MAX145ACPA - 12-Bit 108ksps 2-Ch Serial ADC | Maxim Integrated
部品番号: MAX145ACPA ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $8.2 | $8.20 |
| 10 | $7.38 | $73.80 |
| 100 | $6.5 | $650.00 |
| 500 | $5.85 | $2,925.00 |
| 1,000 | $5.2 | $5,200.00 |
MAX145ACPA 概要
What is a low-power SAR ADC? A successive-approximation register ADC is a precision data converter type that resolves one bit per clock cycle using a binary search against an internal DAC; it sits in the taxonomy analog-to-digital converter -> data converter -> signal chain IC -> semiconductor. Compared with delta-sigma ADCs, SAR parts offer single-cycle latency and deterministic acquisition, which is why they dominate multiplexed multi-channel data-acquisition front ends, sensor readouts, and embedded instrumentation loops.
Key specifications include 108 ksps maximum sampling rate, +/-1 LSB INL (max), +/-1 LSB DNL (no missing codes guaranteed), an internal 2.5 V reference option plus external reference mode, single-ended analog inputs with channel 2 configurable as pseudo-differential, and 1.5 mA maximum supply current at 108 ksps dropping to under 1 microamp in power-down. The MAX145ACPA guarantees 0.1 LSB sample-to-sample crosstalk between its two input channels and provides a serial interface software-select.
Architecturally, the MAX145 combines an input track-and-hold, a capacitive-charge redistribution DAC, a comparator and SAR logic, plus the on-chip oscillator and reference buffer. The auto-power-down feature draws under 1 microamp between conversions, making it ideal for duty-cycled battery measurements. The MAX145ACPA is the pseudo-differential input variant of the family (max 127 distinguishes true-differential MAX144 versus pseudo-differential MAX145 versus single-channel MAX144).
Typical applications include portable data loggers, loop-powered 4-20 mA sensor transmitters, handheld multimeters, battery monitoring boards, thermistor/RTD signal conditioning, and industrial process-control front ends. The wide 2.7 V to 5.25 V supply range lets it share the same rails as the host microcontroller.
When designing with the MAX145ACPA, place a 0.1 microfarat decoupling capacitor close to the supply pin and respect the 8 microsecond acquisition-time minimum after channel switching. Drive CS low to initiate conversion and read the MSB-first data on the falling edge of SCLK per the SPI timing diagram in the datasheet.
This page consolidates distributor pricing for the MAX145ACPA in 8-pin PDIP, drop-in equivalents, comparison against the MAX144 family siblings, and practical design notes that are not aggregated on any single distributor listing.
ドロップイン代替品: MAX145ACPA — 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: MAX145ACPA （同一形状・フットプリント） — 相違点: Package, Resolution, RoHS Status, Sampling Rate, Conversion Time.
クイック比較ツール — 並列比較する代替部品を選択:
MAX145ACPA+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX145BCPA
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
MAX144ACPA
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX144BEUA
✅ ドロップイン✓ 在庫あり
$3.21 / 個
データシートを見る →MAX1202ACAP
✅ ドロップイン✓ 在庫あり
$7.17 / 個
データシートを見る →MAX1243ACPA
✅ ドロップイン✓ 在庫あり
$5.92 / 個
データシートを見る →MAX145ACPA 最大定格＆電気的特性
| 分解能 | 12 bits |
| Number of Channels | 2 |
| サンプリングレート | 108 ksps |
| Supply Voltage Range | +2.7 V to +5.25 V |
| Supply Current (max, 108 ksps) | 1.5 mA |
| Power-Down Current | less than 1 microamp |
| Conversion Time | 7.4 microseconds |
| Wake-Up Time | 2.5 microseconds |
| Input Configuration | Pseudo-differential (CH1, CH2 with COM) |
| 基準電圧 | +2.5 V internal or external |
| INL (max) | +/-1 LSB |
| DNL (max) | +/-1 LSB (no missing codes) |
| Serial Interface | SPI/QSPI/MICROWIRE-compatible |
| 動作温度範囲 | 0 C to +70 C |
| パッケージ | PDIP-8 |
| 実装タイプ | Through-Hole |
| RoHS ステータス | Compliant (Pb-free + suffix) |
| Architecture | SAR (Successive Approximation) |
MAX145ACPA ピン構成
| ピン 1 | VDD — Positive supply voltage, +2.7 V to +5.25 V |
| ピン 2 | CH1 (AIN1) — Analog input channel 1 |
| ピン 3 | AGND — Analog ground |
| ピン 4 | COM — Common reference for pseudo-differential inputs |
| ピン 5 | CH0 (AIN0) — Analog input channel 0 |
| ピン 6 | REF — Reference voltage input/output (internal 2.5 V or external) |
| ピン 7 | DOUT — Serial data output, MSB first |
| ピン 8 | SCLK — Serial clock input (with CS tied low through hardware) |
主な用途
MAX145ACPA の用途: 7 件s: Portable Data Logger, 4-20 mA Loop-Powered Sensor Transmitter, Handheld Digital Multimeter, Battery Monitoring Board, Thermistor/RTD Signal Conditioning, Industrial Process-Control Front End, Touch Panel / Resistive Sensor Interface.
Portable Data Logger
The MAX145ACPA's 108 ksps sampling rate and 2-channel pseudo-differential inputs suit handheld data loggers measuring temperature, voltage, or process signals over battery life. According to the datasheet, the less than 1 microamp power-down current lets the part be duty-cycled, and the 7.4 microsecond conversion supports burst sampling at 10 ms intervals across two analog channels. With +2.7 V to +5.25 V supply range, it shares a lithium or 3 x AA battery stack, while the 12-bit resolution (+/-1 LSB INL) captures sensor transients with 0.024 percent FS precision. Place the IC near the analog inputs with a 0.1 microfarat decoupling capacitor on VDD, and use the 2.5 V internal reference for absolute measurements.
おすすめ
4-20 mA Loop-Powered Sensor Transmitter
The MAX145ACPA's +2.7 V minimum supply and less than 1 microamp power-down current make it ideal for 4-20 mA loop-powered sensor transmitters that must operate within a tight 3.5 mA budget. According to the datasheet, the pseudo-differential inputs accept a bridge sensor referenced to a common COM pin, while the 2.5 microsecond wake-up enables sub-millisecond conversion cycles between long sleeps. The 12-bit resolution provides 0.024 percent FS precision adequate for industrial sensor standards. The serial SPI/QSPI/MICROWIRE interface connects directly to a low-power microcontroller that modulates the loop current.
おすすめ
Handheld Digital Multimeter
The MAX145ACPA's 12-bit resolution, +/-1 LSB linearity, and 108 ksps sampling rate suit handheld digital multimeters measuring DC and AC signals across multiple ranges. According to the datasheet, the two pseudo-differential channels can be configured to measure voltage and current simultaneously, while the internal 2.5 V reference eliminates external precision components. The +2.7 V to +5.25 V supply range lets the part run from a 9 V battery regulated down to 5 V or 3.3 V, and the small 8-pin PDIP/μMAX package fits in compact meter housings.
おすすめ
Battery Monitoring Board
The MAX145ACPA's low supply current (1.5 mA at 108 ksps, less than 1 microamp in power-down) and wide +2.7 V to +5.25 V supply range make it ideal for battery monitoring boards in UPS, e-bike, and portable medical devices. According to the datasheet, the two pseudo-differential channels can monitor individual cell voltages in a stacked battery pack, while the 12-bit resolution captures cell imbalance with millivolt precision. The serial 3-wire interface connects directly to a battery-management microcontroller without external glue logic.
おすすめ
Thermistor/RTD Signal Conditioning
The MAX145ACPA's pseudo-differential inputs are well suited to thermistor and RTD signal conditioning where ratiometric measurements reject lead-resistance errors. According to the datasheet, the two channels can be configured to measure a thermistor divider and a reference voltage simultaneously, enabling ratiometric temperature conversion. The internal 2.5 V reference can be used to drive the reference resistor, while the 12-bit resolution provides 0.1 degree Celsius precision for industrial temperature sensing. The wide supply range supports both 3.3 V and 5 V host microcontrollers.
おすすめ
Industrial Process-Control Front End
The MAX145ACPA's industrial temperature grade (0 C to +70 C commercial) and pseudo-differential inputs make it a fit for industrial process-control front ends measuring 0-10 V or 4-20 mA signals. According to the datasheet, the 108 ksps sampling rate supports multiplexed multi-channel measurements, while the 12-bit resolution provides 0.024 percent FS precision. The 3-wire SPI/QSPI/MICROWIRE interface connects directly to industrial PLC or microcontroller peripherals, and the small 8-pin PDIP/μMAX package enables compact DIN-rail module designs.
おすすめ
Touch Panel / Resistive Sensor Interface
The MAX145ACPA's pseudo-differential input architecture and 108 ksps sampling rate suit resistive touch-panel or position-sensor interfaces where two channels must be read ratiometrically. According to the datasheet, the less than 1 microamp power-down current enables aggressive duty cycling to extend battery life in handheld instruments. The 12-bit resolution provides 0.024 percent FS position precision, and the wide supply range supports 3.3 V and 5 V system rails. The 3-wire SPI interface requires only three microcontroller pins.
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: MAX145ACPA — 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 | MAX145ACPA+ | MAX144ACPA | MAX144BEUA | MAX1202ACAP | MAX1243ACPA |
|---|---|---|---|---|---|---|
| Package | PDIP-8 | PDIP-8 (same) | PDIP-8 (same) | μMAX-8 (SMD variant) | PDIP-8 (same) | PDIP-8 (same) |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Number of Channels | 2 (pseudo-differential) | 2 (pseudo-differential) | 2 (true differential) | 2 (true differential) | 1 (differential) | 1 (single-ended) |
| Supply Voltage Range | +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 | +/-5 V bipolar | +2.7 V to +5.25 V |
| Internal Reference | 2.5 V | 2.5 V | 2.5 V | 2.5 V | External only | External only |
| Serial Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI | SPI/QSPI/MICROWIRE |
主な差別化要因
- Pseudo-differential input configuration with internal 2.5 V reference （vs MAX144ACPA)
- 2-channel multiplexed input in 8-pin PDIP （vs MAX1243ACPA)
- Less than 1 microamp power-down current （vs MAX1202ACAP)
設計ノート
The MAX145ACPA's automatic power-down reduces quiescent current to less than 1 microamp between conversions, with a 2.5 microsecond wake-up time per the datasheet. For battery-powered designs, duty-cycle conversions to a 1-10 Hz effective sample rate rather than running continuously. Place a 0.1 microfarat decoupling capacitor within 5 mm of the VDD pin to suppress digital noise coupling into the analog front end.
Do not leave the REF pin floating when using the internal reference - the datasheet requires a 0.1 microfarat bypass capacitor on REF for stability. When using an external reference, ensure the reference source can source/sink the dynamic current drawn during conversion. The pseudo-differential inputs require the COM pin to be driven to within +/-0.1 V of analog ground to maintain linearity at the input common-mode range.
For 108 ksps full-rate operation, route the SPI clock (SCLK) and data (DOUT) traces over a continuous ground plane and keep trace lengths under 50 mm to avoid ringing. According to the datasheet timing diagram, hold CS low for the entire conversion-and-readout cycle, and ensure SCLK rise/fall times are under 20 ns to meet setup/hold timing at 108 ksps.
Estimated: At continuous 108 ksps with 3.3 V supply, the MAX145ACPA draws 1.5 mA typical, dissipating roughly 5 mW - well within the PDIP-8 thermal limit. However, in sealed enclosures at +70 C ambient, verify with a thermocouple measurement that junction temperature stays below +150 C, especially when sampling multiple channels at maximum rate.
コンプライアンス情報
MAX145ACPA+ ordering code is Pb-free/RoHS compliant per Maxim product page. Legacy MAX145ACPA (no + suffix) uses SnPb finish. AEC-Q100 not applicable for this commercial-grade part. Refer to MAX145AEPA for extended temperature grade.
