Apalis Carrier Board Design Guide - Toradex

Apalis Carrier Board Design Guide2.6.3 Reference Schematics2.6.3.1 24-bit Display Schematic ExampleThe parallel RGB interface can cause problems with EMC compliance when used with a high pixelclock frequency. This can be made worse if a display is connected over flat flex cables. Therefore,the flat flex cables should be kept as short as possible. Series resistors in the data lines reduce theslew rate of the signals which instead reduces the radiation problem but can also introduce signalquality and timing related problems. The serial resistor value is a trade-off between reduction ofelectromagnetic radiation and signal quality. A good starting value is 22Ω.Some displays feature an I 2 C interface for reading out the EDID PROM or additional controls suchas contrast and hue. If the carrier board provides no other display interface with DDC, it isrecommended that the I2C2 on the Apalis module be used for the DDC. If the DDC is used, makesure that I 2 C device(s) on the RGB display do not interfere with the DDC address 50h. Otherwise,use a different I 2 C interface on the Apalis module. The I 2 C interfaces on the Apalis module have a3.3V logic level. If the display requires a 5V interface, add an I 2 C logic level shifter.X1LMXM3_239BKL1_PWM 239243 MXM3_243LCD1_PCLK245 MXM3_245LCD1_VSYNC247 MXM3_247LCD1_HSYNC249 MXM3_249LCD1_DE286 MXM3_286BKL1_ON251 MXM3_251LCD1_R0253 MXM3_253LCD1_R1255 MXM3_255LCD1_R2257 MXM3_257LCD1_R3259 MXM3_259LCD1_R4261 MXM3_261LCD1_R5263 MXM3_263LCD1_R6265 MXM3_265LCD1_R7269 MXM3_269LCD1_G0271 MXM3_271LCD1_G1273 MXM3_273LCD1_G2275 MXM3_275LCD1_G3277 MXM3_277LCD1_G4279 MXM3_279LCD1_G5281 MXM3_281LCD1_G6283 MXM3_283LCD1_G7287 MXM3_287LCD1_B0289 MXM3_289LCD1_B1291 MXM3_291LCD1_B2293 MXM3_293LCD1_B3295 MXM3_295LCD1_B4297 MXM3_297LCD1_B5299 MXM3_299LCD1_B6301 MXM3_301LCD1_B7Apalis - Digital RGB12 of 25MM70-314-310B1X1Y205 MXM3_205I2C2_SDA207 MXM3_207I2C2_SCLApalis - Display DDC25 of 25MM70-314-310B1X1D24POWER_ENABLE_MOCI26RESET_MOCI#28RESET_MICO#37WAKE1_MICO#Apalis - System Control4 of 25MM70-314-310B1LCD[0..29]R1 22R PWM_BKL1R2 22R LCD1_PCLKR3 22R LCD1_VSYNCR4 22R LCD1_HSYNCR5 22R LCD1_DER6 22R BKL1_ONR7 22R LCD1_R0R8 22R LCD1_R1R9 22R LCD1_R2R10 22R LCD1_R3R11 22R LCD1_R4R12 22R LCD1_R5R13 22R LCD1_R6R14 22R LCD1_R7R15 22R LCD1_G0R16 22R LCD1_G1R17 22R LCD1_G2R18 22R LCD1_G3R19 22R LCD1_G4R20 22R LCD1_G5R21 22R LCD1_G6R22 22R LCD1_G7R23 22R LCD1_B0R24 22R LCD1_B1R25 22R LCD1_B2R26 22R LCD1_B3R27 22R LCD1_B4R28 22R LCD1_B5R29 22R LCD1_B6R30 22RR37 22R I2C2_SDA22R I2C2_SCLR39LCD1_B7JP133.3V2V_DDC15V3.3VV_DDC V_DDCIC1100K R3127C1 VREF1 VREF2R32 R33100nF16V 18 1.8K 1.8KR35 R34 GND EN1.8K 1.8K100nF C2I2C2_DDC[0..1]16VGNDGNDI2C2_SCL36R36SCL1 SCL222RI2C2_SDA45R38SDA1 SDA222RPCA9306DCTTL1500mA220R@100MHzL2500mA220R@100MHzC3 C44.7pF 4.7pFGNDFigure 30: 24-bit parallel RGB display reference schematicDisplay ConnectorX21GND25V33.3V43.3VLCD1_B75LCD1_B66LCD1_B57LCD1_B48LCD1_B39LCD1_B2 10LCD1_B1 11LCD1_B0 1213GNDLCD1_G7 14LCD1_G6 15LCD1_G5 16LCD1_G4 17LCD1_G3 18LCD1_G2 19LCD1_G1 20LCD1_G0 2122GNDLCD1_R7 23LCD1_R6 24LCD1_R5 25LCD1_R4 26LCD1_R3 27LCD1_R2 28LCD1_R1 29LCD1_R0 3031GNDLCD1_PCLK 32LCD1_HSYNC 33LCD1_VSYNC 34LCD1_DE 35BKL1_ON 36PWM_BKL1 37I2C2_DDC_SCL_C 38I2C2_DDC_SDA_C 39RESET_MOCI# 40FH12-40S-0.5SV(55)Toradex AG l Altsagenstrasse 5 l 6048 Horw l Switzerland l +41 41 500 48 00 l www.toradex.com l info@toradex.com Page | 35