Epson RTC-4543SB - Manual (Page 14)

RTC - 4543 SA/SB
Page - 11 MQ - 252 - 03
11. Reference Data
(1) Example of Frequency-Temperature Characteristics
θ
T = +25
°
C Typ.
α
= -0.035
×
10
-6
/
°
C 2 Typ.
Temperature [°C]
-150
-140
-130
-120
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
+10
-50 -40 -30 -20 -10 0 +10 +20 +30 +40 +50 +60 +70 +80 +90+100
F
req
ue
nc
y
fT ∆
× 10 -6
Determining the frequency stability (clock accuracy)
1.The frequency-temperature characteristics can be
approximated by the following equation:
∆
f T =
α
( θ
T - θ
X ) 2
∆ f T : Frequency deviation at any given temperature
α( /° C 2 )
: Second-order temperature
: Highest temperature(+25 ° C ± 5 ° C)
: Any given temperature
θ
T ( ° C)
θ
X ( ° C)
((-0.035 ± 0.005) × 10 -6 / ° C 2 )
2. In order to determine the clock accuracy, add in the
frequency tolerance and the voltage characteristics.
∆
f/f =
∆
f/f 0 +
∆
f T +
∆
fv
∆
f : Clock accuracy at any given temperature
and voltage (frequency stability)
: Frequency accuracy
∆
T
∆
v
: Frequency deviation at any given temperature
: Frequency deviation at any given voltage
/f
∆ f/f
0
f
f
3. Determining the daily error
Daily error =
∆
f/f
×
86400 (seconds)
With error of 11.574
×
10-
6
, the error of the clock is
about one second per day.
(2)Example of Frequency-Voltage
Characteristics
Frequency [ × 10 -6 ]
-1.0
0.0
+1.0
2 3 4 5
Conditions
5 V reference Voltage,
Ta=+25
° C
-2.0 Supply voltage (V DD )[V]
(3)Example of Current Consumption-Voltage
Characteristics
Current consumpiton[ µ A ]
1.0
2.0
2.0 3.0 4.0 5.0
Conditions
No load, Ta=+25 ° C
Supply voltage (V DD ) [V]
0.0
Note : This data shows values obtained from a sample lot.