MAX165ACWN - 5µs 8-Bit ADC with Track/Hold | Maxim Integrated
MPN: MAX165ACWN ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.5 | $6.50 |
| 10 | $5.85 | $58.50 |
| 100 | $5.2 | $520.00 |
| 500 | $4.65 | $2,325.00 |
| 1,000 | $4.2 | $4,200.00 |
MAX165ACWN Overview
An 8-bit ADC (analog-to-digital converter) is a data-acquisition building block that quantizes an analog input signal into 256 discrete digital codes for processing by a microcontroller, microprocessor, or DSP. ADC chips fall within the broader data-converter family (ADC/DAC) and bridge the analog signal-chain and digital logic domains. Successive-approximation-register (SAR) ADCs such as the MAX165 provide deterministic latency and a single-shot conversion, making them ideal for multiplexed instrumentation and process-control front ends.
Key features include a 5 µs typical conversion time (200 ksps throughput), a built-in track/hold amplifier, an on-chip 2.46 V reference (15 mA drive capability), and a parallel µP-compatible interface. The MAX165 operates from ±5 V supplies (or +5 V / -12 V), accepts 0 V to 5 V unipolar or ±5 V bipolar analog inputs, and provides three-state latched outputs that interface directly to 8-bit data buses. Operating temperature spans 0°C to +70°C (C-grade).
Internally, the MAX165 uses a charge-redistribution SAR architecture with a laser-trimmed thin-film resistor ladder, which delivers monotonicity over the full operating range and eliminates the need for an external sample-and-hold in most applications. The internal reference uses a buried-zener topology, providing low temperature drift and excellent line regulation.
Typical applications include process-control and industrial data acquisition, portable instrumentation, panel meters and digital voltmeters, embedded µP/µC analog input modules, and precision threshold-detection circuits. The wide SOIC package and standard control signals (CS, RD, BUSY) ease integration with 8051, 68HC11, Z80, and similar 8-bit controllers.
When designing with the MAX165, take care to bypass the analog supply with a 10 µF tantalum plus 0.1 µF ceramic capacitor close to the AVDD pin, and decouple the digital supply separately. The reference output (REF) requires a 4.7 µF bypass to ground for stable operation - omitting this capacitor is a common cause of degraded linearity.
This page synthesizes distributor pricing, drop-in alternatives in the same SOIC-18 footprint, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for MAX165ACWN — 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 MAX165ACWN (same form factor and footprint) — differing in Package, Operating Temperature, RoHS Status, Conversion Time, Number of Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX165ACWN+
✅ Drop-In✓ In Stock
$7.4 / Unit
View Datasheet →MAX165BCWN+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX165BEWN+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX165AEWN
✅ Drop-In📋 Reference alternative (not in catalog)
MAX165BCWN
✅ Drop-In✓ In Stock
$12.4 / Unit
View Datasheet →MAX165ACWN Maximum Ratings & Electrical Characteristics
| Resolution | 8 bit |
| Number of Channels | 1 Input |
| Architecture | SAR (Successive Approximation Register) |
| Conversion Time | 5 µs (typical) |
| Sampling Rate | 200 ksps |
| Input Voltage Range | 0 V to 5 V unipolar; ±5 V bipolar |
| Data Interface | Parallel |
| Reference Type | Internal 2.46 V (15 mA drive) |
| Supply Voltage (Analog) | +5 V |
| Supply Voltage (Digital) | +5 V |
| Negative Supply | -12 V (or -5 V option) |
| Operating Temperature | 0°C to +70°C (C-grade) |
| Package | 18-SOIC (0.295 inch / 7.50 mm width) |
| Mounting Type | Surface Mount |
| Track/Hold | Integrated on-chip |
| RoHS Status | Non-compliant (original CWN package) |
MAX165ACWN Pin Configuration
| Pin 1 | CS — Chip Select (active-low, starts conversion) |
| Pin 2 | DB0 — Data Bit 0 (LSB, three-state) |
| Pin 3 | DB1 — Data Bit 1 (three-state) |
| Pin 4 | DB2 — Data Bit 2 (three-state) |
| Pin 5 | DB3 — Data Bit 3 (three-state) |
| Pin 6 | DB4 — Data Bit 4 (three-state) |
| Pin 7 | DB5 — Data Bit 5 (three-state) |
| Pin 8 | DB6 — Data Bit 6 (three-state) |
| Pin 9 | DB7 — Data Bit 7 (MSB, three-state) |
| Pin 10 | GND — Digital ground |
| Pin 11 | REF — Internal 2.46 V reference output (4.7 µF bypass required) |
| Pin 12 | AIN — Analog input |
| Pin 13 | AVDD — Analog +5 V supply |
| Pin 14 | DVDD — Digital +5 V supply |
| Pin 15 | VEE — Negative supply (-12 V or -5 V) |
| Pin 16 | RD — Read (active-low, enables data outputs) |
| Pin 17 | BUSY — Conversion-in-progress (active-high) |
| Pin 18 | RANGE/BIPOLAR — Input range select (unipolar/bipolar mode) |
Typical Applications
MAX165ACWN is suitable for 6 applications: Process Control and Industrial Data Acquisition, Portable Digital Multimeters and Panel Meters, Microcontroller Analog Input Modules, Precision Threshold Detection Circuits, Embedded Sensor Signal Digitization, Legacy Industrial Control Board Repair.
Process Control and Industrial Data Acquisition
The MAX165ACWN's 5 µs conversion time and ±5 V bipolar input range suit 4-20 mA loop-powered process signals after current-to-voltage conversion. With its integrated track/hold and internal 2.46 V reference, the part replaces a multi-chip discrete ADC front end in PLC analog input modules, where its 18-SOIC footprint simplifies board layout and its 0°C to +70°C commercial temperature grade meets most factory-floor enclosures. The parallel interface drops directly onto 8051 or 68HC11 data buses without glue logic.
Recommended
Portable Digital Multimeters and Panel Meters
Battery-powered DMMs and panel meters use the MAX165ACWN for its single +5 V / -12 V supply operation and 200 ksps throughput, which is sufficient for 3.5-digit multimeter display update rates. The internal 2.46 V reference with 15 mA drive eliminates the need for an external reference IC, reducing bill-of-materials cost. The 5 µs conversion time provides fast auto-ranging settling without the complexity of integrating-type ADCs.
Recommended
Microcontroller Analog Input Modules
Embedded 8-bit microcontroller boards (8051, Z80, 68HC11) integrate the MAX165ACWN as a parallel-bus ADC peripheral, with CS, RD, and BUSY signals matching standard memory-mapped I/O timing. The 8-bit resolution maps cleanly to legacy 8-bit data paths, and the 5 µs conversion time is fast enough for keyboard scan, joystick position, and potentiometer-based user-input digitization. The internal reference and track/hold reduce external component count on space-constrained boards.
Recommended
Precision Threshold Detection Circuits
Threshold-detection and window-comparator applications use the MAX165ACWN to digitize slowly-varying sensor signals and compare them to software-set limits. The SAR architecture provides deterministic single-shot conversion with no pipeline delay, ideal for closed-loop control loops where latency must be predictable. The on-chip 2.46 V reference provides a stable comparison threshold independent of supply variations.
Recommended
Embedded Sensor Signal Digitization
Sensor readout boards digitize strain-gauge, thermocouple, and bridge outputs through the MAX165ACWN's ±5 V bipolar input range, which directly accepts conditioned signals without extra level-shifting. The 5 µs conversion time supports vibration and pressure sensor sampling at rates up to 200 ksps. The internal track/hold preserves signal integrity for rapidly multiplexed sensor inputs.
Recommended
Legacy Industrial Control Board Repair
Maintenance and repair of legacy industrial control boards benefit from the MAX165ACWN's drop-in compatibility with newer MAX165B-grade parts (MAX165BCWN+, MAX165BEWN+), allowing field upgrades without PCB rework. The 18-SOIC package has remained standard for the MAX165 family, and the parallel interface timing is preserved across grades, so firmware requires no changes when swapping grades.
Recommended
Recommended Products Summary
Engineering reference data for MAX165ACWN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX165ACWN+ | MAX165BCWN+ | MAX165BEWN+ | MAX165AEWN | MAX165BCWN |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 18-SOIC (0.295 in) | 18-SOIC (0.295 in) - same | 18-SOIC (0.295 in) - same | 18-SOIC (0.295 in) - same | 18-SOIC (0.295 in) - same | 18-SOIC (0.295 in) - same |
| Resolution | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit |
| Conversion Time | 5 µs | 5 µs | 5 µs | 5 µs | 5 µs | 5 µs |
| Sampling Rate | 200 ksps | 200 ksps | 200 ksps | 200 ksps | 200 ksps | 200 ksps |
| INL (max) | ±1 LSB | ±1 LSB | ±0.5 LSB (better) | ±0.5 LSB (better) | ±1 LSB | ±0.5 LSB (better) |
| Operating Temperature | 0°C to +70°C | 0°C to +70°C | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C | 0°C to +70°C |
| RoHS Status | Non-compliant (legacy CWN) | RoHS-compliant (+ suffix) | RoHS-compliant | RoHS-compliant | Non-compliant (legacy) | Non-compliant (legacy) |
Key Differentiators
- Integrated reference + track/hold in 18-SOIC (vs MAX165BCWN+)
- Legacy CWN vs current + suffix (vs MAX165ACWN+)
- Parallel µP-compatible interface (vs MAX1168)
Design Notes
The MAX165ACWN requires separate analog (AVDD) and digital (DVDD) +5 V rails plus a negative supply (VEE = -12 V or -5 V). Per the MAX165 datasheet, AVDD and DVDD should be driven from separate regulator outputs or RC-filtered from a common rail to prevent digital switching noise from coupling into the analog front end and degrading linearity. Bypass AVDD with a 10 µF tantalum in parallel with a 0.1 µF ceramic placed within 5 mm of the pin.
Estimated: the internal 2.46 V reference (pin 11, REF) requires a 4.7 µF bypass capacitor to ground for stable operation. Omitting this capacitor is the most common cause of linearity degradation and excessive noise on the converted result. The reference has 15 mA drive capability, so the bypass capacitor should be a low-ESR tantalum or ceramic type placed directly at the REF pin.
Route analog input traces away from digital data bus traces (DB0-DB7) to minimize crosstalk. Place the MAX165ACWN's analog ground pin (GND, pin 10) directly to the analog ground plane, and connect the digital ground returns through a single-point connection near the ADC to avoid ground-loop-induced conversion errors. Keep the AIN trace short and surround it with a guard trace tied to analog ground.
The BUSY signal (pin 17) indicates conversion-in-progress and is active-high. Monitor BUSY to avoid reading the data bus during conversion - reading during BUSY-high yields invalid data. The CS (pin 1) and RD (pin 16) signals must satisfy the timing parameters in the datasheet's timing diagrams (tCS-setup, tRD-min) to guarantee correct operation at 200 ksps.
Compliance Information
Legacy MAX165ACWN (CWN suffix, no +) is non-RoHS due to SnPb lead finish. Use MAX165ACWN+ (RoHS-compliant lead-free) for new production. AEC-Q100 not applicable - this part targets industrial/commercial data acquisition, not automotive.
