MAX338CPE+ - 8:1 CMOS Analog Multiplexer | Analog Devices
MPN: MAX338CPE+ ✓ ActiveMAX338CPE+ Overview
An analog multiplexer is a semiconductor switch that connects one selected input channel to a shared output. The MAX338CPE+ belongs to the CMOS analog switch and multiplexer hierarchy, where low-leakage CMOS construction supports high-impedance measurement circuits. Its 8:1 configuration reduces the number of physical input connections required when a controller must inspect several voltage, sensor, or diagnostic signals sequentially. The common output can then feed an ADC, measurement instrument, amplifier, or further signal-processing stage.
Key features include eight selectable analog inputs, a single-ended common output, and a single 16-pin PDIP package. According to the Analog Devices MAX338 product page, the MAX338 and MAX339 devices are improved multiplexers that are pin-compatible upgrades for the industry-standard DG508A and DG509A families. The MAX338 family also supports both single and dual power-supply arrangements. These features distinguish it from multiplexer products that require one supply rail only or provide a different channel-to-pin arrangement.
The MAX338CPE+ is a monolithic CMOS device intended to route low-frequency analog signals. Its channel count, supply range, and legacy DIP footprint are particularly useful when creating test fixtures, sensor interfaces, process-control equipment, or diagnostic systems that need to remain compatible with an existing 16-pin design. Because the common output carries the selected channel, the source impedance, signal amplitude, settling behavior, and downstream input range remain important system-level considerations.
Typical uses include eight-way sensor selection, automated test equipment, industrial control signal routing, laboratory measurement systems, and instrumentation with multiple analog sources. The same-package DG508A and DG509A reference points are also useful when evaluating a design that was originally built around those established multiplexers. The MAX339 provides a related 4:1 dual-channel function rather than the MAX338's single 8:1 arrangement.
When laying out the circuit, place the multiplexer close to the source and destination analog paths to minimize parasitic capacitance and resistance. Keep high-impedance traces short, provide a stable supply reference, and avoid excessive loading on the common output. Engineers should also confirm the exact channel pin assignments, control truth table, electrical limits, and operating-temperature grades in the manufacturer datasheet before treating the part as a production drop-in replacement.
This page consolidates verified manufacturer and distributor information, supply configurations, package details, drop-in references, and practical selection guidance. It distinguishes documented pin-compatible alternatives from broader functional equivalents so procurement and engineering decisions can be made without confusing a multiplexer upgrade with a merely similar switch.
Drop-in alternatives for MAX338CPE+ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
MAX339CPE+
✅ Drop-In📋 Reference alternative (not in catalog)
MAX338CPE
✅ Drop-In📋 Reference alternative (not in catalog)
MAX338CPA+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
DG508AD
✅ Drop-In📋 Reference alternative (not in catalog)
DG509AD
✅ Drop-In📋 Reference alternative (not in catalog)
MAX338CPE+ Specifications
| Product Type | 8:1 single-ended CMOS analog multiplexer |
| Number of Channels | 8 analog input channels |
| Number of Circuits | 1 circuit |
| On-Resistance | 400 ohm per DigiKey listing; 650 ohm per chipdig listing |
| Single-Supply Voltage Range | 4.5 V to 30 V |
| Dual-Supply Voltage Range | ±4.5 V to ±20 V |
| Supply Topology | Single supply or dual supply |
| Technology | CMOS |
| Signal Type | Single-ended analog |
| Leakage Characteristic | Low-leakage |
| Package | 16-pin PDIP |
| Mounting Type | Through hole |
| Industry-Standard Reference | Pin-compatible upgrade for DG508A and DG509A |
MAX338CPE+ 16-pin pdip Pin Configuration Guide
Pin configuration for MAX338CPE+ (16-pin pdip package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for MAX338CPE+.
Refer to the datasheet for full pin configuration.
Typical Applications
MAX338CPE+ is suitable for 6 applications: Eight-Channel Sensor Signal Selection, Automated Test Equipment Signal Routing, Industrial Process-Control Inputs, Laboratory Multimeter and Data Acquisition, Legacy Instrumentation Upgrade, Diagnostic and Service Test Fixture.
Eight-Channel Sensor Signal Selection
The MAX338CPE+ fits eight-way analog sensor selection because it routes one of eight single-ended inputs to a common output. The verified MAX338 family data identifies low-leakage CMOS construction, while the manufacturer supports operation from a single 4.5 V to 30 V supply or dual ±4.5 V to ±20 V rails. A controller can cycle the address and enable controls to present different sensor voltages to an ADC or measurement front end. The 16-pin PDIP package also remains practical for through-hole laboratory and industrial fixtures. Before implementation, engineers should confirm channel leakage, input common-mode range, settling time, and the exact address truth table in the manufacturer datasheet.
Recommended
Automated Test Equipment Signal Routing
The MAX338CPE+ is appropriate for automated test equipment that must connect multiple test points to a shared instrument channel. Its 8:1 architecture replaces eight separate relay or switch paths, while the documented 4.5 V to 30 V single-supply or ±4.5 V to ±20 V dual-supply operation supports both bench and industrial fixtures. Distributor records list on-resistance as 400 ohm or 650 ohm under different source records, so fixture design must preserve sufficient signal bandwidth and load margin. Use short PCB traces, stable analog grounding, and a common reference between the multiplexer and measurement circuitry. Verify the control timing and channel specifications before using it for high-accuracy or high-speed measurements.
Recommended
Industrial Process-Control Inputs
The MAX338CPE+ can consolidate multiple analog process inputs in an industrial controller by selecting one of eight channels for conversion or control. Its low-leakage CMOS construction is useful when the source impedance is high, while the broad documented supply options support both 24 V-oriented positive systems and bipolar instrumentation. The through-hole PDIP package also eases repair and prototyping of legacy control boards. Designers should establish the required common-mode range, channel resistance, isolation, and operating temperature for the factory environment. Input protection and grounding also need consideration because industrial transducer wiring can expose the multiplexer to transients beyond its normal signal range.
Recommended
Laboratory Multimeter and Data Acquisition
The MAX338CPE+ is well suited to laboratory measurement systems requiring several low-frequency voltage inputs to share one analog measurement channel. The common output can feed an ADC, buffer, or front panel instrument while digital address and enable controls select the active source. Its 8:1 channel count expands measurement capacity without requiring eight separate analog input stages, and its legacy PDIP footprint is convenient for serviceable test fixtures. Because the available listings contain different on-resistance values of 400 ohm and 650 ohm, the selected configuration should be checked against source impedance and accuracy requirements. Low-leakage behavior also makes it preferable to simple mechanical switching for high-impedance probes.
Recommended
Legacy Instrumentation Upgrade
The MAX338CPE+ offers a practical upgrade path for legacy instrumentation originally designed around DG508A and DG509A multiplexers because Analog Devices identifies the MAX338 and MAX339 as pin-compatible upgrades for those industry-standard families. The 16-pin PDIP arrangement preserves the physical footprint, while the MAX338's low-leakage CMOS implementation serves modern high-impedance measurement needs. The exact control truth table and common-output arrangement must still be compared with the original device, especially where DG509A's dual 4:1 organization was used. Validate signal range, supply sequencing, and protection requirements before production replacement to avoid changing the behavior of a previously qualified system.
Recommended
Diagnostic and Service Test Fixture
The MAX338CPE+ fits compact diagnostic fixtures that must interrogate multiple analog service points without a large switching matrix. Eight single-ended inputs can be scanned sequentially through one common output, simplifying the connector count and the number of analog front-end channels required by a service instrument. The through-hole PDIP package is particularly useful in fixtures assembled for maintainability or field replacement. The documented 4.5 V to 30 V single-supply range supports common industrial service voltages, although the selected test equipment may use bipolar rails, which are also supported at ±4.5 V to ±20 V. Check channel capacitance, off isolation, leakage, and control timing before setting the fixture measurement bandwidth.
Recommended
Recommended Products Summary
Engineering reference data for MAX338CPE+ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MAX339CPE+ | MAX338CPE | MAX338CPA+ | DG508AD | DG509AD |
|---|---|---|---|---|---|---|
| Package | PDIP-16 | PDIP-16 | PDIP-16 | PDIP-16 | PDIP-16 | PDIP-16 |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Intersil | Intersil |
| Multiplexer Configuration | Single 8:1 | Dual 4:1 | Single 8:1 | Single 8:1 | 8:1 legacy reference | Dual 4:1 legacy reference |
| Industry-Standard Upgrade Reference | MAX338 is identified as a pin-compatible upgrade for DG508A and DG509A | MAX339 is identified as a pin-compatible upgrade for DG508A and DG509A | MAX338 is identified as a pin-compatible upgrade for DG508A and DG509A | MAX338 is identified as a pin-compatible upgrade for DG508A and DG509A | Legacy reference device | Legacy reference device |
Key Differentiators
- Provides an 8:1 single-ended configuration in a serviceable 16-pin PDIP package (vs MAX339CPE+)
- Explicitly positioned as a pin-compatible upgrade for two industry-standard multiplexer families (vs DG508AD)
- Supports both positive-only and bipolar analog supply arrangements (vs MAX338CPA+)
Design Notes
Route the eight analog inputs, common output, supply pins, and digital controls with short analog traces and a continuous ground reference. The MAX338CPE+ is a 16-pin PDIP device intended for through-hole assembly, so place it close to the source connectors and measurement circuitry. Avoid sharing narrow paths with high-current switching nodes. Because distributor listings report 400 ohm and 650 ohm on-resistance under different source records, preserve signal-source impedance margins and verify bandwidth and attenuation against the exact datasheet test conditions.
Do not assume that sharing a package guarantees identical behavior. MAX338 provides a single 8:1 multiplexer, while MAX339 provides a dual 4:1 arrangement and DG509AD is identified as a legacy dual 4:1 reference. Compare the address truth table, enable polarity, common-output mapping, supply pins, and signal limits before substitution. Also verify whether the original circuit expects a single +4.5 V to +30 V rail or a bipolar ±4.5 V to ±20 V supply configuration.
Treat the selected analog channel and common output as a finite-resistance path. With on-resistance records of 400 ohm and 650 ohm, impedance can become material when driving a high-impedance ADC, precision amplifier, or long cable. Keep the output path short, use a suitable acquisition bandwidth, and place any required buffer immediately after the common output. Validate leakage, off-isolation, capacitance, charge injection, and settling time using the manufacturer datasheet before setting a narrow measurement window.
Decouple the supply pins close to the device using the capacitance and placement recommended by the manufacturer datasheet. A stable low-noise supply is especially important when the selected channel carries a small measurement signal because supply ripple can appear as measurement error. The component supports single and dual supplies, but those modes are not automatically equivalent in control-logic levels or common-mode behavior. Confirm the intended rail arrangement, voltage tolerances, and sequencing requirements against the original circuit before energizing a modified board.
Compliance Information
The supplied verified records identify the MAX338 family as active and describe MAX338CPE+, but they do not explicitly extract RoHS, REACH, halogen-free, lead-free, or conflict-minerals statements. The plus suffix is therefore not treated as independent proof of compliance.