MAX3490ECPA - 12Mbps RS-485 Transceiver | Maxim Integrated
MPN: MAX3490ECPA ✓ ActiveMAX3490ECPA Overview
An RS-485/RS-422 transceiver is an interface IC that converts logic-level signals into differential bus voltages and converts received differential voltages back into digital logic. The MAX3490ECPA belongs to the MAX3483E family of low-power transceivers designed for industrial, instrumentation, and data-communication links where both long-distance noise immunity and compact integration are important.
The principal operating characteristics include a 3.3 V supply, ±15 kV ESD protection, operation at up to 12 Mbps, and slew-rate-limited true RS-485/RS-422 operation. Its one-driver/one-receiver configuration supports point-to-point and multidrop network arrangements when the bus topology, termination, and grounding strategy are designed correctly. The 8-pin PDIP package also supports conventional through-hole PCB assembly and prototyping.
Slew-rate limiting reduces the rate at which the differential driver changes state, limiting high-frequency energy that can couple into adjacent circuitry. This behavior is particularly useful on long cables or in systems where reducing edge-related ringing and crosstalk is more important than maximizing data rate. The device should still be evaluated with the intended cable length, topology, termination network, and grounding arrangement.
Typical applications include industrial control networks, instrumentation links, data acquisition systems, building automation equipment, and point-to-point data communications. The MAX3490ECPA is appropriate when the system uses 3.3 V logic, requires integrated transmit and receive functions, and can tolerate the operating-speed limitations of a through-hole PDIP package.
For a new design, confirm the exact driver-enable and receiver-enable polarity, supply decoupling, bus termination, and fail-safe behavior against the manufacturer pin description and datasheet before fabrication. Place the device near the bus connector when practical to minimize unprotected trace length and reduce ESD exposure.
This product record combines the manufacturer’s family-level functional information, package details, operating characteristics, and practical interface design guidance. It also provides drop-in family alternatives, comparison parameters, and application-focused engineering context to support component selection before schematic capture.
Drop-in alternatives for MAX3490ECPA — 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 MAX3490ECPA (same form factor and footprint) — differing in Driver Output Type, Package, Maximum Data Rate, Supply Voltage, Driver Count.
MAX3490CPA+
✅ Drop-InContact for price
View Datasheet →MAX3490EEPA+
✅ Drop-InContact for price
View Datasheet →MAX3483EEPA+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX3485EEPA+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX3486EEPA+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX3488EEPA+
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →MAX3491EEPA+
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX3490ECPA Specifications
| Product Type | RS-485/RS-422 transceiver |
| Supply Voltage | 3.3 V |
| Maximum Data Rate | 12 Mbps |
| ESD Protection | ±15 kV |
| Driver Count | 1 |
| Receiver Count | 1 |
| Supported Standards | True RS-485 and RS-422 |
| Driver Output Type | Slew-rate-limited differential output |
| Logic Supply | 3.3 V |
| Package | 8-pin PDIP |
| Mounting Type | Through-hole |
| Terminal Count | 8 |
| Package Shape | Rectangular |
| Temperature Grade | Commercial |
| Family | MAX3483E family |
MAX3490ECPA rectangular Pin Configuration Guide
Pin configuration for MAX3490ECPA (rectangular 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 MAX3490ECPA.
Refer to the datasheet for full pin configuration.
Typical Applications
MAX3490ECPA is suitable for 6 applications: Industrial Control and Automation, Instrumentation and Data Acquisition, Building Automation and HVAC Equipment, Point-to-Point Data Communication, LED Lighting and Ballast Control, Communication and Networking Equipment.
Industrial Control and Automation
The MAX3490ECPA fits industrial controller links that use a 3.3 V RS-485 bus for connecting sensors, actuators, remote I/O, or production equipment. Its one-driver/one-receiver architecture covers the common half-duplex data path, while ±15 kV ESD protection improves interface robustness in industrial environments. Slew-rate-limited operation limits the speed of differential edge transitions and can reduce high-frequency coupling on factory cabling. The 8-pin PDIP format is particularly convenient for equipment that uses through-hole assembly. During design, establish bus termination at the physical endpoints, avoid excessive stub lengths, and use a common-reference strategy appropriate to the installed cable.
Recommended
Instrumentation and Data Acquisition
The MAX3490ECPA is appropriate for RS-485 connections between laboratory instruments, sensors, and centralized acquisition equipment operating from 3.3 V. The ±15 kV ESD rating supports protection at accessible equipment interfaces, while the receiver converts differential bus voltage into a logic signal for the acquisition controller. Its slew-rate-limited driver can help control cable ringing in installations where instrument leads act as unterminated or variable-length transmission lines. Use the manufacturer pin description to implement the logic-side driver-enable and receiver-enable controls correctly, and follow the recommended interface grounding method for the installed equipment to avoid injecting ground-potential differences into the bus.
Recommended
Building Automation and HVAC Equipment
MAX3490ECPA can connect thermostats, environmental controllers, fan drives, and supervisory equipment over a 3.3 V RS-485 network. Its one-driver/one-receiver configuration is useful for a half-duplex controller-to-node link, and the ESD-protected bus interface is suited to equipment installed near motors, relays, and long building cable runs. Slew-rate-limited signaling reduces the amount of high-frequency energy launched onto the network, helping control ringing when cable length and topology are properly engineered. Keep the transceiver close to the external connector where practical, place protection and termination according to the interface topology, and validate communication margins at the longest expected cable length and worst-case node spacing.
Recommended
Point-to-Point Data Communication
The MAX3490ECPA supports point-to-point RS-422 or RS-485 links between two circuit boards, remote instrument sections, or communication modules when both endpoints use 3.3 V logic. In RS-422, the differential driver and receiver provide noise-tolerant signaling over balanced cabling, while the same device can support half-duplex RS-485 arrangements. The 12 Mbps-class datasheet listing makes it suitable for moderate-rate equipment links, although actual throughput depends on the selected revision’s specified limit and bus conditions. Use twisted-pair cable, terminate the differential pair according to the topology, and verify logic thresholds and propagation timing against the end systems to prevent marginal behavior at the maximum data rate.
Recommended
LED Lighting and Ballast Control
The MAX3490ECPA can connect a lighting controller to remote LED drivers, dimming modules, or monitoring boards over a 3.3 V differential bus. This allows a central controller to exchange status and commands over a bus that is less susceptible to noise than a single-ended connection, especially near switching power stages. The ±15 kV ESD protection strengthens the transceiver’s suitability for externally accessible wiring, and the through-hole PDIP package simplifies assembly in larger controller boards. Keep the bus wiring separated from high-current LED return paths, use a single-point grounding approach where possible, and confirm the driver-enable sequence so the transceiver is not driven during board reset or power transitions.
Recommended
Communication and Networking Equipment
The MAX3490ECPA is usable for auxiliary RS-485 management ports in gateways, routers, interface modules, and industrial network equipment. A 3.3 V transceiver supports direct connection to many modern controllers, and the integrated driver and receiver reduce the external component count for a single differential port. Slew-rate-limited operation is beneficial when the bus connects through cables near high-speed digital circuitry because it moderates edge energy and can limit ringing. Place the device near the connector or protection network, maintain the recommended spacing from switching regulators and clock sources, and ensure the system firmware controls bus direction correctly to avoid contention when multiple nodes transmit.
Recommended
Recommended Products Summary
Engineering reference data for MAX3490ECPA — comparison, design guidance, and compliance information.
Selection Guide
Use a MAX3483E-family alternative when its particular enable, receiver, timing, or auxiliary functions better match the system, while retaining the same 3.3 V and ±15 kV ESD class. Do not select an alternative solely because it fits an 8-pin footprint: confirm the numbered pins, enable polarity, bus-idle behavior, data-rate limit, and temperature range. For new designs, compare the MAX3490ECPA with ADM485JNZ and SP485EMN-L/TR for alternative RS-485 functions, and with ISO1042BDWR when galvanic isolation is required. The MAX3490ECPA is the direct choice when the specified MAX3490-family behavior and PDIP implementation are priorities.
Comparison with Alternatives
| Parameter | This Product | MAX3490CPA | MAX3490EEPA+ | MAX3483EEPA+ | MAX3485EEPA+ | MAX3491EEPA+ |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | PDIP-8 | PDIP-8 | PDIP-8 | PDIP-8 | PDIP-8 | PDIP-8 |
| Supply Voltage | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V |
| Driver Count | 1 | 1 | 1 | 1 | 1 | 1 |
| Receiver Count | 1 | 1 | 1 | 1 | 1 | 1 |
| Supported Standards | True RS-485 and RS-422 | RS-485 and RS-422 | RS-485 and RS-422 | RS-485 and RS-422 | RS-485 and RS-422 | RS-485 and RS-422 |
| Driver Timing | Slew-rate limited | Slew-rate limited | Slew-rate limited | Slew-rate limited | Slew-rate limited | Slew-rate limited |
Key Differentiators
- Combines one driver and one receiver in a single 3.3 V interface IC (vs MAX3490CPA)
- Uses a through-hole 8-pin PDIP package suitable for conventional PCB assembly (vs MAX3490EEPA+)
- Provides a documented 3.3 V operating point with ±15 kV ESD protection (vs MAX3483EEPA+)
- Slew-rate-limited differential signaling reduces transition-edge energy (vs MAX3485EEPA+)
Design Notes
Place the MAX3490ECPA as close as practical to the external bus connector so that the unprotected board traces between the connector and transceiver remain short. Route the A and B differential pair together over a continuous ground plane, keep the pair away from switching nodes and high-current return paths, and avoid adding unnecessary stubs. The through-hole package permits relatively forgiving component placement, but connector protection and cable routing still dominate ESD exposure.
Do not assume that a matching package alone guarantees a drop-in replacement. Verify the ECPA pinout, supply pins, enable polarity, receiver enable polarity, and thermal-grade ordering code against the manufacturer data sheet before substituting another MAX3483E-family part. For a half-duplex RS-485 link, coordinate driver-enable and receiver-enable control so that multiple transmitters never drive the bus simultaneously. Also confirm termination placement so that termination resistors appear only at the physical ends of the bus.
Treat the differential pair as a controlled-impedance transmission line even at moderate data rates. Use twisted-pair cable, maintain consistent routing geometry, and account for connector and adapter parasitics. The slew-rate-limited driver reduces edge energy and ringing, but it does not eliminate reflections caused by incorrect topology, excessive stub length, or missing termination. Validate the worst-case cable length, node spacing, logic thresholds, and propagation delay in the assembled system rather than relying only on nominal data-rate ratings.
Decouple the 3.3 V supply close to the device with the capacitance and placement recommended in the manufacturer application guidance. Keep the transceiver supply return connected to the appropriate interface ground and route return currents away from bus-cable currents. Verify that the supply remains within the device’s specified operating range during startup and shutdown; enable sequencing should prevent a controller from driving the bus while the transceiver or connected node is in an indeterminate state.
Compliance Information
The available product information does not state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. AEC-Q100 is marked not_applicable because the listed temperature grade is commercial rather than automotive.