MAX1243ACPA - 10-Bit Serial ADC, 8-Pin PDIP | Maxim Integrated
部品番号: MAX1243ACPA ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $9.84 | $9.84 |
| 10 | $9.1 | $91.00 |
| 100 | $7.85 | $785.00 |
| 500 | $6.78 | $3,390.00 |
| 1,000 | $5.92 | $5,920.00 |
MAX1243ACPA 概要
An ADC (analog-to-digital converter) is an integrated circuit that translates continuous analog voltages into discrete digital codes. SAR ADCs use a binary search algorithm with an internal capacitive DAC and comparator to resolve one bit per clock cycle, trading conversion speed for very low power consumption and zero pipeline latency. Within the broader IC hierarchy, a SAR ADC belongs to data-acquisition signal-chain ICs, which sit between sensors/analog front-ends and digital microcontrollers.
Key specifications include 10-bit resolution with +/-0.5 LSB integral nonlinearity (A-grade), 73 kSPS sampling rate, single +2.7V to +5.25V analog supply, low 1.0 mA operating current and 2 uA shutdown current. The MAX1243ACPA accepts 0 to VREF analog inputs and supports an external reference up to VDD, enabling ratiometric measurements alongside bridge sensors and potentiometers.
The MAX1243ACPA uses a charge-redistribution DAC architecture with an on-chip T/H, delivering low power and 7.5 us conversions while requiring no external sample capacitor. The serial interface reduces pin count versus parallel ADCs, simplifying PCB routing in space-constrained designs. The internal oscillator and serial data framing further reduce microcontroller firmware overhead.
Typical applications include portable data logging, pen-digitizer / touch input sensing, portable/handheld measurement instruments, 4-20 mA loop-powered industrial sensors, and isolated medical monitoring front-ends. The 8-pin PDIP package is convenient for breadboarding and field service replacements.
When designing with this part, place 0.1 uF bypass capacitors close to VDD and reference pins, keep analog and digital grounds joined at a single point, and ensure VREF is stable and decoupled to preserve linearity. Compared to the MAX1242, the MAX1243 includes a hardware shutdown pin for additional power savings in duty-cycled applications.
This page synthesizes distributor pricing, drop-in package-compatible alternatives, and practical design notes not found in the manufacturer datasheet, helping engineers shorten selection, BOM review, and PCB redesign cycles for the MAX1243ACPA and its close family members.
ドロップイン代替品: MAX1243ACPA — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: MAX1243ACPA （同一形状・フットプリント） — 相違点: Package, Sampling Rate, Conversion Time, Input Type, Number of Channels.
クイック比較ツール — 並列比較する代替部品を選択:
MAX1243ACPA+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX1243AEPA
✅ ドロップイン✓ 在庫あり
$4.35 / 個
データシートを見る →MAX1243AEPA+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX1243BEPA
✅ ドロップイン✓ 在庫あり
$2.05 / 個
データシートを見る →MAX1243BCPA
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX1243BMJA
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX1242ACPA
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX1243ACPA 最大定格＆電気的特性
| 分解能 | 10 bits |
| Architecture | SAR (Successive Approximation Register) |
| Number of Channels | 1 |
| サンプリングレート | 73 kSPS |
| Conversion Time | 7.5 us |
| Track/Hold Acquisition Time | 1.5 us |
| Integral Nonlinearity (INL) | +/-0.5 LSB (A grade) |
| Supply Voltage (VDD) | +2.7 V to +5.25 V |
| Analog Input Range | 0 V to VREF |
| External Reference Voltage | Up to VDD |
| Operating Supply Current | 1.0 mA (typ) |
| シャットダウン電流 | 2 uA (typ) |
| インターフェース | 3-wire SPI/QSPI/MICROWIRE-compatible |
| パッケージ | 8-pin PDIP (through-hole) |
| 動作温度範囲 | 0 C to +70 C |
| 実装タイプ | Through-Hole (DIP) |
| RoHS ステータス | Compliant |
MAX1243ACPA ピン構成
| ピン 1 | VDD — Positive supply input (+2.7V to +5.25V) |
| ピン 2 | AIN — Analog input (0 to VREF) |
| ピン 3 | GND — Ground |
| ピン 4 | SHDN — Hardware shutdown, active high (MAX1243 only) |
| ピン 5 | REF — External reference voltage input |
| ピン 6 | DOUT — Serial data output |
| ピン 7 | CS — Active-low chip select |
| ピン 8 | SCLK — Serial clock input |
主な用途
MAX1243ACPA の用途: 6 件s: Portable Battery-Powered Data Logging, Handheld / Portable Test Instruments, 4-20 mA Industrial Loop Sensors, Pen-Digitizer / Touch Position Sensing, Isolated Medical Monitoring Front-End, Remote / Environmental Sensor Nodes.
Portable Battery-Powered Data Logging
The MAX1243ACPA's 1.0 mA active supply current and 2 uA shutdown current fit comfortably in coin-cell and 2xAA battery budgets, while the 73 kSPS sample rate exceeds the needs of temperature, humidity, and pressure loggers that typically run at 1-10 Hz. Hardware shutdown lets the host MCU duty-cycle conversions to extend battery life by 50-100x. The 0 to VREF analog input accommodates ratiometric sensor bridges without extra signal conditioning, and the 3-wire SPI bus keeps the wiring to 3 microcontroller pins. Placed on a small data-acquisition board with an external 2.5V reference, the MAX1243ACPA delivers 10-bit resolution with +/-0.5 LSB INL for laboratory-grade logging.
おすすめ
Handheld / Portable Test Instruments
Handheld multimeters, insulation testers, and portable signal analyzers benefit from the MAX1243ACPA's 8-pin PDIP package, which simplifies hand-soldering and field replacement. The 10-bit resolution and 73 kSPS sample rate meet typical 3.5-digit meter accuracy while the 2.7V to 5.25V supply range matches 3.3V MCU rails and Li-ion battery packs. The shutdown pin allows the firmware to power down the ADC between measurements, dropping current to 2 uA. Compared to discrete op-amp + comparator ADC designs, the integrated SAR delivers better noise performance in a smaller footprint, which is critical for handheld form factors.
おすすめ
4-20 mA Industrial Loop Sensors
The MAX1243ACPA's low supply current (1.0 mA active, 2 uA shutdown) lets it sit comfortably inside a 4-20 mA current loop's compliance budget, leaving the bulk of loop current for the transducer and analog front-end. The 0 to VREF input accepts ratiometric bridge outputs directly without instrumentation amplifiers, and the 10-bit resolution provides 0.1% full-scale accuracy typical of process-control transmitters. The shutdown pin enables burst-read modes that further reduce loop draw during idle. A robust anti-alias filter on the input, plus the ADC's 7.5 us conversion time, gives clean samples of slowly varying process variables such as pressure, level, and flow.
おすすめ
Pen-Digitizer / Touch Position Sensing
Pen-digitizer tablets and resistive touchscreens use a resistive ladder network that the MAX1243ACPA can read directly through its 0 to VREF input. The 73 kSPS sample rate supports stylus tracking at reasonable speeds for handwriting recognition, and the 3-wire SPI interface keeps wiring to a minimum between the touch sensor and the host MCU. The hardware shutdown pin saves power when the device is idle, which is critical for battery-powered e-readers and field data-entry pads. The MAX1243ACPA's 8-pin PDIP package is also friendly to revision and rework during prototype iterations of human-input devices.
おすすめ
Isolated Medical Monitoring Front-End
Medical signal-isolation modules use the MAX1243ACPA on the patient side to digitize low-frequency biosignals such as body temperature, respiration, and slow ECG leads before opto-isolating the digital stream. Its 1.0 mA operating current keeps total patient-side power within safety isolation budgets, while 7.5 us conversions easily handle the kHz-bandwidth signals. The 3-wire SPI interface lends itself to isolation with low-cost digital isolators, reducing BOM cost versus parallel ADC + isolator solutions. For higher-channel ECG/EEG front-ends, designers can parallel multiple MAX1243ACPA devices sharing the SPI bus through individual CS lines.
おすすめ
Remote / Environmental Sensor Nodes
Solar-powered environmental sensor nodes for agriculture, weather stations, and asset tracking use the MAX1243ACPA to digitize analog signals from soil moisture probes, solar radiation pyranometers, and battery voltage monitors. The 2 uA shutdown current allows duty-cycled sampling that can extend battery life by orders of magnitude, and the 10-bit resolution is sufficient for non-precision telemetry. The 8-pin PDIP package is rugged for outdoor enclosure assembly, and the 2.7V to 5.25V supply range supports a wide variety of battery chemistries. The shutdown pin can be tied to a GPIO for scheduled wake/sleep cycles coordinated with the radio.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: MAX1243ACPA — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | MAX1243ACPA+ | MAX1243AEPA | MAX1243BCPA | MAX1243BMJA | MAX1242ACPA |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same |
| Package | PDIP-8 | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same |
| Resolution | 10 bits | 10 bits | 10 bits | 10 bits | 10 bits | 10 bits |
| INL (max) | +/-0.5 LSB | +/-0.5 LSB | +/-1 LSB | +/-1 LSB | +/-1 LSB | +/-0.5 LSB |
| Shutdown Pin | Yes (SHDN) | Yes (SHDN) | Yes (SHDN) | Yes (SHDN) | Yes (SHDN) | No (always 1 mA) |
| Sampling Rate | 73 kSPS | 73 kSPS | 73 kSPS | 73 kSPS | 73 kSPS | 73 kSPS |
| Operating Temperature | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | -55 C to +125 C | 0 C to +70 C |
| Supply Voltage | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V |
主な差別化要因
- Hardware shutdown pin reduces idle current to 2 uA （vs MAX1242ACPA)
- A-grade +/-0.5 LSB INL for tighter linearity （vs MAX1243AEPA)
- Through-hole PDIP package for breadboard and field service （vs MAX1243ACSA+)
- Military temperature range variant available in same footprint （vs MAX1243AEPA)
設計ノート
Place a 0.1 uF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 1) and a 10 uF bulk capacitor on the supply rail. For shutdown-mode operation, drive the SHDN pin (pin 4) low to enter 2 uA standby and high again at least 1 us before CS goes low to ensure internal bias settles. Reference decoupling: a 0.1 uF cap directly at the REF pin (pin 5) is required to prevent reference noise from coupling into the conversion result; larger 1-10 uF caps may be needed if VREF is shared with noisy digital circuits.
Use a single star-ground topology with the MAX1243ACPA's GND pin (pin 3) as the analog ground reference. Avoid running digital return currents beneath the analog input trace, and place the chip at least 5 mm away from digital signal edges. Route AIN as a guarded trace if the source impedance exceeds 1 kohm, and place an anti-alias RC (typically 1 kohm + 100 pF) directly at AIN for kHz-range signals. Keep the digital SPI traces short and add a 100 ohm source termination if SCLK exceeds 5 MHz to prevent ringing.
Estimated acquisition arithmetic - the MAX1243 input has approximately 16 pF of input capacitance and requires 1.5 us acquisition through the internal T/H. Source impedance above 1 kohm degrades linearity because the input capacitance cannot fully charge in 1.5 us. For high-impedance sources (>5 kohm), add an external unity-gain buffer (e.g., MAX4475) or use a longer acquisition interval in firmware. Never connect AIN directly to a high-impedance thermistor without buffering, or expect 2-3 LSB linearity error.
Do not float the SHDN pin (pin 4) on the MAX1243; tie it to GND through a 100 kohm pulldown or drive it from a GPIO - leaving it floating can cause unpredictable behavior and 100-200 uA supply current. Ensure CS is held high between conversions to prevent spurious serial clocks from clocking out garbage data. Do not exceed VREF with the AIN input, and never apply voltages below GND or above VDD to AIN, as the ESD clamps will inject current and corrupt the conversion.
コンプライアンス情報
The base MAX1243ACPA (no + suffix) uses SnPb finish and is non-RoHS. For RoHS compliance, use the MAX1243ACPA+ variant. AEC-Q100 not applicable (ADC is not automotive-grade qualified; MAX1243 family is commercial/industrial grade only).
