MAX1270AENG - 12-Bit 8-Ch 110ksps SPI/QSPI ADC, +5V, DIP-24 | Maxim
MPN: MAX1270AENG ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $63.71 | $63.71 |
| 10 | $59.2 | $592.00 |
| 100 | $52.3 | $5,230.00 |
| 250 | $47.45 | $11,862.50 |
| 500 | $41.85 | $20,925.00 |
MAX1270AENG Overview
What is a SAR ADC? A successive-approximation register analog-to-digital converter is a precision data-conversion architecture that performs one bit per clock cycle using an internal DAC and comparator to converge on the analog input voltage. SAR ADCs sit in the hierarchy Data Acquisition System (DAS) > ADC > data converter > mixed-signal IC, and are favored where low-latency, deterministic conversions and small footprint matter more than ultra-high sampling rates. The MAX1270 also integrates an 8-channel input MUX, track/hold, reference, and serial host interface into a single IC, eliminating external signal-conditioning glue for low-channel-count systems.
Key features include 12-bit resolution with 0.5 LSB linearity, software-selectable unipolar input ranges of 0 to VREF, 0 to VREF/2, bipolar ±VREF/2 and ±VREF (with VREF = 4.096 V internal or external), an internal 4.096 V reference (MAX1270A variant), ±17 V fault-protected analog inputs that survive transients beyond the supply rails, and a 2.5 MHz bandwidth track/hold. Throughput of 110 ksps at a 5 MHz SPI clock is paired with a 3-wire SPI/QSPI/MICROWIRE-compatible serial interface and an internal or external serial clock source.
Architecture-wise the device combines an 8-to-1 input multiplexer, a fully differential capacitive-DAC-based SAR core, on-chip reference, and SPI logic in a single CMOS die. Power dissipation is held low at typically 6 mA (operating) and 10 µA (shutdown), simplifying thermal management even at 110 ksps continuous conversion. Hardware averaging and an external acquisition input simplify synchronization to system interrupts or timer events.
Typical applications include industrial process-control front-ends, multi-channel data loggers, battery-pack monitoring, programmable logic controller (PLC) analog input modules, and embedded sensor conditioning for instrumentation. Designers choose the MAX1270AENG for fault-tolerant analog inputs where field wiring may carry transients.
A practical design trade-off is selecting the correct input range for signal headroom versus resolution: ±VREF/2 maximizes dynamic range for bipolar sensors, while 0 to VREF/2 doubles LSB resolution for low-level unipolar signals such as thermocouples or strain gauges.
This page synthesizes authorized distributor stock, drop-in DIP-24 alternatives, and application design guidance for the MAX1270AENG - compiling practical knowledge across datasheet, lifecycle and footprint domains that a single distributor page typically does not cover.
Drop-in alternatives for MAX1270AENG — 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 MAX1270AENG (same form factor and footprint) — differing in Number of Channels, Resolution, Manufacturer, Operating Temperature Range, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX1270AENG+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1270BENG+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1270ACNG+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX1270BCNG+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX162ACNG+
✅ Drop-In✓ In Stock
$10.85 / Unit
View Datasheet →MAX1270AENG Maximum Ratings & Electrical Characteristics
| Manufacturer | Maxim Integrated (now part of Analog Devices) |
| Resolution | 12 bit |
| Number of Channels | 8 |
| Sampling Rate | 110 ksps |
| Number of ADCs | 1 |
| Data Interface | MICROWIRE, QSPI, SPI, Serial (3-wire) |
| Input Type | Pseudo-Differential / Single-Ended, MUX |
| Supply Voltage | 5 V single supply |
| Analog Supply Voltage Range | 4.75 V to 5.25 V |
| Input Voltage Range (Software-Selectable) | 0 to VREF, 0 to VREF/2, ±VREF, ±VREF/2 |
| Internal Reference Voltage | 4.096 V (MAX1270A) |
| Linearity (DNL) | 0.5 LSB (max) |
| Bandwidth (Track/Hold) | 5 MHz |
| Fault-Protected Analog Inputs | ±17 V (without damage) |
| Operating Temperature | 0 °C to +70 °C |
| Package / Case | 24-DIP (0.300 inch, 7.62 mm) |
| Mounting Type | Through-Hole |
| Architecture | SAR (Successive Approximation) |
| Screening Level | Commercial |
| RoHS Status | Compliant |
| Sampling Rate (Per Second) | 110 k (per manufacturer family) |
MAX1270AENG Pin Configuration
| Pin 1 | AIN0 — Analog input channel 0 (8-channel MUX) |
| 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 — Analog and digital ground |
| Pin 10 | REF — Reference input/output (4.096 V internal for A variant) |
| Pin 11 | VDD — +5 V analog and digital supply |
| Pin 12 | SCLK — Serial clock input |
| Pin 13 | DIN — Serial data input (configuration byte) |
| Pin 14 | DOUT — Serial data output (conversion result) |
| Pin 15 | CS — Chip-select, active low |
| Pin 16 | SSTRB — Strobe output (conversion-complete status, optionally used) |
| Pin 17 | AINCOM — Analog input common (return for ± inputs) |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
| Pin 21 | NC — Not connected (per datasheet) |
| Pin 22 | NC — Not connected (per datasheet) |
| Pin 23 | NC — Not connected (per datasheet) |
| Pin 24 | NC — Not connected (per datasheet) |
Typical Applications
MAX1270AENG is suitable for 7 applications: Industrial Process Control Analog Input Module, Multi-Channel Data Logger and Sensor Aggregator, Battery-Stack Monitoring and BMS Telemetry, Programmable Logic Controller Analog Input Cards, Embedded Instrumentation and Test Equipment Front-End, Building Automation and HVAC Multi-Sensor Hub, Medical Sensor Signal Aggregation Front-End.
Industrial Process Control Analog Input Module
The MAX1270AENG's ±17 V fault-protected analog inputs and 8-channel MUX suit industrial PLC analog input cards where field wiring can carry switching transients above the 5 V supply. Eight inputs multiplex into one 12-bit 110 ksps SAR converter, eliminating the need for a per-channel protection front-end. Designers connect 4-20 mA loop signals through a 250 Ω sense resistor for 1-5 V inputs and use ±VREF/2 range for ±10 V scaled outputs.
Recommended
Multi-Channel Data Logger and Sensor Aggregator
Eight channel inputs let one MAX1270AENG serve thermocouple, RTD and strain-gauge sensors simultaneously through external signal conditioning. The internal 4.096 V reference provides up to 1 mV LSB resolution on the 0-4.096 V range, sufficient for K-type thermocouple cold-junction compensation. Hardware averaging via the configuration register reduces line-noise on slow data-logger channels while preserving 110 ksps on fast inputs.
Recommended
Battery-Stack Monitoring and BMS Telemetry
With ±17 V fault protection on each input, the MAX1270AENG can be connected directly to multi-cell battery stacks above the +5 V supply without external dividers for low-voltage stacks. Eight cells can be monitored through one IC, reducing BMS BOM. The low 6 mA operating and 10 µA shutdown currents extend battery life in portable battery-test equipment and cell-balancing monitors.
Recommended
Programmable Logic Controller Analog Input Cards
PLC analog input modules use the MAX1270AENG to digitize up to 8 analog signals per chip with 0.5 LSB DNL, ensuring closed-loop control fidelity. The SPI/QSPI/MICROWIRE-compatible 3-wire interface integrates directly with popular PLC microcontroller modules over SPI. Internal clock mode saves a host oscillator when deterministic timing is unnecessary, supporting cost-optimized low-density analog modules.
Recommended
Embedded Instrumentation and Test Equipment Front-End
Handheld digital multimeters and oscilloscope front-ends use the MAX1270AENG for multi-range measurement. Internal 4.096 V reference and software-selectable ±VREF/2 range allow a single IC to serve 4 V, 5 V, 10 V and 20 V full-scale measurements, simplifying analog front-end design. Rapid successive-approximation conversion yields deterministic sample timing that lowers measurement uncertainty in calibrated test gear.
Recommended
Building Automation and HVAC Multi-Sensor Hub
In HVAC controllers and smart-building gateways, the MAX1270AENG aggregates 8 analog sensor streams - temperature, humidity via analog transducer, gas sensor, light level - to a single microcontroller. The internal reference reduces BOM for cost-optimized commercial HVAC hardware. Low shutdown current (< 10 µA) keeps idle power minimal when the system is in sleep mode, supporting ENERGY STAR efficiency targets.
Recommended
Medical Sensor Signal Aggregation Front-End
Medical monitoring peripherals and portable diagnostic devices use the MAX1270AENG to consolidate multiple low-frequency patient-sensor signals - ECG leads, SpO2 photodiode current, temperature probes - into one 110 ksps 12-bit data stream. Fault-protected inputs tolerate electrocautery and defibrillator transients exceeding the 5 V supply. The DIP-24 package simplifies medical-grade through-hole assembly common in clinical instrumentation, with each ADC channel providing deterministic conversion latency for synchronized multi-lead acquisition.
Recommended
Recommended Products Summary
Engineering reference data for MAX1270AENG — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX1270AENG+ | MAX1270BENG+ | MAX1270ACNG+ | MAX1270BCNG+ | MAX162ACNG+ |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 24-PDIP | 24-PDIP - same | 24-PDIP - same | 24-PDIP - same | 24-PDIP - same | 24-PDIP - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Number of Channels | 8 | 8 | 8 | 8 | 8 | 8 |
| Internal Reference | Yes (4.096 V) | Yes (4.096 V) | No (external only) | Yes (4.096 V) | No (external only) | Yes |
| Operating Temperature | 0 to +70 C | 0 to +70 C | 0 to +70 C | -40 to +85 C | -40 to +85 C | -40 to +85 C |
| Fault-Protected Inputs | ±17 V | ±17 V | ±17 V | ±17 V | ±17 V | ±17 V |
| Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
Key Differentiators
- ±17 V fault-protected analog inputs on every channel (vs MAX162ACNG+)
- On-chip 4.096 V internal reference with VREF output (vs MAX1270BENG+)
- 110 ksps throughput with software-selectable internal/external clock (vs MAX1270ACNG+)
Design Notes
Place the 0.1 µF decoupling capacitor as close as possible between VDD (pin 11) and GND (pin 9), with a 10 µF bulk on the supply rail within ~2 cm. Bypass the REF pin with a 0.1 µF ceramic (and a 10 µF tantalum for highest accuracy) on the MAX1270A internal-reference variant. Keep analog and digital traces separated, and use a star ground at the AGND/DGND-adjacent pin to minimize conversion noise.
Avoid applying more than ±17 V on analog inputs even in shutdown, as the MUX ESD diodes will clamp; the device survives ±17 V transient but DC operation beyond the range is not specified. When selecting the input range, ensure the chosen range covers the expected signal peaks - selecting 0-VREF/2 range for a true bipolar signal saturates the converter. Use the configuration-register's external/internal clock bit to choose deterministic SPI timing when sample-rate accuracy matters.
Route the SPI lines (SCLK, DIN, DOUT, CS) away from the analog inputs. Place a 100 Ω series-termination on SCLK and DOUT when the MCU is more than 50 mm from the ADC to suppress SPI ringing that could fold into the conversion. For remote analog inputs longer than 100 mm, twist the input wires with a ground return to reject common-mode noise; maximize ADC sample settling with a low-pass RC at the AIN pins if signals are < 1 kHz.
Compliance Information
Lead-free RoHS-compliant finish per Maxim datasheet. Commercial-grade part (0 to +70 C); not AEC-Q100 qualified - choose MAX1270ACNG for extended industrial -40 to +85 C. Halogen-free status not explicitly stated in verified data.
