MAX1275ACTC+T - 12-Bit 1.8Msps SAR ADC | Maxim Integrated
N.º da peça: MAX1275ACTC+T ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $8.92 | $8,92 |
| 10 | $7.95 | $79,50 |
| 100 | $6.78 | $678,00 |
| 500 | $5.92 | $2.960,00 |
| 1.000 | $5.18 | $5.180,00 |
| 2.500 | $4.75 | $11.875,00 |
MAX1275ACTC+T Visão geral
Key specifications include a 1.8 Msps sampling rate, ±1 LSB INL (DNL) linearity, an internal 2.5V reference (with the option of an external reference), true-differential input bandwidth sufficient for AC measurements, and low power dissipation suitable for battery-powered and portable designs. The part supports both unipolar (0 to VREF) and bipolar (±VREF) input ranges.
An ADC (analog-to-digital converter) is a mixed-signal integrated circuit that samples a continuous-time analog signal and converts each sample into a discrete digital code. SAR (successive-approximation register) ADCs use a binary-search algorithm with an internal DAC, offering an excellent trade-off between speed, accuracy, and power consumption. The MAX1275 sits in the data-converter hierarchy: ADC -> SAR ADC -> 12-bit ADC -> low-power single-supply ADC. The 1.8 Msps throughput and 12-bit resolution place it in the mainstream precision-sensing tier above 10-bit general-purpose ADCs but below 14-/16-bit precision converters, making it well-suited for industrial control, motor control, and base-station applications.
Architecturally, the MAX1275 uses a charge-redistribution DAC together with a low-noise comparator and on-chip track/hold, achieving true-differential sampling that rejects common-mode noise - a critical feature in motor-drive and process-control environments where ground bounce and switching transients dominate. The internal 2.5V reference removes the need for an external precision reference in many designs, reducing BOM cost and PCB area, while still allowing external reference drive for tighter gain calibration.
Typical applications include industrial process control loops (4-20 mA sensor digitisation), motor control current/voltage sensing, base-station RF power-detector digitisation, data-acquisition front-ends, and handheld instrumentation. Its single 3V supply and serial interface also make it attractive for portable test gear and medical monitoring devices.
When designing with the MAX1275ACTC+T, ensure the analog and digital grounds are joined at a single point near the exposed pad, place the 0.1 µF + 10 µF decoupling pair as close as possible to AVDD/DVDD, and route the SPI signals with characteristic impedance control to avoid coupling digital noise back into the analog front-end.
This page synthesises distributor pricing, drop-in alternatives within the MAX1274/MAX1275 family and competitive cross-brand 12-bit 1.8 Msps ADCs, and practical design notes drawn from the Maxim datasheet - information not consolidated on a typical distributor product page.
Alternativas drop-in para MAX1275ACTC+T — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com MAX1275ACTC+T (mesmo formato e footprint) — diferindo em Package, Resolution, Architecture, Input Type, Sampling Rate.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
MAX1274AETC+
✅ Drop-In✓ Em estoque
$4.42 / unidade
Ver ficha técnica →MAX1275ACTC+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX1079CTC+T
✅ Drop-In ⚠️ Especificações não verificadas✓ Em estoque
$3.55 / unidade
Ver ficha técnica →MAX1275ACTC+T Classificações máximas e características elétricas
| Resolução | 12 bits |
| Taxa de amostragem | 1.8 Msps |
| Architecture | SAR (Successive Approximation) |
| Number of Input Channels | 1 (true-differential) |
| Input Type | True differential |
| Analog Supply Voltage (AVDD) | 2.7 V to 3.6 V |
| Digital Supply Voltage (DVDD) | 2.7 V to 3.6 V |
| Internal Reference | 2.5 V |
| External Reference Option | Yes |
| INL (Integral Non-Linearity) | ±1 LSB (max) |
| Digital Interface | SPI / QSPI / MICROWIRE-compatible serial |
| Input Range | 0 to VREF (unipolar) or ±VREF (bipolar) |
| Faixa de temperatura de operação | 0 °C to +70 °C (commercial) |
| Encapsulamento | 12-pin TQFN (4 x 4 mm), 0.80 mm height, MO-220 |
| Terminal Form | No-lead (HVQCCN) |
| Screening Level | Commercial |
Configuração de pinos do MAX1275ACTC+T
| Pino 1 | AIN+ — Positive analog input (true-differential) |
| Pino 2 | AIN- — Negative analog input (true-differential) |
| Pino 3 | GND — Analog ground |
| Pino 4 | REF — Reference voltage input/output (internal 2.5V) |
| Pino 5 | AVDD — Analog supply voltage (2.7V to 3.6V) |
| Pino 6 | DVDD — Digital supply voltage (2.7V to 3.6V) |
| Pino 7 | DGND — Digital ground |
| Pino 8 | CS — Chip select (active low) |
| Pino 9 | SCLK — Serial clock input |
| Pino 10 | DOUT — Serial data output |
| Pino 11 | CNVST — Conversion start input |
| Pino 12 | EP — Exposed pad - solder to analog ground |
Aplicações típicas
MAX1275ACTC+T é adequado para 6 aplicaçãos: Industrial Process Control, Motor Control Current Sensing, Base-Station RF Power Detection, Data Acquisition Systems, Handheld Test & Measurement, Medical Monitoring Equipment.
Industrial Process Control
The MAX1275ACTC+T is widely used in industrial process-control loops to digitise 4-20 mA or 0-10 V sensor signals with high accuracy. Its ±1 LSB INL delivers the DC linearity required for closed-loop PID control, while its 1.8 Msps throughput handles multiplexed multi-channel scan cycles within tens of microseconds per channel. The true-differential input stage rejects common-mode ground noise generated by motor drives and relay switching on the factory floor. Operating from a single 2.7V-3.6V supply, the device integrates easily into 3.3V PLC backplanes, while its SPI-compatible serial interface connects directly to host microcontrollers or ARM Cortex-M processors. According to the Maxim datasheet, the MAX1274/MAX1275 are explicitly recommended for process-control applications.
Recomendado
Motor Control Current Sensing
In brushless DC and servo motor drives, the MAX1275ACTC+T digitises shunt-resistor current-sense signals and back-EMF voltages with the speed and accuracy required for field-oriented control. Its 1.8 Msps sampling rate captures PWM-cycle current ripple at 20 kHz switching frequencies with substantial oversampling headroom, while its true-differential input rejects the large common-mode transients generated by the half-bridge switching. The ±1 LSB INL ensures torque-loop linearity, and the serial interface is robust against the EMI-rich environment inside an inverter enclosure. Power dissipation is low enough to run from the 3.3V rail derived from the motor-control MCU. The Maxim datasheet highlights motor control as a primary target application, validating the choice.
Recomendado
Base-Station RF Power Detection
The MAX1275ACTC+T digitises the output of RF logarithmic detectors and directional coupler sense channels in cellular and Wi-Fi base stations, supporting closed-loop transmit-power calibration. Its 1.8 Msps throughput easily handles the 100 kHz bandwidth of the detector output, while the 12-bit resolution provides 72 dB of dynamic range (10*log2(2^12)) sufficient for tracking transmit-power setpoints. The true-differential input eliminates ground-loop errors between the RF front-end and the baseband DSP board, and the internal 2.5V reference removes the need for an external precision reference. The device's serial interface streams samples directly into DSPs or FPGAs running the power-control loop. According to Maxim application notes, the MAX1275 family is recommended for base-station applications.
Recomendado
Data Acquisition Systems
In multi-channel data-acquisition systems and PC-based measurement front-ends, the MAX1275ACTC+T serves as the per-channel digitiser for strain-gauge, thermocouple, and load-cell signals. Its 1.8 Msps throughput allows each channel to oversample noisy transducer signals and apply digital filtering, while the true-differential input pair is ideal for bridge-type sensors. The internal 2.5V reference simplifies precision designs, and the SPI-compatible serial interface allows multiple MAX1275 devices to share a single bus for 8-/16-channel systems. According to the Maxim datasheet, the device's combination of speed, accuracy, and small TQFN package makes it attractive for dense DAQ boards where PCB real estate is limited.
Recomendado
Handheld Test & Measurement
Portable digital multimeters, oscilloscope front-ends, and field-test instruments benefit from the MAX1275ACTC+T's combination of 1.8 Msps throughput, 12-bit resolution, and 3V single-supply operation. Battery-powered designs appreciate the low power dissipation, while the compact 4x4 mm TQFN package fits inside handheld enclosures. The true-differential input eliminates the need for input signal conditioning on many sensor types, and the internal reference reduces the BOM for cost-sensitive consumer test gear. The serial interface connects directly to low-cost Cortex-M0 microcontrollers, keeping the total BOM under tight targets. Maxim datasheet application information validates portable instrumentation as a target use case.
Recomendado
Medical Monitoring Equipment
The MAX1275ACTC+T supports medical monitoring devices such as patient monitors, pulse oximeters, and ECG front-ends where precision low-noise digitisation is essential. Its true-differential input rejects mains-frequency common-mode interference from the patient environment, while its 12-bit resolution captures the small dynamic range of bioelectric signals (typically 1 mV amplitude). The 1.8 Msps throughput is more than sufficient for ECG bandwidths (typically 0.05-150 Hz) and pulse-oximetry sample rates, leaving processing headroom for digital filtering and motion-artifact rejection algorithms. The single 3V supply runs from common battery chemistries, and the SPI interface simplifies connection to medical-grade microcontrollers. Always verify IEC 60601 compliance of the complete medical device; the ADC itself is not a medical-grade qualification.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para MAX1275ACTC+T — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | MAX1274AETC+ | MAX1275ACTC+ | MAX1079CTC+T |
|---|---|---|---|---|
| Package | 12-pin TQFN (4x4) | 12-pin TQFN (4x4) - same | 12-pin TQFN (4x4) - same | 12-pin TQFN - same |
| Brand | Maxim Integrated | Maxim Integrated (same-brand) | Maxim Integrated (same-brand) | Maxim Integrated (same-brand) |
| Resolution | 12 bits | 12 bits | 12 bits | 10 bits |
| Architecture | SAR | SAR | SAR | SAR |
| Input Channels | 1 true-differential | 1 true-differential | 1 true-differential | 1 single-ended |
| Interface | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI |
Principais diferenciais
- True-differential input stage in 4x4 mm TQFN (vs MAX1079CTC+T)
- 1.8 Msps throughput with ±1 LSB INL (vs MAX1274AETC+)
- Integrated 2.5V reference with external override (vs MAX1225CTC+T)
Notas de projeto
Use a star-ground topology with the analog ground (AGND) and digital ground (DGND) joined at a single point adjacent to the exposed pad (EP) of the 12-pin TQFN package. Place the 0.1 µF + 10 µF decoupling pair as close as possible to the AVDD and DVDD pins, with the smaller capacitor nearer to the IC. Route the SPI clock and data signals on the opposite side of the PCB from analog traces to minimise digital-to-analog crosstalk on the AIN+/- inputs.
The true-differential AIN+/AIN- input pair delivers maximum common-mode noise rejection - preserve this by routing the two traces as a tightly-coupled differential pair with characteristic impedance matching the source. For each CNVST rising edge, ensure the SCLK signal is clean and that DOUT transitions are captured on the correct edge per the datasheet timing diagram; if SPI run-length exceeds ~10 mm, add a series damping resistor near the driver. Estimated: at 1.8 Msps with 12-bit resolution, the converter's analog input bandwidth must support ~900 kHz signal bandwidth to honour Nyquist.
Although the MAX1275ACTC+T operates from a 2.7V-3.6V single supply, the analog and digital supply rails should be derived from a common 3.3V regulator and filtered with ferrite beads to prevent digital switching noise (up to tens of mA during SCLK edges) from coupling back into the analog front-end. The internal 2.5V reference requires a 0.1 µF + 10 µF capacitor pair on the REF pin; bypassing this pin poorly increases AC noise and degrades effective resolution. Estimated: a typical 1.8 Msps conversion draws 1-2 mA per Msps from AVDD at 3.3V.
Do not apply analog inputs that exceed AVDD + 0.3V or fall below AGND - 0.3V, as the input ESD diodes will conduct and distort the conversion. Ensure the common-mode voltage of AIN+/AIN- stays within the supply rails to avoid input-stage saturation; use a front-end op-amp (e.g., MAX9632) if the source is bipolar (±10V) or floating. Finally, verify the CNVST pulse width meets the minimum tCNVH specification in the datasheet timing table; an overly short pulse will not initiate conversion and will result in a stuck DOUT line.
The 4x4 mm TQFN-12 package with exposed pad has a low thermal resistance (typically 40-50 °C/W on a 2 oz 1 square inch copper pour), and the MAX1275ACTC+T dissipates well under 100 mW even at the 1.8 Msps sampling rate. No external heatsink is required for normal operation. However, the exposed pad must be soldered to the PCB thermal land and connected to AGND to provide both thermal dissipation and low-impedance analog grounding; missing the EP solder joint can cause erratic operation and overheating during sustained conversion.
Informações de conformidade
RoHS and REACH status not explicitly confirmed in the retrieved distributor datasheets; refer to the official Analog Devices product page for the most current compliance declarations. Lead-free termination is standard for Maxim's TQFN packaging; halogen-free status was not retrieved. AEC-Q100 is not applicable since this part is commercial grade (0 °C to +70 °C) rather than automotive qualified.
