COMMON ANODE VS COMMON CATHODE DRIVER
These components have market-proven solutions for common anode technology but are still in the early stages for common cathode technology.Features: This driver is an upgraded version of TB6600, subdivided up to 32 segments, suitable for high-segment use.Īpplicable stepper motor: 42, 57, 86 type 2 phase 4 phase (4 lines 6 lines 8 lines)Ģ. H – bridge bipolar constant – current drive ģ. Up to 4.0A of the eight output current options Ĥ. Up to 32 subdivision of the subdivision mode optional ĥ. Input signal high speed photoelectric isolation Ĩ. Semi-enclosed enclosure can be more stringent environment ĩ. To provide energy-saving semi-automatic current lock function ġ0. Built-in temperature protection and overcurrent protection.ġ. CP +: pulse signal input positive terminalģ. DIR +: motor positive, reverse control positive sideĤ. DIR-: motor positive, reverse control negativeĥ. EN +: motor off-line control positive terminalġ. VCC: DC power supply positive (Note: 10V ■ Common cathode technology reduces forward voltage drop by reducing the supply voltage of red LEDs, however, this requires the use of more power supplies, which further increases the complexity of the component layout on PCBs. If the ed LED current accounts for 50% of the total current, then we can save 50%*(5-2.8)/5=22%, Therefore, there is a theoretical 17.6%~22% power savings using common cathode technology over common anode technology. ■ Assuming that under common anode mode a 5V voltage is used as the unified power, under common cathode mode a 2.8V is used for red LEDs, and all other conditions are the same, if the current of red LEDs accounts for 40% of the total current, then we can quickly calculate the percentage of power saved: 40%*(5-2.8)/5=17.6%. By using common cathode technology, LED display can reduce excessive heat and power consumption, pixel failure rate, and ghost lines (tailing effect), thus improving LED display’s overall performance. Moreover, there are no extra line-scanning devices needed to achieve this. ■ Based on accurate power control, common cathode technology can reduce the power consumption of the entire system by reducing the red LEDs’ supply voltage. Consequently, less heat is produced as less power is consumed. Because of this separate and precise power supply, the power efficiency is higher. ■ In common cathode mode, the LED display provides RGB LEDs with separate voltage based on actual needs (2.8V for the red LED, and 3.8V for the green and blue LEDs). ■ In common anode mode, the LED display provides RGB LEDs with a unified voltage higher than 3.8V (such as 5V), therefore the power consumption is high. The forward voltage drop is reduced, and as a result, there is less internal conduction resistance. Voltage and current are precisely distributed based on individual needs, then to the negative ends of ICs. ■ In common cathode mode, the LED display’s current first passes through LED diodes with R, G, and B LEDs separately powered. ■ In common anode mode, the current of LED displays flows from PCB to LED diodes, and the RGB LEDs are powered with the same power source at the same power rate, and therefore the forward voltage drop is increased. Under line-scanning drive mode, LED displays can be categorized into two types: the common cathode and the common anode.Īs the name implies, common anode means individual LEDs are connected via their positive ends and driven by negative ends and common cathode means individual LEDs are connected via their negative ends and driven by positive ends, and in common cathode mode, R, G, B chips are separately powered with voltage and current precisely distributed to red, green, and red diodes, and the current passes the diodes then to the negative ends of ICs. However, when LED displays began to be used for indoor applications using smaller pitch products, the space available for electronic components was squeezed, and as a result, dynamic scan drive (line-scanning drive) based on time-division multiplexing (TDM) came into being. In the early stage, LED displays were mostly used for outdoor applications using larger pitch products, which did not have a physical space limit for driver ICs as they were designed with static scan drive.