MAX166BEPP - 5µs 8-Bit µP-Compatible ADC with T/H | Maxim Integrated
MPN: MAX166BEPP ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.49 | $14.49 |
| 10 | $13.04 | $130.40 |
| 100 | $11.59 | $1,159.00 |
| 500 | $10.14 | $5,070.00 |
| 1,000 | $8.69 | $8,690.00 |
MAX166BEPP Overview
What is an ADC? An analog-to-digital converter is a data-conversion integrated circuit that samples a continuous analog input voltage and converts it into a discrete digital code. The MAX166BEPP belongs to the successive-approximation-register (SAR) ADC family, which sits within the broader data-converter IC category, itself a sub-category of signal-chain semiconductors. The µP-compatible output bus and 8-bit resolution make it a classic component for embedded data-acquisition front-ends.
Key features include a 5 µs (typical) conversion time, on-chip track/hold that supports input signals up to 50 kHz (386 mV/µs slew rate), a built-in +2.5 V reference, and low power dissipation. The parallel data interface uses standard microprocessor read cycles, allowing the ADC to be memory-mapped or port-mapped directly to common 8-bit controllers and DSPs of its era.
The MAX166 architecture uses a successive-approximation register with a capacitive-charge redistribution DAC array. The integrated T/H eliminates the need for an external sample-and-hold amplifier, simplifying the analog front-end. Operating from a single +5 V supply (with an optional -5 V for bipolar input ranges), the part consumes roughly 70 mW during active conversion.
Typical applications include digital signal processing front-ends, process control data acquisition, portable instrumentation, and anywhere a microcontroller needs a compact 8-bit analog input channel.
When designing with the MAX166BEPP, ensure the analog input is driven by a low-impedance source (a buffer amp is recommended) to avoid sample-rate-dependent gain errors. The reference decoupling capacitor and the supply bypass layout directly affect the noise floor at low signal levels.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the Maxim datasheet alone.
Drop-in alternatives for MAX166BEPP — 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 MAX166BEPP (same form factor and footprint) — differing in Architecture, Package, Data Interface, RoHS Status, Conversion Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX166BEPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX166AEPP+
✅ Drop-In✓ In Stock
$5.3 / Unit
View Datasheet →MAX166BCPP+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX166AEPP+
✅ Drop-In✓ In Stock
$5.3 / Unit
View Datasheet →ADC0802LCWMX/NOPB
✅ Drop-In✓ In Stock
$5.44 / Unit
View Datasheet →ADC0804LCWMX
✅ Drop-In✓ In Stock
$2.05 / Unit
View Datasheet →MAX166BEPP Maximum Ratings & Electrical Characteristics
| Resolution | 8 bit |
| Conversion Time | 5 us (typical) |
| Number of Channels | 1 |
| Number of ADCs | 1 |
| Sampling Type | Successive Approximation with Track/Hold |
| Input Signal Bandwidth | 50 kHz |
| Input Slew Rate | 386 mV/us |
| Architecture | SAR (Successive Approximation Register) |
| Data Interface | Parallel (uP-compatible) |
| Internal Reference | Yes (on-chip voltage reference) |
| Supply Voltage | +5 V (single supply) |
| Operating Temperature | Industrial grade (per "B" suffix) |
| Package | 20-pin PDIP (EPP) |
| Mounting Type | Through-Hole |
| RoHS Status | unknown |
| Pin Count | 20 |
MAX166BEPP Pin Configuration
| Pin 1 | VSS — Negative supply (typically -5V for bipolar input, or GND for unipolar operation) |
| Pin 2 | AIN — Analog input |
| Pin 3 | REF — Reference voltage input/output (internal reference) |
| Pin 4 | AGND — Analog ground |
| Pin 5 | DB0 — Data bit 0 (LSB, tri-state) |
| Pin 6 | DB1 — Data bit 1 (tri-state) |
| Pin 7 | DB2 — Data bit 2 (tri-state) |
| Pin 8 | DB3 — Data bit 3 (tri-state) |
| Pin 9 | DB4 — Data bit 4 (tri-state) |
| Pin 10 | DB5 — Data bit 5 (tri-state) |
| Pin 11 | DB6 — Data bit 6 (tri-state) |
| Pin 12 | DB7 — Data bit 7 (MSB, tri-state) |
| Pin 13 | DGND — Digital ground |
| Pin 14 | INT — Interrupt output - goes low at end of conversion |
| Pin 15 | RD — Read input (active low) - initiates conversion and enables data bus |
| Pin 16 | WR — Write input (active low) |
| Pin 17 | CS — Chip select (active low) |
| Pin 18 | CLK — Clock input |
| Pin 19 | VDD — Positive supply (+5V) |
| Pin 20 | NC — Not connected (per datasheet) |
Typical Applications
MAX166BEPP is suitable for 6 applications: Process Control Data Acquisition, Portable Digital Voltmeter / Multimeter, Audio Signal Digitization (8-bit digital audio), Embedded Sensor Front-End, DSP / Microcontroller Analog Input Channel, Industrial Control Panel Readout.
Process Control Data Acquisition
The MAX166BEPP's 5 µs conversion time and integrated track/hold make it well-suited to industrial process-control data-acquisition front-ends. Placed on a single +5 V analog rail, the part digitizes 4-20 mA or 0-10 V transducer signals after a buffer amplifier, then drives the parallel bus of an 8051-class or HC11 microcontroller for closed-loop control. The 8-bit resolution (~39 mV LSB on a 10 V scale) is sufficient for setpoint control and alarm thresholds. Compared to a newer SPI-based ADC, the parallel interface removes interrupt overhead and is deterministic, an advantage in legacy process controllers. The industrial temperature grade also handles factory-floor thermal environments.
Recommended
Portable Digital Voltmeter / Multimeter
For handheld DMM designs, the MAX166BEPP's integrated track/hold and reference eliminate the need for an external precision reference and SHA, simplifying the BOM. The 5 µs conversion time is fast enough for sub-second auto-ranging updates, while the parallel µP-compatible bus feeds directly into low-cost 8-bit microcontrollers. The industrial-grade temperature range and single +5 V supply suit battery-powered instruments with a switching boost. The 8-bit result gives ~0.4% full-scale resolution, adequate for most general-purpose voltage, current, and resistance measurement.
Recommended
Audio Signal Digitization (8-bit digital audio)
With a 50 kHz input bandwidth and 386 mV/µs slew rate, the MAX166BEPP can digitize full-bandwidth audio signals up to 8 kHz Nyquist. This suits digital-audio recorders, simple voice-recognition front-ends, and audio-trigger circuits in security applications. The integrated T/H is critical because external SHA-less designs suffer sampling-glitch distortion. Designers typically precede the ADC with a 4-pole anti-alias filter and place the MAX166BEPP in a memory-mapped slot where the host DMA fills a buffer. The 8-bit dynamic range (~48 dB) matches telephone-grade speech; for higher fidelity choose a 12/16-bit ADC.
Recommended
Embedded Sensor Front-End
The MAX166BEPP's parallel interface and 8-bit resolution make it a simple 'one-channel sensor digitizer' for embedded boards. A resistive bridge (load cell, strain gauge) is excited by a constant current source, amplified by an instrumentation amp, and fed to the ADC's analog input. The MCU reads the digital byte via a single read cycle, applies calibration coefficients, and forwards the result via UART/CAN/Bluetooth. Compared to a SPI ADC, the parallel interface occupies more pins but avoids protocol overhead in tight loops. The 5 µs conversion rate suits low-bandwidth sensors (temperature, pressure, humidity).
Recommended
DSP / Microcontroller Analog Input Channel
In mixed signal designs the MAX166BEPP provides a single 5 µs analog input to legacy 8-bit microcontrollers (8051, HC11, Z80) and to digital signal processors without integrated ADCs. The µP-compatible interface supports memory-mapped and port-mapped read cycles; an address decoder (74HC138) selects the chip, and a read strobe (RD) clocks the conversion into the data bus. The result can trigger DMA or interrupt routines on the host, allowing background sampling during CPU-intensive tasks. The internal reference keeps the analog front-end self-contained, ideal for compact DSP evaluation boards.
Recommended
Industrial Control Panel Readout
Control panels in factory automation frequently read potentiometer or transducer positions through a dedicated ADC. The MAX166BEPP is well-matched to this role: industrial temperature grade, single +5 V supply, and a parallel bus that drives the display driver directly. The conversion result updates the LCD/LED indicator within microseconds, providing real-time feedback to operators. Compared to switching ADCs of similar speed, the SAR architecture of the MAX166BEPP has no input latency and exhibits no switching noise that could couple into nearby analog channels.
Recommended
Recommended Products Summary
Engineering reference data for MAX166BEPP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX166BEPP+ | MAX166AEPP+ | MAX166BCPP+ | ADC0802 | ADC0804 |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Texas Instruments | Texas Instruments |
| Package | PDIP-20 (EPP) | PDIP-20 (EPP) - same | PDIP-20 (EPP) - same | PDIP-20 (EPP) - same | PDIP-20 - same | PDIP-20 - same |
| Resolution | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit |
| Conversion Time | 5 us | 5 us | 5 us | 5 us | 100 us | 100 us |
| Architecture | SAR with T/H | SAR with T/H | SAR with T/H | SAR with T/H | SAR | SAR |
| Integrated Reference | Yes (+2.5V nominal) | Yes (+2.5V) | Yes (+2.5V) | Yes (+2.5V) | No (external required) | Yes (with external cap) |
| Data Interface | Parallel uP-compatible | Parallel uP-compatible | Parallel uP-compatible | Parallel uP-compatible | Parallel | Parallel |
| Supply Voltage | +5 V (single supply) | +5 V | +5 V | +5 V | +5 V | +5 V |
| Temperature Grade | Industrial (B-grade) | Industrial | Industrial | Industrial | Industrial | Industrial |
Key Differentiators
- Integrated track/hold eliminates external SHA (vs ADC0804)
- Faster conversion time (vs ADC0804)
- Internal reference designed for -5 V to +5 V bipolar inputs (vs MAX166AEPP)
Design Notes
The MAX166BEPP requires a low-impedance analog input source. Without an input buffer amplifier, the sample-and-hold acquisition time degrades and gain errors appear at faster clock rates. Add a TL082/Maxim MAX412 op-amp follower within 50 mm of the AIN pin and 100 ohm source resistance is a practical maximum. Estimated: with 1 kohm source impedance, the acquisition error rises about 1 LSB at 5 µs conversion.
Decouple VDD with a 0.1 µF ceramic capacitor placed within 5 mm of the VDD pin and a 10 µF tantalum bulk capacitor near the chip. Keep AGND and DGND returned to a single-point star ground near the ADC; do not run digital return currents under the analog supply pin. Reference decoupling (REF pin) is critical for noise: place the reference cap directly on the REF pin to AGND.
Route the parallel data bus (DB0-DB7) as a tightly-coupled group with matched lengths to keep skew within a fraction of the read-cycle setup time. Place the MAX166BEPP close to the host microprocessor's data bus connector to minimize capacitive loading; otherwise increase the number of wait states. The CS, RD, and INT signals should be guarded against crosstalk by a ground trace on both sides.
The MAX166BEPP draws approximately 70 mW during active conversion according to the Maxim datasheet. For bipolar analog inputs (e.g. ±5 V, ±10 V), add a -5 V VSS rail; ensure the negative rail is sequenced after VDD to avoid latch-up. Estimated: under bipolar operation, total supply current rises roughly 30-40% versus unipolar mode.
Compliance Information
RoHS/REACH compliance not stated in provided data. The '+' suffix variant (MAX166BEPP+) is the lead-free/RoHS version per Maxim/Mouser part-number conventions; base MAX166BEPP is the older SnPb finish. AEC-Q100 not applicable - this is an industrial-grade ADC, not automotive-qualified.
