SPT2AF-6PF20PPM Seiko Instruments, SPT2AF-6PF20PPM Datasheet - Page 12

• Manufacturer Part Number: SPT2AF-6PF20PPM
• Description: CRYSTAL 32.768KHZ 6PF SMD
• Manufacturer: Seiko Instruments
• Series: SP-T2A-Fr
• Type: kHz Crystal (Tuning Fork)r

Specifications of SPT2AF-6PF20PPM

• Frequency: 32.768kHz
• Frequency Tolerance: ±20ppm
• Load Capacitance: 6pF
• Operating Mode: Fundamental
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 4-SOJ, 5.50mm pitch
• Size / Dimension: 0.343" L x 0.146" W (8.70mm x 3.70mm)
• Height: 0.098" (2.50mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency Stability: -
• Other names: 728-1004-2

DRIVE LEVEL (DL)
The drive level of a crystal unit is shown by the level of the operating power or the current consumption (see Figures ,
10, and 11).
Operating the crystal unit at an excessive power level will result in the degradation of its characteristics, which may
cause frequency instability or physical failure of the crystal chip.
Design your circuit within absolute maximum drive level.
OSCILLATION FREQUENCY AND LOAD CAPACITANCE (C
The load capacitance (C
represented by an effective equivalent capacitance that is loaded from the oscillation circuit to both ends of the
crystal unit (see Figure 12).
The oscillation frequency varies depending upon the load capacitance of the oscillation circuit. In order to obtain
the desirable frequency accuracy, matching between the load capacitances of the oscillation circuit and the crystal
unit is required. For the use of the crystal unit, match the load capacitances of the oscillation circuit with the load
capacitances of the crystal unit.
12
Cgs
Oscillation Circuit Design Precautions
L
1
Figure 
Cg
C
1
C
0
R
X'tal
Rf
1
Cos
Figure 12
L
Cd
) is a parameter for determining the frequency of the oscillation circuit. The C
Rd
Load capacitance : C
C
Cs=Stray capacitance of
L
Cds
=
the circuit
Cg Cd
Cg+Cd
Cg
+Cs
Figure 10
Rf
L
I
X
Rd
Cd
∆
f/f
(x 10 )
0
120
100
−20
−40
−6
80
60
40
20
0
Crystal unit
Le
Re
5 6
I
X
8
10
Figure 13
Oscillation
circuit
12
Load Capacitance C
14
L
Figure 11
)
16
C
−R
18
L
VT-200-F 32.768kHz
C
L
Drive Level: DL
DL:
Re:
Re:
=12.5pF
20
I
X
Quartz Crystal 2011
:
I
R
Current
Effective resistance
22
X
2
L
1
• Re
(1+C
24
Typ.
0
26
/C
L
28
)
2
(pF)
L
is