LED drivers typically require external power transistors. However, STMicroelectronics offers a cost-effective and programmable alternative with the LED1202QTR. This versatile driver can handle up to twelve 20mA LEDs, providing a flexible solution for various applications. 

Understanding the LED1202QTR:

STMicroelectronics provides a comprehensive overview of the LED1202QTR's internal components, as depicted in the figure. The driver communicates via the widely-used I2C bus, making it compatible with most microcontrollers.  

LED1202 simplified block diagram.png

The driver sinks current from the LEDs through its twelve control pins, with each channel supporting up to 20mA of forward current. This capability is sufficient to power small to medium-sized RGB LEDs, allowing for the batching of three channels per LED. To simplify control, it is advisable to assign color components sensibly, such as assigning CS0/CS3/CS6 to R. This way, the I2C control program can easily determine the control register addresses.  

Value-Added Functions:

The LED1202QTR requires only two 1uF MLCC capacitors as external components. However, practical experience suggests that additional capacitors on the LED power supply enhance system stability.  

LED1202 local address table

In terms of address space limitations, STMicroelectronics has implemented a connection scheme (illustrated in the table) that enables one I2C controller to communicate with up to eight integrated circuits, overcoming the usual constraints posed by the number of address pins.  

Furthermore, the LED1202QTR offers a sophisticated dimming engine for smooth brightness transitions and an EMI-minimizing feature called phase shift. By offsetting the switching of individual LEDs, this feature reduces peak current drawn from the power supply, resulting in reduced noise on the power rails, as observed in tests conducted by OEMSecrets.  

LED1202 Phase-shift feature scheme

Availability and Pricing:

Based on an OEMSecrets scan, the LED1202QTR variant is priced at an average of around 1.5 EUR in quantities of one hundred (Accurate based on publication date). The BGA version, LED1202JR, is priced slightly higher at an average of 1.6 EUR and is currently less readily available. It's worth noting that during the chip crisis, the LED1202 stock was affected, similar to ST's "digital IC portfolio," due to the shortage of STM32 MCUs. 


When driving a small number of LEDs, the LED1202QTR offers a simple and I2C-addressable solution. Its affordability, programmability, and support for up to twelve 20mA LEDs make it a versatile choice for various applications. STMicroelectronics' LED1202QTR presents an opportunity to simplify LED driving while providing control and flexibility.