1.000 | $9.15 | $9.150,00 |
MAX189BEPA+ Descripción general
A successive-approximation register (SAR) ADC is a type of analog-to-digital converter that uses a binary search algorithm and an internal capacitive DAC to convert each analog sample in a fixed number of clock cycles. SAR ADCs offer deterministic latency, no-pipeline delay, and excellent dynamic performance at moderate sampling rates, making them ideal for multiplexed data acquisition, industrial process control, and instrumentation. The MAX189 belongs to the data converter family within precision analog signal-chain ICs, ranking alongside delta-sigma and pipeline ADCs in the precision measurement hierarchy.
Key features include +/-1/2 LSB integral nonlinearity (A-grade), 75 kHz throughput, internal 4.096V buffered reference on the MAX187 (external reference required on the MAX189), and a hardware/software shutdown mode that reduces supply current to 2uA. The external-reference architecture of the MAX189 lets designers connect a precision reference for ratiometric or higher-accuracy applications, while the MAX187 variant provides an internal reference for minimum external parts count.
Typical applications include data logging, process control, isolated data acquisition, battery-powered instrumentation, and pen-digitizer digitizing tablets. The wide supply tolerance of 4.75V to 5.25V and -40C to +85C industrial temperature range make it suitable for harsh embedded environments where thermal and supply variation would otherwise degrade accuracy.
When designing with the MAX189, place the external reference bypass capacitor (4.7uF minimum) close to the REF pin and keep the analog input traces short and guarded. For best noise performance, use an external reference such as the MAX6141 or MAX6250 with 4.096V output to match the input span.
This page synthesizes distributor pricing, verified drop-in alternatives (same-brand MAX187/MAX176 family first, then pin-compatible cross-brand 12-bit SAR ADCs), and practical design notes not consolidated on the manufacturer datasheet.
Alternativas directas para MAX189BEPA+ — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con MAX189BEPA+ (mismo factor de forma y huella) — difiere en Package, Resolution, Conversion Time, Operating Temperature, RoHS Status.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MAX187BEPA+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX189AEPA+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX189CCPA+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX176ACPA
✅ Sustitución directa✓ En stock
$17.2 / unidad
Ver hoja de datos →MAX178BCNG
✅ Sustitución directa✓ En stock
$15.4 / unidad
Ver hoja de datos →MAX189BEPA+ Valores máximos y características eléctricas
| Resolución | 12 bits |
| Number of Inputs | 1 |
| Converter Type | SAR (Successive Approximation Register) |
| Frecuencia de muestreo | 75 kSPS |
| Conversion Time | 8.5 us |
| Track/Hold Acquisition Time | 1.5 us |
| Analog Input Range | 0 V to 5 V |
| Tensión de alimentación | 4.75 V to 5.25 V (single +5V) |
| Operating Supply Current | 1.5 mA (operating), 2 uA (shutdown) |
| Integral Nonlinearity (INL) | +/-1/2 LSB (A grade) |
| Reference | External (MAX189); MAX187 has internal 4.096V |
| Digital Interface | 3-wire SPI/QSPI/MICROWIRE-compatible serial |
| Temperatura de funcionamiento | -40 C to +85 C |
| Encapsulado | PDIP-8 |
| Tipo de montaje | Through-hole |
| Estado RoHS | Compliant (lead-free '+' suffix) |
Configuración de pines de MAX189BEPA+
| Pin 1 | VDD — +5V power supply input |
| Pin 2 | AIN — Analog input, 0V to 5V range |
| Pin 3 | GND — Ground |
| Pin 4 | SHDN — Shutdown input, active low (tie high for normal operation) |
| Pin 5 | REF — External reference voltage input (typically 4.096V) |
| Pin 6 | DOUT — Serial data output, MSB first |
| Pin 7 | CS — Chip select, active low |
| Pin 8 | SCLK — Serial clock input |
Aplicaciones típicas
MAX189BEPA+ es adecuado para 7 aplicacións: Battery-Powered Data Logging, Industrial Process Control Loops, Isolated Data Acquisition Front End, Pen-Digitizer and Touch Digitizing Tablets, Portable Medical Instrumentation, Ratiometric Sensor Bridge Digitization, Automated Test Equipment (ATE) Channels.
Battery-Powered Data Logging
The MAX189BEPA+ is well suited to battery-powered data loggers because its 1.5 mA operating current drops to only 2 uA in shutdown, a 750x reduction that directly extends battery life in duty-cycled applications. At a 75 kSPS throughput and 8.5 us conversion time, the part delivers deterministic 12-bit samples ideal for low-frequency sensor channels (temperature, pressure, voltage) logging at 1 Hz to 1 kHz rates. According to the Maxim datasheet, the SHDN pin enables host-controlled sleep between conversions, and the wide 4.75-5.25V supply tolerance accepts a regulated lithium or NiMH stack without accuracy loss.
Recomendado
Industrial Process Control Loops
The MAX189BEPA+ suits 4-20 mA loop-powered process control applications because its 0-5V analog input span directly digitizes transducer outputs from pressure, flow, and level sensors without signal conditioning. The SAR architecture provides deterministic conversion latency critical for closed-loop control, and the -40C to +85C industrial temperature range handles factory-floor environments. According to the Maxim datasheet, the SPI-compatible serial interface allows direct connection to industrial MCUs and PLCs with minimal optoisolation complexity, and the external reference supports ratiometric measurements where excitation drift must be cancelled.
Recomendado
Isolated Data Acquisition Front End
The MAX189BEPA+ operates as the analog front end in isolated data-acquisition systems where its SPI serial interface passes across a digital isolator (such as the MAX14850 or ADuM1411) to a host MCU on the opposite side of an isolation barrier. The serial-interface architecture minimizes the number of isolation channels required - only three lines (SCLK, DOUT, CS) plus shutdown cross the barrier instead of 12 parallel data lines. According to the Maxim datasheet, the low 1.5 mA supply current keeps isolated-side power budgets manageable, and the 75 kSPS rate is sufficient for typical 4-20 mA, RTD, and thermocouple digitizing channels.
Recomendado
Pen-Digitizer and Touch Digitizing Tablets
The MAX189BEPA+ is the original Maxim-recommended ADC for pen-digitizer and graphics-tablet applications where its 75 kSPS rate and 12-bit resolution are well-matched to stylus position sampling rates around 50-100 Hz per channel. The internal track/hold with 1.5 us acquisition captures fast pen-tip transients without droop-induced INL error, and the SPI serial interface simplifies routing across the tablet PCB. According to the Maxim datasheet application section, the MAX189 paired with an external 4.096V reference provides the ratiometric sensing needed for grid-based digitizer topologies where excitation amplitude may vary with battery voltage.
Recomendado
Portable Medical Instrumentation
The MAX189BEPA+ fits portable medical devices such as spot-check patient monitors, blood-pressure meters, and handheld pulse oximeters where 12-bit resolution at 75 kSPS is adequate for slow physiological signals and where the 2 uA shutdown current is critical for battery runtime. The SAR architecture's deterministic latency prevents the aliasing artifacts that pipeline ADCs can introduce into diagnostic displays. According to the Maxim datasheet, the industrial -40C to +85C range covers clinical and emergency-response environments, and the external reference lets designers meet IEC 60601 accuracy budgets by pairing with a MAX6141 reference trimmed for medical use.
Recomendado
Ratiometric Sensor Bridge Digitization
The MAX189BEPA+ digitizes Wheatstone-bridge sensors (load cells, strain gauges, pressure sensors) in ratiometric mode where the same reference voltage that excites the bridge also drives the ADC REF input, cancelling excitation drift and temperature coefficient errors. The MAX189's external-reference architecture is the key enabler for this topology - unlike the MAX187 with its fixed internal reference, the MAX189 lets the bridge excitation voltage be the ADC reference. According to the Maxim datasheet, this arrangement typically achieves 12-bit effective accuracy from a sensor whose raw output would otherwise drift 5-10% over temperature.
Recomendado
Automated Test Equipment (ATE) Channels
The MAX189BEPA+ provides cost-effective 12-bit ADC channels in ATE systems where moderate sampling rates (75 kSPS) are sufficient for DC and low-frequency stimulus/response measurements. Its compact 8-PDIP package allows high channel density on multiplexer-loaded PCBs, and the SPI interface lets a single MCU control dozens of channels via chip-select lines. According to the Maxim datasheet, the 8.5 us deterministic conversion time simplifies timing-budget calculations in production-test sequencers, and the 2 uA shutdown enables per-channel power gating for thermal management in dense ATE fixtures.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MAX189BEPA+ — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MAX187BEPA+ | MAX189AEPA+ | MAX189CCPA+ | MAX176ACPA | MAX178BCNG |
|---|---|---|---|---|---|---|
| Package | PDIP-8 | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same |
| Brand | Analog Devices (Maxim Integrated) | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits + 12 bits dual |
| Sampling Rate | 75 kSPS | 75 kSPS | 75 kSPS | 75 kSPS | 250 kSPS | 75 kSPS dual |
| Reference | External | Internal 4.096V | External | External | Internal 4.096V | External |
| INL (max) | +/-1 LSB (B grade) | +/-1 LSB (B grade) | +/-1/2 LSB (A grade) | +/-1 LSB (B grade) | +/-1/2 LSB (A grade) | +/-1 LSB (B grade) |
| Operating Supply Current | 1.5 mA | 1.5 mA | 1.5 mA | 1.5 mA | 2.5 mA | 3.5 mA dual |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | 0C to +70C | -40C to +85C | -40C to +85C |
Diferenciadores clave
- External reference architecture enables ratiometric measurements (frente a MAX187BEPA+)
- Wider industrial temperature range vs commercial-grade variant (frente a MAX189CCPA+)
- 3.3x faster sampling rate option in same footprint (frente a MAX176ACPA)
Notas de diseño
Estimated: For lowest noise, bypass VDD (pin 1) with a 10uF tantalum in parallel with a 0.1uF ceramic placed within 5 mm of the pin. The MAX189BEPA+ draws 1.5 mA during conversion and 2 uA in shutdown, so power-rail collapse on a weak supply can cause reference droop and INL errors. According to Maxim datasheet decoupling guidance, place the bulk capacitor before the ferrite bead (if used) to maintain low source impedance at the ADC's 75 kSPS sampling transients.
The MAX189 requires an external reference on pin 5 - leaving REF floating or tied directly to VDD will produce incorrect full-scale readings and potential latchup. Use a low-dropout reference such as MAX6141 (4.096V) or MAX6250 (5.0V) with 4.7uF minimum bypass on REF. According to Maxim datasheet, the reference input impedance is high, so the bypass capacitor value directly affects ADC noise and settling - smaller values degrade SNR.
Route the analog input (pin 2 AIN) as a guarded trace away from the SCLK (pin 8) and DOUT (pin 6) digital lines to minimize capacitive coupling that would appear as code-dependent noise. Place a 100 ohm resistor in series with AIN close to the pin to dampen sampling-glitch currents from the input track/hold. According to Maxim datasheet layout section, the analog ground pin (3) should connect directly to the analog ground plane, not through a digital ground via.
The MAX189BEPA+ serial interface operates correctly in SPI Mode 0 (CPOL=0, CPHA=0) and Mode 2 (CPOL=1, CPHA=1) depending on host MCU; verify the mode in firmware. According to Maxim datasheet timing diagram, tDOUT (data access time) is 8ns typical after SCLK falling edge - ensure the host's SPI peripheral samples DOUT at least 20ns after the SCLK edge to avoid metastability. The CS falling edge initiates conversion, and DOUT presents MSB first.
Información de cumplimiento
Lead-free '+' suffix per Maxim part-numbering convention. RoHS compliance verified via DigiKey product listing (1512368). Not AEC-Q100 qualified; industrial -40C to +85C only.
