Part Number: DS90UB948-Q1
Hi ti team,
Condition:
Imax6 8*data+1*Clk LVDS to DS90ub947 through one line to DS90ub948,output 8*data+2*Clk LVDS to Screen,CLK is 52Mhz, Video 1920*720P LVDS(RGB888)
test in temperature from 25C to 80C
Phenomenon: 4pcs out of 100pcs had flash screens once or twice in the process of temperature rise at about 72 degrees or 60degrees. At the same time, ub948 Lock Pin has been falls
Have done some experiments:
1, Replace a new DS90ub948 to test in 80 degrees high temperature will not appear
2, Have changed the Ub947 below Reg#
and Ub948 0x41 has changed the 0x1F, no effect, the phenomenon will still appear.
3, For the main machine ub947 side and the display screen ub948 side test in 80 degrees, the problem is to follow the display screen ub948 side. The main machine ub947 will not appear flash black screen when it is tested in high temperature alone.
4, We have test ub947 input clock jitter and ub948 eye diagram as follows in in 25 degrees
Single Clk jitter data report waveform such as attachment " input clk" , test value 0.017251UI < 0.2UI
Read out Clk jitter data waveform reports such as attachment " input clk-2" , test value is 0.17217UI < 0.2UI
Use differential probe-direct point ub948 to mark two points as follows: output point yellow, register with prepared 0 x 56(3) to 1 Enable
Test results report waveforms such as attachment "data": no eye map at all
Question:
1, Are there any other suggestions for rectification on ub947 or ub948?
2,Show under normal temperature is very good, why the eye diagram that tests out can be very bad, whether test method has a problem
