MAX1240CCPA - 12-Bit 73ksps Serial ADC, 2.7V | Maxim Integrated
부품 번호: MAX1240CCPA ✗ 단종| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $7.5 | $7.50 |
| 10 | $6.8 | $68.00 |
| 100 | $6.1 | $610.00 |
| 500 | $5.4 | $2,700.00 |
| 1,000 | $4.75 | $4,750.00 |
MAX1240CCPA 개요
An ADC (analog-to-digital converter) is a mixed-signal integrated circuit that converts continuous analog voltages into discrete digital codes. The successive-approximation register (SAR) architecture used here performs a binary search across an internal capacitive DAC, settling one bit per clock cycle to produce a 12-bit code in N conversion cycles. SAR ADCs sit within the data-converter family alongside delta-sigma, pipeline, and flash converters, and are favored for low-power, medium-speed, single-shot sampling in instrumentation and portable equipment.
Key features of the MAX1240CCPA include an internal 2.5V reference (eliminating an external reference IC), 4.5 mW typical power consumption at 73 ksps, 5 uW power-down mode for battery savings, and an 8-pin PDIP footprint that simplifies through-hole prototyping. The differential nonlinearty is +/-1 LSB max with no missing codes over the operating range. Bipolar input signals can be accommodated by shifting the input common-mode voltage with a resistor network when an external reference is used.
Typical applications include portable data acquisition, pen digitizers, battery-powered instrumentation, loop-powered sensors, and isolated industrial monitoring. The internal reference and small footprint make it a strong choice where board area, BOM count, and quiescent current all matter - for example, handheld multimeters and 4-20 mA loop-powered transmitters. The 3-wire serial interface glues directly to most microcontrollers without external glue logic.
When designing with this part, ensure the supply decoupling (10uF + 0.1uF) is placed within 5 mm of the VDD pin. The reference bypass capacitor (4.7uF typical) is mandatory - omitting it degrades conversion accuracy. The SHDN pin allows the supply current to drop to under 10 uA between conversions for battery-powered duty-cycled designs. This page synthesizes distributor pricing, drop-in alternatives, and practical engineering guidance not found in the manufacturer datasheet.
드롭인 대체품: MAX1240CCPA — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: MAX1240CCPA (동일 폼 팩터 및 풋프린트) — 차이점: Data Interface, Input Type, Mounting Type, Operating Temperature, Package.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
MAX1240CCPA+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX1240BCPA+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX1240AEPA+
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
MAX1240BEPA+
✅ 드롭인✓ 재고 있음
$5.55 / 개
데이터시트 보기 →MAX1241CCPA+
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
MAX1240CCPA 최대 정격 & 전기적 특성
| 분해능 | 12 bits |
| Number of Channels | 1 |
| 샘플링 속도 | 73 ksps |
| Input Type | Single-Ended |
| Architecture | SAR (Successive Approximation) |
| 공급 전압 | +2.7 V to +3.6 V |
| Supply Current (typ) | 1.5 mA at 73 ksps |
| Power-Down Current | 5 uW (typ) |
| Internal Reference | 2.5 V |
| Conversion Time | 7.5 us |
| Track/Hold Acquisition | 1.5 us |
| Data Interface | SPI / QSPI / MICROWIRE-compatible (3-wire serial) |
| 동작 온도 | 0 C to +70 C (commercial, "C" suffix) |
| 패키지 | 8-pin PDIP (CCPA = PDIP-8, 0.300 inch) |
| 실장 유형 | Through-Hole |
| MSL 레벨 | 1 (unlimited, through-hole) |
| Lifecycle | Obsolete (per distributor listings) |
MAX1240CCPA 핀 구성
| 핀 1 | VDD — +2.7V to +3.6V supply input; bypass with 10uF + 0.1uF |
| 핀 2 | AIN — Analog input; single-ended input range 0 to VDD |
| 핀 3 | REF — Internal 2.5V reference output; bypass with 4.7uF to AGND |
| 핀 4 | AGND — Analog ground |
| 핀 5 | DGND — Digital ground |
| 핀 6 | DOUT — Serial data output; 12-bit MSB-first on SCLK falling edges |
| 핀 7 | SCLK — Serial clock input; up to 2.1 MHz |
| 핀 8 | CS — Chip select, active low; drives SHDN when tied to GND |
일반적인 애플리케이션
MAX1240CCPA 적합 용도: 7 애플리케이션s: Portable Data Acquisition, Battery-Powered Instrumentation, Loop-Powered 4-20 mA Sensor Transmitters, Pen Digitizers and Touch Tablets, Isolated Industrial Monitoring, Portable Patient Monitoring, Automotive Sensor Interfaces.
Portable Data Acquisition
The MAX1240CCPA fits portable data acquisition because of its 12-bit resolution, 73 ksps sampling rate, and 5 uW power-down mode for duty-cycled battery operation. The internal 2.5V reference eliminates an external reference IC, reducing BOM count in space-constrained handheld designs. Placed on a 4-layer PCB with the MCU SPI bus and a 10uF + 0.1uF VDD bypass network, it delivers full 12-bit accuracy across the 0-2.5V input range while drawing under 1.5 mA during active conversion. The 8-pin PDIP footprint supports through-hole prototyping and field-replaceable instrumentation modules.
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Battery-Powered Instrumentation
The MAX1240CCPA suits battery-powered instrumentation thanks to its +2.7V to +3.6V single supply that runs directly from a single Li-ion cell, plus its 5 uW power-down mode for sleep intervals between conversions. Internal 2.5V reference trims to +/-1% and removes the need for a separate reference IC, saving both board area and quiescent current. Used in handheld DMMs and field data loggers, the MAX1240CCPA typically runs at 1-10 ksps effective rate, drawing under 200 uA average from a 3V cell - good for weeks of operation on standard batteries.
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Loop-Powered 4-20 mA Sensor Transmitters
The MAX1240CCPA is well-suited to loop-powered 4-20 mA sensor transmitters where total loop current must stay below 3.6 mA for the sensor electronics. Its 1.5 mA active supply current and 5 uW power-down mode leave ample current budget for the 4-20 mA loop regulator and sensor excitation. The 12-bit resolution over a 1.25V input span yields 305 uV LSB - more than adequate for thermocouple, RTD, and bridge-sensor digitization. The internal 2.5V reference can also serve as the bridge excitation rail, further reducing external component count.
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Pen Digitizers and Touch Tablets
The MAX1240CCPA handles the position-sensing analog front end in pen digitizers and touch tablets. The 73 ksps sampling rate supports 100+ points-per-second pen tracking, while the 12-bit resolution over a 0-VDD input span provides sub-1000 LSB position quantization across typical 12-inch tablets. SPI/QSPI/MICROWIRE-compatible interface connects directly to the digitizer controller MCU. Low power consumption extends battery life in wireless pen-tablet designs, and the small 8-pin PDIP package simplifies the analog mixed-signal PCB layout by isolating the ADC away from noisy digital regions.
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Isolated Industrial Monitoring
The MAX1240CCPA serves isolated industrial monitoring modules where one side of an isolation barrier needs to digitize analog sensor signals. Its 3-wire SPI interface crosses digital isolators cleanly with only three channels required (CS, SCLK, DOUT), minimizing the isolator cost. The +2.7V to +3.6V supply fits 3.3V isolated rails commonly derived from small DC-DC converters on the field side. Internal 2.5V reference allows direct connection to 0-2.5V sensor outputs without external scaling, and the commercial temperature grade (0 C to +70 C) covers most indoor control-cabinet environments.
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Portable Patient Monitoring
The MAX1240CCPA fits portable patient monitoring devices such as pulse oximeters, single-channel ECG patches, and wearable vital-sign monitors. Its 12-bit resolution digitizes pulse-oximeter photodiode currents over a 0-2.5V range with sufficient accuracy for SpO2 calculation. The 5 uW power-down mode extends battery life to multiple days between charges - a key wearability requirement. The 8-pin PDIP footprint aids through-hole prototyping for medical device labs, and the +2.7V to +3.6V supply runs directly from a Li-ion cell.
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Automotive Sensor Interfaces
The MAX1240CCPA suits automotive sensor interface modules such as cabin temperature sensors, battery monitor inputs, and HVAC controls. Its 12-bit resolution over the 0-2.5V input span provides ample accuracy for these low-bandwidth applications, while the 73 ksps sampling rate exceeds the needs of slow thermal and pressure sensors. The internal 2.5V reference can serve as a low-current excitation source for resistive sensor bridges. For under-hood or engine-compartment placement, the MAX1240AEPA+ (AEC-Q100 variant) is the preferred choice; the MAX1240CCPA suits cabin and body-electronics applications only.
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추천 제품 요약
엔지니어링 참조 데이터: MAX1240CCPA — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | MAX1240CCPA+ | MAX1240BCPA+ | MAX1240AEPA+ | MAX1240BEPA+ | MAX1241CCPA+ |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | PDIP-8 (0.300 inch) | 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 |
| Sampling Rate | 73 ksps | 73 ksps | 73 ksps | 73 ksps | 73 ksps | 73 ksps |
| Supply Voltage | +2.7V to +3.6V | +2.7V to +3.6V | +2.7V to +3.6V | +2.7V to +3.6V | +2.7V to +3.6V | +2.7V to +5.25V |
| Internal Reference | 2.5V internal | 2.5V internal | 2.5V internal | 2.5V internal | 2.5V internal | External reference required |
| Operating Temperature | 0 C to +70 C (commercial) | 0 C to +70 C | -40 C to +85 C (industrial) | -40 C to +85 C (automotive, AEC-Q100) | -40 C to +85 C | 0 C to +70 C |
| AEC-Q100 Qualified | No | No | No | Yes | No | No |
| Lead-Free (Pb-free) | No (SnPb finish) | Yes (RoHS) | Yes (RoHS) | Yes (RoHS) | Yes (RoHS) | Yes (RoHS) |
주요 차별점
- Internal 2.5V reference removes external reference IC (vs MAX1241CCPA+)
- Lower supply voltage matches single-cell Li-ion operation (vs MAX1241CCPA+)
- Commercial temperature grade is sufficient for most indoor applications (vs MAX1240BCPA+)
- 8-pin PDIP package aids through-hole prototyping and field repair (vs MAX1240BCSA+ (SO-8 variant))
설계 노트
VDD decoupling is critical - place a 10 uF tantalum (or ceramic with sufficient voltage rating) in parallel with a 0.1 uF ceramic within 5 mm of the VDD pin. Long VDD traces create inductive spikes that couple into the reference and degrade noise performance. For battery applications, add a 100 ohm ferrite bead in series with VDD to suppress switching noise from upstream DC-DC converters that could otherwise modulate the ADC reference.
Route analog and digital grounds as separate nets, joining only at the IC's AGND/DGND pins (star-ground configuration). Keep the AIN trace short and surrounded by analog ground; avoid running the SCLK and DOUT traces parallel to AIN. Estimated: AIN trace capacitance of 5 pF combined with the source impedance sets the track/hold settling time - constant 5 pF is well within the 1.5 us acquisition budget for source impedances below 1 kohm.
The internal 2.5V reference must be bypassed with a 4.7 uF capacitor at the REF pin to AGND - omitting this capacitor degrades conversion accuracy by several LSBs. For best noise performance, use a low-ESR ceramic or tantalum capacitor and place it within 3 mm of the pin. Driving AIN from a high-impedance source (>5 kohm) requires an external op-amp buffer because the internal switch-capacitor input draws charge transients during acquisition.
Do not apply analog input voltages outside 0 to VDD - voltages above VDD or below AGND forward-bias the input ESD diodes and inject noise into the substrate. Do not toggle SCLK while CS is high (idle) - stray SCLK edges can corrupt the conversion state machine. Do not leave CS floating - it must be tied either high (idle) or actively driven low during conversion. Estimated: a floating CS pin picks up ~50 mV of noise in pickup which can falsely trigger conversions.
Power dissipation in this ADC is dominated by the active-mode supply current (~1.5 mA at 73 ksps), so at VDD=3.6V the IC dissipates about 5.4 mW worst-case - no thermal management needed for the PDIP-8 package. The bigger thermal concern is local reference drift: the internal 2.5V reference shifts approximately +/-50 ppm/C, which over a 70 C rise equates to 8.75 mV of full-scale drift. For high-accuracy applications, use the SHDN mode to keep the IC warm only during active conversions, or add an external reference for tighter stability.
규정 준수 정보
MAX1240CCPA (no + suffix) is a SnPb (leaded) PDIP-8 - non-RoHS. The lead-free RoHS variant is MAX1240CCPA+ (different orderable part number). REACH and conflict-mineral status not explicitly documented in the verified web data. AEC-Q100 qualification requires the MAX1240AEPA+ variant. Recommend MAX1240CCPA+ for new RoHS-compliant designs.
