ATR0601 Datasheet, PDF (11/17 Pages) ATMEL Corporation – GPS FRONT-END IC

ATR0601 [Preliminary]
Figure 9-5. Recommended IF-filter: Layout versus Schematic
13 14 15 16
Ca
Cb
Lc
Ld
B
Le
Lf
13 14
15 16
Ca
Lc Ld
Cb
Le ^Lf
A
VCC
Note:
Mutual inductance between the four inductors Lc - Lf plays an important role in the IF-filter charac-
teristics. In any design, the layout arrangement shown in Figure 9-5 on page 11 should be
resembled as close as possible. Measures: A = 2.8 mm; B = 1.4 mm; Lc - Lf: Wirewound SMD
inductors, 0603 size. (Please see Table 10-1).
Table 9-1.
Specification of GPS Crystals Appropriate for the Application Example Shown in
Figure 9-1 on page 9
Parameter
Comment
Min. Typ. Max. Units
Frequency Characteristics
Fundamental Frequency
Nominal frequency referenced to
25°C
23.104
MHz
Calibration tolerance
Frequency at 23°C ±2°C
7.0 ±ppm
Frequency deviation
Over operating temperature range
15.0 ±ppm
Temperature range
Operating temperature range
–40.0
+85.0 °C
Electrical
Load capacitance (CL)
18.5
19.5
pF
Equivalent Series Resistance (ESR)
Fundamental
Specification
7
12
23
Ω
Table 9-2.
Specification of GPS Crystals Appropriate for the Application Example Shown in
Figure 9-2 on page 9
Parameter
Comment
Min. Typ. Max. Units
Equivalent Series Resistance (ESR)
Fundamental
Specification
7
40
Ω
Note: All other parameters as specified in Table 9-1.
11
4866A–GPS–08/05