TCA9803 Level-Translating I2C Bus Buffer/Repeater |

This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.
Level-Translating I2C Bus Buffer/Repeater



The TCA9803 is a dual-channel bidirectional buffer intended for I2C bus and SMBus/PMBus systems. It provides bidirectional level shifting (up-translation and down-translation) between low voltages (down to 0.8 V) and higher voltages (1.65 V to 3.6 V). The TCA9803 features an internal current source on the B-side of the device, allowing the removal of external pull-up resistors on the B-side. The current source also provides an improved rise time and ultra-low power consumption.

The TCA9803 is able to provide true buffering (rather than a pass-FET solution) without using a static voltage offset or incremental offset. This means that the VOL on both the A and B sides of the TCA9803 are very low (approximately 0.2 V), helping to eliminate communication issues as a result of fixed VIL thresholds. Another key feature of the TCA9803 is that there are no power sequencing requirements, or power supply dependencies. VCCA can be greater than, less than, or equal to VCCB. This gives the system designer flexibility with how the TCA9803 is used.

The TCA9803 is part of a four device family with varying current source strengths (see the Device Comparison Table).


  • Two-Channel Bidirectional Buffer
  • Integrated Current Source on B-side, Requires No External B-Side Resistors
  • Ultra-Low Power Consumption
  • No Static-Voltage Offset, Low VOL
  • I2C Bus and SMBus Compatible
  • Operating Supply Voltage Range of 0.8 V to 3.6 V on A-side
  • Operating Supply Voltage Range of 1.65 V to 3.6 V on B-side
  • Active-High Repeater Enable Input
  • Powered-Off High Impedance I2C Bus Pins on A-Side
  • Powered-Off Back-Power Protection I2C Bus Pins
  • Support for Clock Stretching and Multiple Master Arbitration
  • Family of Current Source Options from 0.5 mA to 3 mA

All trademarks are the property of their respective owners.


Compare all products in I2C level shifters, buffers & hubs Email Download to Excel
Part number Order VCCA (Min) (V) VCCA (Max) (V) VCCB (Min) (V) VCCB (Max) (V) Supply restrictions Frequency (Max) (kHz) Features Operating temperature range (C) Approx. price (US$) Package Group Rating
TCA9803 Order now 0.8     3.6     1.65     3.6     No rule     400     Buffer
Enable Pin    
-40 to 125     0.27 | 1ku     VSSOP | 8     Catalog    
TCA9517 Order now 0.9     5.5     2.7     5.5     VCCA <= VCCB     400     Buffer
Enable Pin    
-40 to 85     0.30 | 1ku     SOIC | 8
VSSOP | 8    
TCA9617A Order now 0.8     5.5     2.2     5.5     VCCA <= VCCB     1000     Buffer
Enable Pin    
-40 to 85     0.31 | 1ku     VSSOP | 8     Catalog