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Analog Devices Inc./Maxim Integrated MAX1294BEEI
- Part No.:
- MAX1294BEEI
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 28-SSOP (0.154", 3.90mm Width)
- Datasheet:
-
MAX1294BEEI.pdf
- Description:
- IC ADC 12BIT SAR 28QSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,055
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Product details
Overview
MAX1294BEEI from Maxim Integrated is a 12-bit successive-approximation ADC with internal +2.5V reference, 420ksps sampling rate, 6-channel single-ended / 3-channel pseudo-differential analog input, and parallel 12-bit interface - designed for low-power data-acquisition systems requiring precise analog sensing in industrial control and patient monitoring.
For engineers reviewing the MAX1294BEEI datasheet, MAX1294BEEI pinout, MAX1294BEEI application, or MAX1294BEEI equivalent, this page delivers verified specifications, validated pin functions, confirmed operating modes (internal/external clock & acquisition), real-world use cases, and two technically documented alternative parts - all specific to the -40°C to +85°C, 28-pin QSOP, ±1 LSB INL variant.
Technical Context
The MAX1294BEEI implements a charge-redistribution SAR architecture with integrated track/hold (6MHz full-power bandwidth), software-configurable unipolar/bipolar and single-ended/pseudo-differential input modes, and dual power-down states (standby and full shutdown). Its control byte (D7–D0) configures channel selection (A2–A0), acquisition mode (ACQMOD), polarity (UNI/BIP), and clock source (D6/D7).
It supports both internal clock mode (3.6µs conversion time, CLK tied high/low) and external clock mode (100kHz–7.6MHz), with timing-critical signals including WR-triggered acquisition start, INT-driven interrupt read, and CS-gated three-state digital I/O - all operating from a single +5V supply with <2.8mA active current at 420ksps.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 12-bit SAR with no missing codes over temperature |
| Sampling Rate | 420ksps maximum - enables real-time capture of 175kHz sine inputs with >68dB SINAD |
| INL / DNL | ±1 LSB / ±1 LSB - ensures monotonicity and ≤0.024% full-scale linearity error |
| Analog Input Range | Unipolar: 0V to +2.5V; Bipolar: −1.25V to +1.25V - selectable via control byte bit UNI/BIP |
| Power Consumption | 2.8mA at 420ksps; 2µA in full shutdown - supports battery operation with fast wake-up (2µs) |
| Reference | +2.5V internal bandgap (±20ppm/°C TC, 4.7µF bypass required) - eliminates external reference component |
| Interface | Parallel 12-bit three-state bus (D0–D11) with CS/WR/RD/INT handshaking - direct µP compatibility without glue logic |
Pinout & Package
MAX1294BEEI is housed in a 28-pin QSOP package (5.3mm × 10.2mm, 0.65mm pitch), optimized for space-constrained PCB layouts while maintaining thermal performance up to +85°C ambient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CH0–CH5 | Analog input channels | 6 single-ended or 3 pseudo-differential inputs; CH0–CH5 enabled per A2–A0 address bits |
| COM | Analog ground reference | Sets zero-code voltage in single-ended mode; must remain stable to ±0.5 LSB during conversion |
| REF / REFADJ | Reference buffer output / adjustment | REF outputs +2.5V (bypass with 4.7µF); REFADJ disables internal ref when tied to VDD for external reference use |
| CS, WR, RD, INT | Digital control & status | Active-low chip select (tri-states outputs); WR latches config/start conversion; RD enables data read; INT flags completion |
| D0–D11 | Three-state parallel data bus | 12-bit output (unipolar = binary, bipolar = two's complement); high-impedance when CS = high |
| VDD, GND | Power supply | +5V analog supply only; requires 0.1µF local bypass at VDD pin |
Key Features
| Feature | Design Value |
|---|---|
| Software-configurable input topology | Selects 6-channel single-ended or 3-channel pseudo-differential mode via SGL/DIF bit - adapts to sensor signal type without hardware change |
| Two-tier power-down | Standby mode (≤1µA) retains configuration; full shutdown (≤2µA) cuts reference and T/H - extends battery life between measurements |
| Internal clock option | Eliminates external clock source; fixed 3.6µs conversion time with CLK pin tied high/low - reduces BOM count and layout complexity |
| Fast wake-up & interrupt-driven read | 2µs wake-from-shutdown; INT asserts low on conversion completion - enables deterministic µP polling or IRQ servicing |
| Robust analog input protection | Clamps to GND/VDD (−300mV to VDD+300mV); tolerates ±50mV overvoltage with ≤4mA current - protects against transient coupling in noisy environments |
Applications
| Industrial Process Monitoring | Patient Vital Sign Acquisition |
|---|---|
Use Scenario: Continuous logging of temperature, pressure, and flow sensor outputs in PLC-based control cabinets with limited power budget. IC Role / Device Role / Timing Role: Primary ADC digitizing 6 analog sensor channels at 100ksps, using internal reference and standby power-down between samples. Use Value: Eliminates external reference and clock components; 2.8mA active current enables 5-year battery life in wireless sensor nodes. |
Use Scenario: Portable ECG and SpO₂ monitor acquiring biopotential signals with high common-mode rejection and low noise floor. IC Role / Device Role / Timing Role: Bipolar-mode ADC capturing differential lead signals (CH0–CH1) with COM referenced to right-leg drive, synchronized via INT interrupt. Use Value: ±1.25V bipolar range matches typical ECG amplitude; 68dB SINAD ensures clean waveform reconstruction at 420ksps undersampling. |
| Energy Metering Subsystem | Touchscreen Controller Interface |
Use Scenario: AC mains voltage/current sampling in smart meter front-end, requiring accurate RMS calculation over multiple cycles. IC Role / Device Role / Timing Role: High-linearity ADC converting isolated CT/PT outputs in unipolar mode, leveraging 350kHz full-linear bandwidth for harmonic analysis. Use Value: ±1 LSB INL guarantees <0.1% energy measurement error; internal reference stability (±20ppm/°C) maintains calibration across temperature drift. |
Use Scenario: Resistive touchscreen digitizer measuring X/Y electrode voltages in handheld HMI devices with tight board area constraints. IC Role / Device Role / Timing Role: Fast 420ksps ADC scanning 6 touch channels (CH0–CH5) in single-ended mode, using internal clock to minimize µP GPIO usage. Use Value: 28-pin QSOP footprint fits compact display modules; 2µs wake-up enables responsive touch detection with <10ms latency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 12-bit parallel-output ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX1294ACEI | Same 28-pin QSOP package and pinout; ±0.5 LSB INL (vs. ±1 LSB); 0°C to +70°C temp range | Higher linearity required in lab-grade instrumentation; not rated for extended industrial temperature range | Select MAX1294ACEI only if ±0.5 LSB INL is mandatory and operating environment stays within 0°C–70°C. |
| ADS7822U | 8-pin SOIC, SPI interface, 200ksps, internal reference; no parallel bus or multi-channel mux | Lower pin count and simpler interface needed; trade-off: reduced speed, single channel, serial protocol overhead | Choose ADS7822U for cost-sensitive, space-limited designs where 200ksps and single-ended input suffice. |
Compared with MAX1294ACEI, the MAX1294BEEI trades 0.5 LSB linearity for extended −40°C to +85°C operation - critical for outdoor or factory-floor deployment. Against ADS7822U, it delivers 2.1× higher throughput, 6-channel flexibility, and parallel µP interfacing - at the cost of larger package and higher pin count.
Availability
MAX1294BEEI is available at Aetrix Electronics and suitable for industrial process monitoring, portable medical devices, energy metering subsystems, and touchscreen controller interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX1294BEEI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in precision analog, mixed-signal, and power-management ICs for demanding industrial, medical, and communications applications.
The MAX1294BEEI belongs to Maxim's high-performance data-acquisition ADC family, engineered for low-power, multi-channel, microprocessor-compatible digitization in space- and power-constrained systems - particularly where internal reference integration and flexible input configuration reduce system-level design effort.
FAQ
What is the operating temperature range of the MAX1294BEEI?
The MAX1294BEEI is rated for −40°C to +85°C ambient operation, making it suitable for industrial control cabinets, outdoor metering equipment, and portable medical devices exposed to wide environmental conditions. This extended range distinguishes it from the 0°C to +70°C MAX1294ACEI variant, and is validated across all electrical specifications including INL, gain error, and reference stability.
Does the MAX1294BEEI require an external clock source?
No - the MAX1294BEEI supports both internal and external clock modes. In internal clock mode (D7=1, D6=0), it generates its own 7.6MHz clock internally, requiring only CLK pin tied high or low to prevent floating. This eliminates external oscillator components and simplifies timing design, though external acquisition mode is recommended for sub-50ps aperture jitter requirements.
How many analog input channels does the MAX1294BEEI support?
The MAX1294BEEI supports six analog input channels (CH0–CH5) in single-ended mode, or three pseudo-differential pairs (CH0/CH1, CH2/CH3, CH4/CH5) - selected via A2–A0 address bits in the control byte. This 6-/3-channel capability is fixed for the MAX1294 series; the MAX1296 variant offers only two single-ended channels.
What is the reference voltage specification for the MAX1294BEEI?
The MAX1294BEEI integrates a +2.5V bandgap reference with ±20ppm/°C temperature coefficient and 4.7µF capacitor bypass requirement at the REF pin. Output voltage is guaranteed 2.49V to 2.51V at +25°C, and remains stable across the full −40°C to +85°C range - enabling accurate, self-contained analog-to-digital conversion without external reference components.
Can the MAX1294BEEI operate from a 3.3V supply?
No - the MAX1294BEEI requires a single +5V ±10% analog supply (VDD = 4.5V to 5.5V) and is not 3.3V compatible. Its internal reference, track/hold stage, and digital interface are all specified only for +5V operation. For +3V systems, consider the pin-compatible MAX1295/MAX1297 family, which shares identical functionality but is rated for 2.7V to 3.6V supply.
MAX1294BEEI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 28-SSOP (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Number of Bits:
- 12
- Sampling Rate (Per Second):
- 420k
- Number of Inputs:
- 3, 6
- Input Type:
- Pseudo-Differential, Single Ended
- Data Interface:
- Parallel
- Configuration:
- MUX-S/H-ADC
- Ratio - S/H:ADC:
- 1:1
- Number of A/D Converters:
- 1
- Architecture:
- SAR
- Reference Type:
- External, Internal
- Voltage - Supply, Analog:
- 5V
- Voltage - Supply, Digital:
- 5V
- Features:
- -
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 28-QSOP
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
MAX1294BEEI FAQ
1.How can I place an order for MAX1294BEEI through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX1294BEEI on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX1294BEEI reliable?
The price and inventory of MAX1294BEEI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX1294BEEI is usually 5 days.
3.What payment methods are accepted for MAX1294BEEI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX1294BEEI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX1294BEEI?
MAX1294BEEI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX1294BEEI order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX1294BEEI?
For technical support, including MAX1294BEEI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX1294BEEI requirements.
6.How does Aetrix verify that MAX1294BEEI is sourced from the original manufacturer or authorized distributors?
All MAX1294BEEI products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX1294BEEI meets industry standards.
7.What is the process for return or replacement of MAX1294BEEI?
All MAX1294BEEI units undergo pre-shipment inspection (PSI). If there is an issue with MAX1294BEEI, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX1294BEEI part is unused and in its original packaging.
Return procedure for MAX1294BEEI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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