AR0238
www.onsemi.com
18
I/O TIMING
By default, the AR0238 launches pixel data, FV, and LV
with the falling edge of PIXCLK. The expectation is that the
user captures DOUT[11:0], FV, and LV using the rising edge
of PIXCLK.
See Figure 13 below and Table 7 on page 18 for I/O
timing (AC) characteristics.
EXTCLK
PIXCLK
Data[11:0]
LINE_VALID/
FRAME_VALID
Pxl_0 Pxl_1 Pxl_2 Pxl_n
t
PFL
t
PLL
t
FP
t
RP
t
F
t
R
90% 90% 90% 90%
10% 10% 10% 10%
t
EXTCLK
t
PD
t
PLH
t
PFH
FRAME_VALID Leads LINE_VALID
by 6 PIXCLKs
FRAME_VALID Trails LINE_VALID
by 6 PIXCLKs
Figure 13. I/O Timing Diagram
Table 7. I/O TIMING CHARACTERISTICS
Symbol Definition Condition Min Typ Max Unit
f
EXTCLK1s
Input Clock Frequency 6 – 48 MHz
t
EXTCLK1
Input Clock Period 20.8 – 166 ns
t
R
Input Clock Rise Time – 3 – ns
t
F
Input Clock Fall Time – 3 – ns
t
RP
Pixclk Rise Time 2 3.5 5 ns
t
FP
Pixclk Fall Time 2 3.5 5 ns
Clock Duty Cycle 45 50 55 %
t
CP
EXTCLK to PIXCLK Propagation Delay Nominal Voltages,
PLL Disabled
10 14 18 ns
f
PIXCLK
PIXCLK Frequency Default, Nominal
Voltages
6 – 74.25 MHz
t
PD
PIXCLK to Data Valid Default, Nominal
Voltages
0 2.5 5 ns
t
PFH
PIXCLK to FV HIGH Default, Nominal
Voltages
−2 3 6 ns
t
PLH
PIXCLK to LV HIGH Default, Nominal
Voltages
−2 3 6 ns
t
PFL
PIXCLK to FV LOW Default, Nominal
Voltages
−2 2.5 6 ns
t
PLL
PIXCLK to LV LOW Default, Nominal
Voltages
−2 2.5 6 ns
C
LOAD
Output Load Capacitance – <10 – pF
C
IN
Input Pin Capacitance – 2.5 – pF
NOTE: I/O timing characteristics are measured under the following conditions:
− Temperature is 25°C ambient
− 10 pF load
− 1.8 V I/O supply voltage
