Datasheet

DS1085L
19 of 21
7) DAC and OFFSET register settings must be configured to maintain the clock frequency within this
range. Correct operation of the device is not guaranteed if these limits are exceeded.
8) Frequency settles faster for small charges in value. During a change, the frequency changes smoothly
from the original value to the new value.
9) This indicates the time taken between power-up and the outputs becoming active. An on-chip delay is
intentionally introduced to allow the oscillator to stabilize. t
stab
is equivalent to approximately 8000
clock cycles and hence depends on the programmed clock frequency.
10) Output voltage swings can be impaired at high frequencies combined with high-output loading.
11) After this period, the first clock pulse is generated.
12) A device must internally provide a hold time of at least 300ns for the SDA signal (referred to the
V
IH MIN
of the SCL signal) in order to bridge the undefined region of the falling edge of SCL.
13) The maximum t
HD:DAT
need only be met if the device does not stretch the LOW period (t
LOW
) of the
SCL signal.
14) A fast mode device can be used in a standard mode system, but the requirement t
SU:DAT
> 250ns must
then be met. This is automatically the case if the device does not stretch the LOW period of the SCL
signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data
bit to the SDA line at least t
R MAX
+ t
SU:DAT
= 1000ns + 250ns = 1250ns before the SCL line is
released.
15) C
B
—total capacitance of one bus line in picofarads; timing referenced to 0.9V
CC
and 0.1V
CC
.
16) EEPROM write begins after a STOP condition occurs.
17) Typical frequency shift due to aging is ±0.5%. Aging stressing includes Level 1 moisture reflow preconditioning (24hr
+125
°C bake, 168hr 85°C/85%RH moisture soak, and 3 solder reflow passes +240 +0/-5°C peak) followed by 1000hr max
V
CC
biased 125°C HTOL, 1000 temperature cycles at -55°C to +125°C, 96hr 130°C/85%RH/5.5V HAST and 168hr 121°C/2
ATM Steam/Unbiased Autoclave.
Figure 5. MASTER FREQUENCY TEMPERATURE VARIATION
MASTER FREQUENCY TEMPERATURE
VARIATION
-2.00
-1.50
-1.00
-0.50
0.00
0.50
1.00
1.50
2.00
33 41.25 49.5 57.75 66
MAST ER OSCILLATOR FREQUENCY (MHz)
FREQUENCY % CHANGE FROM 25°C