Part A
ADM3491ARZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2506 PCS
- Package
- SOIC-14
- Series
- Interface - Drivers, Receivers, Transceivers
Replacement verdict
Compatible functional replacement candidate
The ADM3491ARZ is a functionally compatible replacement candidate for the ADM3491AR, as both parts share the same RS-485 transceiver architecture, supply voltage range, and SOIC-14 package footprint. The primary distinction is the RoHS-compliant Z-suffix designation on the ADM3491ARZ, which reflects lead-free construction rather than any change in electrical function. Designers should confirm solder profile compatibility and inventory availability before substituting, but no circuit redesign is expected.
Function and Protocol
High match
Supply Voltage Range
High match
Package and Pinout
High match
RoHS Compliance
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADM3491ARZ | ADM3491AR | Why it matters |
|---|---|---|---|
| Manufacturer | Analog Devices Inc. | Analog Devices Inc. | Same manufacturer ensures consistent design, documentation, and quality standards. |
| Function | 3.3 V, full-duplex RS-485/RS-422 transceiver | 3.3 V, full-duplex RS-485/RS-422 transceiver | Identical device function confirms the parts are intended for the same communication interface role. |
| Data Rate | Up to 12 Mbps | Up to 12 Mbps | Matching maximum data rate ensures equivalent throughput capability in the target bus design. |
| Supply Voltage | 3.0 V to 3.6 V (3.3 V nominal) | 3.0 V to 3.6 V (3.3 V nominal) | Same supply range guarantees the parts are interchangeable in the same power rail design. |
| Duplex Mode | Full duplex | Full duplex | Duplex mode must match because it determines the number of bus lines and the transceiver's pin function. |
| Number of Drivers / Receivers | 1 driver / 1 receiver | 1 driver / 1 receiver | Identical driver/receiver count confirms the same channel configuration for the bus node. |
| Mounting Type | Surface mount | Surface mount | Same mounting type ensures the part fits the same PCB assembly process and footprint style. |
| Package / Case | 8-SOIC (0.154 in, 3.90 mm width) | 8-SOIC (0.154 in, 3.90 mm width), tube packaging | The Z suffix denotes lead-free/RoHS-compliant molding compound and packaging, which affects compliance and soldering process requirements. |
| RoHS / Lead-Free Status | RoHS compliant, lead-free | Non-RoHS, contains lead (Pb) | RoHS compliance is critical for regulatory compliance and is the primary functional difference between the Z and non-Z variants. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Matching temperature range ensures equivalent environmental robustness for industrial applications. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADM3491ARZ | ADM3491AR |
|---|---|---|
| Part Status | Active | Obsolete |
| Type | Transceiver | Transceiver |
| Protocol | RS422, RS485 | RS422, RS485 |
| Number of Drivers / Receivers | - | 1/1 |
| Duplex | Full | Full |
| Receiver Hysteresis | 50 mV | 50 mV |
| Data Rate | 10Mbps | 10Mbps |
| Voltage - Supply | 3V ~ 3.6V | 3V ~ 3.6V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | - | ADM3491 |
| Number of Drivers/Receivers | 1/1 | - |
Frequently asked questions
What is the difference between the ADM3491ARZ and the ADM3491AR?
The ADM3491ARZ and ADM3491AR are functionally identical RS-485/RS-422 transceivers from Analog Devices. The primary difference is the suffix: the "Z" designation indicates RoHS-compliant packaging, while the ADM3491AR is the non-RoHS version. Both are specified for the same electrical performance and are offered in the same 14-lead SOIC package.
Are the ADM3491ARZ and ADM3491AR pin-compatible?
Yes. Both devices use the same 14-lead SOIC (R-14) package with identical pin assignments, so they are pin-compatible and share the same PCB land pattern.
Can the ADM3491ARZ be used as a drop-in replacement for the ADM3491AR?
Yes, from an electrical and footprint standpoint the ADM3491ARZ is a drop-in replacement for the ADM3491AR. The only practical distinction is that the ADM3491ARZ is the RoHS-compliant variant, which may matter for regulatory and compliance requirements rather than circuit function.
What are the key specifications shared by the ADM3491ARZ and ADM3491AR?
Both are 3.3 V, full-duplex RS-485/RS-422 transceivers with a data rate of up to 10 Mbps, a 1/8 unit load allowing up to 256 nodes on the bus, and integrated ESD protection. They operate over the industrial temperature range of −40 °C to +85 °C.
Do the ADM3491ARZ and ADM3491AR support the same data rate and bus loading?
Yes. Both devices support data rates up to 10 Mbps and feature a 1/8 unit load receiver input impedance, permitting up to 256 transceivers to share a single RS-485 bus.
Which variant should be selected for RoHS-compliant designs?
The ADM3491ARZ should be selected for RoHS-compliant designs, as the "Z" suffix denotes lead-free, RoHS-compliant construction. The ADM3491AR is the non-RoHS version and is generally not preferred for new designs requiring environmental compliance.
Are the ADM3491ARZ and ADM3491AR specified over the same temperature range?
Yes. Both the ADM3491ARZ and ADM3491AR are specified for operation over the industrial temperature range of −40 °C to +85 °C.