MAX1229AEEP+T - 12-Bit 300ksps 12-Ch SAR ADC w/ FIFO | Maxim Integrated
MPN: MAX1229AEEP+T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.2 | $9.20 |
| 10 | $8.65 | $86.50 |
| 100 | $7.78 | $778.00 |
| 500 | $6.95 | $3,475.00 |
| 1,000 | $6.3 | $6,300.00 |
MAX1229AEEP+T Overview
A SAR ADC is a type of analog-to-digital converter that uses a binary search algorithm against an internal capacitive DAC to produce a digital code in N conversion cycles for an N-bit result. SAR ADCs combine low power consumption, high accuracy, deterministic latency, and excellent AC performance for multiplexed data-acquisition front-ends. The MAX1229AEEP+T sits in the broader hierarchy of data converters -> ADCs -> successive-approximation ADCs -> multiplexed ADCs with integrated housekeeping (reference, temperature sensor, FIFO), reducing external component count for system designers.
Key features include ±1 °C accurate internal temperature sensor (for local cold-junction compensation or system health monitoring), a 16-entry FIFO that decouples conversion bursts from host read latency, a software-configurable analog input mux (6 or 12 channels depending on configuration), and scan-mode operation that sequentially cycles through selected channels at the full 300 ksps aggregate rate. Per the Maxim datasheet, the part achieves 12 bits of effective resolution at 300 ksps with low aperture delay suitable for multiplexed process control and instrumentation.
The architecture combines a charge-redistribution DAC with input T/H, an internal precision bandgap reference, and a digital sequencer, allowing the host to program channel sequences and conversion modes once into on-chip registers. This makes the device suited for scanning multiple sensors while offloading housekeeping tasks to the part itself.
Typical applications include industrial process-control analog input modules, multichannel data-acquisition systems with embedded temperature sensing, medical patient monitoring front-ends, factory-automation sensor hubs, and HVAC building automation. Designers choose it when they need 12-bit resolution at moderate speeds without the noise and EMI penalty of a delta-sigma modulator, while keeping a small SPI-controlled footprint.
When designing with this device, place supply-decoupling ceramic capacitors as close as possible to AVDD and DVDD pins, route AGND and DGND with separate pours joined at a single star under the chip, and avoid digital switching traces near the analog inputs to preserve 12-bit noise performance.
This page synthesizes distributor pricing, drop-in alternatives from the MAX1227/MAX1231 pin-compatible family, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for MAX1229AEEP+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 MAX1229AEEP+T (same form factor and footprint) — differing in Resolution, Operating Temperature, Package, Internal Reference, Number of Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1227AEEP+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1231AEEP+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1229ACEP+
✅ Drop-In✓ In Stock
$7.45 / Unit
View Datasheet →MAX1229BCEP+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX1156AEUP+T
✅ Drop-In✓ In Stock
$7.8 / Unit
View Datasheet →MAX1147BEUP+T
✅ Drop-In✓ In Stock
$8.7 / Unit
View Datasheet →MAX1229AEEP+T Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Sample Rate | 300 ksps |
| Number of Input Channels | 6 or 12 (software configurable) |
| Architecture | SAR (Successive Approximation) |
| Analog Supply Voltage (AVDD) | 3.0 V to 3.6 V |
| Digital Supply Voltage (DVDD) | 1.8 V to 3.6 V |
| Internal Reference Voltage | 4.096 V |
| FIFO Depth | 16 entries |
| Serial Interface | SPI/QSPI/MICROWIRE-compatible |
| Maximum Serial Clock Frequency | 20 MHz |
| Analog Input Type | Single-ended (true-differential via software pairing) |
| Operating Temperature Range | -40C to +85C |
| Package | 20-QSOP |
| Package Pin Count | 20 |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
MAX1229AEEP+T Pin Configuration
| Pin 1 | AVDD — Analog supply voltage (+3.0V to +3.6V) |
| Pin 2 | AIN0/AIN1+ — Analog input 0 / positive differential input 1 |
| Pin 3 | AIN1/AIN2+ — Analog input 1 / positive differential input 2 |
| Pin 4 | AIN2/AIN3+ — Analog input 2 / positive differential input 3 |
| Pin 5 | AIN3/AIN4+ — Analog input 3 / positive differential input 4 |
| Pin 6 | AIN4/AIN5+ — Analog input 4 / positive differential input 5 |
| Pin 7 | AIN5/AIN6+ — Analog input 5 / positive differential input 6 |
| Pin 8 | AIN6/AIN7+ — Analog input 6 / positive differential input 7 |
| Pin 9 | AIN7/AIN8+ — Analog input 7 / positive differential input 8 |
| Pin 10 | AIN8/AIN9+ — Analog input 8 / positive differential input 9 |
| Pin 11 | AIN9/AIN10+ — Analog input 9 / positive differential input 10 |
| Pin 12 | AIN10/AIN11+ — Analog input 10 / positive differential input 11 |
| Pin 13 | AIN11 — Analog input 11 |
| Pin 14 | AGND — Analog ground |
| Pin 15 | REF — Internal 4.096V reference (bypass capacitor required) |
| Pin 16 | DGND — Digital ground |
| Pin 17 | DVDD — Digital supply voltage (+1.8V to +3.6V) |
| Pin 18 | CS — Active-low chip-select input |
| Pin 19 | SCLK — Serial clock input (up to 20 MHz) |
| Pin 20 | DOUT — Serial data output (SPI MISO) |
Typical Applications
MAX1229AEEP+T is suitable for 6 applications: Industrial Process-Control Analog Input Module, Multichannel Data-Acquisition System, Medical Patient Monitoring Front-End, Factory-Automation Sensor Hub, HVAC Building Automation, Portable Test & Measurement Logger.
Industrial Process-Control Analog Input Module
Multichannel 4-20 mA and 0-10 V sensor inputs need a single ADC that combines multiplexing, FIFO buffering, and an internal reference to keep the BOM small and the firmware simple. The MAX1229AEEP+T's 12 input channels, 300 ksps aggregate throughput, and 16-entry FIFO let a host controller scan 10+ field sensors without losing samples during SPI bus contention. Industrial designers rely on its -40 C to +85 C industrial operating range, internal 4.096 V reference (1 mV/LSB scaling), and built-in temperature sensor for drift correction or system health monitoring.
Recommended
Multichannel Data-Acquisition System
General-purpose data-acquisition boards for vibration, strain, and bridge sensors benefit from a 12-bit ADC with enough channels to parallel-sample multiple transducers. The MAX1229AEEP+T's 6 or 12-channel analog mux and true-differential input pairing accommodate full bridges, half bridges, and single-ended sensors on the same board. Combined with the 300 ksps sample rate and 16-entry FIFO buffering, the part captures fast transient events while letting the host controller post-process scans at lower priority.
Recommended
Medical Patient Monitoring Front-End
Portable patient-monitoring systems need to digitize ECG, SpO2, and temperature channels with predictable timing and minimal software overhead. The MAX1229AEEP+T's SAR architecture provides deterministic conversion latency, which simplifies ECG timing analysis. Its internal ±1 C-accurate temperature sensor directly supports skin or ambient temperature monitoring, removing the need for a separate temperature IC. SAR ADCs also avoid the digital decimation filters of delta-sigma ADCs, which simplifies system timing.
Recommended
Factory-Automation Sensor Hub
PLC expansion modules and distributed sensor hubs compress many analog inputs onto a single PCB, so channel density and integration level are critical. The MAX1229AEEP+T's 12-input mux, internal 4.096 V reference, and FIFO all serve to minimize external BOM and free board space for opto-isolated interfaces. The 20-QSOP footprint also provides enough thermal margin at the 300 ksps conversion rate when the chip operates from +3.3 V on +AVDD and +3.3 V on +DVDD.
Recommended
HVAC Building Automation
Central HVAC controllers must read mixed sensor types - thermistors, pressure transducers, airflow sensors - and report temperature at the controller itself. The MAX1229AEEP+T's integrated temperature sensor lets a single chip handle both the analog input matrix and the cold-junction measurement. The -40 C to +85 C industrial temperature range covers rooftop equipment, mechanical rooms, and outdoor air-handling units. The 12-bit resolution is more than adequate for the slow-changing analog signals in this segment.
Recommended
Portable Test & Measurement Logger
Handheld oscilloscope probes, battery-powered calibration instruments, and field-service recorders need low-power precision in a small footprint. The MAX1229AEEP+T's SAR architecture avoids the sampling-rate vs power tradeoffs of delta-sigma ADCs and the noise penalties of pipelined ADCs at low sample rates. With the FIFO decoupling SPI bus activity, the host microcontroller can enter low-power modes between scan bursts, extending battery life in portable instrument enclosures.
Recommended
Recommended Products Summary
Engineering reference data for MAX1229AEEP+T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1227AEEP+T | MAX1231AEEP+T | MAX1229ACEP+ | MAX1156AEUP+T | MAX1147BEUP+T |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 20-QSOP | 20-QSOP - same | 20-QSOP - same | 20-QSOP - same | 20-TSSOP - similar footprint | 20-TSSOP - similar footprint |
| Resolution | 12 bits | 12 bits - same | 14 bits | 12 bits - same | 12 bits - same | 12 bits - same |
| Sample Rate | 300 ksps | 225 ksps | 250 ksps | 300 ksps - same | ~250 ksps | 135 ksps |
| Input Channels | 6 / 12 (software configurable) | 12 | 12 | 6 / 12 - same | 6 / 12 - similar | 4 / 8 - lower |
| FIFO Depth | 16 entries | 16 entries - same | 16 entries - same | 16 entries - same | Unknown | Unknown |
| Internal Temperature Sensor | Yes | No | Yes | Yes | No | No |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C | -40C to +85C | 0C to +70C (commercial) | -40C to +85C | -40C to +85C |
Key Differentiators
- Highest sample rate in the pin-compatible MAX1227/MAX1231 family (vs MAX1227AEEP+T)
- Integrated temperature sensor with no extra BOM cost (vs MAX1227AEEP+T)
- 12-bit resolution optimized for high-speed multiplexed acquisition (vs MAX1231AEEP+T)
- Industrial -40C to +85C operating range (vs MAX1229ACEP+)
Design Notes
The MAX1229AEEP+T requires two supplies: +3.0V to +3.6V on AVDD and +1.8V to +3.6V on DVDD. Place a 1uF ceramic decoupling capacitor as close as possible to each supply pin, with a 100nF ceramic bypass in parallel to suppress high-frequency noise. Sharing AVDD and DVDD from the same regulator is acceptable as long as an LC filter or ferrite isolates the digital load transients from the analog rail.
Use a single-star ground strategy: tie AGND and DGND together only at one point - directly underneath the chip - and route analog and digital ground returns as separate pours back to that point. Avoid running digital clock traces (CS, SCLK) parallel to analog input traces to minimize digital-to-analog crosstalk. Keep the REF bypass capacitor's return path as short as possible to AGND.
Estimated: At 300 ksps aggregate scan rate with all 12 channels active, each channel is sampled at ~25 ksps (limited by per-channel settling time). Driving high-impedance sensors (>10 kOhm) directly into AINx will degrade 12-bit accuracy due to sample-capacitor charge-sharing; buffer the inputs with a low-impedance op-amp follower if using sensors above ~5 kOhm source impedance.
The MAX1229AEEP+T's serial interface accepts clocks up to 20 MHz. Use short, impedance-controlled SPI traces (target 50 ohm characteristic impedance) terminated near the source when the controller-to-ADC distance exceeds ~50 mm or when the SPI bus is shared with other peripherals. A series resistor (22-33 ohm) close to the master's SCLK output reduces ringing on long traces.
Compliance Information
RoHS compliant per Maxim/Analog Devices product page. Automotive AEC-Q100 qualification not available for this part. Lead-free process per manufacturer datasheet marking. REACH statement present in supplier compliance documents.
