MAX186ACPP - 12-Bit 8-Ch 133kHz Serial ADC | Maxim/Analog Devices
MPN: MAX186ACPP ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $21.16 | $21.16 |
| 10 | $18.79 | $187.90 |
| 25 | $17.45 | $436.25 |
| 100 | $15.68 | $1,568.00 |
| 500 | $14.12 | $7,060.00 |
| 1,000 | $12.78 | $12,780.00 |
MAX186ACPP Overview
A Data Acquisition System (DAS) is an integrated analog front-end that combines multiplexing, sample-and-hold, and ADC functionality in a single chip, eliminating the need for external analog signal conditioning. DAS devices sit at the analog boundary of mixed-signal systems, feeding the host microcontroller's digital domain. The MAX186ACPP belongs to the successive-approximation-register (SAR) ADC family - the workhorse architecture for multiplexed multi-channel data acquisition in industrial, instrumentation, and process-control applications.
Key differentiating specifications include: 133 kHz maximum sampling rate, 1.5 mA operating supply current, 2 µA power-down current, internal 4.096 V reference, 8 single-ended or 4 differential input channels, and ±5 V true bipolar analog input range. The serial interface reduces pin count and simplifies isolated or distributed data acquisition layouts, while the 12-bit resolution delivers 1 LSB = 1 mV at the 4.096 V full-scale reference.
The MAX186 uses a capacitive charge-redistribution SAR architecture with an on-chip calibration logic that corrects internal capacitor mismatch each conversion. The internal reference can be overridden by an external reference voltage applied to the REF pin, enabling ratiometric measurements where the excitation source doubles as the reference. The SHDN pin reduces quiescent current to 2 µA for battery-powered portable applications.
Typical applications include process control and industrial automation, portable data loggers, battery-powered instrumentation, isolated data acquisition front-ends, panel meters, and multi-sensor embedded systems. The 8-channel mux eliminates external analog switches for typical multi-channel transducer monitoring.
When designing with this device, place 0.1 µF bypass capacitors close to the supply pins and a 4.7 µF tantalum capacitor on the REF pin. The serial clock and chip-select traces should be kept short to avoid digital coupling into the analog inputs. For 50/60 Hz noise rejection, use averaging or synchronized sampling at integer multiples of the line frequency.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical PCB layout guidance not found in the manufacturer datasheet alone.
Drop-in alternatives for MAX186ACPP — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX186CCPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX186BCPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX186DCPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX186BEPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX186CEPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX186ACPP Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Number of Channels | 8 single-ended / 4 differential |
| Sampling Rate | 133 kHz max |
| Input Type | Single-Ended or Differential |
| Architecture | SAR (Successive Approximation) |
| Supply Voltage (Digital) | 5 V |
| Analog Input Range | 0 to 5 V (single) or ±5 V (bipolar) |
| Operating Supply Current | 1.5 mA typical |
| Power-Down Current | 2 µA typical |
| Internal Reference Voltage | 4.096 V (MAX186 only) |
| Serial Interface | SPI / QSPI / MICROWIRE-compatible |
| Package | 20-pin PDIP (through-hole) |
| Operating Temperature | 0 °C to +70 °C (commercial 'C' grade) |
| Track/Hold | Internal, 4 MHz bandwidth |
| RoHS Status | Non-compliant (PDIP package) |
MAX186ACPP Pin Configuration
| Pin 1 | SCLK — Serial clock input |
| Pin 2 | DOUT — Serial data output (ADC result) |
| Pin 3 | DIN — Serial data input (channel config) |
| Pin 4 | AIN0 — Analog input channel 0 |
| Pin 5 | AIN1 — Analog input channel 1 |
| Pin 6 | AIN2 — Analog input channel 2 |
| Pin 7 | AGND — Analog ground |
| Pin 8 | CS — Active-low chip select |
| Pin 9 | SHDN — Shutdown input (active high) |
| Pin 10 | VSS — Digital ground reference |
| Pin 11 | REF — Reference voltage I/O (4.096V internal on MAX186) |
| Pin 12 | INT — Interrupt / end-of-conversion output |
| Pin 13 | AIN3 — Analog input channel 3 |
| Pin 14 | AIN4 — Analog input channel 4 |
| Pin 15 | AIN5 — Analog input channel 5 |
| Pin 16 | AIN6 — Analog input channel 6 |
| Pin 17 | AIN7 — Analog input channel 7 |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | VDD — +5V digital supply |
Typical Applications
MAX186ACPP is suitable for 7 applications: Industrial Process Control, Portable Battery-Powered Data Loggers, Multi-Sensor Embedded Systems, Isolated Data Acquisition Front-Ends, Panel Meters and Digital Instrumentation, Medical Diagnostic Equipment, Automotive Diagnostic Systems.
Industrial Process Control
The MAX186ACPP is well-suited for industrial process-control PLCs and DCS analog input modules where 8 single-ended or 4 differential analog channels must be digitized with 12-bit precision at moderate bandwidth. The 133 kHz sampling rate supports 8 channels scanned at 16 kHz per channel, fast enough for temperature, pressure, and flow transmitters with sub-second settling. The integrated 8-channel mux eliminates external analog switches, reducing BOM cost in multi-channel PLC backplanes. The internal 4.096 V reference gives 1 mV/LSB resolution for industrial signal conditioning. Bipolar ±5 V input range allows direct connection to current-loop transmitters with 4-20 mA sense resistors, while the SPI interface simplifies isolated data acquisition front-ends using digital isolators on the serial lines.
Recommended
Portable Battery-Powered Data Loggers
The MAX186ACPP's 2 µA power-down current makes it ideal for handheld and battery-powered data loggers that periodically wake to sample sensors and return to sleep between measurements. The 1.5 mA operating current at +5 V (7.5 mW) supports hundreds of conversions per battery charge when duty-cycled via the SHDN pin. The internal 4.096 V reference eliminates the need for a separate reference IC, reducing quiescent drain. The serial interface minimizes microcontroller GPIO usage and allows operation from low-power MCUs like the MAX32620 or MAX78000. Field data loggers for environmental monitoring, agricultural sensors, and portable medical instruments benefit from this low-duty-cycle power profile.
Recommended
Multi-Sensor Embedded Systems
The MAX186ACPP's 8 input channels and integrated track-and-hold simplify multi-sensor embedded systems such as HVAC controllers, building automation panels, and IoT edge nodes. A single chip can digitize multiple thermistors, photocells, humidity sensors, and 4-20 mA transducer outputs without external analog switches. The 12-bit resolution provides adequate precision for set-point control and trend logging. The SPI interface supports fast readouts to embedded hosts like MAX78000, STM32, or PIC microcontrollers. With an MCU-controlled SHDN pin, the ADC can sleep between sensor readings, achieving microamp-level quiescent current in the overall system.
Recommended
Isolated Data Acquisition Front-Ends
The MAX186ACPP's serial interface makes it ideal for isolated data acquisition modules used in medical equipment, industrial safety barriers, and high-voltage measurement systems. Only four digital signals (SCLK, DOUT, DIN, CS) plus a chip-select need to cross the digital isolator, dramatically reducing the cost of optical or transformer isolation compared to parallel-output ADCs that would require 12+ isolation channels. The MAX186ACPP's 12-bit precision suits motor-drive current monitoring, isolated thermocouple conditioning, and patient-isolated ECG signal acquisition where galvanic isolation is mandatory. The ±5 V bipolar input range accommodates industrial transducer outputs on the analog side of the barrier.
Recommended
Panel Meters and Digital Instrumentation
The MAX186ACPP is well-suited for digital panel meters, weigh scales, and process indicators that need accurate DC measurement with serial interface to a display controller or MCU. The internal 4.096 V reference eliminates external reference drift in field-deployed instruments. The 8-channel mux allows multi-range digital multimeters to measure voltage, current (via sense resistor), and temperature (via RTD/thermistor) with a single ADC. The 133 kHz sampling rate easily handles 60 Hz line-frequency-rejecting averaging on power-quality meters. The 20-pin PDIP package supports hand-soldering in low-volume industrial product runs.
Recommended
Medical Diagnostic Equipment
The MAX186ACPP's 12-bit resolution and bipolar ±5 V input range suit medical diagnostic instruments such as bench-top analyzers, patient monitors, and laboratory pipette controllers. The integrated 8-channel mux digitizes multiple physiological sensor channels (e.g., SpO2, temperature, and respiration) without external switching. The SPI-compatible serial interface enables clean digital isolation for patient-connected equipment meeting IEC 60601 leakage requirements. The low 2 µA power-down current extends battery life in portable point-of-care devices. The commercial 'C' grade 0-70 °C operating range covers hospital and lab environments.
Recommended
Automotive Diagnostic Systems
The MAX186ACPP can be used in non-safety automotive diagnostic equipment, including engine analyzers, OBD-II test instruments, and battery management service tools. The 8-channel input supports simultaneous monitoring of battery voltage, starter current, alternator ripple, and individual cell voltages in 12V/24V vehicle systems. The bipolar ±5 V input range captures both positive and negative signal excursions around ground, useful for inductive current probes and hall-effect sensors. The serial interface reduces wiring in service-bay cable assemblies, while the 133 kHz sampling rate captures transient events like injector pulses and crank-position signals.
Recommended
Recommended Products Summary
Engineering reference data for MAX186ACPP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX186CCPP+ | MAX186BCPP+ | MAX186DCPP+ | MAX186BEPP+ | MAX186CEPP+ |
|---|---|---|---|---|---|---|
| Package | PDIP-20 (through-hole) | PDIP-20 - same | PDIP-20 - same | PDIP-20 - same | PDIP-20 - same | PDIP-20 - same |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 133 kHz | 133 kHz | 133 kHz | 133 kHz | 133 kHz | 133 kHz |
| Number of Channels | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF |
| Internal Reference | 4.096 V | 4.096 V | 4.096 V | 4.096 V | 4.096 V | 4.096 V |
| Temperature Grade | 0C to +70C (C-grade) | 0C to +70C | 0C to +70C | 0C to +70C | -40C to +85C (E-grade) | -40C to +85C (E-grade) |
| Linearity Grade | A-grade | C-grade (tighter) | B-grade (tighter) | D-grade (tightest) | B-grade | C-grade |
| Operating Supply Current | 1.5 mA | 1.5 mA | 1.5 mA | 1.5 mA | 1.5 mA | 1.5 mA |
| Power-Down Current | 2 uA | 2 uA | 2 uA | 2 uA | 2 uA | 2 uA |
Key Differentiators
- Internal 4.096V reference eliminates external reference IC (vs MAX188ACPP)
- Pin-compatible upgrade path within MAX186 family (vs MAX186BCPP+)
- Through-hole package for legacy and prototype designs (vs MAX186AEAP+ (SSOP-20))
- Lowest cost C-grade option in MAX186 family (vs MAX186CCPP+)
Design Notes
Estimated: Decouple VDD (pin 20) and VSS (pin 10) with a 0.1 µF ceramic capacitor placed within 5 mm of the supply pins, plus a 10 µF tantalum bulk capacitor. The reference pin (pin 11, REF) requires a 4.7 µF tantalum or low-ESR ceramic bypass capacitor as recommended in the manufacturer datasheet typical application circuit. Use separate analog (AGND, pin 7) and digital (VSS, pin 10) ground returns that meet only at one point near the power supply.
Route the analog input traces (AIN0-AIN7) away from the serial interface lines (SCLK, DOUT, DIN, CS) and digital outputs to minimize digital-to-analog crosstalk. Keep the AIN traces short and use a ground guard trace around sensitive analog inputs if possible. The PDIP-20 package simplifies through-hole prototyping layouts but for production consider migrating to the MAX186AEAP+ (SSOP-20) to reduce PCB area and improve digital noise immunity.
Do not leave the SHDN pin (pin 9) floating - tie to VSS for normal operation, drive high to enter 2 µA power-down mode. Ensure the CS line is held high between conversions; if CS is left low, the device enters the internal clock mode and consumes additional current. When using external reference mode (MAX188 only - the MAX186ACPP has internal reference), the REF pin must still be bypassed with at least 4.7 µF. Avoid driving the analog inputs beyond ±15 V absolute maximum or device damage may occur.
For 50/60 Hz mains rejection in industrial environments, sample at integer multiples of the line frequency (e.g., 16.667 kHz per channel for 60 Hz, or compute running average over 100 ms windows). The MAX186ACPP's track/hold has 4 MHz bandwidth, so use an external input RC filter (typically 1 kΩ/100 pF, ~1.6 MHz cutoff) before each AIN channel for noise reduction without aliasing the 133 kHz sampling clock. Verify timing margins against the serial interface specification in the datasheet when running SCLK above 2 MHz.
Compliance Information
MAX186ACPP (without '+' suffix) is not RoHS-compliant due to the PDIP-20 lead-finish. The RoHS variant MAX186ACPP+ is available from authorized distributors. Not AEC-Q100 qualified (consumer/commercial temperature grade).
