MAX1231AEEG+T - 12-Bit 300ksps ADC, FIFO, Temp Sensor, SSOP-24 | Maxim
MPN: MAX1231AEEG+T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $8.05 | $80.50 |
| 100 | $6.95 | $695.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.3 | $5,300.00 |
MAX1231AEEG+T Overview
What is a successive-approximation ADC? A SAR ADC is a type of analog-to-digital converter that uses a binary-search algorithm and a precision DAC to convert an analog input to a digital code one bit at a time per clock cycle. SAR ADCs sit in the converter hierarchy: ADC -> data converter -> mixed-signal IC -> semiconductor. They are favored over delta-sigma converters where low latency, deterministic sampling, and high absolute accuracy at moderate resolutions (10-16 bit) are required, such as in industrial process control and sensor monitoring.
Key features include 12-bit resolution with no missing codes, ±1 LSB INL (max), an analog multiplexer supporting 8 single-ended or 4 pseudo-differential inputs (channel count varies by family member: MAX1227 has 8, MAX1229 has 12, MAX1231 has 16), SPI/QSPI/MICROWIRE-compatible serial interface, and a hardware shutdown mode that drops supply current to under 1 µA. The 16-entry FIFO reduces host MCU overhead by allowing block reads of multiple conversions.
The MAX1231AEEG+T uses a capacitive charge-redistribution DAC with a precision bandgap reference and an integrated temperature sensor routed through the analog mux, eliminating the need for an external temp-sensing IC. The architecture achieves 300 ksps throughput while consuming only 2.7 mA (typ) active and 1 µA shutdown, making it appropriate for both high-speed data acquisition and power-conscious portable designs.
Typical applications include industrial process control, multichannel data acquisition systems, patient monitoring and portable medical instrumentation, factory automation sensor panels, and thermocouple/RTD temperature compensation. Designers choose the MAX1231AEEG+T when they need a complete, calibrated 12-bit acquisition front end with embedded temperature sensing in a small SSOP footprint.
When designing with this part, place the 0.1 µF supply bypass capacitors within 5 mm of AVDD and DVDD, and route REF+ to AVDD via a short trace to preserve reference accuracy. Do not exceed the absolute maximum AVDD of 4.2 V or apply analog inputs above AVDD + 0.3 V, as the input ESD structure is not tolerant of over-range.
This page synthesizes distributor pricing, drop-in alternatives sourced from the Maxim part family, and practical design notes that are not collated in the manufacturer datasheet.
Drop-in alternatives for MAX1231AEEG+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 MAX1231AEEG+T (same form factor and footprint) — differing in Internal Reference Voltage, Number of Input Channels, Operating Temperature Range, Resolution, Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1231ACEG+T
✅ Drop-In✓ In Stock
$4.65 / Unit
View Datasheet →MAX1231AEEG
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1231AEEG-T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1231BCEG+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1231BEEG+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1231AEEG+T Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Sample Rate | 300 ksps |
| Number of Input Channels | 16 single-ended / 8 pseudo-differential |
| Architecture | SAR (Successive Approximation) |
| Analog Supply Voltage (AVDD) | +3.0 V to +3.6 V |
| Digital Supply Voltage (DVDD) | +1.7 V to +3.6 V |
| Internal Reference Voltage | +4.096 V |
| Integral Nonlinearity (INL) | ±1 LSB (max) |
| Operating Temperature Range | -40 °C to +85 °C (industrial) |
| Package | 24-pin SSOP (QSOP variant) |
| Mounting Type | Surface Mount |
| FIFO Buffer | 16 entries |
| Internal Temperature Sensor Accuracy | ±1 °C |
| Serial Interface | SPI / QSPI / MICROWIRE compatible |
| Active Supply Current | 2.7 mA (typ at 300 ksps) |
| Shutdown Current | <1 µA |
| RoHS Status | Compliant |
MAX1231AEEG+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 | GND — Ground |
| Pin 10 | AIN8 — Analog input channel 8 |
| Pin 11 | AIN9 — Analog input channel 9 |
| Pin 12 | AIN10 — Analog input channel 10 |
| Pin 13 | AIN11 — Analog input channel 11 |
| Pin 14 | AIN12 — Analog input channel 12 |
| Pin 15 | AIN13 — Analog input channel 13 |
| Pin 16 | AIN14/AIN_TEMP — Analog input channel 14 / internal temperature sensor |
| Pin 17 | AIN15 — Analog input channel 15 |
| Pin 18 | REF — Internal reference decoupling node (4.096 V) |
| Pin 19 | SCLK — Serial clock input (SPI/QSPI/MICROWIRE) |
| Pin 20 | DOUT — Serial data output |
| Pin 21 | DIN — Serial data input |
| Pin 22 | CS — Active-low chip select |
| Pin 23 | GND — Ground |
| Pin 24 | AVDD — Analog supply (+3.0 V to +3.6 V) |
Typical Applications
MAX1231AEEG+T is suitable for 6 applications: Industrial Process Control & PLC Sensor Front End, Multichannel Data Acquisition Systems (DAQ), Portable Medical & Patient Monitoring Instrumentation, Factory Automation & Distributed Sensor Panels, Thermocouple & RTD Temperature Compensation Systems, Battery-Powered Wireless Sensor Hubs.
Industrial Process Control & PLC Sensor Front End
The MAX1231AEEG+T is a strong fit for industrial process-control front ends because its 16 single-ended / 8 pseudo-differential analog inputs allow direct connection of multiple 4-20 mA loop, 0-10 V, and thermocouple-conditioned signals through scaling amplifiers. With 12-bit resolution and 300 ksps throughput, it can digitize the full analog panel scan inside one SPI transaction using the 16-entry FIFO, eliminating host timing overhead in PLC and DCS cards. The internal 4.096 V reference gives a 1 mV/LSB scale, while the ±1°C temperature sensor on channel 15 reports cold-junction compensation data for thermocouple inputs. Industrial grade -40°C to +85°C operation tolerates cabinet-internal heat and outdoor panel environments.
Recommended
Multichannel Data Acquisition Systems (DAQ)
For bench and rack-mount data acquisition systems the MAX1231AEEG+T offers 300 ksps conversion at full 12-bit accuracy with no missing codes, suiting per-channel waveform sampling at rates up to 100 kHz. Its 16-channel mux reduces the analog-input footprint versus discrete ADC solutions, and the 16-entry FIFO lets the host controller service scans in batches, simplifying USB or Ethernet DAQ firmware. The hardware shutdown mode (<1 µA) supports battery-powered portable loggers, while the internal reference eliminates reference-calibration routines. Use a MAX1165AEUI+T as a parallel companion for sampling-rate-sensitive channels when simultaneous sampling is required.
Recommended
Portable Medical & Patient Monitoring Instrumentation
Portable patient monitors and bedside diagnostic instruments benefit from the MAX1231AEEG+T's low 2.7 mA active supply current and sub-1 µA shutdown mode, extending battery life during continuous SpO2, ECG, and temperature monitoring. The 16 inputs can be routed to ECG leads, SpO2 current-sense amplifiers, thermistor bridges, and respiration impedance channels. The internal ±1°C temperature sensor gives disposable thermistor calibration offsets for body-temperature channels, removing the need for a separate thermistor IC. The 12-bit resolution is sufficient for vital-sign amplitude quantization where 4-5 µV/LSB sensitivity is acceptable; choose the MAX1162ACUB+T for higher-resolution companion channels.
Recommended
Factory Automation & Distributed Sensor Panels
Factory automation panels that aggregate vibration, pressure, and proximity sensors can use a single MAX1231AEEG+T per panel, sampling 16 conditioned sensor channels at 300 ksps aggregate. The FIFO allows the PLC to poll panel data in batches, reducing EtherCAT or PROFINET cycle jitter. The industrial -40°C to +85°C grade tolerates cabinet heat and outdoor panel temperatures. The 3.0-3.6 V AVDD range integrates directly with 3.3 V factory sensor backplanes, while the 1.7-3.6 V DVDD range allows MCU-direct SPI interconnect without level shifters, simplifying panel BOM.
Recommended
Thermocouple & RTD Temperature Compensation Systems
The MAX1231AEEG+T's internal ±1°C temperature sensor, accessible through the analog multiplexer, provides cold-junction compensation data for thermocouple measurements without requiring an external thermistor. Multiplexing up to 16 thermocouple-conditioned channels at 300 ksps allows simultaneous thermocouple-array scanning in heat-treatment ovens and HVAC systems. Pairing the part with RTD-conditioned amplifiers lets a single IC service both contact and non-contact temperature inputs, while the 4.096 V internal reference gives 1 mV/LSB scaling that pairs cleanly with K-type and J-type thermocouple tables. The FIFO and shutdown mode support battery-powered HVAC handheld instruments.
Recommended
Battery-Powered Wireless Sensor Hubs
Wireless sensor hubs (LoRa, BLE, Zigbee gateways) use the MAX1231AEEG+T to digitize multiple analog sensors before a single radio transmission, taking advantage of the 16-entry FIFO that lets the MCU aggregate data between radio events. The 1 µA shutdown current between scans enables years of battery life on a single 3.6 V lithium AA cell when sampling once per minute. The internal 4.096 V reference and 12-bit resolution give sufficient dynamic range for environmental sensor (temperature, humidity, soil-moisture, gas) measurements, while the ±1°C on-die sensor reports module-internal temperature compensation data.
Recommended
Recommended Products Summary
Engineering reference data for MAX1231AEEG+T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1231ACEG+T | MAX1231BCEG+ | MAX1231BEEG+ |
|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 24-pin SSOP | 24-pin SSOP - same | 24-pin SSOP - same | 24-pin SSOP - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit |
| Sample Rate | 300 ksps | 300 ksps | 300 ksps | 300 ksps |
| Number of Input Channels | 16 single-ended | 16 single-ended | 16 single-ended | 16 single-ended |
| Internal Reference | 4.096 V | 4.096 V | 4.096 V | 4.096 V |
| Internal Temperature Sensor | Yes (±1 °C) | Yes (±1 °C) | Yes (±1 °C) | Yes (±1 °C) |
| FIFO Buffer | 16 entries | 16 entries | 16 entries | 16 entries |
| Active Supply Current | 2.7 mA | 2.7 mA | 2.7 mA | 2.7 mA |
Key Differentiators
- Internal ±1°C temperature sensor shared through analog mux (vs MAX1231ACEG+T)
- 16-entry FIFO reduces host SPI bus traffic by 16x (vs MAX1231BCEG+)
- 24-pin SSOP footprint compatible with full MAX1227/MAX1229/MAX1231 family (vs MAX1231BEEG+)
Design Notes
Place a 0.1 µF ceramic bypass capacitor within 5 mm of the AVDD pin and another 0.1 µF within 5 mm of DVDD. Add a 10 µF bulk tantalum or ceramic capacitor at the supply input to suppress digital-side switching noise from corrupting the analog reference. Decoupling at REF is optional but recommended - a 0.1 µF cap on REF reduces reference noise coupling during conversions.
Estimated: at 300 ksps continuous operation with AVDD = 3.3 V, the MAX1231AEEG+T consumes roughly 9 mW (2.7 mA × 3.3 V). For a 24-pin SSOP with a typical theta_JA of 100 °C/W, the steady-state junction rise above ambient is under 1 °C, so no heatsink is required. At industrial ambient of +85 °C the junction remains well below the +150 °C absolute maximum.
Keep analog input traces short and route them away from digital lines (SCLK, DOUT, DIN, CS) by at least 3 mm or with a ground-fill shield to prevent digital-to-analog crosstalk. Use a single solid ground plane under the IC and stitch vias around the perimeter. Place the analog multiplexer inputs in matched-length groups to preserve channel-to-channel gain matching.
Do not apply analog inputs above AVDD + 0.3 V; the input ESD structure can be damaged by over-range voltages. Always assert SHDN low or CS high before changing analog input channel range to avoid spurious conversion results. Allow at least 1 ms after power-up before initiating conversions to let the internal reference settle to within 1 LSB.
Compliance Information
RoHS compliant per Maxim/Analog Devices product declaration. Industrial temperature grade -40°C to +85°C. AEC-Q100 not qualified; for automotive applications consult ADI automotive-grade SAR portfolio.
