MAX170CCPA - 12-Bit 125kSPS Serial ADC w/ Reference | Maxim
MPN: MAX170CCPA ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.92 | $6.92 |
| 10 | $6.05 | $60.50 |
| 100 | $5.3 | $530.00 |
| 500 | $4.62 | $2,310.00 |
| 1,000 | $3.95 | $3,950.00 |
MAX170CCPA Overview
An ADC (Analog-to-Digital Converter) is a semiconductor device that converts a continuous analog input voltage into a discrete digital code proportional to the magnitude of the input. Successive-approximation ADCs like the MAX170 use a binary-search algorithm through an internal DAC and comparator, balancing speed, resolution, and die cost. They sit in the broader taxonomy of data-converter ICs (sub-family: SAR ADC), which themselves belong to the data acquisition and signal-chain semiconductor category. Internal voltage references simplify design by eliminating the need for an external precision reference.
Key features include 5.6 us conversion time, 125 kSPS throughput, an on-chip 2.5 V reference (15 ppm/C typ drift), ±0.5 LSB integral nonlinearity (INL), and SPI/QSPI/MICROWIRE-compatible serial output. The MAX170 also supports an external reference input when higher accuracy or ratiometric measurements are required. Power-down mode reduces supply current to under 10 uA between conversions, ideal for battery-powered or low-duty-cycle instrumentation.
Architecturally, the MAX170 uses a charge-redistribution DAC array combined with a high-speed comparator and successive-approximation register (SAR). The buried-zener reference provides low noise and excellent long-term stability, while the CMOS process keeps power consumption low without sacrificing dynamic performance. The serial interface minimizes pin count, making the device suitable for space-constrained designs.
Typical applications include portable data loggers, pen-tablet digitizers, battery-powered instrumentation, process-control isolated front ends, and isolated 4-20 mA loop sensing. The internal reference and high throughput also suit point-of-load monitoring in industrial PLC modules.
When designing with the MAX170CCPA, provide 10 uF (tantalum) + 0.1 uF (ceramic) decoupling on VDD and ensure the REF pin is bypassed with a 4.7 uF capacitor to minimize reference noise. The serial clock can idle high or low; verify timing against your MCU's SPI mode configuration.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for MAX170CCPA — 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 MAX170CCPA (same form factor and footprint) — differing in Package, Reference Type, Conversion Time, Sampling Rate, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX170CCPA+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX170CEPA+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX170DCPA+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX170BCPA
✅ Drop-In📋 Reference alternative (not in catalog)
MAX170ACPA
✅ Drop-In📋 Reference alternative (not in catalog)
MAX170CCPA Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Sampling Rate | 125 kSPS |
| Conversion Time | 5.6 us |
| Architecture | SAR (Successive Approximation) |
| Number of Channels | 1 |
| Input Type | Single-Ended |
| Interface | Serial (SPI/QSPI/MICROWIRE compatible) |
| Supply Voltage | +4.75 V to +5.25 V |
| Supply Current (active) | 1.5 mA typ |
| Power-Down Current | < 10 uA |
| Internal Reference | 2.5 V buried-zener |
| External Reference Range | 2.4 V to VDD |
| INL (max) | ±0.5 LSB |
| Operating Temperature | 0 C to +70 C (Commercial) |
| Package | 8-pin PDIP |
| RoHS Status | Non-compliant (PDIP, SnPb lead finish) |
MAX170CCPA Pin Configuration
| Pin 1 | VDD — +5V analog supply |
| Pin 2 | AIN — Analog input (single-ended, 0 to VREF) |
| Pin 3 | GND — Analog/digital ground |
| Pin 4 | SCLK — Serial clock input (SPI, max 5 MHz) |
| Pin 5 | DOUT — Serial data output, MSB first |
| Pin 6 | REF — 2.5 V internal reference / external ref input |
| Pin 7 | CS — Chip select / shutdown (active low) |
| Pin 8 | NC — Not connected (per datasheet) |
Typical Applications
MAX170CCPA is suitable for 6 applications: Portable Data Logger, Pen-Tablet Digitizer Front End, Battery-Powered Instrumentation, Process Control Isolated Front End, Point-of-Load Monitoring in Industrial PLCs, Isolated 4-20 mA Current Loop Sensing.
Portable Data Logger
The MAX170CCPA's 125 kSPS throughput, integrated 2.5 V reference, and <10 uA power-down current make it ideal for handheld battery-powered data loggers. It samples slowly-varying analog signals (temperature, voltage, pressure) with 12-bit accuracy, stores results via the SPI interface to an external flash MCU, then powers down between bursts to extend battery life. The internal reference eliminates the need for a separate precision reference IC, saving BOM cost and PCB space in compact handheld enclosures.
Recommended
Pen-Tablet Digitizer Front End
In pen-tablet digitizer designs, the MAX170CCPA samples the X/Y position sensing signals at up to 125 kSPS with 12-bit resolution, providing smooth line tracing and accurate pen-tip tracking. Its 5.6 us conversion time is fast enough to keep up with a moving stylus, and the integrated reference stabilizes conversion accuracy across the operating temperature range. The serial SPI interface reduces wiring on the digitizer board, leaving more space for the sensor matrix and stylus antennae.
Recommended
Battery-Powered Instrumentation
The MAX170CCPA's low 1.5 mA active supply current and <10 uA shutdown current let portable instruments run for years on a single lithium cell. Typical applications include handheld digital multimeters, portable environmental analyzers, and wireless sensor nodes that wake periodically to sample a sensor and transmit results via radio. The internal 2.5 V reference provides measurement consistency across the battery discharge curve, ensuring accurate readings from full charge to nearly depleted.
Recommended
Process Control Isolated Front End
Industrial process-control front ends require high-noise-immunity ADC sampling for 4-20 mA loop signals, RTD outputs, and thermocouple inputs. The MAX170CCPA, with its robust serial interface and integrated reference, sits behind an isolation barrier (digital isolator) and samples process variables at 125 kSPS. Designers use its single-ended input to digitize a single channel per chip, multiplying throughput by stacking one MAX170 per channel - cost-effective for low-channel-count systems.
Recommended
Point-of-Load Monitoring in Industrial PLCs
Programmable Logic Controllers (PLCs) monitor point-of-load voltages and currents on each output channel. The MAX170CCPA, in 8-PDIP, fits easily on the PLC's analog front-end PCB and digitizes sensor signals with 12-bit accuracy. Its wide 0 to 70 C operating range suits factory-floor enclosures, and the serial interface lets multiple MAX170 chips share a single SPI bus on the PLC backplane, reducing MCU pin count and wiring complexity.
Recommended
Isolated 4-20 mA Current Loop Sensing
In 4-20 mA current-loop sensing modules, the MAX170CCPA digitizes the loop-derived voltage with 12-bit accuracy and sends the result across an isolation barrier via SPI. Its internal 2.5 V reference is bypassed with a 4.7 uF capacitor for low-noise measurements required by industrial sensor standards. The shutdown pin enables the host MCU to power down the ADC between conversions, reducing loop power consumption and minimizing heat dissipation in dense DIN-rail-mounted I/O modules.
Recommended
Recommended Products Summary
Engineering reference data for MAX170CCPA — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX170CCPA+ | MAX170CEPA+ | MAX170DCPA+ | MAX170BCPA |
|---|---|---|---|---|---|
| Package | PDIP-8 | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same | PDIP-8 - same |
| Brand | Maxim Integrated (ADI) | Maxim Integrated (ADI) | Maxim Integrated (ADI) | Maxim Integrated (ADI) | Maxim Integrated (ADI) |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 125 kSPS | 125 kSPS | 125 kSPS | 125 kSPS | 125 kSPS |
| Operating Temperature | 0 to +70 C (Commercial) | 0 to +70 C | -40 to +85 C (Extended) | -40 to +85 C (Industrial) | 0 to +70 C |
| INL (max) | ±0.5 LSB | ±0.5 LSB | ±0.5 LSB | ±0.5 LSB | ±0.25 LSB (tighter) |
| Internal Reference | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V |
| RoHS Status | Non-compliant (SnPb) | Compliant (lead-free) | Compliant (lead-free) | Compliant (lead-free) | Non-compliant (SnPb) |
| Lifecycle | Obsolete | Active (recommended replacement) | Active | Active | Last time buy |
Key Differentiators
- Integrated 2.5 V buried-zener reference (vs MAX170CCPA+)
- RoHS-compliant lead-free variant available (vs MAX170CCPA (obsolete SnPb))
- Wide temperature-range family members (vs MAX170CCPA (0 to +70 C only))
Design Notes
Bypass VDD (pin 1) with a 10 uF tantalum in parallel with a 0.1 uF ceramic, placed within 5 mm of the pin. The MAX170's 1.5 mA active supply current has sharp switching transients during the internal DAC settling; insufficient decoupling causes reference noise and degraded INL. For battery-powered applications, use the SHDN pin (active low) to drop supply current below 10 uA between conversions, but allow 20 ms reference wake-up time after SHDN goes high.
Route AIN (pin 2) as a guarded, short trace surrounded by ground. The 4 pF internal sample capacitor charges through any source impedance during acquisition; series resistance above 1 kohm degrades THD. Place the REF bypass capacitor (4.7 uF) directly on pin 6 with a short ground return. Keep digital signals (SCLK, DOUT, CS) away from AIN to avoid capacitive coupling of clock edges into the analog input.
The MAX170's serial interface runs up to 5 MHz SCLK. Source-terminate SCLK with a 33 ohm resistor if the MCU-to-ADC trace exceeds 25 mm, or if the SPI bus has multiple loads. Use a logic analyzer to verify setup/hold timing on first prototypes - timing violations on CS or SCLK can cause data corruption that looks like ADC noise. The DOUT pin transitions on SCLK falling edge; ensure the host MCU samples on the rising edge.
Do not drive AIN above VDD +0.3 V or below GND -0.3 V (absolute maximum ratings). Exceeding this range can latch up the CMOS input protection diodes and permanently damage the ADC. When using an external reference, ensure the REF pin is overdriven with a low-impedance source (< 1 ohm) and that the external reference voltage is within the 2.4 V to VDD window - below 2.4 V the internal reference buffer saturates and INL degrades.
Compliance Information
MAX170CCPA (SnPb finish) is non-RoHS; MAX170CCPA+ (lead-free) variant is RoHS compliant. REACH compliance per Maxim product declaration. Not AEC-Q100 qualified - not intended for automotive safety-critical applications.
