MAX1225CTC+ - 12-Bit 1.5Msps Differential ADC | Maxim Integrated
부품 번호: MAX1225CTC+ ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $5.92 | $5.92 |
| 10 | $5.32 | $53.20 |
| 100 | $4.74 | $474.00 |
| 500 | $4.27 | $2,135.00 |
| 1,000 | $3.79 | $3,790.00 |
MAX1225CTC+ 개요
An ADC (analog-to-digital converter) is a semiconductor device that samples continuous analog voltage signals and converts them into discrete digital codes for processing by microcontrollers, DSPs, or FPGAs. Within the broader taxonomy, the MAX1225CTC+ belongs to successive-approximation-register (SAR) ADCs, which sit under the data-converter IC family and the data-acquisition product category. SAR ADCs are prized for deterministic latency, low power consumption, and the absence of pipeline delay, making them ideal for multiplexed multi-channel systems and event-triggered sampling.
Key features of the MAX1225CTC+ include a high-speed SPI/QSPI/MICROWIRE-compatible serial interface, true-differential analog inputs with ±VREF input range, an internal 2.5V reference (with the option to use an external reference), and a 12-pin TQFN package measuring just 4mm x 4mm. The device supports both internal and external clock operation and offers an active-low shutdown pin to minimize idle current. The exposed thermal pad lowers junction-to-ambient thermal resistance, supporting reliable operation across the -40C to +85C commercial temperature range.
The MAX1225CTC+ uses a charge-redistribution SAR architecture and an input track-and-hold capable of handling signals beyond the Nyquist frequency with minimal distortion. At 1.5Msps, the converter settles in approximately 670ns per conversion, and the serial data interface shifts out the 12-bit result MSB-first in 12 clock cycles, allowing easy connection to most modern microcontrollers. The internal reference is trimmed to ±1% accuracy, eliminating the need for external reference components in cost-sensitive designs.
Typical applications include data acquisition systems, industrial process control, portable instrumentation, and medical monitoring equipment. It is also well suited for motor control feedback, weigh scales, and remote sensor interfaces where true-differential inputs reject ground-loop noise in long cable runs. The combination of single 3V supply operation and low power consumption makes it attractive for battery-powered handheld instruments.
When designing with this ADC, ensure the input common-mode voltage stays within the specified 0.1V to VDD-0.1V range for true differential sampling. Bypass the supply pin with a 0.1uF ceramic capacitor placed as close as possible to the exposed pad, which must be soldered to the ground plane for thermal dissipation. For best SNR performance, drive the differential inputs with low-impedance op-amps such as the MAX4162 or MAX4245.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives, and practical design notes that go beyond the manufacturer datasheet alone, giving engineers a one-stop reference for sourcing and applying the MAX1225CTC+ in real designs.
드롭인 대체품: MAX1225CTC+ — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: MAX1225CTC+ (동일 폼 팩터 및 풋프린트) — 차이점: Package, Sampling Rate, Input Type, Operating Temperature, Resolution.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MAX1224CTC+
✅ 드롭인✓ 재고 있음
$2.28 / 개
데이터시트 보기 →MAX1165AEUI+T
✅ 드롭인✓ 재고 있음
$8.9 / 개
데이터시트 보기 →MAX1165BEUI+T
✅ 드롭인✓ 재고 있음
$9.3 / 개
데이터시트 보기 →MAX1162ACUB+T
✅ 드롭인✓ 재고 있음
$5.74 / 개
데이터시트 보기 →MAX1202ACAP
✅ 드롭인✓ 재고 있음
$7.17 / 개
데이터시트 보기 →MAX11164ETC+T
✅ 드롭인✓ 재고 있음
$5.54 / 개
데이터시트 보기 →MAX1225CTC+ 최대 정격 & 전기적 특성
| 분해능 | 12 bits |
| 샘플링 속도 | 1.5 Msps (max) |
| Number of Channels | 1 (true-differential) |
| Input Type | True differential |
| Architecture | SAR (Successive Approximation Register) |
| 공급 전압 | 2.7 V to 3.6 V (single 3V supply) |
| Supply Current (active) | 3 mA (typ) at 1.5 Msps |
| Supply Current (shutdown) | 1 uA (max) |
| 입력 전압 범위 | ±VREF (differential) |
| Internal Reference | 2.5 V |
| External Reference Range | 1 V to VDD |
| INL (적분 비선형성) | ±1 LSB (max) |
| DNL (Differential Nonlinearity) | ±1 LSB (max, no missing codes) |
| SNR | 70 dB (typ) |
| SINAD | 69 dB (typ) |
| SFDR | 86 dBc (typ) |
| THD | -84 dB (typ) |
| Aperture Delay | 15 ns (typ) |
| Serial Interface | SPI/QSPI/MICROWIRE-compatible |
| 동작 온도 범위 | -40 C to +85 C |
| 패키지 | 12-pin TQFN, 4 mm x 4 mm with exposed pad |
| 실장 유형 | Surface Mount |
| RoHS 상태 | Compliant |
| MSL 레벨 | 1 |
MAX1225CTC+ 핀 구성
| 핀 1 | AIN+ — Positive differential analog input |
| 핀 2 | AIN- — Negative differential analog input |
| 핀 3 | GND — Ground |
| 핀 4 | REF — Reference voltage input/output (2.5V internal) |
| 핀 5 | REFCAP — Reference bypass capacitor |
| 핀 6 | VDD — Positive supply voltage (2.7V to 3.6V) |
| 핀 7 | CS — Active-low chip select (serial interface) |
| 핀 8 | DOUT — Serial data output |
| 핀 9 | SCLK — Serial clock input |
| 핀 10 | SHDN — Active-low shutdown (logic low powers down device) |
| 핀 11 | CNVST — Convert start input (initiates conversion on rising edge) |
| 핀 12 | EP — Exposed thermal pad (must be soldered to ground) |
일반적인 애플리케이션
MAX1225CTC+ 적합 용도: 7 애플리케이션s: Industrial Data Acquisition Systems, Medical Patient Monitoring, Motor Control and Servo Feedback, Portable Instrumentation and Handheld Test Equipment, Weigh Scales and Load Cell Digitization, Audio and Vibration Analysis, Sensor Signal Conditioning and IoT Edge Nodes.
Industrial Data Acquisition Systems
The MAX1225CTC+ is well suited for multi-channel industrial data-acquisition front-ends digitizing thermocouple, RTD, and 4-20mA loop signals. Its true-differential input rejects common-mode ground noise that is common on long factory-floor cables, while the 1.5 Msps throughput supports oversampling for software averaging that improves effective resolution by 1-2 bits. The 70 dB SNR and ±1 LSB INL guarantee full 12-bit accuracy across the -40C to +85C industrial temperature range. Compared with a pipeline ADC, the SAR architecture provides zero-latency deterministic sampling required for closed-loop control loops.
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Medical Patient Monitoring
Portable ECG, pulse-oximeter, and patient monitor designs benefit from the MAX1225CTC+'s combination of true-differential inputs, 70 dB SNR, and 3 mA active supply current. The differential architecture rejects 50/60 Hz mains pickup that couples into long electrode leads, while the small 4 mm x 4 mm TQFN footprint keeps the analog front-end compact in handheld form factors. The internal 2.5V reference eliminates calibration drift typical of external references. The SAR architecture's deterministic conversion timing simplifies synchronization with the microcontroller's interrupt-driven sampling, which is critical for real-time waveform capture.
추천
Motor Control and Servo Feedback
The MAX1225CTC+ digitizes current-sense amplifier outputs in three-phase motor control loops, where 1.5 Msps throughput captures PWM current ripple accurately and supports 20 kHz control loops with substantial oversampling. Its true-differential inputs accept the high common-mode dv/dt transients from the bridge switching without saturating. The deterministic SAR latency of approximately 670 ns aligns well with the PWM duty cycle, allowing the controller to read ADC results in the same PWM period they were triggered in. The exposed thermal pad on the TQFN package handles the sustained power dissipation in enclosed industrial drives.
추천
Portable Instrumentation and Handheld Test Equipment
Battery-powered digital multimeters, oscilloscope front-ends, and field test instruments use the MAX1225CTC+ for its single 3V supply operation and only 3 mA active current draw. The internal 2.5V reference eliminates bulky external reference ICs, saving board area and power. The active-low shutdown pin reduces quiescent current to 1 uA between conversions, extending battery life in intermittent-sampling applications. Its small 4 mm x 4 mm TQFN package supports handheld form factors, while the SPI-compatible interface connects directly to most ARM Cortex-M microcontrollers without glue logic.
추천
Weigh Scales and Load Cell Digitization
Weigh-scale designs leverage the MAX1225CTC+'s true-differential inputs and 70 dB SNR to digitize bridge-type load cell outputs directly without instrumentation amplifiers in many cases. The differential architecture cancels thermoelectric offsets and ground loops common in industrial weighing installations. Its 1.5 Msps throughput supports averaging over many conversion cycles, which improves effective resolution to 14-15 bits when 256x or higher oversampling is applied. The exposed-pad TQFN package provides stable thermal performance in NTEP-certified commercial scales that require minimal drift over temperature.
추천
Audio and Vibration Analysis
Audio spectrum analyzers and vibration-monitoring front-ends use the MAX1225CTC+ for its 70 dB SNR and 86 dBc SFDR, which preserve harmonic content critical to FFT analysis. The 1.5 Msps throughput supports sampling of audio-bandwidth inputs (typically up to 500 kHz) with significant anti-aliasing margin. The SAR architecture's lack of latency allows continuous-stream FFTs without the gaps caused by pipeline ADC conversion delays. The internal 2.5V reference is suitable for audio-bandwidth applications where absolute DC accuracy matters less than AC linearity.
추천
Sensor Signal Conditioning and IoT Edge Nodes
IoT edge nodes digitizing strain gauges, pressure sensors, and analog front-end signals benefit from the MAX1225CTC+'s low power and true-differential inputs. The differential architecture rejects common-mode noise from long sensor cables in outdoor deployments. The 3 mA active current and 1 uA shutdown current suit battery-powered wireless sensor nodes that wake periodically to take readings. The small 4 mm x 4 mm TQFN footprint plus SPI-compatible interface integrates easily with low-power MCUs such as the MAX32660 or MAX32625 in complete sensor node designs.
추천
추천 제품 요약
엔지니어링 참조 데이터: MAX1225CTC+ — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MAX1224CTC+ | MAX11164ETC+T | MAX1165AEUI+ | MAX1162ACUB+T | MAX1202ACAP |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 12-pin TQFN (4x4 mm) | 12-pin TQFN (4x4 mm) - same | 12-pin TQFN (3x3 mm) - similar | 28-pin TSSOP - different | 10-pin uMAX - different | 20-pin SSOP - different |
| Resolution | 12 bits | 12 bits | 12 bits | 14 bits | 14 bits | 12 bits |
| Sampling Rate | 1.5 Msps | 225 ksps | 500 ksps | 200 ksps | 200 ksps | 200 ksps |
| Input Type | True differential | True differential | True differential | True differential | Pseudo-differential | Single-ended |
| Supply Voltage | 2.7 V to 3.6 V | 2.7 V to 3.6 V | 2.7 V to 3.6 V | 4.75 V to 5.25 V | 4.75 V to 5.25 V | 4.75 V to 5.25 V |
| Internal Reference | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V |
| Serial Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
주요 차별점
- True 1.5 Msps throughput with same-family pin compatibility (vs MAX1224CTC+)
- Smallest 12-pin TQFN (4x4 mm) with true-differential inputs in this speed class (vs MAX1165AEUI+)
- Single 3V supply operation eliminates dual-rail requirements (vs MAX1202ACAP)
설계 노트
The exposed thermal pad (Pin 12) MUST be soldered to a ground plane island no smaller than 4 mm x 4 mm on the top layer. Without proper thermal pad soldering, junction temperature can rise 30-40 C above ambient, degrading linearity. Place a 0.1 uF ceramic bypass capacitor within 3 mm of the VDD pin (Pin 6) and a 10 uF tantalum or ceramic capacitor at the regulator output. The REFCAP pin (Pin 5) requires a 0.1 uF ceramic capacitor placed within 2 mm for reference stability; this capacitor is critical to achieving the datasheet SNR specification.
Drive the differential inputs (AIN+ and AIN-) with matched-impedance, low-capacitance traces routed as a differential pair. Trace length mismatch greater than 5 mm degrades common-mode rejection above 100 kHz. Use a low-noise op-amp such as the MAX4162 or MAX4245 in a unity-gain buffer configuration, with the buffer placed within 10 mm of the ADC input pins to minimize parasitic capacitance. Keep analog input traces away from digital clock traces (SCLK, CNVST) by at least 3 trace-widths to avoid digital-to-analog crosstalk that appears as spurious tones in the FFT output.
Do not operate the MAX1225CTC+ with input common-mode voltage outside the 0.1V to VDD-0.1V range - exceeding this range saturates the input track-and-hold and distorts the conversion result. The active-low SHDN pin (Pin 10) must be pulled HIGH (to VDD) for normal operation; if left floating, the device enters an indeterminate state that may either continuously convert or shut down unpredictably. The CNVST pin (Pin 11) rising edge starts the conversion - ensure SCLK is idle (low) during conversion to avoid corrupting the conversion. Do not apply external reference voltage while the internal reference is enabled (this creates contention); use the REF pin only for one mode at a time.
Estimated: At VDD=3.3V, the MAX1225CTC+ draws 3 mA active (9.9 mW total power). Power supply rejection above 1 MHz is limited, so use a linear regulator (such as the MAX8887) rather than a switching converter for the ADC supply rail to avoid switching noise coupling into the analog inputs through the supply pin. Add a ferrite bead in series with the analog supply and a 10 uF + 0.1 uF capacitor network to filter high-frequency switching ripple. In low-power designs, use the SHDN pin to gate conversions and drop quiescent current to 1 uA between samples.
Implement a four-layer PCB stack-up with a continuous ground plane on layer 2 directly beneath the top signal layer; this provides the lowest inductance return path for high-speed digital signals. Route the SCLK trace with controlled impedance (50 ohms single-ended) and place a 33 ohm series resistor near the SCLK source to dampen reflections. The DOUT trace should be series-terminated at the source side with a 33 ohm resistor if trace length exceeds 25 mm. Use guard traces (grounded) around the AIN+/AIN- differential pair to reduce noise coupling from adjacent digital signals.
규정 준수 정보
RoHS and REACH compliance confirmed per Maxim Integrated product page. Lead-free (Pb-free) matte-tin finish. Not AEC-Q100 qualified - commercial-grade temperature range (-40C to +85C). Halogen-free status not explicitly stated in available data.
