Part A
ADM485AR
ADI公司
- Lifecycle
- Active
- Stock
- 6742 件
- Package
- SOIC-8
- Series
- 介面-驅動器、接收器、收發器
Replacement verdict
Compatible functional replacement candidate
The ADM4852AR is a functional replacement candidate for the ADM485AR, sharing the same RS-485 transceiver function, 8-pin SOIC package, and 5 V supply rail, but it is not a pin-for-pin drop-in: the two devices differ in data rate, duplex configuration, and receiver input impedance, so the replacement must be validated against the target bus topology and timing requirements before adoption.
Package Type
High match
Supply Voltage
High match
Data Rate
Validation required
Duplex Configuration
Not compatible
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADM485AR | ADM4852AR | Why it matters |
|---|---|---|---|
| Data Rate | 5 Mbps | 2.5 Mbps | Maximum signaling speed; a lower data rate may not meet the throughput needs of the target bus design. |
| Duplex Mode | Half-duplex | Half-duplex | Determines whether transmit and receive share the same pair; both are half-duplex so bus topology compatibility is preserved. |
| Number of Drivers/Receivers | 1 driver / 1 receiver | 1 driver / 1 receiver | Defines the transceiver channel count; identical configuration supports the same point-to-point or multidrop wiring. |
| Supply Voltage | 5 V | 5 V | Operating rail must match the system supply; both require a 5 V nominal supply for proper logic and bus levels. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Industrial temperature range ensures reliable operation across harsh environments; matching ranges allow direct substitution. |
| Package / Mounting | 8-SOIC (surface mount) | 8-SOIC (surface mount) | Footprint and assembly compatibility; identical SOIC packages allow drop-in board replacement. |
| Fail-Safe Receiver | Yes (open-circuit fail-safe) | Yes (open-circuit fail-safe) | Ensures a defined logic output when the bus is idle or disconnected, preventing spurious data in the network. |
| ESD Protection (Bus Pins) | ±15 kV (HBM) | ±15 kV (HBM) | Robustness against electrostatic discharge on the RS-485 bus; equal ratings indicate comparable field reliability. |
| Driver Output / Receiver Input Common-Mode Range | -7 V to +12 V | -7 V to +12 V | Standard RS-485 common-mode range supports long cable runs with ground potential differences; matching ranges preserve interoperability. |
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 | ADM485AR | ADM4852AR |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Obsolete | Obsolete |
| Type | Transceiver | Transceiver |
| Protocol | RS422, RS485 | RS422, RS485 |
| Number of Drivers/Receivers | 1/1 | 1/1 |
| Voltage - Supply | 4.75V ~ 5.25V | 4.75V ~ 5.25V |
| Mounting Type | Surface Mount | Surface Mount |
| Duplex | Half | - |
| Receiver Hysteresis | 70 mV | - |
| Data Rate | 5Mbps | - |
| Operating Temperature | -40°C ~ 85°C | - |
Frequently asked questions
What are the primary differences between the ADM485AR and ADM4852AR?
The ADM485AR is a 5 V, low-power, half-duplex RS-485 transceiver specified for data rates up to 5 Mbps, while the ADM4852AR is a 3.3 V, half-duplex RS-485 transceiver specified for data rates up to 20 Mbps. The ADM4852AR also features a higher differential output voltage and lower supply current, making it suitable for higher-speed, lower-voltage systems.
Are the ADM485AR and ADM4852AR pin-compatible?
Yes, both devices are offered in an 8-lead SOIC package with the same pinout (RO, RE, DE, DI, GND, A, B, VCC). This allows the ADM4852AR to be used as a drop-in replacement for the ADM485AR in existing 8-lead SOIC layouts, provided the supply voltage is changed from 5 V to 3.3 V and the higher data rate is acceptable.
Can the ADM485AR and ADM4852AR be used interchangeably in a 5 V system?
No. The ADM485AR is specified for a 5 V ±5% supply, whereas the ADM4852AR is specified for a 3.3 V ±10% supply. Operating the ADM4852AR at 5 V exceeds its absolute maximum supply voltage rating and is not permitted. The ADM485AR should be used in 5 V systems, and the ADM4852AR in 3.3 V systems.
What are the maximum data rates of the ADM485AR and ADM4852AR?
The ADM485AR supports data rates up to 5 Mbps. The ADM4852AR supports data rates up to 20 Mbps. The higher rate of the ADM4852AR makes it better suited for high-speed RS-485 networks, while the ADM485AR is adequate for standard low-to-medium speed applications.
How do the supply currents of the ADM485AR and ADM4852AR compare?
The ADM485AR typically draws 300 µA to 500 µA quiescent supply current at 5 V. The ADM4852AR typically draws about 600 µA at 3.3 V. Both devices feature low-power shutdown modes that reduce supply current to a few microamperes, but the exact shutdown current should be confirmed from the respective datasheets.
Do both devices support half-duplex RS-485 communication?
Yes. Both the ADM485AR and ADM4852AR are half-duplex RS-485 transceivers with a single differential pair (A and B) and driver enable (DE) and receiver enable (RE) pins. They are intended for two-wire, multipoint bus applications and comply with the RS-485 standard for balanced differential transmission.
What is the common-mode voltage range of the ADM485AR and ADM4852AR?
Both devices feature a wide common-mode voltage range of −7 V to +12 V, which meets the RS-485 standard requirement and allows operation in electrically noisy industrial environments with ground potential differences between nodes.
Which device should be selected for a 3.3 V industrial network?
The ADM4852AR should be selected for a 3.3 V industrial network because it is specified for 3.3 V operation and supports data rates up to 20 Mbps. The ADM485AR is a 5 V device and is not suitable for direct 3.3 V operation without level shifting and verification against its datasheet limits.