TCA9548A I2C Multiplexer

Name: TCA9548A I2C Multiplexer
Brand: Texas Instruments
Availability: InStock

TCA9548A

Texas Instrumentsinterface io display

The TCA9548A is a low-voltage 1-to-8 bidirectional I2C switch that fans an upstream bus out to eight selectable channels. It resolves target address conflicts and supports voltage-level translation between 1.8V and 5V buses.

Manufacturer datasheet

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In stock

Specifications

Operating Voltage: 1.65 to 5.5 V
Supply Current: 50 µA
Standby Current Max: 2 µA
Channels: 8
Interface: I2C
I2c Clock Speed Max: 400 kHz
Switch On Resistance: 10 Ω
I2c Address Pins: 3
Operating Temperature Range: -40 to 125 °C
Package Types: TSSOP-24, VQFN-24, VSSOP-24

Pinout

Pin	Name	Functions	Notes
1	A0	—	Address input 0. Connect directly to VCC or ground
2	A1	—	Address input 1. Connect directly to VCC or ground
3	RESET	—	Active-low reset input. Pull up to VCC if not used
4	SD0	I2C	Serial data channel 0
5	SC0	I2C	Serial clock channel 0
6	SD1	I2C	Serial data channel 1
7	SC1	I2C	Serial clock channel 1
8	SD2	I2C	Serial data channel 2
9	SC2	I2C	Serial clock channel 2
10	SD3	I2C	Serial data channel 3
11	SC3	I2C	Serial clock channel 3
12	GND	GND	Ground
13	SD4	I2C	Serial data channel 4
14	SC4	I2C	Serial clock channel 4
15	SD5	I2C	Serial data channel 5
16	SC5	I2C	Serial clock channel 5
17	SD6	I2C	Serial data channel 6
18	SC6	I2C	Serial clock channel 6
19	SD7	I2C	Serial data channel 7
20	SC7	I2C	Serial clock channel 7
21	A2	—	Address input 2. Connect directly to VCC or ground
22	SCL	I2C	Upstream serial clock bus
23	SDA	I2C	Upstream serial data bus
24	VCC	POWER	Supply voltage

Interactive pinout

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TCA9548A

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Starter code

Community starter examples — minimal, unofficial, and provided to get you wiring fast. Verify against the manufacturer datasheet before relying on them.

Arduino (C++)

arduino

// TCA9548A 8-channel I2C multiplexer — community starter example
// No library needed: write a bitmask to the mux to pick channel(s).
#include <Wire.h>

const byte MUX = 0x70;   // A2..A0 = 000

void selectChannel(uint8_t ch) {       // ch 0..7
  Wire.beginTransmission(MUX);
  Wire.write(1 << ch);
  Wire.endTransmission();
}

void setup() {
  Serial.begin(115200);
  Wire.begin();
}

void loop() {
  selectChannel(0);     // now talk to the device on channel 0
  // ... your sensor.read() here ...
  delay(1000);
}

MicroPython

python

# TCA9548A I2C mux (ESP32) — community starter example
# No driver needed: write 1<<channel to the mux address
from machine import Pin, I2C
import time

i2c = I2C(0, scl=Pin(22), sda=Pin(21))
MUX = 0x70

def select(ch):
    i2c.writeto(MUX, bytes([1 << ch]))

while True:
    select(0)          # talk to channel 0's device
    time.sleep(1)

Wiring

Pin	Arduino Uno R3	ESP32 DevKitC (WROOM-32)	Notes
VCC	+5V	3V3	1.65-5.5 V
GND	GND	GND
SCL	A5/SCL	GPIO22	I2C clock
SDA	A4/SDA	GPIO21	I2C data
SD0..SC7	-	-	8 downstream I2C buses (SDn/SCn) to your sensors
A0/A1/A2	-	-	Address select -> 0x70-0x77

Typical uses

Putting many same-address I2C devices on one bus
Expanding past I2C address conflicts