MAX1231ACEG+T - 12-Bit 300ksps ADC, 16-Ch, FIFO, QSOP-24 | ADI
MPN: MAX1231ACEG+T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.45 | $7.45 |
| 10 | $6.95 | $69.50 |
| 100 | $6.1 | $610.00 |
| 500 | $5.3 | $2,650.00 |
| 1,000 | $4.65 | $4,650.00 |
MAX1231ACEG+T Overview
An SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a type of data converter that uses a binary-search algorithm with an internal DAC and comparator to digitize an analog input in N conversion cycles for N bits of resolution. SAR ADCs offer deterministic latency, no pipeline delay, excellent DC accuracy, and are well-suited for multiplexed multi-channel data acquisition at moderate speeds, sitting in the broader hierarchy: ADC -> data converter -> mixed-signal IC -> semiconductor.
Key features of the MAX1231ACEG+T include 300 ksps throughput, an internal 2.5V reference (4.096V on the B-grade), ±1 °C internal temperature sensor accuracy, a 16-entry FIFO for host offload, SPI/QSPI/MICROWIRE-compatible serial interface, 3 V or 3.3 V single-supply operation, low 1.6 mA (typ) operating current, software-configurable unipolar/bipolar and single-ended/differential input ranges (0 to VREF, ±VREF, 0 to 2×VREF, ±2×VREF), and QSOP-24 footprint. The FIFO allows the part to capture bursts while the host processor is busy with other tasks.
The architecture combines a low-charge-distribution input T/H with a precision SAR core, an internal bandgap-derived reference, and a digital serial engine that supports daisy-chaining of multiple MAX1227/MAX1229/MAX1231 devices on a single SPI bus. The analog inputs can be configured as 8 single-ended channels (A-com version), 16 single-ended channels (B/C versions), or as differential pairs, and the internal temperature sensor die measurement simplifies system thermal monitoring.
Typical applications include industrial process control and data acquisition, system health monitoring with on-die temperature sensing, multichannel instrumentation, battery-powered portable data loggers, factory automation sensor interfaces, and medical patient monitoring front ends. The FIFO and channel-scan modes simplify firmware by offloading periodic scan housekeeping from the host MCU.
When designing with this device, ensure that the analog input signals remain within the absolute maximum ratings (GND - 0.3 V to VDD + 0.3 V), use the recommended 0.1 µF ceramic bypass capacitor on VDD placed within 5 mm of the pin, and configure the serial-interface clock polarity/phase to match the host controller. Unused analog inputs should be tied to a defined mid-supply voltage to minimize crosstalk.
This page synthesizes distributor pricing, pin-compatible same-family Maxim drop-in alternatives, and practical design notes that are not available in the standalone manufacturer datasheet, including FIFO mode configuration guidance and SPI daisy-chain wiring tips.
Drop-in alternatives for MAX1231ACEG+T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MAX1231ACEG+T (same form factor and footprint) — differing in Number of Input Channels, Operating Temperature Range, Internal Reference Voltage, Package, Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1231BCEG+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1231AEEG+T
✅ Drop-In✓ In Stock
$5.3 / Unit
View Datasheet →MAX1231ACEG+
✅ Drop-In✓ In Stock
$6.37 / Unit
View Datasheet →MAX1231BEEG+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1231ACEG+T Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Sampling Rate | 300 ksps |
| Number of Input Channels | 8 or 16 single-ended (4 or 8 differential) |
| Architecture | SAR (Successive Approximation Register) |
| Input Type | Single-Ended / Differential (software configurable) |
| Data Interface | SPI / QSPI / MICROWIRE-compatible serial |
| Supply Voltage | 3 V or 3.3 V nominal |
| Supply Current (operating, 300 ksps) | 1.6 mA (typ) |
| Internal Reference Voltage | 2.5 V (A-grade) |
| External Reference Range | 1.0 V to VDD |
| Input Voltage Range | 0 to VREF / ±VREF / 0 to 2×VREF / ±2×VREF |
| Internal FIFO | 16 entries |
| Internal Temperature Sensor Accuracy | ±1 °C |
| Linearity Error (INL) | ±1 LSB (max) |
| Operating Temperature Range | 0 °C to +70 °C (commercial, C-grade) |
| Package | 24-pin QSOP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
MAX1231ACEG+T Pin Configuration
| Pin 1 | AIN0 — Analog input channel 0 |
| Pin 2 | AIN1 — Analog input channel 1 |
| Pin 3 | AIN2 — Analog input channel 2 |
| Pin 4 | AIN3 — Analog input channel 3 |
| Pin 5 | AIN4 — Analog input channel 4 |
| Pin 6 | AIN5 — Analog input channel 5 |
| Pin 7 | AIN6 — Analog input channel 6 |
| Pin 8 | AIN7 — Analog input channel 7 |
| Pin 9 | AIN8 — Analog input channel 8 |
| Pin 10 | AIN9 — Analog input channel 9 |
| Pin 11 | AIN10 — Analog input channel 10 |
| Pin 12 | AIN11 — Analog input channel 11 |
| Pin 13 | AIN12 — Analog input channel 12 |
| Pin 14 | AIN13 — Analog input channel 13 |
| Pin 15 | AIN14 — Analog input channel 14 |
| Pin 16 | AIN15 — Analog input channel 15 |
| Pin 17 | REF — Reference input/output (2.5 V internal) |
| Pin 18 | GND — Ground |
| Pin 19 | VDD — Supply voltage (3.0 V to 3.6 V) |
| Pin 20 | CS — Chip select (active-low) |
| Pin 21 | SSTRB — Serial strobe output (conversion ready) |
| Pin 22 | DOUT — Serial data output |
| Pin 23 | DIN — Serial data input |
| Pin 24 | SCLK — Serial clock input |
Typical Applications
MAX1231ACEG+T is suitable for 6 applications: Industrial Process Control & Data Acquisition, System Health Monitoring with On-Die Temperature Sensing, Multichannel Instrumentation and Sensor Interfaces, Battery-Powered Portable Data Loggers, Factory Automation Sensor Interfaces, Medical Patient Monitoring Front End.
Industrial Process Control & Data Acquisition
The MAX1231ACEG+T's 16 single-ended (or 8 differential) analog inputs, 300 ksps throughput, and bipolar ±VREF/±2×VREF input ranges make it ideal for industrial process control panels. Per the datasheet, the part interfaces directly to 4-20 mA current-loop sensors through a shunt resistor, accepting signals that swing around ground without external level shifting. Its ±1 LSB INL ensures accurate measurement of thermocouple, pressure-transducer, and level-sensor outputs in PLC and DCS modules. The internal temperature sensor also tracks local ambient or board-level temperature for system health monitoring.
Recommended
System Health Monitoring with On-Die Temperature Sensing
The MAX1231ACEG+T integrates a ±1 °C accuracy on-die temperature sensor readable through the same SPI interface used for analog conversions. According to the Maxim datasheet, the temperature channel is selected via the configuration register and shares the same conversion pipeline, allowing the host MCU to monitor board or system temperature without an extra I2C/SPI temperature-sensor IC. Combined with the 16-entry FIFO, the part can periodically scan analog inputs while logging temperature trends for predictive maintenance and thermal shutdown protection in servers, switches, and industrial controllers.
Recommended
Multichannel Instrumentation and Sensor Interfaces
The MAX1231ACEG+T's flexible input configuration supports measurement bridges, RTDs, and strain-gauge signals through its software-configurable differential inputs and external-reference pin. Per the Maxim datasheet, the input T/H consumes low charge, minimizing disturbance to high-impedance sensor front-ends, while the 300 ksps throughput allows simultaneous sampling of vibration, pressure, and force sensors. The SPI-compatible serial interface supports daisy-chaining of multiple MAX1231 devices on a single SPI bus for expanding channel count in test-and-measurement instruments and laboratory data loggers.
Recommended
Battery-Powered Portable Data Loggers
The MAX1231ACEG+T draws only 1.6 mA (typical) at full 300 ksps throughput and supports 3.0-3.6 V single-supply operation, making it well-suited for battery-powered portable data loggers. According to the Maxim datasheet, the part includes software-controlled shutdown and reduced-power modes that drop current consumption to microamp levels between conversions, extending battery life in handheld environmental monitors, wearable health trackers, and remote IoT sensor nodes. The 16-entry FIFO allows the host MCU to sleep for extended periods while the ADC autonomously accumulates samples.
Recommended
Factory Automation Sensor Interfaces
The MAX1231ACEG+T's 16 single-ended analog inputs accept a wide variety of factory-floor sensor outputs including 0-10 V process signals, 4-20 mA current loops, and bridge-style transducers. According to the Maxim datasheet, the bipolar input range and software-configurable channel scan enable a single ADC to replace multiple discrete signal conditioners in PLC analog input modules and motor-control feedback boards. Its QSOP-24 footprint allows compact board layouts for high-density DIN-rail I/O modules and robotic controller cards.
Recommended
Medical Patient Monitoring Front End
The MAX1231ACEG+T's combination of 16 analog inputs, 12-bit resolution, and ±1 °C internal temperature sensor enables multi-parameter patient monitoring front ends in bedside monitors and portable ECG/blood-oxygen devices. Per the Maxim datasheet, the differential input mode supports direct connection to bio-potential electrodes with common-mode rejection, while the FIFO accommodates burst sampling of ECG waveforms without CPU intervention. The serial interface simplifies galvanic isolation through digital isolators, supporting patient-safety isolation requirements in IEC 60601-compliant medical equipment.
Recommended
Recommended Products Summary
Engineering reference data for MAX1231ACEG+T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1231BCEG+T | MAX1231AEEG+T | MAX1231ACEG+ | MAX1231BEEG+T | MAX1229ACEP+ |
|---|---|---|---|---|---|---|
| Brand | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) |
| Package | 24-QSOP | 24-QSOP - same | 24-QSOP - same | 24-QSOP - same | 24-QSOP - same | 20-QSOP - different |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 300 ksps | 300 ksps | 300 ksps | 300 ksps | 300 ksps | 300 ksps |
| Input Channels | 16 SE / 8 Diff | 16 SE / 8 Diff | 16 SE / 8 Diff | 16 SE / 8 Diff | 16 SE / 8 Diff | 12 SE / 6 Diff |
| Internal Reference | 2.5 V | 4.096 V | 2.5 V | 2.5 V | 4.096 V | 2.5 V |
| Operating Temperature | 0 to +70 °C (C-grade) | 0 to +70 °C | -40 to +85 °C (E-grade) | 0 to +70 °C | -40 to +85 °C | 0 to +70 °C |
| Internal FIFO | 16 entries | 16 entries | 16 entries | 16 entries | 16 entries | 16 entries |
| Internal Temp Sensor | Yes (±1 °C) | Yes (±1 °C) | Yes (±1 °C) | Yes (±1 °C) | Yes (±1 °C) | Yes (±1 °C) |
Key Differentiators
- Integrated ±1 °C on-die temperature sensor alongside ADC channels (vs MAX1225CTC+T)
- 16-entry FIFO reduces SPI bus overhead and host load (vs MAX1202ACAP)
- 300 ksps throughput with deterministic SAR latency (vs MAX1224CTC+)
Design Notes
Power the MAX1231ACEG+T from a clean 3.0-3.6 V rail with a 0.1 µF ceramic bypass capacitor placed within 5 mm of the VDD pin and a 10 µF bulk capacitor at the regulator output. Per the Maxim datasheet, VDD also serves as the reference-bypass node; inadequate decoupling directly increases noise on the analog inputs and degrades INL. Estimated: noise from a 50 mV ripple on VDD can introduce ~2 LSB of conversion error if not filtered.
Route the SPI signals (CS, SCLK, DIN, DOUT, SSTRB) as short, impedance-controlled traces and keep them separated from the analog input traces with a ground guard trace to prevent digital noise coupling. The REF pin must be bypassed with a 0.1 µF ceramic capacitor to GND as close as possible to the pin. Per Maxim reference designs, place the analog ground return path directly to the GND pin without sharing vias with digital return currents.
Unused analog inputs should be tied to a defined mid-supply voltage (VDD/2) to minimize crosstalk to active channels, not left floating. Ensure that analog input voltages remain within GND - 0.3 V to VDD + 0.3 V; exceeding the absolute maximum rating can permanently degrade the input ESD structures. Per the Maxim datasheet, the FIFO read pointer must be reset at startup to avoid reading stale data from previous power cycles.
When daisy-chaining multiple MAX1227/MAX1229/MAX1231 devices on a single SPI bus, connect DOUT of each upstream device to DIN of the next device and tie all CS lines individually to the host. Per the Maxim datasheet, the maximum SCLK frequency is up to 4.8 MHz at VDD = 3.3 V; exceeding this can cause data corruption. Use a logic-level translator if your host MCU SPI operates at 1.8 V or 5 V logic levels.
Compliance Information
RoHS and REACH compliant per Maxim Integrated (now Analog Devices) product declaration. Lead-free finish. Not AEC-Q100 qualified - choose MAX1231AEEG+T or MAX1231BEEG+T for extended industrial temperature grades.
