MAX145ACUA - 12-Bit 108ksps 1-Ch SAR ADC, 8-µMAX | Analog Devices
N.º de pieza: MAX145ACUA ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $9.88 | $9,88 |
| 10 | $8.95 | $89,50 |
| 100 | $7.42 | $742,00 |
| 500 | $6.18 | $3.090,00 |
| 1.000 | $5.1 | $5.100,00 |
MAX145ACUA Descripción general
A SAR (successive-approximation-register) ADC is a type of analog-to-digital converter that uses a binary search through an internal DAC to convert an analog input to a digital code one bit per clock cycle. SAR ADCs combine very low latency (one conversion cycle, no pipeline delay), excellent DC accuracy, and simple serial interfaces. They sit within the broader category of data converters (ADC/DAC) under signal-chain ICs and are typically the right choice when a system needs deterministic single-shot sampling at moderate speeds, low power, and small footprint - as opposed to high-speed pipeline ADCs or integrating ADCs optimized for very low noise at slow rates.
The MAX145 family delivers 108 ksps sampling at 0.9 mA (with VDD = +3 V) and drops to just 100 µA at 10 ksps and 10 µA at 1 ksps. Power-down current is 0.2 µA, making the part ideal for battery-powered and portable data-acquisition systems. The internal 2.5 MHz typ oscillator and the integrated track/hold eliminate the need for an external precision clock and a front-end sample-and-hold amplifier.
Typical applications include pen-digitizers, portable instrumentation, data loggers, isolated measurement front-ends, and 4–20 mA loop-powered sensors. The MAX145 is also well suited for medical monitoring accessories and industrial process control modules that must operate for long periods from a small battery.
When designing with the MAX145ACUA, ensure the analog input remains within the pseudo-differential common-mode range and that REF+ / REF- decoupling is placed as close as possible to the pins. For systems that require true bipolar or fully differential inputs, prefer the MAX144 (single-ended) or a dedicated delta-sigma ADC instead.
This page consolidates distributor pricing, drop-in alternatives, and engineering notes that supplement the manufacturer datasheet, including selection guidance versus the MAX144 and competitor 8-pin SAR ADCs.
Alternativas directas para MAX145ACUA — 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 MAX145ACUA (mismo factor de forma y huella) — difiere en Package, Conversion Time, Resolution, Architecture, Number of Channels.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MAX144ACUA
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX145AEUA
✅ Sustitución directa✓ En stock
$5.49 / unidad
Ver hoja de datos →MAX145BEUA
✅ Sustitución directa ⚠️ Especificaciones sin verificar✓ En stock
$5.92 / unidad
Ver hoja de datos →MAX144BEUA
✅ Sustitución directa ⚠️ Especificaciones sin verificar✓ En stock
$3.21 / unidad
Ver hoja de datos →MAX145AEUA+T
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX145ACUA+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX144AEUA+T
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MAX144BCUA
✅ Sustitución directa✓ En stock
$7.91 / unidad
Ver hoja de datos →MAX145ACUA Valores máximos y características eléctricas
| Manufacturer | Analog Devices / Maxim Integrated |
| Part Number | MAX145ACUA |
| Función | 12-bit SAR Analog-to-Digital Converter (ADC) |
| Number of Channels | 2 (1 pseudo-differential per the MAX145 family) |
| Number of Bits | 12 |
| Frecuencia de muestreo | 108 ksps |
| Architecture | Successive Approximation Register (SAR) |
| Supply Voltage (VDD) | +2.7 V to +5.25 V |
| Supply Current (108 ksps, VDD = 3.6 V) | 0.9 mA typ |
| Supply Current (10 ksps, VDD = 3.6 V) | 100 µA typ |
| Supply Current (1 ksps, VDD = 3.6 V) | 10 µA typ |
| Power-Down Current | 0.2 µA typ |
| Conversion Time | 7.4 µs (incl. track/hold acquisition) |
| Wake-Up Time | 2.5 µs |
| Digital Interface | 3-wire SPI/QSPI/MICROWIRE-compatible serial |
| Internal Clock | Yes (on-chip, 2.5 MHz typ) |
| Track/Hold | Internal |
| Reference Input | External (REF+, REF-) |
| Encapsulado | 8-pin µMAX / uSOP |
| Operating Temperature (A grade) | 0 °C to +70 °C |
| Tipo de montaje | Surface Mount |
| Estado RoHS | Compliant (lead-free variants) |
Configuración de pines de MAX145ACUA
| Pin 1 | VDD — Positive supply input, +2.7 V to +5.25 V |
| Pin 2 | AIN0 — Analog input channel 0 (positive input for pseudo-differential operation) |
| Pin 3 | AIN1 — Analog input channel 1 (negative input for pseudo-differential operation, or second single-ended input on MAX144) |
| Pin 4 | GND — Ground / 0 V reference |
| Pin 5 | REF- — Negative reference voltage input (typically GND) |
| Pin 6 | REF+ — Positive reference voltage input (sets full-scale range) |
| Pin 7 | DOUT — Serial data output (SPI/QSPI/MICROWIRE-compatible) |
| Pin 8 | SCLK/active-low CS — Serial clock input / active-low chip select (3-wire serial interface) |
Aplicaciones típicas
MAX145ACUA es adecuado para 6 aplicacións: Portable Data-Acquisition Modules, Pen Digitizers and Touch Panels, Industrial Process-Control Isolated Front-Ends, Medical Monitoring Accessories, Battery-Powered Sensor Hubs and IoT Nodes, Handheld Test and Measurement Instruments.
Portable Data-Acquisition Modules
The MAX145ACUA fits portable data-acquisition modules because of its 108 ksps throughput and ultra-low power profile: 0.9 mA at full speed and just 10 µA at 1 ksps. Its pseudo-differential input rejects common-mode noise from long sensor cables, while the internal 2.5 MHz clock and track/hold eliminate external analog components. Placed between a sensor bridge and a low-power MCU, it provides deterministic single-shot latency that pipeline or sigma-delta ADCs cannot match, and the 0.2 µA power-down current extends battery life when the host sleeps between conversions.
Recomendado
Pen Digitizers and Touch Panels
The MAX145ACUA is well suited to pen-digitizer and touch-panel front ends because of its 108 ksps sampling and 7.4 µs conversion time, which captures stylus position updates at rates above the human-perceptible latency threshold. The pseudo-differential input rejects electrical noise injected from the LCD backlight and panel drivers, while the 3-wire SPI interface connects directly to common microcontroller serial ports. Compared with integrating ADCs, the SAR architecture provides immediate conversions without digital averaging delay, which is critical for real-time coordinate tracking.
Recomendado
Industrial Process-Control Isolated Front-Ends
The MAX145ACUA's 12-bit resolution and pseudo-differential input make it ideal for isolated industrial process-control front ends reading 4-20 mA loop-powered sensors and thermocouple pre-amplifier outputs. The +2.7 V to +5.25 V single-supply operation simplifies isolated DC-DC design, while automatic power-down (0.2 µA) limits loop current draw during idle. Combined with a digital isolator on the SPI lines, the result is a compact, low-noise isolated ADC channel with deterministic latency for safety and instrumentation loops.
Recomendado
Medical Monitoring Accessories
The MAX145ACUA serves medical monitoring accessories such as handheld pulse oximeters, blood-pressure cuffs, and personal ECG event recorders that require low power, small size, and reliable DC accuracy. The 12-bit SAR architecture gives instantaneous single-conversion latency, which simplifies R-wave detection and event-trigger algorithms, and the 0.9 mA active current extends battery life across multi-day monitoring sessions. Its pseudo-differential input also suppresses common-mode interference from mains-powered bedside equipment.
Recomendado
Battery-Powered Sensor Hubs and IoT Nodes
IoT sensor hubs and remote wireless nodes benefit from the MAX145ACUA's tiered power profile - 0.9 mA at 108 ksps, 100 µA at 10 ksps, 10 µA at 1 ksps, and 0.2 µA in power-down - which scales automatically with throughput demand. Combined with a low-power MCU that wakes the ADC only for scheduled samples, average current stays well below 50 µA, supporting multi-year coin-cell operation for HVAC, leak, and occupancy sensors. The SPI-compatible serial interface shares bus pins with most low-power MCUs.
Recomendado
Handheld Test and Measurement Instruments
Handheld digital multimeters and field service instruments benefit from the MAX145ACUA's combination of 12-bit resolution and low supply current when measuring analog signals from sensors and transducers in the field. The internal track/hold eliminates an external sample-and-hold stage, simplifying the analog front end, while the 8-pin µMAX package saves board space in compact handheld enclosures. The pseudo-differential input improves common-mode rejection when measuring across long test leads in noisy environments.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MAX145ACUA — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MAX144ACUA | MAX145AEUA | MAX145ACUA+ | MAX144BCUA |
|---|---|---|---|---|---|
| Brand | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated |
| Package | 8-pin µMAX / uSOP | 8-pin µMAX / uSOP - same | 8-pin µMAX / uSOP - same | 8-pin µMAX / uSOP - same | 8-pin µMAX / uSOP - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sampling Rate | 108 ksps | 108 ksps | 108 ksps | 108 ksps | 108 ksps |
| Number of Input Channels | 1 pseudo-differential | 2 single-ended | 1 pseudo-differential | 1 pseudo-differential | 2 single-ended |
| Supply Voltage | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V | +2.7 V to +5.25 V |
| Supply Current (108 ksps, 3.6 V) | 0.9 mA typ | 0.9 mA typ | 0.9 mA typ | 0.9 mA typ | 0.9 mA typ |
| Power-Down Current | 0.2 µA typ | 0.2 µA typ | 0.2 µA typ | 0.2 µA typ | 0.2 µA typ |
| Operating Temperature | 0 °C to +70 °C (A grade) | 0 °C to +70 °C | -40 °C to +85 °C (E grade) | 0 °C to +70 °C | -40 °C to +85 °C (B grade) |
| Serial Interface | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE | 3-wire SPI/QSPI/MICROWIRE |
Diferenciadores clave
- Pseudo-differential input architecture (frente a MAX144ACUA)
- Commercial temperature grade option (frente a MAX145AEUA)
- Lead-free RoHS-compliant drop-in version (frente a MAX145ACUA+)
Notas de diseño
Use the MAX145ACUA's automatic power-down mode aggressively in battery applications: drive SCLK/static low between conversions so the internal oscillator and bias circuitry shut down. At 1 ksps the part draws only 10 µA typ, and power-down current is 0.2 µA typ, so average system current can drop by two orders of magnitude versus always-on operation. Decouple VDD with a 0.1 µF ceramic placed within 5 mm of the VDD pin, plus a 1 µF bulk capacitor if the source impedance is high.
Keep the analog input traces (AIN0, AIN1) and reference traces (REF+, REF-) short and surrounded by a grounded copper pour to minimize coupled digital noise. The REF+ pin sets full scale; for best DNL/INL use a low-noise reference such as the MAX6126 or MAX6129 with a 0.1 µF + 10 µF decoupling pair. Avoid running SCLK or DOUT traces parallel to AIN traces to prevent digital coupling into the analog front end.
Do not exceed VDD on the analog inputs; with VDD = 5.25 V and REF = 2.5 V, AIN0 must remain within 0 V to REF. For pseudo-differential operation, ensure AIN1 stays within the part's common-mode range to avoid linearity errors. The MAX145 has one pseudo-differential channel - if two true single-ended inputs are needed, use the MAX144 family, not a second MAX145. Finally, the 'A' temperature grade is commercial (0 °C to +70 °C); for industrial environments specify the 'E' suffix part (MAX145AEUA) which is pin-compatible.
Información de cumplimiento
Lead-free RoHS-compliant variants available with '+' suffix (MAX145ACUA+). Industrial-grade variants (MAX145AEUA) available for -40 °C to +85 °C operation. AEC-Q100 qualification not applicable for this commercial-grade ADC.
