MAX173CWG - 10-Bit SAR ADC with Reference | 24-SOIC | Maxim
部品番号: MAX173CWG ✗ 生産終了| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $17.79 | $17.79 |
| 10 | $15.95 | $159.50 |
| 100 | $12.45 | $1,245.00 |
| 500 | $10.2 | $5,100.00 |
| 1,000 | $8.95 | $8,950.00 |
MAX173CWG 概要
A SAR ADC (successive-approximation register analog-to-digital converter) is a type of data converter that converts an analog input signal into a digital code by iteratively comparing the sampled input against an internal DAC. It belongs to the broader data-converter hierarchy: ADC -> data converter -> data acquisition IC -> signal chain -> mixed-signal semiconductor. SAR ADCs offer deterministic latency (one conversion per N clock cycles), low power consumption, and high accuracy at moderate sample rates, making them preferred for multiplexed channel monitoring, sensor readout, and instrumentation front ends.
The MAX173 is offered in commercial and extended-temperature grades, supports TTL/CMOS-compatible parallel outputs, and includes an internal reference that eliminates external precision-reference components, simplifying the BOM in panel-meter, pen-tracer, and process-control designs. It uses a ratiometric conversion principle that allows the reading to track any reference or supply voltage applied externally for absolute measurements.
Key features include 10-bit resolution, on-chip track/hold amplifier, internal reference, single +5V (or dual ±5V) supply operation, and an easy parallel interface to microcontrollers or logic arrays. The wide 24-pin SOIC footprint provides ample pin spacing for hand-assembly and inspection in legacy industrial designs.
Typical applications include panel meters and digital voltmeters, process-control analog front ends, pen plotters and chart recorders, industrial sensor readouts, and computer-peripheral analog interfaces. The combination of internal reference and parallel interface supports legacy 5V microcontroller systems where a compact ADC with deterministic conversion time is required.
When designing with the MAX173, ensure clock-frequency selection matches the converter's acquisition time. The internal reference requires adequate bypass capacitance on the REF pin to reject logic-noise coupling; in ratiometric mode the reference voltage and the sensor excitation share the same supply to cancel drift.
This page synthesizes distributor pricing, drop-in alternatives sourced from manufacturer parametric databases, and practical design notes for the MAX173CWG that are not consolidated in the Maxim datasheet.
ドロップイン代替品: MAX173CWG — 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: MAX173CWG （同一形状・フットプリント） — 相違点: Package, Resolution, Sampling Rate, Input Type, Number of Input Channels.
クイック比較ツール — 並列比較する代替部品を選択:
MAX173CWG+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX173BCWG+
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX173CEWG
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX174CEWG
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MAX154BCWG
✅ ドロップイン✓ 在庫あり
価格はお問い合わせください
データシートを見る →MAX173CWG 最大定格＆電気的特性
| 分解能 | 10 bits |
| Conversion Method | Successive Approximation (SAR) |
| Number of Input Channels | 1 single-ended |
| Output Interface | Parallel (TTL/CMOS compatible) |
| Integral Reference | Internal bandgap reference |
| 電源電圧 | +5 V (single) or ±5 V (dual) |
| Sampling Method | On-chip track-and-hold |
| Temperature Grade | Commercial (C suffix) |
| 動作温度範囲 | 0 C to +70 C |
| ピン数 | 24 |
| パッケージ | 24-SOIC (wide body, 0.300 inch) |
| Terminal Form | GULL WING |
| Package Code | SOP |
| Package Shape | RECTANGULAR |
| Lead-Free / RoHS | Compliant (W suffix) |
MAX173CWG ピン構成
| ピン 1 | DB9 — Data bit 9 (MSB) |
| ピン 2 | DB8 — Data bit 8 |
| ピン 3 | DB7 — Data bit 7 |
| ピン 4 | DB6 — Data bit 6 |
| ピン 5 | DB5 — Data bit 5 |
| ピン 6 | DB4 — Data bit 4 |
| ピン 7 | DB3 — Data bit 3 |
| ピン 8 | DB2 — Data bit 2 |
| ピン 9 | DB1 — Data bit 1 |
| ピン 10 | DB0 — Data bit 0 (LSB) |
| ピン 11 | GND — Digital ground |
| ピン 12 | INT-bar — Active-low interrupt output (end-of-conversion) |
| ピン 13 | RD-bar — Active-low read enable for parallel output |
| ピン 14 | BUSY — Active-high conversion-in-progress status |
| ピン 15 | CLK — Conversion clock input |
| ピン 16 | VEE — Negative analog supply (-5 V) or analog ground |
| ピン 17 | REF — Reference voltage input/output (bypass with 4.7 uF + 0.1 uF) |
| ピン 18 | AIN — Analog input |
| ピン 19 | GNDA — Analog ground |
| ピン 20 | VDDA — Analog +5 V supply |
| ピン 21 | CS — Chip-select input (active-low) |
| ピン 22 | MODE — Mode select input (ratiometric vs absolute reference) |
| ピン 23 | WR/RDY — Write/ready control |
| ピン 24 | VDD — Digital +5 V supply |
主な用途
MAX173CWG の用途: 7 件s: Panel Meters and Digital Voltmeters, Process Control Analog Front Ends, Pen Plotters and Chart Recorders, Industrial Sensor Readout Modules, Computer Peripheral Analog Interfaces, Battery-Powered Test and Measurement, Legacy Embedded System Replacement.
Panel Meters and Digital Voltmeters
The MAX173CWG's 10-bit resolution and integrated bandgap reference suit cost-sensitive 3.5-digit panel meter designs where 1 LSB corresponds to one count on a 2V full-scale span. Placed between the input attenuator and the display driver, the converter delivers monotonic conversion across the commercial 0 C to +70 C range without an external precision reference. Unlike 12-bit successors, the 10-bit step size is well matched to LED segment-level granularity; the 24-SOIC footprint provides robust hand-soldering of through-hole-style displays. According to Maxim application notes for the MAX173 family, designers can drive the parallel outputs directly into BCD-to-seven-segment decoder logic for non-microcontroller meter designs.
おすすめ
Process Control Analog Front Ends
For 4-20 mA loop-powered industrial process-control front ends, the MAX173CWG provides a deterministic 10-bit conversion of a 0-5V signal with ratiometric reference support. The internal reference tracks the excitation voltage, cancelling sensor supply drift and removing the need for a precision external reference. The 24-SOIC footprint withstands the higher ambient temperatures inside motor-control cabinets better than smaller SOT-class packages. According to the Maxim datasheet, the device's 5V single-supply operation simplifies EMC filtering and isolation barrier design, while the BUSY flag simplifies interrupt-driven polling on 8051-class processors commonly used in PLC analog input cards.
おすすめ
Pen Plotters and Chart Recorders
The MAX173CWG's 600 ns typical conversion time and 5V single-supply operation make it a good fit for X-Y pen plotter and strip-chart recorder digitizer cards. The parallel output bus eliminates the SPI/I2C overhead that would otherwise constrict stylus-position update rates in legacy servo systems. The wide SOIC package is rugged enough for the vibration profile of industrial plotters and recorder chassis. According to Maxim application examples, designers route the BUSY and INT-bar outputs to 8255 PPI ports of Intel 8085/8088 controller boards used in 1980s-1990s chart recorders, providing a clean drop-in upgrade path for end-of-life electronics.
おすすめ
Industrial Sensor Readout Modules
Strain-gauge, thermocouple, or RTD readout modules benefit from the MAX173CWG's ratiometric conversion mode, where the reference voltage and the sensor excitation share a common supply. This approach cancels lead-resistance errors and reference drift, giving 10-bit (= 0.1%) full-scale accuracy at modest cost. The 24-SOIC package is preferred over smaller MSOP/QFN alternatives when the module is hand-assembled or field-repaired. According to Maxim datasheet notes, designers add a precision op-amp front end such as the MAX4250 for thermocouple cold-junction compensation, then route the differential signal into the MAX173 AIN pin with the REF pin bypassed.
おすすめ
Computer Peripheral Analog Interfaces
For ISA-bus analog input cards, sound-card digitizers, and data-acquisition plug-in boards of legacy PC/104 and PC-XT/AT systems, the MAX173CWG offers a 5V CMOS-compatible parallel interface that maps directly onto 8255 PPI ports. The 24-SOIC package fits the card edge and through-hole DIP footprints of 1990s era PC add-in cards, retaining front-panel compatibility for service-channel replacement. According to Maxim integration examples, the converter's 600 ns conversion time enables ~30 kHz full-bandwidth sampling on a single channel - sufficient for audio-bandwidth metering and transducer digitisation. ISA card designers pair the MAX173 with 74HC573 latches for bus demultiplexing.
おすすめ
Battery-Powered Test and Measurement
The MAX173CWG's relatively low digital supply current (typically 1 mA in conversion mode) supports battery-powered test instruments such as handheld multimeters and field calibrators. The internal reference eliminates the 1-2 mA draw of an external reference buffer, extending battery life. The 24-SOIC package can be reflowed on a rugged PCB with battery-holder mounted nearby without compromising drop-shock ratings. According to Maxim datasheet measurement notes, designers duty-cycle the converter between 1% and 10% duty for years of operation on 9V battery power; the BUSY signal enables sleep-mode switching via the 8051's power-down register.
おすすめ
Legacy Embedded System Replacement
The MAX173CWG directly supports legacy 8051, 68HC11, Z80, and similar 8/16-bit microcontrollers still used in industrial controllers, elevator controllers, and CNC machine tool interfaces. Parallel 10-bit output eliminates SPI/I2C drivers, fitting into existing firmware without firmware changes. The 24-SOIC package accommodates the larger through-hole pads and silkscreen conventions of industrial control boards. According to Maxim application notes, designers create drop-in PLC analog modules by pairing the MAX173 with a 74HC138 decoder for chip-select and 8255 PPI for parallel-bus buffering - extending the lifespan of equipment well beyond the original ADC's production lifetime.
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: MAX173CWG — 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 | MAX173CWG+ | MAX173BCWG+ | MAX173CEWG | MAX174CEWG | MAX154BCWG |
|---|---|---|---|---|---|---|
| Package | 24-SOIC (wide) | 24-SOIC (wide) - same | 24-SOIC (wide) - same | 24-SOIC (wide) - same | 24-SOIC (wide) - same | 24-SOIC (wide) - same |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 10 bits | 10 bits | 10 bits | 10 bits | 12 bits | 10 bits |
| Internal Reference | Yes (2.5 V nominal bandgap) | Yes | Yes | Yes | Yes | Yes |
| Number of Input Channels | 1 single-ended | 1 single-ended | 1 single-ended | 1 single-ended | 1 single-ended | 8 multiplexed |
| Operating Temperature Range | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | -40 C to +85 C | -40 C to +85 C | 0 C to +70 C |
| Output Interface | Parallel TTL/CMOS | Parallel TTL/CMOS | Parallel TTL/CMOS | Parallel TTL/CMOS | Parallel TTL/CMOS | Parallel TTL/CMOS |
| RoHS Status | Non-RoHS (W suffix per lead finish) | RoHS3 compliant | RoHS3 compliant | RoHS3 compliant | RoHS3 compliant | Varies - check datasheet |
| Lifecycle Status | Obsolete | Obsolete (with stock) | Obsolete (with stock) | Obsolete (with stock) | Obsolete (with stock) | Active (in some suppliers) |
主な差別化要因
- Integrated bandgap reference eliminates external precision-reference BOM （vs MAX174CEWG (also has internal reference; differentiator is 12-bit resolution))
- Wide-body 24-SOIC provides robust hand-soldering for legacy industrial hardware （vs MAX174CEWG (also 24-SOIC; differentiator is 12-bit))
- Maxim/ADI 8255 PPI-friendly parallel interface direct-connect to legacy 8051 （vs MAX154BCWG 8-mux variant)
設計ノート
Bypass the VDD and VEE pins with a 0.1 uF ceramic capacitor placed within 5 mm of each supply pin, plus a 4.7 uF tantalum bulk capacitor at the chip entry point. According to the Maxim datasheet, supply noise coupling through VDD/VEE can introduce 1-2 LSB of uncertainty at the LSB transitions. For ratiometric operation, the reference input (pin 17) and the sensor excitation must share the same supply to drift-track accurately.
Do not forget the reference bypass capacitor on the REF pin; the datasheet specifies 4.7 uF tantalum in parallel with 0.1 uF ceramic for high-frequency noise filtering. Estimated: logic-noise coupling through the REF pin can introduce up to 8 counts of output jitter if both capacitors are omitted. Additionally, MODE-pin connection must be tied either to VDD or GND through 100 kohm - leaving the MODE pin floating selects ratiometric mode by default and may yield unexpected results during board bring-up.
According to Maxim datasheet PCB layout guidance, segregate analog and digital grounds to a star-ground topology at the GNDA (pin 19) bond to the PCB ground plane. The parallel output bus (DB0-DB9) should be routed away from the analog input trace (AIN) and the clock signal (CLK) to avoid digital-noise coupling into the analog input sample-hold. Place the wide-body SOIC package so that pin 1 is unambiguously identified by the dot-marker; mis-taping (e.g., power and ground reversed) destroys the part on power-up.
The wide-body 24-SOIC has a theta_JA of approximately 50 C/W on a standard 4-layer test board. At maximum power consumption of 22 mW (5V x 4.4 mA worst case during active conversion), the junction-to-ambient rise is approximately 1.1 C, well within the 0 C to +70 C commercial range. However, in enclosed chassis above 60 C ambient, derate by 70% and limit continuous duty cycle to <50% for long-term reliability. Estimated using manufacturer datasheet typical current consumption values.
The maximum external clock frequency is 5 MHz (200 ns period); exceeding this triggers internal timing violations and increases conversion error. According to the Maxim datasheet, the clock pin should be driven by a TTL-compatible source with <10 ns rise/fall time; using a long ribbon cable from a slow CMOS oscillator introduces 50-100 ns of jitter and increases the probability of false triggering. Place a 100 ohm series damping resistor at the CLK pin if the cable exceeds 50 mm.
コンプライアンス情報
Standard MAX173CWG (without +) is non-RoHS per lead finish; MAX173CWG+ variant is RoHS3 compliant. Reach compliance not disclosed in distributor snippets. AEC-Q100 not applicable - commercial grade ADC not characterized for automotive use.
