MAX1294BCEI-T - 420ksps 12-Bit 6-Ch +5V ADC | Maxim Integrated
MPN: MAX1294BCEI-T ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.2 | $9.20 |
| 10 | $8.28 | $82.80 |
| 100 | $7.36 | $736.00 |
| 500 | $6.5 | $3,250.00 |
| 1,000 | $5.78 | $5,780.00 |
MAX1294BCEI-T Overview
An ADC (analog-to-digital converter) is a semiconductor device that converts continuous analog signals into discrete digital codes for processing by microcontrollers, DSPs, or FPGAs. Successive-approximation-register (SAR) ADCs like the MAX1294BCEI-T sample-and-hold the input, then use an internal DAC and comparator to converge on the digital code one bit per clock cycle. SAR ADCs sit in the signal chain hierarchy between the analog sensor/front-end and the digital processor, and are favored for their deterministic latency, low power consumption, and excellent DC accuracy compared to delta-sigma or pipeline architectures.
Key features of the MAX1294BCEI-T include 12-bit resolution with ±0.5 LSB integral nonlinearity, 420ksps throughput, software-selectable unipolar/bipolar input ranges, an internal +2.5V reference (with REFADJ pin for external trim), and a high-speed parallel interface. The internal reference eliminates the need for an external precision reference, reducing BOM cost and board space while maintaining the noise performance required for industrial and instrumentation applications.
Architecturally, the MAX1294 uses a charge-redistribution SAR core with an input track-and-hold amplifier capable of handling fast multiplexed signals. Its low aperture delay and aperture jitter make it suitable for simultaneous-sampling-like accuracy across channels when paired with a fast external mux. The device operates from a single +5V analog supply with a separate VLOGIC supply (3V to 5V) for the parallel bus.
Typical applications include industrial process control, multichannel data-acquisition systems, portable instrumentation, motor control feedback loops, and medical patient monitoring. When designing with this part, place a 0.1µF ceramic bypass capacitor close to the VDD pin and a 10µF bulk capacitor on the +5V rail to minimize digital noise coupling into the analog input stages.
Drop-in alternatives for MAX1294BCEI-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 MAX1294BCEI-T (same form factor and footprint) — differing in Interface, Number of Channels, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
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View Datasheet →MAX1295BEEI-T
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MAX1294BCEI-T Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Number of Channels | 6 single-ended / 3 pseudo-differential |
| Sample Rate | 420 ksps |
| Architecture | SAR (Successive Approximation Register) |
| Input Voltage Range | 0 V to +5 V (unipolar); ±5 V (bipolar) |
| Supply Voltage (Analog) | +5 V |
| Supply Voltage (Digital/Logic) | +3 V to +5 V |
| Internal Reference | +2.5 V |
| Integral Nonlinearity (INL) | ±0.5 LSB (max) |
| Interface | Parallel |
| Package | 28-pin SSOP (QSOP) |
| Mounting Type | Surface Mount |
| Operating Temperature | 0°C to +70°C (commercial grade "C") |
MAX1294BCEI-T Pin Configuration
| Pin 1 | AIN0 — Analog Input 0 |
| Pin 2 | AIN1 — Analog Input 1 |
| Pin 3 | AIN2 — Analog Input 2 |
| Pin 4 | AIN3 — Analog Input 3 |
| Pin 5 | AIN4 — Analog Input 4 |
| Pin 6 | AIN5 — Analog Input 5 |
| Pin 7 | REFADJ — Reference Adjust Input |
| Pin 8 | REF — +2.5V Reference Output |
| Pin 9 | GND — Ground |
| Pin 10 | VDD — +5V Analog Supply |
| Pin 11 | VLOGIC — +3V to +5V Digital Supply |
| Pin 12 | CONVST — Conversion Start Input |
| Pin 13 | CS — Chip Select (active low) |
| Pin 14 | RD — Read Input (active low) |
| Pin 15 | HBEN — High-Byte Enable |
| Pin 16 | DOUT11 — Data Output Bit 11 (MSB) |
| Pin 17 | DOUT10 — Data Output Bit 10 |
| Pin 18 | DOUT9 — Data Output Bit 9 |
| Pin 19 | DOUT8 — Data Output Bit 8 |
| Pin 20 | DOUT7 — Data Output Bit 7 |
| Pin 21 | DOUT6 — Data Output Bit 6 |
| Pin 22 | DOUT5 — Data Output Bit 5 |
| Pin 23 | DOUT4 — Data Output Bit 4 |
| Pin 24 | DOUT3 — Data Output Bit 3 |
| Pin 25 | DOUT2 — Data Output Bit 2 |
| Pin 26 | DOUT1 — Data Output Bit 1 |
| Pin 27 | DOUT0 — Data Output Bit 0 (LSB) |
| Pin 28 | NC — Not Connected (per datasheet) |
Typical Applications
MAX1294BCEI-T is suitable for 6 applications: Industrial Process Control, Multichannel Data Acquisition Systems, Motor Control Feedback Loops, Portable Instrumentation, Medical Patient Monitoring, Power Supply Monitoring.
Industrial Process Control
The MAX1294BCEI-T's 6 single-ended input channels, ±0.5 LSB INL, and 420 ksps throughput make it ideal for industrial process control systems where multiple sensor signals (temperature, pressure, flow, level) must be digitized simultaneously. The internal +2.5V reference eliminates the need for external precision references, reducing BOM cost while maintaining the accuracy required for closed-loop control. Paired with an external multiplexer or sensor conditioning front-end, the ADC handles multiple 4-20mA or 0-10V process signals with 12-bit (0.024% FS) resolution, suitable for PLC analog input modules. The +5V supply integrates directly with industrial backplane rails, and the parallel interface connects to FPGAs or microcontrollers for deterministic real-time control.
Recommended
Multichannel Data Acquisition Systems
For portable and benchtop data acquisition (DAQ) systems, the MAX1294BCEI-T offers 6-channel multiplexing at 420 ksps aggregate throughput, enabling rapid scanning of multiple analog signals under software control. The internal track-and-hold and SAR architecture provide deterministic latency, critical for waveform capture applications. With 12-bit resolution and ±5V input range, the ADC digitizes signals from sensors, transducers, and test fixtures without external signal conditioning. The parallel interface allows direct connection to FPGAs for custom timing and triggering. The 28-pin QSOP package fits compact DAQ card form factors, and the commercial temperature grade (0°C to +70°C) suits laboratory and factory environments.
Recommended
Motor Control Feedback Loops
Brushless DC (BLDC) and stepper motor control systems require high-speed current and voltage feedback for precise torque and position regulation. The MAX1294BCEI-T's 420 ksps sample rate captures motor phase currents with sufficient bandwidth for field-oriented control (FOC) algorithms running at 20-40 kHz PWM frequencies. The 6-channel input mux digitizes three phase currents plus DC bus voltage, temperature, and auxiliary signals in a single ADC. With ±0.5 LSB INL, the ADC provides accurate current sensing for torque ripple reduction. The parallel interface connects directly to motor control DSPs and FPGAs with deterministic conversion latency.
Recommended
Portable Instrumentation
Handheld multimeters, oscilloscopes, and field test instruments benefit from the MAX1294BCEI-T's combination of multi-channel input, moderate power consumption, and small 28-pin QSOP footprint. The 6 input channels digitize voltage, current, temperature, and frequency signals from instrument front-ends. With 12-bit resolution and 420 ksps throughput, the ADC captures transient signals in portable oscilloscope applications. The internal +2.5V reference simplifies calibration and reduces external component count, critical for compact handheld designs. However, for battery-powered designs with strict power budgets, the MAX1295 (+3V version) is the recommended alternative due to its lower supply voltage.
Recommended
Medical Patient Monitoring
Medical patient monitoring equipment (ECG, pulse oximetry, multi-parameter monitors) requires reliable multi-channel analog signal digitization with good linearity and low noise. The MAX1294BCEI-T provides 6 single-ended channels suitable for ECG lead signals, SpO2 photodiode currents, temperature, respiration, and auxiliary inputs. The 12-bit resolution and 420 ksps throughput capture ECG waveforms with sufficient fidelity for heart rate detection and arrhythmia analysis. For medical designs requiring long-term product support and traceability, designers should verify the NRND status impact and consider the MAX1300 series as a modern alternative with active lifecycle status and enhanced diagnostics.
Recommended
Power Supply Monitoring
Telecom and server power supply units require multi-rail voltage and current monitoring for telemetry, fault detection, and efficiency optimization. The MAX1294BCEI-T's 6-channel input multiplexer monitors +5V, +12V, +3.3V, and auxiliary rails, plus current sense amplifier outputs, within a single ADC. With ±0.5 LSB INL, the ADC provides accurate voltage telemetry for PMBus-compatible monitoring systems. The 420 ksps throughput captures fast transient responses during load steps and fault events. The parallel interface integrates with power supply controllers and supervisory ASICs that implement digital power management protocols.
Recommended
Recommended Products Summary
Engineering reference data for MAX1294BCEI-T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1294BCEI+T | MAX1294BEEI-T | MAX1295BEEI-T | MAX1297BEEI-T |
|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 28-pin SSOP (QSOP) | 28-pin SSOP (QSOP) - same | 28-pin SSOP (QSOP) - same | 28-pin SSOP (QSOP) - same | 28-pin SSOP (QSOP) - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sample Rate | 420 ksps | 420 ksps | 420 ksps | 250 ksps | 250 ksps |
| Number of Channels | 6 single-ended / 3 pseudo-differential | 6 / 3 | 6 / 3 | 6 / 3 | 6 / 3 |
| Supply Voltage | +5 V | +5 V | +5 V | +3 V | +3 V |
| Temperature Range | 0°C to +70°C (commercial) | 0°C to +70°C | -40°C to +85°C (extended) | -40°C to +85°C (extended) | -40°C to +85°C (extended) |
| Internal Reference | +2.5 V | +2.5 V | +2.5 V | +2.5 V | +2.5 V |
| Interface | Parallel | Parallel | Parallel | Parallel | Parallel |
Key Differentiators
- Integrated +2.5V reference eliminates external reference BOM (vs External reference designs (typical competing ADCs))
- 6-channel input multiplexer in 28-pin QSOP (vs MAX1296 (8 channels, 24-pin QSOP))
- Higher throughput than 3V MAX1295/MAX1297 counterparts (vs MAX1295BEEI-T (+3V version))
Design Notes
The MAX1294BCEI-T requires separate analog (VDD, +5V) and digital (VLOGIC, +3V to +5V) supply pins. Place a 0.1µF ceramic bypass capacitor as close as possible to the VDD pin, with a 10µF bulk tantalum or ceramic capacitor on the +5V rail within 1 inch of the IC. The VLOGIC supply should be well-regulated to prevent digital noise coupling into the analog inputs through the internal logic interface. Use a ferrite bead or LC filter between the analog and digital +5V rails if they originate from the same source.
Route the analog input traces (AIN0-AIN5) as short as possible and away from digital switching signals to minimize crosstalk. Use a ground plane under the ADC to provide low-impedance return paths for high-frequency switching currents. Place the reference capacitor (typically 4.7µF ceramic) directly on the REF pin with a short, low-inductance trace. For pseudo-differential operation, route the negative inputs as parallel traces with their positive counterparts to maintain matched impedance.
The MAX1294BCEI-T's input track-and-hold requires the input source to settle within 1 LSB (0.6 mV at 5V FS) before the conversion starts. If using an external multiplexer, select an MUX with low on-resistance (<100Ω) and low charge injection to prevent transient errors at channel switching. Add a buffer amplifier (such as the MAX4250) between high-impedance sensors and the ADC inputs to provide the required acquisition time margin. Apply an RC anti-aliasing filter (typically 1kΩ + 1nF = 159 kHz cutoff) to attenuate out-of-band noise before digitization.
Do not exceed the absolute maximum analog input voltage of VDD + 0.3V on any AIN pin - overvoltage can latch the input ESD protection structure and permanently damage the part. Ensure the CONVST pulse width meets the datasheet minimum (typically 20 ns) and is clean of digital noise. Do not leave unused AIN pins floating; tie them to mid-scale (VREF/2) or ground to prevent noise pickup that could couple into adjacent active channels through the internal mux.
Compliance Information
Compliance information not directly verified in provided web data. RoHS and lead-free status should be confirmed on the Analog Devices product page or by requesting a compliance certificate from the manufacturer. The part is not AEC-Q100 qualified; not intended for automotive safety-critical applications.
