SN75176 Pinout
SN75176 RS-485 Transceiver · Half-duplex RS-485 differential bus transceiver (same pinout as the MAX485).
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | RO · R | Output | Receiver output (to your UART RX) |
| 2 | RE · /RE | Control | Receiver enable (active-low) |
| 3 | DE | Control | Driver enable (active-high) |
| 4 | DI · D | Input | Driver input (from your UART TX) |
| 5 | GND | GND | Ground |
| 6 | A | I/O | Non-inverting bus line A |
| 7 | B | I/O | Inverting bus line B |
| 8 | VCC | Power | Supply + (5V) |
How to read the SN75176 pinout
- 01
Find pin 1
One end of the chip has a half-circle notch or a dot; with the notch facing up, the top-left pin is pin 1.
- 02
Count counter-clockwise
Count counter-clockwise from pin 1: go down the left side first, then up the right side from the bottom.
- 03
Check the table below
Look up each pin's function by number in the table below; power/ground are color-coded, and alternate-function signals are in parentheses.
Frequently asked questions
How do I control transmit vs receive direction?
Tie /RE (pin 2) and DE (pin 3) together to one GPIO: drive it LOW to receive, HIGH to transmit. Half-duplex means only one device drives the bus at a time.
Do I need termination resistors?
On longer buses, yes — put ~120Ω across A–B at each far end of the line to match the cable impedance and stop reflections.
Pinout data comes from TI SN75176 datasheet (standard DIP-8 numbering). Refer to the actual device datasheet as authoritative for the pinout.