5075 series
Measurement circuit
Drive Level
30
25
20
VDD
VSS
0.1µF
Crystal
XT
Tektronix CT-6
XTN
VC
Q
Current Probe
IX'tal
15
10
CLOUT = 15pF
VDD = 3.3V
5
0
VDD = 2.5V
2
0.0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
VC [V]
DL = (I ) × Re
X’tal
DL: drive level
I
: current flowing to crystal (RMS value)
Re: crystal effective resistance
X’tal
V
= 2.5V, 3.3V, f
= 27MHz, Ta = R.T.
DD
OUT
Negative Resistance
Frequency [MHz]
25 30 35
Frequency [MHz]
25 30 35
15
20
40
45
15
0
20
40
45
0
VC = 0V
VC = 0V
−200
−200
VC = 1.25V
VC = 2.5V
VC = 1.65V
VC = 3.3V
−400
−600
−800
−400
−600
−800
V
= 2.5V, C0 = 2pF, Ta = R.T.
V
= 3.3V, C0 = 2pF, Ta = R.T.
DD
DD
Measurement circuit
VDD
VSS
C0 = 2pF
0.1µF
Network Analyzer
(Agilent 4396B)
S-Parameter Test Set
(Agilent 85046A)
XT
XTN
VC
Q
Note. "C0" value is set, concerning the actual crystal characteristics connected between XT and XTN. The data is measured with Agilent 4396B using
NPC’s original measurement jig. The values may vary with measurement jig and conditions.
SEIKO NPC CORPORATION —11
NPC [ NIPPON PRECISION CIRCUITS INC ]
