OLIMEX© 2018
A20-OLinuXino-MICRO user's manual
8.2 Board revision
Remember to check the schematics and the board design files to compare the differences.
Revision
Notable changes
B
Initial release of the board
C
1. Resistor matrix RM23 gets replaced by: R133,R134,R135
2. Adjusted the package of H5TQ2G63BFR/MEM4G16D3EABG-125
3. R12 and R15 values changed to 0R
4. NAND_E jumper is changed from PTH to SMD closed
5. 5V_SATA_PWR connector (altogether with 2×2uF) is changed from
WF2S to DW02S and placed near the PWR jack instead of original
position
6. GPIO-4 is now correctly named GPIO-1
7. There is a signal for the power of of the SATA – PB8/SATA-PWR-EN
(r136, c216, r138, t1, t137, fet4)
8. A jumper between 5V_E_SATA and 5V_PWR_SATA is added
9. The micro SD card connector is changed
D
Resistor optimizations
E
1. Adjusted and optimized the position of PCB names
2. R16 changed from 237R to 330R, for stability purposes
3. R7, R9 also changed from 237R to 330R, for stability purposes
4. R41 and R104 changed from 1k/1% to 390R for better sync signal
and to improve the VGA signal (allowing it to work at FullHD)
F
1. Added 10M resistor in parallel to 32768 crystal else there might
be hang-ups
2. Changed to 32768 crystal to SMD one
3. Few libraries updated
4. Added pads of two tantalum capacitors C222 and C223 near the
USB-host
5. Positions adjusted – A20, NAND, SPIFLASH, LAN, matrix,
capacitors, CARDs and other
6. Added tantalum capacitor 220uF/10V to ISPOUT
7. R48(13k/1%) changed to 6.8k/1% so there would be 1A of current
on USB1; USB2 still gets 523mA maximum
G
1. Added a 220uF/tant to SATA PWR
2. C216 changed from 100n to 22uF/6.3V, this improves hard-disk
switching on
3. Update of all component libraries. HDMI connector is changed to
a new package.
4. Now not placing ESD protection buffers due to hardware
difficulties with their placement
H (unreleased)
1. Changed the LAN part of the design, added two capactiors
1nF/2kV/X7R/1206, and 1nF/2kV/X7R/1206_or_1M, also the matrix is
now 0402 with 49.9 ohm at 1%.
2. Major polygon changes.
3. Removed HDMI protection circuit(RCLAMP0524P becomes NA).
4. Preparation for memory changes from MEM4G16D3EABG-125 to
K4B4G1646D-BCK0.
5. Position of C95 and C96 slightly adjusted, so that they are not
under GPIO-1 and LAN. USB_OTG polygon changed. USB_HOST polygon
adjusted. Removed few viases.
6. Added few more vias for the VCC.
7. Improved white print. Year and revision updated. Web-site
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