Epson RTC-4543SA, RTC-4543SB manual 14

RTC - 4543 SA/SB

11.Reference Data

(1)Example of Frequency-Temperature Characteristics

				θ T = +25 ° C Typ.
		α	=	-0.035 ⋅ 10-6/ ° C 2 Typ.
	⋅ 10-6
	+10
	0
	-10
	-20
	-30
∆ fT	-40
	-50
	-60
Frequency	-70
	-80
	-90
	-100
	-110
	-120
	-130
	-140
	-150
	-50 -40 -30		-20	-10 0 +10 +20 +30 +40 +50 +60 +70 +80 +90+100
					Temperature [°C]

Determining the frequency stability (clock accuracy)

1.The frequency-temperature characteristics can be approximated by the following equation:

∆fT = α (θ T-θX)2

∆ fT	: Frequency deviation at any given temperature
α( /° C2)	: Second-order temperature
	((-0.035±0.005)⋅ 10-6/°C2)

θT(° C) : Highest temperature(+25 ° C± 5 ° C)

θX(° C) : Any given temperature

2.In order to determine the clock accuracy, add in the frequency tolerance and the voltage characteristics.

∆f/f = ∆ f/f0 + ∆ fT + ∆ fv

∆	f/f	: Clock accuracy at any given temperature
		and voltage (frequency stability)
∆	f/f 0	: Frequency accuracy

∆fT : Frequency deviation at any given temperature

∆fv : Frequency deviation at any given voltage

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				(3)Example of Current Consumption-Voltage
Characteristics				Characteristics
Frequency [ ⋅ 10-6]				Current consumpiton[ ∝ A ]
	Conditions					Conditions
						No load, Ta=+25 ° C
	5 V reference Voltage,
+1.0
	Ta=+25 ° C			2.0
0.0	2	3	4	5
-1.0				1.0
-2.0			Supply voltage (VDD)[V]
				0.0	2.0	3.0	4.0	5.0
						Supply voltage (VDD) [V]

Note : This data shows values obtained from a sample lot.

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