DS1085 Datasheet, PDF (18/21 Pages) Dallas Semiconductor – EconOscillator Frequency Synthesizer

DS1085
AC ELECTRICAL CHARACTERISTICS: 2-WIRE INTERFACE
(V_CC = 5V ±5%, T_A = 0°C to +70°C.)
PARAMETER
SYMBOL CONDITION MIN TYP MAX UNITS NOTES
SCL Clock Frequency
f_SCL
Fast mode
Standard mode
400
100
kHz
14
Bus Free Time Between
Fast mode
1.3
a STOP and START
t_BUF
ms
Condition
Standard mode 4.7
Hold Time (Repeated)
START Condition
LOW Period of SCL
HIGH Period of SCL
Setup Time for a
Repeated START
t_HD:STA
Fast mode
Standard mode
0.6
4.0
t_LOW
Fast mode
Standard mode
1.3
4.7
t_HIGH
Fast mode
Standard mode
0.6
4.0
t_SU:STA Fast mode
0.6
Standard mode 4.7
ms
11
ms
ms
ms
Data Hold Time
Data Setup Time
Rise Time of Both SDA
and SCL Signals
Fall Time of Both SDA
and SCL Signals
Setup Time for STOP
Capacitive Load for
each Bus Line
NV Write-Cycle Time
t_HD:DAT
t_SU:DAT
t_R
t_F
t_SU:STO
C_B
t_WR
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
Fast mode
Standard mode
0
0
100
250
20 +
0.1C_B
20 +
0.1C_B
0.6
4.0
0.9
ms
ns
300
1000
ns
300
1000
ns
ms
400
pF
10
ms
12, 13
14
15
15
15
16
NOTES:
1) All voltages are referenced to ground.
2) This is the absolute accuracy of the master oscillator frequency at the default settings.
3) This is the percent frequency change that is observed in output frequency with changes in voltage
from nominal voltage at a temperature of T_A = +25°C.
4) This is the percentage frequency change from the +25°C frequency due to temperature at a nominal
voltage of 5V.
5) The maximum temperature change varies with the master frequency setting. The minimum occurs at
the default master frequency (f_default). The maximums occur at the extremes of the master oscillator
frequency range (66MHz or 133MHz). (See Figure 5 below.)
6) 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.
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.
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