MAX485-CD4069 RS-485 Module with Auto Data Direction Control – Pinout Diagram & Reference

Complete pinout diagram and pin reference for the MAX485-CD4069 RS-485 communication module with automatic data direction control.
MAX485-CD4069 RS485 Module Pinout Diagram Featured Image CIRCUITSTATE Electronics

MAX485 from Maxim is a low-power transceiver intended for RS-485 and RS-422 applications. It is a half-duplex driver with a Unit Load (UL) rating of 1 and therefore you can have up to 32 MAX485s on a single RS-485 bus. The data rate is up to 2.5 Mbps. MAX485 is available in 8-pin packages of various forms and the typical supply voltage is 5V. Its IO voltage is also 5V which means you can interface it directly to any 5V microcontroller. There are many easy-to-interface breakout modules available for using MAX485 in your applications. One such module is the one that combines a MAX485 with a CD4069 hex inverter. The module features auto data direction control which eliminates the need for two extra GPIO pins. Instead, the direction of data transmission is automatically determined by the RX and TX pins states. So you only need the power supply lines and the TX and RX lines for interfacing. We have an in-depth RS485 communication tutorial using the same module which you can find below.

What is RS485 and how to use MAX485 and Arduino for long distance serial communication featured image

What is RS-485 & How to Use MAX485 with Arduino for Reliable Long-Distance Serial Communication

Learn about the industry-favorite RS-485 (EIA-485) wired communication interface standard and learn how to interface the MAX485 module with Arduino.

MAX485 Specifications

Data Rate2.5 Mbps
Data Rate at 1200 m110 Kbps
Slew-rate LimitedNo
Quiescent Current300 uA
Number of receivers on the bus32 (1 UL)
Pin Count8
Working Voltage3 – 12 V (5V typical)

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MAX485 Pinout

MAX485 RS-485 communication IC pinout
MAX485 pinout
Signal NameDescription
ANon-inverting Signal
BInverting Signal
DIDriver Input
ROReceiver Output
DEDriver Enable
REReceiver Enable (Active LOW)
VCCPositive supply voltage
GNDNegative supply voltage
MAX485 pin description

CD4069 Pinout

CD4060 Hex Inverter Digital Logic IC Pinout

Pinout Diagram

Latest Revision: Rev 0.1, 07-12-2022
Design by: Vishnu Mohanan
License: CC-BY-SA 4.0

Pinouts are based on the latest documentation from the manufacturer. While we try our best to be accurate and up-to-date here, we can not guarantee correctness. Please also double-check the pin assignments with that from the official documentation. If you found any errors here, please let us know in the comments. We will update our designs ASAP.


MAX485-CD4069 module pinout


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Pin Reference

RS-485 ModuleDescription
VCCPositive supply voltage
RXDModule data receive pin. Send data through this pin.
TXDModule data transmit pin. Read data from this pin.
A+Positive line of RS-485
B-Negative line of RS-485
SCSignal Common

When connecting one RS-485 module another RS-485 module you must only connect the A+, B- and SC lines. You don’t necessarily to share the VCC or GND supplies.


Below is a reverse-engineered schematic of the module.

RS485 Serial Communication Tutorial with Arduino and MAX485 Module Schematic
MAX485-CD4069 reverse-engineered schematic
  1. What is RS-485 & How to Use MAX485 with Arduino for Reliable Long-Distance Serial Communication – CIRCUITSTATE Electronics
  2. MAX485 – Datasheet [PDF]
  3. CD4069 Hex Inverter – Datasheet [PDF]
  4. Original TIA/EIA-485 Standard Specification [PDF]
  5. RS-485 Serial Interface Explained – CUI Devices
  6. Explanation of Maxim RS-485 Features – Analog Devices
  7. RS485 Cabling – Why you need 3 wires for 2-wire RS485?
  8. Basics of RS-485 – Texas Instruments [PDF]
  9. RS-422 / RS-485 Industrial Standards
  10. What is RS-485 and how is it used in industrial control systems? – RealPars
  11. How do I wire RS485 devices? – Innon
  12. Wiring of RS485 Communications Networks – Schneider Electric
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Vishnu Mohanan

Vishnu Mohanan

Founder and CEO at CIRCUITSTATE Electronics

Articles: 88

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