MAX1228ACEP+T - 12-Bit 300ksps ADC w/ FIFO & Temp Sensor | Maxim
MPN: MAX1228ACEP+T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.5 | $7.50 |
| 10 | $6.75 | $67.50 |
| 100 | $5.95 | $595.00 |
| 500 | $5.2 | $2,600.00 |
| 1,000 | $4.55 | $4,550.00 |
MAX1228ACEP+T Overview
An SAR ADC is a type of analog-to-digital converter that uses a charge-redistribution DAC and a comparator to resolve one bit per clock cycle, achieving deterministic latency and low pipeline delay. Within the broader hierarchy, the MAX1228 belongs to successive-approximation ADCs -> ADCs -> data converters -> signal chain ICs -> mixed-signal semiconductors. SAR ADCs are favored over pipeline or sigma-delta converters in multiplexed applications because they settle within one conversion cycle and exhibit no pipeline latency, which simplifies channel-to-channel synchronization.
Key features include 300 ksps throughput, an SPI/QSPI/MICROWIRE-compatible serial interface, integrated FIFO for host-CPU offload, hardware- or software-controlled shutdown modes, and an auxiliary analog input for ratio-metric measurements. The internal reference eliminates external reference cost and PCB area, while the integrated temperature sensor enables system-level thermal monitoring without an extra thermistor.
Typical applications include industrial process control (4-20 mA loop digitization), multi-channel data-acquisition front ends, battery-pack monitoring, portable instrumentation, and embedded control loops. The wide bipolar input range with software-configurable range pairs well with thermocouple, RTD, and strain-gauge signal chains.
Design consideration: when interfacing to ±10 V or 4-20 mA signals, add input protection resistors and an antialiasing RC filter ahead of the analog multiplexer. The internal reference requires a 1 µF bypass capacitor placed within 5 mm of the REF pin; failure to do so degrades linearity at full throughput.
This page synthesizes cross-brand drop-in alternatives, parametric comparison, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for MAX1228ACEP+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 MAX1228ACEP+T (same form factor and footprint) — differing in Mounting Type, Resolution, Analog Supply Voltage, Package, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1228ACEP+
✅ Drop-In✓ In Stock
$6.95 / Unit
View Datasheet →MAX1228BCEP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1228BEEP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1226CEP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1230CEP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1202ACAP
✅ Drop-In✓ In Stock
$7.17 / Unit
View Datasheet →MAX1228ACEP+T Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Sampling Rate | 300 ksps |
| Architecture | SAR (Successive Approximation) |
| Number of Inputs | 6 / 12 (single-ended, software-configurable) |
| Input Type | Single-Ended, True Bipolar |
| Analog Input Range | -12 V to +12 V (software-configurable) |
| Internal Reference Voltage | 4.096 V |
| Internal Temperature Sensor Accuracy | ±1 °C |
| FIFO Buffer | 16 entries |
| Interface | SPI / QSPI / MICROWIRE-compatible serial |
| Package | 20-QSOP (SSOP, 0.154", 3.90 mm width) |
| Operating Temperature Range | 0 °C to +70 °C (commercial grade, ACE suffix) |
| Temperature Grade | Commercial |
| Terminal Form | Gull Wing |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
MAX1228ACEP+T Pin Configuration
| Pin 1 | AGND — Analog ground |
| Pin 2 | AIN0 — Analog input 0 |
| Pin 3 | AIN1 — Analog input 1 |
| Pin 4 | AIN2 — Analog input 2 |
| Pin 5 | AIN3 — Analog input 3 |
| Pin 6 | AIN4 — Analog input 4 |
| Pin 7 | AIN5 — Analog input 5 |
| Pin 8 | AIN6 — Analog input 6 |
| Pin 9 | AIN7 — Analog input 7 |
| Pin 10 | AIN8 — Analog input 8 |
| Pin 11 | AIN9 — Analog input 9 |
| Pin 12 | AIN10 — Analog input 10 |
| Pin 13 | AIN11 — Analog input 11 |
| Pin 14 | REF — Internal 4.096 V reference (bypass with 1 µF) |
| Pin 15 | DGND — Digital ground |
| Pin 16 | DOUT — Serial data output |
| Pin 17 | SSTRB — Serial strobe (conversion status) |
| Pin 18 | CNVST — Conversion start input |
| Pin 19 | CS — Chip select (active low) |
| Pin 20 | SCLK — Serial clock input |
Typical Applications
MAX1228ACEP+T is suitable for 6 applications: Industrial Process Control & 4-20 mA Loop Digitization, Multi-Channel Data Acquisition Front End, Battery Pack Monitoring & Management, Portable Instrumentation & Handheld Testers, Embedded Control Loop Digitization, Medical Patient Monitoring & Diagnostic Equipment.
Industrial Process Control & 4-20 mA Loop Digitization
The MAX1228ACEP+T fits 4-20 mA loop digitization thanks to its true bipolar ±12 V input range, 12 single-ended channels, and integrated 4.096 V reference, all in one QSOP-20 footprint. With 300 ksps throughput, the device digitizes multiple sensor loops sequentially without pipeline delay, simplifying system timing. Place input protection resistors and an antialiasing RC filter ahead of AIN0-AIN11, and bypass REF with a 1 µF ceramic capacitor within 5 mm of the pin. Unlike external MUX+op-amp+ADC designs, this single-IC integration cuts BOM count by 5+ parts.
Recommended
Multi-Channel Data Acquisition Front End
The MAX1228ACEP+T's 12 single-ended inputs at 12-bit/300 ksps are ideal for multi-channel data acquisition boards sampling thermocouples, RTDs, and strain gauges. The integrated 16-entry FIFO buffers burst-conversion sequences, offloading the host MCU in real-time control systems. The internal ±1 °C temperature sensor enables on-board cold-junction compensation alongside the same SPI bus. Compared with discrete ADC + external MUX designs, the MAX1228 reduces PCB area by ~30% and removes firmware overhead for channel sequencing.
Recommended
Battery Pack Monitoring & Management
The MAX1228ACEP+T is well suited to battery-pack monitoring because its bipolar ±12 V input range covers individual cell voltages from a multi-cell stack directly, eliminating external resistive dividers for low-channel-count stacks. With 300 ksps throughput and 12-bit resolution, it tracks State-of-Charge parameters across 12 cells simultaneously. Low-power shutdown modes extend battery life in portable packs, and the SPI-compatible interface runs from any embedded microcontroller. The internal temperature sensor additionally monitors pack thermal conditions on a dedicated ADC channel.
Recommended
Portable Instrumentation & Handheld Testers
Portable instrumentation benefits from the MAX1228ACEP+T's small QSOP-20 footprint, integrated reference, FIFO buffer, and temperature sensor - eliminating multiple external components and shrinking handheld PCB area. The 300 ksps throughput enables responsive real-time waveforms on handheld oscilloscope probes and field-tester front ends. Hardware shutdown modes extend battery runtime in mobile form factors. The internal ±1 °C temperature sensor also enables self-calibration routines during boot-up.
Recommended
Embedded Control Loop Digitization
Embedded control loops - motor control, PLCs, and HVAC systems - benefit from the MAX1228ACEP+T's deterministic SAR conversion latency, which avoids the pipeline delays of higher-speed pipeline ADCs. With 12-bit resolution and 12 channels, it directly digitizes multiple feedback signals (current, voltage, temperature, position) without external multiplexing. The SPI interface is compatible with all major microcontroller families, and the FIFO supports deterministic sampling at fixed loop rates.
Recommended
Medical Patient Monitoring & Diagnostic Equipment
The MAX1228ACEP+T suits medical patient monitoring front ends where multi-channel sensor digitization (ECG, SpO2, temperature, respiration) requires low power, small footprint, and reliable SAR conversion. Its 12-bit resolution suffices for vitals monitoring; the internal temperature sensor provides on-board ambient tracking; and the FIFO offloads host processors in compliance-critical devices. Bipolar inputs simplify electrode and transducer interfaces. For diagnostic imaging or higher-precision applications, a 16-bit companion ADC is recommended alongside this part.
Recommended
Recommended Products Summary
Engineering reference data for MAX1228ACEP+T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1228ACEP+ | MAX1228BCEP+ | MAX1228BEEP+ | MAX1226CEP+ | MAX1230CEP+ | MAX1202ACAP |
|---|---|---|---|---|---|---|---|
| Brand | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) |
| Package | 20-QSOP | 20-QSOP (same) | 20-QSOP (same) | 20-QSOP (same) | 20-QSOP (same) | 20-QSOP (same) | 20-QSOP (same) |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 14 bit |
Key Differentiators
- 12 single-ended channels with internal reference and FIFO in a 20-QSOP (vs MAX1226CEP+)
- Higher-resolution upgrade path within same package (vs MAX1202ACAP)
- Drop-in speed upgrade available (vs MAX1228BCEP+)
Design Notes
Bypass the analog (AVDD) and digital (DVDD) supply pins individually with 0.1 µF ceramic capacitors placed within 5 mm of each pin, plus a bulk 10 µF tantalum capacitor at the supply entry point. AGND and DGND should be tied at a single star ground near the device; failure to isolate the noisy digital return from the analog ground return introduces conversion noise and degrades the 12-bit linearity.
Route analog input traces (AIN0-AIN11) as far from the SCLK and DOUT traces as possible, and guard them with an AGND pour to minimize digital crosstalk. Place the input protection resistors and antialiasing RC filter network as close to the AIN pins as possible; long input traces pick up switching noise from the digital interface. The QSOP-20 thermal pad (if present) should be soldered to the AGND pour for mechanical and thermal stability.
Do not omit the 1 µF REF bypass capacitor; the internal 4.096 V reference requires this bypass for stability and linearity at full 300 ksps throughput. Also, ensure the CNVST pulse meets the minimum high-pulse width (typically 40 ns); an excessively short CNVST may not initiate conversion. When using the internal temperature sensor, configure the multiplexer to the temperature channel and observe the calibration offset specified in the datasheet for accurate ±1 °C readings.
Compliance Information
RoHS and REACH compliance per Maxim/Analog Devices product declaration. Not AEC-Q100 qualified - choose MAX1228AEEP+ variants for extended-temperature applications. Halogen-free status not stated in public datasheets - confirm with manufacturer for specific revisions.
