MAX166AEWP - 8-Bit 200ksps SAR ADC | Maxim Integrated
MPN: MAX166AEWP ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.85 | $6.85 |
| 10 | $6.18 | $61.80 |
| 100 | $5.5 | $550.00 |
| 500 | $4.92 | $2,460.00 |
| 1,000 | $4.4 | $4,400.00 |
MAX166AEWP Overview
An 8-bit successive-approximation ADC (SAR ADC) is a type of data converter that converts an analog input voltage into an 8-bit digital code through a binary-search algorithm executed in N clock cycles (here, ~8 × 500 ns). SAR ADCs sit in the broader hierarchy: ADC → data converter → mixed-signal IC → semiconductor. They are favored over flash ADCs for moderate resolution at low power, and over integrating ADCs for higher sampling rates, making them ideal for embedded systems that need to digitize several analog channels without excessive processor overhead.
Key features of the MAX166AEWP include a parallel output interface that simplifies connection to microprocessors and DSPs, an asynchronous RD and CS handshake for memory-mapped or port-mapped operation, and a hardware power-down pin that drops quiescent current to microamp levels for portable instrumentation. The track/hold front-end samples full-scale input transitions without slewing distortion up to the rated 200 ksamples/s, while the internal reference saves board space compared to discrete-resistor or external-reference designs.
Typical applications include industrial process-control front ends, data-acquisition front ends for 8-bit instrumentation, portable battery-powered metering, multiplexed data-logger channels, and digital-signal-processor (DSP) analog front ends. Industrial temperature-grade variants such as the MAX166AEWP-T operate from -40 °C to +85 °C, supporting factory-floor deployment.
When designing with the MAX166AEWP, ensure the analog input source can drive the track/hold sampling capacitor without attenuation - an op-amp buffer is recommended for high-impedance sources. Decouple both AVDD and DVDD separately with 0.1 μF ceramic capacitors placed within 5 mm of the supply pins, and place the input trace away from noisy digital output lines to preserve 8-bit accuracy.
Drop-in alternatives for MAX166AEWP — 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 MAX166AEWP (same form factor and footprint) — differing in Architecture, Conversion Time, Operating Temperature, Package, Sample Rate.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX166AEWP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX166ACWP
✅ Drop-In📋 Reference alternative (not in catalog)
MAX166AEWP-T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX166DCWP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX166BEWP
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.08 / Unit
View Datasheet →MAX166AEWP Maximum Ratings & Electrical Characteristics
| Resolution | 8 bit |
| Sample Rate | 200 ksamples/s |
| Conversion Time | 5 us (typ) |
| Architecture | Successive Approximation (SAR) |
| Number of Channels | 1 |
| Input Voltage Range | 0 V to 2.46 V (internal reference) / 0 V to 5 V (external) |
| Analog Supply Voltage (AVDD) | 5 V |
| Digital Supply Voltage (DVDD) | 4.75 V to 5.25 V |
| Supply Current (Active) | 4 mA (typ) |
| Supply Current (Power-Down) | 1 uA (typ) |
| Integral Linearity Error (INL) | +/-1/2 LSB (max) |
| Total Unadjusted Error | +/-1 LSB (max) |
| Track/Hold Bandwidth | 4 MHz (typ) |
| Output Interface | Parallel, 8-bit, CS/RD controlled |
| Operating Temperature | -40C to +85C |
| Package | SOIC-20 (0.300 inch, wide-body) |
| Mounting Type | Surface Mount |
MAX166AEWP Pin Configuration
| Pin 1 | DB0 — Data output bit 0 (LSB) |
| Pin 2 | DB1 — Data output bit 1 |
| Pin 3 | DB2 — Data output bit 2 |
| Pin 4 | DB3 — Data output bit 3 |
| Pin 5 | DB4 — Data output bit 4 |
| Pin 6 | AIN — Analog input |
| Pin 7 | REF — Reference voltage input/output |
| Pin 8 | AGND — Analog ground |
| Pin 9 | VSS — Negative supply / ground |
| Pin 10 | PWRDN — Power-down input (active high) |
| Pin 11 | RD — Read input (active low) |
| Pin 12 | CS — Chip select (active low) |
| Pin 13 | DB5 — Data output bit 5 |
| Pin 14 | DB6 — Data output bit 6 |
| Pin 15 | DB7 — Data output bit 7 (MSB) |
| Pin 16 | CLK — Clock input |
| Pin 17 | DGND — Digital ground |
| Pin 18 | AVDD — Analog +5 V supply |
| Pin 19 | DVDD — Digital +5 V supply |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
MAX166AEWP is suitable for 7 applications: Industrial Process Control Front End, Portable Battery-Powered Metering, Data Acquisition Front End for DSP Systems, Multiplexed Data Logger Channels, Embedded Microcontroller Analog Input, Automotive Sensor Interface (Legacy 12 V Systems), Test and Measurement Instrumentation.
Industrial Process Control Front End
The MAX166AEWP fits industrial process-control front ends where 8-bit resolution is sufficient to digitize temperature, pressure, and flow transducer outputs. With 200 ksamples/s throughput and 5 us conversion time, it can multiplex-scan multiple slow channels or sample a single fast control loop at rates well above the 4 kHz Nyquist needs of typical process signals. The industrial -40 °C to +85 °C operating range handles factory-floor environments, while the internal 2.46 V reference simplifies the analog signal chain. Powered from a single +5 V supply plus 5 V digital supply, the part can sit directly on a 5 V microcontroller bus. Compared to a 12-bit ADC, the MAX166AEWP trades resolution for higher sample rate at lower cost.
Recommended
Portable Battery-Powered Metering
The MAX166AEWP suits portable battery-powered metering designs thanks to its 1 uA power-down current and 4 mA active supply current. In a handheld multimeter or data-logger, the part can be switched off between samples to extend battery life by orders of magnitude compared to continuously powered solutions. The integrated track/hold amplifier captures fast transients at up to 200 ksamples/s, suitable for power-quality or transient-recorder products. Operating from a single 5 V rail generated by a boost converter from a 3 V lithium cell, it minimizes battery-management complexity. Compared to integrating ADCs, the SAR topology provides instant conversion results without long integration windows.
Recommended
Data Acquisition Front End for DSP Systems
The MAX166AEWP serves as a data acquisition front end for digital signal processor (DSP) systems that need to digitize analog inputs at moderate resolution with deterministic latency. The parallel 8-bit output interface matches DSP external-memory-interface widths, allowing DMA-driven sample streams with minimal glue logic. The 5 us conversion time gives deterministic acquisition latency, important for control loops or real-time signal processing. The 200 ksamples/s throughput can support audio-bandwidth sampling up to ~100 kHz with Nyquist margin. Operating from 5 V supplies and providing CS/RD-level handshaking, the MAX166AEWP interfaces easily to legacy 5 V DSPs and microcontrollers.
Recommended
Multiplexed Data Logger Channels
The MAX166AEWP works well as the core ADC in a multiplexed data logger where multiple sensor channels are sequentially scanned through an external analog multiplexer. With 200 ksamples/s sample rate, it can digitize 10 channels at 20 ksamples/s aggregate, or 100 channels at 2 ksamples/s, well beyond typical slow-channel data logger needs. The internal track/hold and reference eliminate the per-channel analog conditioning complexity, while the 0 V to 2.46 V input range is compatible with most transducer outputs amplified to a few volts. The SOIC-20 wide-body package provides good thermal dissipation for continuous-operation loggers.
Recommended
Embedded Microcontroller Analog Input
The MAX166AEWP is a natural fit as an external ADC for 8-bit microcontrollers that lack built-in ADCs or need higher sample rates than the integrated ADC provides. The parallel interface connects directly to microcontroller address/data buses, and the CS/RD handshake enables memory-mapped or port-mapped operation in 8051, PIC, or AVR-based designs. The 200 ksamples/s sample rate exceeds most internal MCU ADC capabilities, useful for motor-control feedback or audio-bandwidth sensing. The +5 V supply tolerance matches typical MCU rails without level shifting, simplifying PCB design.
Recommended
Automotive Sensor Interface (Legacy 12 V Systems)
The MAX166AEWP can serve in legacy 12 V automotive sensor-interface modules where its industrial -40 °C to +85 °C temperature rating covers the cabin and engine-bay environments. Digitizing throttle position, MAP sensor, or temperature sensor outputs at 8-bit resolution is sufficient for many ECU subsystems, with the 200 ksamples/s throughput handling multiplexed channel scanning. The wide SOIC-20 package provides robust solder joints that withstand automotive vibration. Note: the MAX166AEWP is not AEC-Q100 qualified; for new automotive designs, use the MAX166AEWP-Q variant or a current-generation AEC-Q100 ADC.
Recommended
Test and Measurement Instrumentation
The MAX166AEWP can act as a fast front-end digitizer in entry-level test and measurement instruments such as handheld oscilloscopes, benchtop multimeters, or waveform loggers. Its 200 ksamples/s sample rate captures audio and ultrasonic-bandwidth signals (up to ~100 kHz with Nyquist margin), while the internal track/hold handles full-scale input slews without distortion. The 5 us deterministic conversion time allows precise timing annotation of acquired samples. The SOIC-20 wide-body package eases hand-soldering for prototype and low-volume production runs typical of instrumentation products.
Recommended
Recommended Products Summary
Engineering reference data for MAX166AEWP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX166AEWP+ | MAX166ACWP | MAX166AEWP-T | MAX166DCWP+ | MAX166BEWP |
|---|---|---|---|---|---|---|
| Package | SOIC-20 (0.300 inch) | SOIC-20 (0.300 inch) - same | SOIC-20 (0.300 inch) - same | SOIC-20 (0.300 inch) - same | SOIC-20 (0.300 inch) - same | SOIC-20 (0.300 inch) - same |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit |
| Sample Rate | 200 ksamples/s | 200 ksamples/s | 200 ksamples/s | 200 ksamples/s | 200 ksamples/s | 200 ksamples/s |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) | -55C to +125C (military) | -40C to +85C (industrial) |
| RoHS / Lead-Free | Leaded (legacy) | RoHS / lead-free | Leaded (legacy) | Leaded (legacy) | RoHS / lead-free | Leaded (legacy) |
| Packaging Format | Tube | Tube | Tube | Tape & Reel | Tube | Tube |
| Lifecycle Status | NRND | NRND | NRND | NRND | Discontinued | NRND |
Key Differentiators
- Industrial temperature range at standard grade (vs MAX166ACWP)
- RoHS-compliant lead-free option available in same footprint (vs MAX166AEWP (leaded))
- Tape-and-reel packaging variant for high-volume assembly (vs MAX166AEWP (tube))
Design Notes
Estimated: the MAX166AEWP draws approximately 4 mA from AVDD and 4 mA from DVDD when sampling at 200 ksamples/s, totaling ~40 mW supply power at 5 V rails. Drive AVDD and DVDD from low-noise sources - any ripple on the analog supply directly couples into the ADC reference, reducing SNR. Use separate regulators or RC-filtered LDO outputs for AVDD versus DVDD, and place 0.1 uF ceramic bypass capacitors within 5 mm of each supply pin. Ground pin VSS and AGND/DGND must connect to a single low-impedance ground plane to avoid ground-loop-induced errors.
Route the analog input trace AIN as a differential pair with its analog ground return to minimize common-mode noise pickup, and keep the trace away from the parallel digital output bus DB0-DB7 by at least 10 mm or shield with a grounded trace. The reference pin REF is sensitive to load transients - if driving an external reference bypass with anything other than the internal source, add a 1 uF or 4.7 uF tantalum bypass capacitor close to the REF pin. Maintain the SOIC-20 land pattern per IPC-7351 wide-body SOIC recommendations for proper solder joint reliability.
The MAX166AEWP inputs accept 0 V to 2.46 V only when using the internal reference; do NOT apply signals beyond 2.46 V to AIN in this configuration or the input ESD diodes will forward-conduct and corrupt the conversion. For higher-voltage signals, use an external resistor divider or op-amp attenuator on the AIN pin. Also note that the CS pin is active-low but should NOT be left floating - tie it to DVDD through a pull-up if not actively driven, or the output bus may spuriously enable. Finally, when sequencing power, bring up AVDD first or simultaneously with DVDD to avoid latch-up.
Source impedance at AIN affects acquisition accuracy: each conversion requires the internal track/hold to settle to within 1/2 LSB (about 9.6 mV at 2.46 V full-scale) within the 5 us acquisition window. A source impedance above 1 kohm may require an input buffer op-amp such as the MAX4166 to maintain full 8-bit accuracy. The MAX166AEWP's track/hold bandwidth of approximately 4 MHz sets the upper-frequency limit of input slew-rate preservation, so audio-bandwidth and ultrasonic-bandwidth signals are reproduced cleanly while faster transitions may alias.
Estimated: at 5 V supplies and 8 mA total active current, the MAX166AEWP dissipates about 40 mW, far below thermal limits for the SOIC-20 wide-body package (which has theta_JA around 70-80 C/W). Junction temperature rise above ambient is roughly 3 C at typical 25 C ambient, well within the 150 C absolute maximum. No heatsinking or thermal copper pour beyond standard SOIC-20 land pattern is required, making the part suitable for compact handheld or portable designs.
Compliance Information
MAX166AEWP is the legacy leaded variant (non-RoHS). Use MAX166AEWP+ (lead-free / RoHS) for RoHS-regulated designs. Not AEC-Q100 qualified; not recommended for new automotive designs.
