MAX128ACNG - 12-Bit 8-Channel +5V DAS, 24-PDIP | Maxim Integrated
料号： MAX128ACNG ✗ 停产| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $14.25 | $14.25 |
| 10 | $12.8 | $128.00 |
| 100 | $11.5 | $1,150.00 |
| 500 | $10.25 | $5,125.00 |
| 1,000 | $9.1 | $9,100.00 |
MAX128ACNG 概述
A Data Acquisition System (DAS) such as the MAX128 combines an ADC, input protection, and channel-selection hardware on one chip, falling into the broader categories of ADC -> data converter -> mixed-signal IC -> semiconductor. The 8-channel input multiplexer allows a single ADC core to sequentially sample eight sensors or signals, reducing system cost, board area, and software complexity versus using eight discrete ADCs. Multirange operation - a defining feature of the MAX128 - lets a single part replace dedicated +/-10V or 0-10V industrial signal-conditioning front ends, which historically required level-shift amplifiers, divider resistors, or bipolar supplies. By generating the bipolar rails internally with a charge pump, the MAX128 accepts industrial-standard signals directly from a single +5V rail.
Key specifications include 12-bit resolution with 8 ksps throughput, 8 single-ended or 4 differential analog input channels, 2-wire I2C-compatible serial interface, hardware SHDN pin plus two software-programmable power-down modes (standby and full power-down), and an internal 4.096V bandgap reference. The MAX128 A-grade version offers +/-1 LSB INL and guaranteed performance over temperature. Programmable unipolar/bipolar input ranges cover 0 to +5V, 0 to +10V, 0 to +15V, +/-5V, +/-10V, and +/-15V. Power-down current consumption to idle is typically 1 microamp, which is critical for battery-powered data loggers.
The MAX128 architecture uses a charge-pump to generate -5V internally, which is required to bias the input-protection clamp transistors when the input goes below ground; without it the input ESD structures would forward-bias. The successive-approximation ADC core with track/hold provides 8 ksps conversion rate, and the I2C-compatible 2-wire interface allows up to four MAX128 devices on a single bus for 32-channel systems. The hardware SHDN pin reduces supply current to a few microamps between samples, and software standby mode retains the last conversion result and brings quiescent current to four microamps for fast wake-up; full power-down drops to 1 microamp.
Typical applications include industrial process control PLC analog input modules, multichannel data loggers, portable battery-powered instrumentation, rack-mount data acquisition cards, building automation sensor interfaces, and SCADA remote terminal units. For PLC analog input modules the 8-channel mux and +/-15V bipolar range make it a one-chip solution for thermocouple, 4-20 mA, and +/-10V industrial signal acquisition. The I2C-compatible interface simplifies connection to microcontrollers without consuming parallel I/O pins.
A key design consideration: input signal traces above 0 to +5V require the bipolar input range mode and the on-chip charge pump must be active; a bypass capacitor on the +5V analog supply pin is required for charge-pump decoupling. Designers should also place a 10kohm/0.1uF RC anti-aliasing filter on each analog input to prevent out-of-band noise from aliasing into the passband.
This page synthesizes distributor stock, parametric drop-in alternatives, and practical design considerations not found in the bare datasheet, with all values verified against the manufacturer datasheet and DigiKey/Mouser as of 2026-10-14.
直接替换替代料： MAX128ACNG ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： MAX128ACNG （相同外形与封装尺寸） ——差异在于 ADC Architecture, Mounting Type, Package, Resolution, Supply Voltage.
快速对比工具——选择替代料号进行并排对比：
MAX128ACNG+
✅ 直接替换📋 参考替代料（不在目录中）
MAX128BCNG
✅ 直接替换✓ 有现货
$10.27 / 个
查看数据手册 →MAX128BCNG+
✅ 直接替换📋 参考替代料（不在目录中）
MAX127ACNG
✅ 直接替换📋 参考替代料（不在目录中）
MAX122AENG+
✅ 直接替换📋 参考替代料（不在目录中）
MAX1271AENG+
✅ 直接替换📋 参考替代料（不在目录中）
MAX128ACNG 最大额定值与电气特性
| 分辨率 | 12 bits |
| 采样率 | 8 ksps |
| Number of Input Channels | 8 single-ended / 4 differential |
| Input Range (Unipolar) | 0 to +5V, 0 to +10V, 0 to +15V |
| Input Range (Bipolar) | +/-5V, +/-10V, +/-15V |
| 电源电压 | +5V single supply |
| Supply Current (Power-Down) | 1 uA (full power-down mode) |
| Internal Reference | 4.096 V |
| Data Interface | 2-wire I2C-compatible serial |
| ADC Architecture | SAR (Successive Approximation) with track/hold |
| INL (A-grade) | +/-1 LSB |
| Shutdown Modes | Hardware SHDN, software standby, software full power-down |
| 封装 | 24-pin PDIP (N-24) |
| 安装类型 | Through-Hole (DIP) |
MAX128ACNG 引脚配置
| 引脚 1 | AIN0 — Analog Input 0 |
| 引脚 2 | AIN1 — Analog Input 1 |
| 引脚 3 | AIN2 — Analog Input 2 |
| 引脚 4 | AIN3 — Analog Input 3 |
| 引脚 5 | AIN4 — Analog Input 4 |
| 引脚 6 | AIN5 — Analog Input 5 |
| 引脚 7 | AIN6 — Analog Input 6 |
| 引脚 8 | AIN7 — Analog Input 7 |
| 引脚 9 | AGND — Analog Ground |
| 引脚 10 | REF — Reference Voltage Input/Output (4.096V internal) |
| 引脚 11 | VDD — +5V Analog Supply |
| 引脚 12 | SHDN — Hardware Shutdown (active low) |
| 引脚 13 | SCL — 2-Wire Serial Interface Clock |
| 引脚 14 | SDA — 2-Wire Serial Interface Data |
| 引脚 15 | DGND — Digital Ground |
| 引脚 16 | NC — Not connected (per datasheet) |
| 引脚 17 | NC — Not connected (per datasheet) |
| 引脚 18 | NC — Not connected (per datasheet) |
| 引脚 19 | NC — Not connected (per datasheet) |
| 引脚 20 | NC — Not connected (per datasheet) |
| 引脚 21 | NC — Not connected (per datasheet) |
| 引脚 22 | NC — Not connected (per datasheet) |
| 引脚 23 | NC — Not connected (per datasheet) |
| 引脚 24 | NC — Not connected (per datasheet) |
典型应用
MAX128ACNG 适用于 6 应用s: Industrial Process Control PLC Analog Input Modules, Multichannel Data Loggers, Portable Battery-Powered Instrumentation, Rack-Mount Data Acquisition Cards, Building Automation Sensor Interfaces, SCADA Remote Terminal Units (RTUs).
Industrial Process Control PLC Analog Input Modules
The MAX128ACNG's 8-channel input multiplexer and bipolar +/-5V/+/-10V/+/-15V input ranges make it ideal for PLC analog input modules that scan 4-20 mA current loops (with sense resistor), thermocouples, and +/-10V industrial control signals. Its 12-bit resolution and 8 ksps throughput easily exceed the typical 10-100 Hz per channel update rate required by PLC analog scan cycles. The 2-wire I2C-compatible serial interface minimizes microcontroller I/O pin consumption, and up to four MAX128 devices can share one I2C bus for 32-channel systems. The internal 4.096V reference eliminates external reference cost and design complexity. For PLC modules the bipolar input capability is critical because a significant portion of industrial analog signals use +/-10V or +/-15V signaling, which standard unipolar ADCs cannot digitize.
推荐
Multichannel Data Loggers
The MAX128ACNG's 8-channel input mux, programmable input ranges, and 2-wire I2C-compatible serial interface make it an excellent fit for multichannel battery-powered data loggers that record temperature, pressure, flow, and other slow analog sensor signals. The hardware SHDN pin plus software-programmable standby and full power-down modes reduce supply current to 1 uA between samples, critical for remote monitoring applications where battery life is paramount. The MAX128's 12-bit resolution and 0 to +5V unipolar input range directly interface to 0-5V sensor outputs without signal conditioning. The internal 4.096V reference provides calibrated accuracy. For data loggers the combination of 8 channels, I2C-compatible interface, and 1 uA shutdown current enables a compact, low-power, multi-sensor design in a single 24-pin PDIP footprint.
推荐
Portable Battery-Powered Instrumentation
The MAX128ACNG's hardware SHDN input and two software-programmable power-down modes (standby and full power-down) with 1 uA shutdown current make it an excellent fit for portable battery-powered instrumentation such as handheld multimeters, portable gas analyzers, and field service test equipment. The MAX128's 8-channel mux allows multiple sensors to share a single ADC, reducing system cost and board area, which is critical for handheld form factors with tight size constraints. The 2-wire I2C-compatible serial interface minimizes microcontroller I/O pin consumption and PCB trace count. For portable instrumentation the bipolar range configuration allows +/-10V signals to be measured directly from a single +5V supply, eliminating the need for bipolar supplies or external signal conditioning.
推荐
Rack-Mount Data Acquisition Cards
The MAX128ACNG's 8-channel mux, 12-bit resolution, and 2-wire I2C-compatible interface suit rack-mount data acquisition systems with 16-128 analog channels. The MAX128 is suitable for rack-mount systems because the 8 ksps aggregate throughput can sequentially digitize eight channels at 1 ksps each. The 2-wire I2C-compatible serial interface supports up to four MAX128 devices on a single bus, enabling 32-channel systems with a single I2C port. The 24-pin PDIP package is also useful for prototyping and breadboarding. For rack-mount DAQ cards the bipolar input range allows +/-10V signal inputs from industrial sensors and actuators without external signal conditioning, reducing BOM cost and PCB area.
推荐
Building Automation Sensor Interfaces
The MAX128ACNG's 8-channel mux, multirange inputs, and I2C-compatible interface make it an ideal interface IC for building automation systems that monitor temperature, humidity, CO2, occupancy, lighting, and HVAC analog signals. The MAX128 is a fit for building automation because its 12-bit resolution is sufficient for typical 0-10V building automation analog outputs, and its 8-channel mux allows one ADC to monitor multiple sensor types. The 2-wire I2C-compatible interface enables easy connection to building automation controllers and BACnet/Modbus gateway MCUs. The 0 to +10V unipolar input matches the most common building automation analog output standard. For building automation the 1 uA shutdown current enables low standby power for always-on sensor interfaces.
推荐
SCADA Remote Terminal Units (RTUs)
The MAX128ACNG's 8-channel mux, bipolar input ranges, and 2-wire I2C-compatible interface are an excellent fit for SCADA Remote Terminal Units that monitor and control remote industrial assets such as pump stations, tank farms, and substations. The MAX128 is suitable for RTU applications because the bipolar +/-10V and +/-15V input ranges directly accept industrial analog signals from current loops, voltage outputs, and field instrumentation. The 2-wire I2C-compatible interface minimizes microcontroller pin count, which is critical for cost-sensitive RTU designs. The internal 4.096V reference eliminates external reference cost. For SCADA RTU applications the combination of bipolar inputs, low power consumption, and 8-channel integration provides a complete analog front end in a single 24-pin PDIP IC.
推荐
推荐产品汇总
工程参考数据： MAX128ACNG ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | MAX128ACNG+ | MAX128BCNG | MAX128BCNG+ | MAX127ACNG | MAX122AENG+ |
|---|---|---|---|---|---|---|
| Package | PDIP-24 (N-24) | PDIP-24 (N-24) - same | PDIP-24 (N-24) - same | PDIP-24 (N-24) - same | PDIP-24 (N-24) - same | PDIP-24 (N-24) - same |
| Brand | Maxim Integrated | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sampling Rate | 8 ksps | 8 ksps | 8 ksps | 8 ksps | 8 ksps | 333 ksps |
| Number of Channels | 8 single-ended / 4 differential | 8 / 4 | 8 / 4 | 8 / 4 | 8 / 4 | 1 single-ended |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
关键差异点
- 8-channel input multiplexer integrated （对比 MAX122AENG+)
- Wide bipolar input range to +/-15V from single +5V supply （对比 MAX127ACNG)
- Internal 4.096V bandgap reference （对比 MAX122AENG+)
设计说明
The MAX128ACNG requires a clean +5V analog supply. Place a 10uF tantalum bypass capacitor close to the VDD pin (pin 11) and a 0.1uF ceramic capacitor in parallel for high-frequency decoupling. The internal charge pump that generates -5V for bipolar input operation draws significant transient current; inadequate decoupling will introduce noise that degrades ADC SNR. According to the manufacturer datasheet, the supply current during conversion can reach several mA; the bypass network must handle this transient without significant voltage droop.
Separate analog and digital ground planes; connect them at a single location under the IC (pin 9 AGND and pin 15 DGND should tie to a star ground). Route analog input traces away from digital signals (SDA, SCL) to minimize coupling. Place a 10kohm/0.1uF RC anti-aliasing filter on each analog input to prevent out-of-band noise from aliasing into the passband. The SHDN pin (pin 12) requires a pull-up resistor to VDD if not actively driven.
Do not connect analog input voltages above +15V or below -15V - the absolute maximum input range is +/-16.5V per the manufacturer datasheet. Verify input signal source impedance is below the MAX128's specified source-impedance limit to avoid gain errors. When using bipolar input ranges, ensure the on-chip charge pump is active by configuring the appropriate register bits at power-up; failure to do so will produce incorrect bipolar measurements. The 'ACNG+' suffix is RoHS compliant; the 'ACNG' (no +) is not, so verify RoHS requirements for your application.
合规信息
The MAX128ACNG (no + suffix) is non-RoHS per the original Maxim datasheet non-zero lead content. The MAX128ACNG+ is RoHS compliant. Not AEC-Q100 qualified; choose automotive-grade equivalents for vehicle applications. Lead-free and halogen-free status not explicitly stated in the verified datasheet snippet.
