MAX158ACWI+ - 8-Channel 8-Bit 400ksps ADC | Maxim Integrated
MPN: MAX158ACWI+ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.42 | $18.42 |
| 10 | $16.55 | $165.50 |
| 100 | $14.22 | $1,422.00 |
| 500 | $12.05 | $6,025.00 |
| 1,000 | $10.18 | $10,180.00 |
MAX158ACWI+ Overview
An ADC (Analog-to-Digital Converter) is a data-acquisition component that converts continuous analog signals into discrete digital codes for processing by microcontrollers, DSPs, or FPGAs. Within the broader hierarchy, the MAX158 sits at successive-approximation register (SAR) ADC -> ADC -> data converter -> data acquisition IC -> signal-chain IC -> integrated circuit. Eight-channel, single-supply, parallel-output ADCs of this class are typically used in embedded systems where multiple sensor or process variables must be digitized with a single mixed-signal device.
Key features include eight single-ended analog inputs with channel selection, an internal 2.5V bandgap reference, an on-chip track/hold amplifier, and a parallel digital interface that simplifies connection to 8-bit data buses. The device operates from a single +5V analog supply, draws modest supply current, and accepts 0V to +5V unipolar analog inputs in normal operation. Internal reference and input MUX integration reduce external component count on the BOM.
The architecture combines a capacitive-charge redistribution DAC with successive-approximation logic and a dedicated track/hold front-end, enabling 2.5 us conversion times per channel. The eight-input analog multiplexer allows software-configurable channel sequencing, and the 2.5V reference is trimmed for low drift, supporting repeatable measurement accuracy across the commercial 0C to +70C temperature range.
Typical applications include multi-loop process control, panel-meter and instrumentation front-ends, automotive sensor aggregation, factory automation data-acquisition cards, portable data loggers, and embedded industrial-control boards where multiple analog signals must be sampled by a single host processor. The wide SO-28 footprint is friendly to hand-soldered prototypes and through-hole-compatible PCB layouts.
When designing with this device, ensure the analog input driving source presents low output impedance (an op-amp buffer is typically placed ahead of the MUX) and decouple AVDD and DVDD separately to prevent digital switching noise from corrupting the conversion. Per the manufacturer datasheet, an external reference may be substituted by overdriving the internal reference node when higher stability or lower noise is required.
Drop-in alternatives for MAX158ACWI+ — 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 MAX158ACWI+ (same form factor and footprint) — differing in Data Interface, Number of Input Channels, Package / Case, Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MAX158BCWI-T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX158AEWI
✅ Drop-In📋 Reference alternative (not in catalog)
MAX158BCWI+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX158ACWI+T
✅ Drop-In📋 Reference alternative (not in catalog)
MAX158BCWI
✅ Drop-In📋 Reference alternative (not in catalog)
MAX158ACWI+ Maximum Ratings & Electrical Characteristics
| Resolution | 8 bit |
| Number of Input Channels | 8 |
| Conversion Time per Channel | 2.5 us (max) |
| Throughput Rate | 400 ksps (sequential 8-channel) |
| ADC Architecture | SAR (Successive Approximation Register) |
| Analog Input Type | Single-ended, unipolar |
| Analog Input Voltage Range | 0 V to +5 V (AVDD-referenced) |
| Analog Supply Voltage (AVDD) | +5 V nominal (single supply) |
| On-Chip Reference Voltage | 2.5 V internal bandgap |
| Reference Source | Internal 2.5V or external overdrive |
| Data Interface | Parallel, 8-bit |
| Track/Hold Amplifier | Integrated on-chip |
| Package / Case | 28-SOIC (Wide, 7.50 mm body) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | 0 C to +70 C (commercial grade "C" suffix) |
| Lead Finish | Lead-free ("+" suffix), RoHS compliant |
| RoHS Status | Compliant |
MAX158ACWI+ Pin Configuration
| Pin 1 | AVDD — Analog +5V supply |
| Pin 2 | AGND — Analog ground |
| Pin 3 | REF — 2.5V reference (internal) / external overdrive |
| Pin 4 | REFADJ — Reference adjust |
| Pin 5 | AIN0 — Analog input channel 0 |
| Pin 6 | AIN1 — Analog input channel 1 |
| Pin 7 | AIN2 — Analog input channel 2 |
| Pin 8 | AIN3 — Analog input channel 3 |
| Pin 9 | AIN4 — Analog input channel 4 |
| Pin 10 | AIN5 — Analog input channel 5 |
| Pin 11 | AIN6 — Analog input channel 6 |
| Pin 12 | AIN7 — Analog input channel 7 |
| Pin 13 | A0 — Channel address bit 0 |
| Pin 14 | A1 — Channel address bit 1 |
| Pin 15 | A2 — Channel address bit 2 |
| Pin 16 | WR — Write / start conversion |
| Pin 17 | RD — Read output data |
| Pin 18 | CS — Chip select (active low) |
| Pin 19 | INT — Conversion complete / interrupt |
| Pin 20 | DVDD — Digital +5V supply |
| Pin 21 | DGND — Digital ground |
| Pin 22 | D0 — Data output bit 0 (LSB) |
| Pin 23 | D1 — Data output bit 1 |
| Pin 24 | D2 — Data output bit 2 |
| Pin 25 | D3 — Data output bit 3 |
| Pin 26 | D4 — Data output bit 4 |
| Pin 27 | D5 — Data output bit 5 |
| Pin 28 | D6/D7 — Data output bits 6 and 7 (per datasheet pinout) |
Typical Applications
MAX158ACWI+ is suitable for 6 applications: Multi-Loop Process Control Data Acquisition, Panel Meter and Instrumentation Front-End, Automotive Sensor Aggregation Module, Factory Automation Sensor Card, Portable Data Logger Front-End, Embedded Industrial Control Board.
Multi-Loop Process Control Data Acquisition
The MAX158ACWI+ fits multi-loop process-control front-ends because its eight single-ended analog inputs accept 0-5V signals from thermocouple amplifiers, pressure sensors, and 4-20mA shunts simultaneously without an external MUX. The 400 ksps aggregate throughput supports simultaneous monitoring of multiple control loops, while the integrated 2.5V reference removes the need for an external precision reference in cost-sensitive PLC modules. Its 8-bit resolution is sufficient for setpoint display, threshold detection, and trend logging in distributed control systems.
Recommended
Panel Meter and Instrumentation Front-End
The MAX158ACWI+ suits panel-meter and bench-instrumentation designs by digitizing multiple front-panel sensor inputs through one mixed-signal device, reducing component count on the BOM. The 2.5 us conversion time supports readings updated at video-frame rates, and the 8-bit resolution is adequate for digital panel meters displaying 0-255 counts. The integrated track/hold and reference simplify the analog front end, allowing the design to fit a single-sided 2-layer PCB typical of low-cost instrumentation.
Recommended
Automotive Sensor Aggregation Module
The MAX158ACWI+ aggregates multiple analog automotive sensors - throttle position, manifold pressure, coolant temperature, and battery voltage - into a single parallel-output byte stream that an automotive MCU reads through its 8-bit data bus. Its 0-5V unipolar input range matches the output range of typical automotive sensor signal-conditioning amplifiers. For under-hood applications requiring -40C to +85C operation, the MAX158AEWI extended-temperature grade is the recommended drop-in upgrade on the same 28-pin footprint.
Recommended
Factory Automation Sensor Card
The MAX158ACWI+ functions as the analog front end on a factory-automation sensor card, digitizing eight 0-5V analog sensor outputs - vibration, temperature, current shunt, and flow - and presenting them as 8-bit parallel data to a host FPGA or microcontroller. The 400 ksps throughput supports vibration-spectrum sampling up to 50 ksps per channel for predictive maintenance. The single +5V supply simplifies the isolated sensor-card power design and the wide SO-28 footprint is friendly to hand-rework on field-deployed cards.
Recommended
Portable Data Logger Front-End
The MAX158ACWI+ serves as the analog-input section of a portable battery-powered data logger that records environmental variables such as temperature, humidity (via 0-5V transducer), pressure, and light level. Its single +5V supply and modest current consumption suit battery designs, and the eight channels let a single IC replace several single-channel ADCs in the BOM. The 0-5V input range accepts the output of most sensor signal-conditioning ICs and the integrated reference minimizes quiescent current draw.
Recommended
Embedded Industrial Control Board
The MAX158ACWI+ integrates eight analog inputs into embedded industrial-control boards where space and BOM count matter - PLC analog-input modules, HMI controllers, and motor-drive feedback boards. Its parallel interface connects directly to an 8-bit microcontroller bus without glue logic, and the integrated track/hold removes the need for an external sample-and-hold amplifier on each channel. The 28-pin wide SOIC is friendly to through-hole-compatible layouts where maintenance staff prefer larger packages.
Recommended
Recommended Products Summary
Engineering reference data for MAX158ACWI+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX158BCWI-T | MAX158AEWI | MAX158BCWI+T | MAX158ACWI+T | MAX158BCWI |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 28-SOIC (Wide) | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same |
| Resolution | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit |
| Input Channels | 8 single-ended | 8 single-ended | 8 single-ended | 8 single-ended | 8 single-ended | 8 single-ended |
| Conversion Time | 2.5 us / channel | 2.5 us / channel | 2.5 us / channel | 2.5 us / channel | 2.5 us / channel | 2.5 us / channel |
| Throughput Rate | 400 ksps | 400 ksps | 400 ksps | 400 ksps | 400 ksps | 400 ksps |
| On-Chip Reference | 2.5V internal | 2.5V internal | 2.5V internal | 2.5V internal | 2.5V internal | 2.5V internal |
| Operating Temperature | 0 C to +70 C (C grade) | 0 C to +70 C (C grade) | -40 C to +85 C (E grade) | 0 C to +70 C (C grade) | 0 C to +70 C (C grade) | 0 C to +70 C (C grade) |
| Linearity Grade | A grade | B grade (tighter INL) | A grade (E temperature) | B grade | A grade | B grade |
Key Differentiators
- Integrated 2.5V reference and 8-channel MUX reduce BOM count (vs Discrete ADC + external MUX + external reference solution)
- A-grade with drop-in upgrade path to tighter linearity (vs MAX158BCWI-T (B-grade))
- Commercial-temperature grade with extended-temperature drop-in option (vs MAX158AEWI (extended -40C to +85C))
- Single +5V supply simplifies power architecture (vs Dual-supply (5V and -5V or 5V and 3.3V) ADC solutions)
Design Notes
Decouple AVDD and DVDD separately with a 0.1uF ceramic capacitor in parallel with a 10uF tantalum or low-ESR electrolytic placed as close as practical to each supply pin. Per the MAX154/MAX158 datasheet, AVDD must be well-regulated because noise on the analog supply couples directly into the conversion result. A ferrite bead between AVDD and the upstream 5V rail is recommended on electrically noisy boards.
Place the analog input traces away from digital output lines (D0-D7) and from the WR/RD/CS strobe lines to avoid digital-to-analog crosstalk during conversion. Per the manufacturer datasheet, ground the AGND and DGND pins with a low-impedance single-point connection at the IC. A solid ground plane under the device and short analog input traces maximize the 8-bit measurement integrity at 400 ksps aggregate throughput.
Drive each analog input with a low-output-impedance buffer (op-amp LT-series or similar) because the input sampling capacitance of the MUX and track/hold can introduce settling errors if the source impedance exceeds the datasheet limit. Estimated: at 2.5 us conversion time and the typical 8-bit acquisition period, a source impedance above approximately 5 kohm may degrade INL by 1 LSB or more. Add a small RC anti-alias filter (typically 1 kohm + 100 pF) at each analog input when sampling wide-bandwidth signals.
Do not leave unused analog input channels floating - tie them to AGND through a 1 kohm resistor to prevent noise pickup that can couple into active channels through the internal MUX. The REF pin should be bypassed with a 0.1uF + 10uF capacitor pair per the manufacturer datasheet. Driving REF with an external reference (overdriving the internal bandgap) is supported but verify the external reference stability before relying on it for absolute accuracy.
Compliance Information
The + suffix per Maxim Integrated ordering nomenclature indicates lead-free, RoHS-compliant lead finish. Reach and conflict-minerals status taken from Maxim Integrated / Analog Devices product page. AEC-Q100 not applicable - C-grade commercial temperature only; for AEC-Q100 applications consider the E-grade MAX158AEWI plus external AEC-Q qualification testing.
