DS1086 Datasheet, PDF (5/14 Pages) Dallas Semiconductor – DS1086 Spread-Spectrum EconOscillator

DS1086 Spread-Spectrum EconOscillator
AC ELECTRICAL CHARACTERISTICS: 2-WIRE INTERFACE (continued)
(V_CC = 5V ±5%, T_A = 0°C to +70°C.)
PARAMETER
Setup Time for STOP
Capacitive Load for Each Bus
Line
NV Write-Cycle Time
Input Capacitance
SYMBOL
t_SU:STO
CONDITION
Fast mode
Standard mode
C_B
(Note 16)
t_WR
C_I
MIN TYP MAX UNITS
0.6
µs
4.0
400
pF
10
ms
5
pF
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
Note 7:
Note 8:
Note 9:
Note 10:
Note 11:
Note 12:
Note 13:
Note 14:
Note 15:
Note 16:
Note 17:
All voltages are referenced to ground.
DAC and OFFSET register settings must be configured to maintain the master oscillator frequency within this range.
Correct operation of the device is not guaranteed if these limits are exceeded.
This is the absolute accuracy of the master oscillator frequency at the default settings.
This is the change that is observed in master oscillator frequency with changes in voltage from nominal voltage at
T_A = +25°C.
This is the percentage frequency change from the +25°C frequency due to temperature at V_CC = 5V. The maximum tem-
perature change varies with the master oscillator frequency setting. The minimum occurs at the default master oscillator
frequency (f_default). The maximum occurs at the extremes of the master oscillator frequency range (66MHz or 133MHz)
(see Figure 2).
The dither deviation of the master oscillator frequency is unidirectional and lower than the undithered frequency.
The integral nonlinearity of the frequency adjust DAC is a measure of the deviation from a straight line drawn between the
two endpoints of a range. The error is in percentage of the span.
This is true when the prescaler = 1.
Frequency settles faster for small changes in value. During a change, the frequency transitions smoothly from the original
value to the new value.
This indicates the time elapsed between power-up and the output becoming active. An on-chip delay is intentionally
introduced to allow the oscillator to stabilize. t_stab is equivalent to approximately 512 master clock cycles and therefore
depends on the programmed clock frequency.
Output voltage swings can be impaired at high frequencies combined with high output loading.
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.
After this period, the first clock pulse is generated.
A device must internally provide a hold time of at least 300ns for the SDA signal (referred to as the V_{IH MIN} of the SCL sig-
nal) in order to bridge the undefined region of the falling edge of SCL.
The maximum t_HD:DAT need only be met if the device does not stretch the LOW period (t_LOW) of the SCL signal.
C_B—total capacitance of one bus line, timing referenced to 0.9 x V_CC and 0.1 x V_CC.
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.
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