MAX176AEPA+ - 12-Bit 250ksps Serial ADC with T/H | Maxim Integrated
MPN: MAX176AEPA+ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $12.95 | $129.50 |
| 100 | $11.2 | $1,120.00 |
| 500 | $9.85 | $4,925.00 |
| 1,000 | $8.65 | $8,650.00 |
MAX176AEPA+ Overview
An ADC is a data converter that translates a continuous analog input voltage into a discrete digital code. Successive-approximation register (SAR) ADCs such as the MAX176AEPA+ perform the conversion in N clock cycles for an N-bit result, balancing conversion speed against power and silicon area. Compared with flash and pipeline architectures, SAR ADCs offer deterministic latency and low noise at moderate sampling rates, making them the de-facto choice for multiplexed 12-bit industrial and instrumentation front ends where they would otherwise require a separate reference and a discrete sample-and-hold.
Key specifications include 12-bit resolution with ±1 LSB (max) linearity, 250 ksps throughput, ±5 V analog input range (unipolar or bipolar with external scaling), and a 0.4 µs track-and-hold acquisition time. The integrated buried-zener reference delivers low drift and low noise, eliminating the need for an external precision reference in many designs. The serial interface reduces pin count and isolates the digital noise from the analog front end, and the device is specified over the -40 °C to +85 °C industrial temperature range.
Internally, the MAX176AEPA+ uses a charge-redistribution DAC switched by a thin-film resistor ladder, a high-bandwidth input track-and-hold capable of digitizing fast signals without slew-rate-induced error, and a buried-zener reference biased from the +5 V and -15 V rails for low temperature coefficient. Its serial interface is compatible with standard SPI/QSPI/MICROWIRE microcontrollers, simplifying the digital board-side connection to a single chip-select, clock, and serial-data line. The combination of low aperture delay and a quiet on-chip reference makes the part well-suited to multiplexed data-acquisition channels sharing a single converter.
Typical applications include industrial process-control data-acquisition front ends, weigh-scale and strain-gauge instrumentation, portable battery-powered measurement, panel-meter signal conditioning, and closed-loop servo control. It also serves medical instrumentation front ends and sensor-signal digitizers where a precision reference and sample-and-hold are needed in a small through-hole footprint.
When designing with the MAX176AEPA+, place the 0.1 µF supply bypass capacitors as close as possible to pins 1, 7, and 8, and provide a low-impedance analog ground return to minimize digital switching noise coupling into the analog input. The +5 V supply should be low-noise, because the reference derives directly from it; for best linearity performance, the negative supply (VSS) should be a clean -12 V to -15 V rail rather than generated locally from the +5 V line.
This page consolidates distributor pricing, drop-in same-family alternatives, and PCB design notes that are not collected in a single location on the manufacturer's datasheet, giving engineers a single decision-grade reference for selecting or replacing the MAX176AEPA+.
Drop-in alternatives for MAX176AEPA+ — 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 MAX176AEPA+ (same form factor and footprint) — differing in Conversion Time, Input Type, Number of Channels, Operating Temperature Range, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX176BEPA+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX176BCPA+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX176AEPA
✅ Drop-In✓ In Stock
$20.2 / Unit
View Datasheet →MAX145BEPA
✅ Drop-In✓ In Stock
$5.29 / Unit
View Datasheet →MAX145AEPA
✅ Drop-In✓ In Stock
$5.2 / Unit
View Datasheet →MAX176AEPA+ Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Sampling Rate | 250 ksps |
| Conversion Architecture | Successive Approximation (SAR) |
| Number of Channels | 1 |
| Input Type | Single-Ended (unipolar or bipolar with scaling) |
| Analog Supply Voltage | +5 V (typ), VSS = -12 V or -15 V |
| Analog Input Range | 0 V to +5 V (unipolar) or ±5 V (bipolar) |
| Track-and-Hold Acquisition Time | 0.4 µs (max) |
| Conversion Time | 3.5 µs (typ) |
| Output Interface | Serial (SPI / QSPI / MICROWIRE compatible) |
| Internal Reference | Buried-zener, on-chip |
| Operating Temperature Range | -40 °C to +85 °C (industrial) |
| Package | 8-pin PDIP (through-hole, plastic DIP-8) |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
| Lead-Free | Yes |
MAX176AEPA+ Pin Configuration
| Pin 1 | VDD — +5 V analog supply |
| Pin 2 | AIN — Analog input |
| Pin 3 | AGND — Analog ground |
| Pin 4 | REF — Reference I/O (internal buried-zener) |
| Pin 5 | VSS — Negative supply (-12 V or -15 V) |
| Pin 6 | GND — Digital ground |
| Pin 7 | DOUT — Serial data output |
| Pin 8 | SCLK — Serial clock input |
Typical Applications
MAX176AEPA+ is suitable for 6 applications: Industrial Process Control Data Acquisition, Weigh Scale and Strain Gauge Instrumentation, Portable Battery-Powered Measurement, Panel Meter and Signal Conditioning, Closed-Loop Servo Control Position Feedback, Medical Instrumentation Front End.
Industrial Process Control Data Acquisition
The MAX176AEPA+'s 12-bit resolution, 250 ksps sampling rate, and integrated track-and-hold make it well-suited to multiplexed industrial process-control front ends. In a typical 4-20 mA loop digitizer, the ADC samples at 250 ksps while a low-pass filter and instrumentation amp condition the input; the buried-zener reference avoids drift in factory-floor temperature swings. According to the Maxim datasheet, the serial SPI/QSPI/MICROWIRE interface isolates digital switching noise from the analog path, critical when multiple channels share a converter over long PCB traces near motor drives.
Recommended
Weigh Scale and Strain Gauge Instrumentation
Weigh-scale and load-cell instrumentation demands the low noise, integrated reference, and differential-friendly front end that the MAX176AEPA+ provides. A bridge sensor with a few mV/V full-scale output is amplified to the ADC's 5 V input span by an external instrumentation amp, and the ADC's 12-bit resolution yields >2000 counts resolution over the scale range. The 0.4 µs track-and-hold acquisition handles step changes in load without slew-induced error, while the on-chip buried-zener reference eliminates the need for an external precision reference that would otherwise drift with ambient temperature in the scale enclosure.
Recommended
Portable Battery-Powered Measurement
Portable handheld DMMs, calibrators, and field instrumentation benefit from the MAX176AEPA+'s low power dissipation and single +5 V plus -12 V supply operation. With typical power below 50 mW, the part can run from a 9 V battery plus a small charge-pump inverter, avoiding the bulk of a discrete -12 V supply. The serial interface uses only three digital lines, freeing microcontroller pins for the display, keypad, and BLE/IrDA link; the 8-pin PDIP also simplifies hand-rework and field replacement of the ADC module.
Recommended
Panel Meter and Signal Conditioning
Digital panel meters and process indicators use the MAX176AEPA+ to digitize 4-20 mA, 0-10 V, or thermocouple-conditioned signals for LCD display. The 12-bit resolution provides 0.024% display resolution, sufficient for most industrial process readouts, and the integrated track-and-hold allows the meter to capture peak or transient values without an external sample-and-hold. The on-chip buried-zener reference ensures the panel meter reading does not drift with the enclosure's internal temperature rise, eliminating field recalibration.
Recommended
Closed-Loop Servo Control Position Feedback
Position feedback in servo and stepper-motor control systems requires deterministic conversion latency and low aperture delay, both of which the MAX176AEPA+'s SAR architecture provides. The ADC reads an encoder or resolver-conditioned analog signal at 250 ksps, and the deterministic per-sample latency simplifies the digital controller's PID loop timing. The serial interface shares the SPI bus with the motor driver, reducing wiring to the moving axis and improving noise immunity compared with parallel-output ADCs.
Recommended
Medical Instrumentation Front End
Patient-monitoring front ends, infusion-pump flow sensors, and bench-top analyzers leverage the MAX176AEPA+'s low noise, integrated reference, and industrial temperature spec. The 12-bit resolution digitizes the conditioned output of pressure, flow, or bio-potential sensors with sufficient resolution for trend display, and the on-chip track-and-hold avoids missed transients. The legacy 8-pin PDIP through-hole package also simplifies medical-device retrofit designs where the original ADC has been discontinued and a pin-compatible replacement is required.
Recommended
Recommended Products Summary
Engineering reference data for MAX176AEPA+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX176BEPA+ | MAX176BCPA+ | MAX176AEPA | MAX145BEPA | MAX145AEPA |
|---|---|---|---|---|---|---|
| Package | PDIP-8 | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sampling Rate | 250 ksps | 250 ksps | 250 ksps | 250 ksps | 200 ksps (-20%) | 200 ksps (-20%) |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR |
| Operating Temperature | -40 °C to +85 °C (industrial) | -40 °C to +85 °C | 0 °C to +70 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Interface | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE | Serial SPI/QSPI/MICROWIRE |
| Internal Reference | Yes (buried-zener) | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Higher sampling rate than MAX145 series with same pinout (vs MAX145AEPA / MAX145BEPA)
- Industrial -40 to +85 °C temperature range vs commercial only (vs MAX176BCPA+)
- Lead-free RoHS-compliant packaging with + suffix (vs MAX176AEPA (no +))
Design Notes
Provide both +5 V (VDD) and a clean -12 V or -15 V (VSS) supply. The buried-zener reference derives its bias from VSS, so a noisy or improperly bypassed VSS will inject reference noise directly into the conversion result. Estimated: at ±15 V supplies and 250 ksps the supply current is on the order of a few mA per rail, so a small linear regulator (78L05/79L15) is sufficient rather than a switching pre-regulator.
Place 0.1 µF ceramic bypass capacitors as close as possible to pins 1 (VDD), 5 (VSS), and 8 (SCLK digital return). Separate analog ground (pin 3) and digital ground (pin 6) at the IC and join them at a single point under the chip; routing digital return currents through analog ground will couple switching noise into AIN. Keep the AIN trace short and guarded with a driven shield if the source impedance is greater than ~5 kΩ.
Do not operate the MAX176AEPA+ without the negative supply connected; the internal reference relies on VSS bias and the output code will not be valid. Do not drive AIN above VDD + 0.3 V or below VSS - 0.3 V, as the input protection clamps can inject charge into the sample capacitor and corrupt the next conversion. The SCLK idle state should be verified against your MCU's SPI mode - the MAX176AEPA+ expects SCLK idle-low (CPOL=0, CPHA=0).
Route the DOUT trace away from the AIN and REF traces to minimize digital-to-analog crosstalk. If the DOUT trace must cross analog traces, cross at right angles and only once. Place the optional input RC anti-alias filter (typically 1 kΩ + 1 nF) within 5 mm of AIN to limit out-of-band noise folded into the 0-250 kHz Nyquist band.
Compliance Information
Lead-free and RoHS compliant per the + suffix in the part number and Maxim Integrated product literature. Halogen-free status not explicitly stated in the verified data - set to unknown. Not AEC-Q100 qualified; for automotive applications consult Analog Devices automotive-grade SAR ADC portfolio.
