Dedicated display driver circuit

Judging from the current pixel display several of the tube, can be divided into: ① scan driver; ② DC drive; ③ current source driver. For indoor screen lattice block, the general use of scanning; for outdoor pipe pixel screen, it is necessary to ensure that the displayed image consistency, stability and highlighted the need to increase the use of DC current source drives the way.

Earlier electronic LED display driver circuit using mostly low-voltage signal and convert the string of CMOS circuits and high current drive bipolar circuit composed of two (such as 74HC595 + MC1413/UNL2803, CD4094/MC14094 + MC1413, 74HC164 +74 HC273 + MC1413 ), This form of drive circuit there is a solder joint, high-cost, low reliability problems.

In response to these shortcomings, the United States TI developed to produce TPIC6B595 (TPIC6C595) application specific integrated circuit (ASIC), and it will convert string and the combined current drive, the ASIC has the following salient features: parallel output drive capability, single Road drive current up to 200mA, can be directly driven LED; wide range of current and voltage, the voltage can be 5 ~ 15V with a flexible choice; serial input, and shift latch, the clock input port has a plastic circuit Schmidt; string And output current, and to absorb current supply are greater than 4mA, even the easy level; high-speed data processing, serial clock frequency, fmax ≥ 25MHz especially suitable for multi-gray color LED display driver.

Wuxi of east China's first large Microelectronics Co., Ltd. in 1998, also produced TPIC6B595 is fully compatible with the ASIC chip AMT9094/9095, but greatly reduced prices. TPIC6B595 because of the parallel output was only 8-bit, full-color high-resolution drivers need to display a larger number of TPIC6B595 and 256 gray-scale control of more trouble.

To this end, U.S. companies TI developed the electronic screen LED display driver application specific integrated circuit TLC5901/5902/5903, this has the advantage of ASIC: the source of constant current output of 5 ~ 80mA (or 10 ~ 120mA); the ability to drive 80mA × 16Bits (Or 120mA × 8Bits); PWM control of the 256 grayscale display; 32 adjustable brightness; clock synchronization of the 8-bit parallel data entry. The chip makes control grayscale 256 more simple way of making current source images showed better consistency, TQFP100 package allows the driver board area has been greatly reduced.

On this basis, TI's development and a better performance LED driver chip TLC5921. Beijing Huahong IC design companies have also developed high-performance LED's 9701 application specific integrated circuit, the ASIC has the following salient features: contains 8 × 16 × 32 arrays to scan data, from static to 1 / 32 dynamic scanning; Data entry and data scanning arrays were used to control the output gray two independent clock; 8-bit parallel data input and 8-bit parallel output data functionality of the Cascade; 16 output data for each driver-side LED current up to More than 80mA each side data output voltage greater than 20V; data output 256 gray; output model with a choice of terminal can be used to odd and even choice of frame; with a non-linear correction control input.


Reference link: http://www.17led.com/LEDdisplay/2008-04/48p4.html