Rainbow Electronics ATR0630 - Manual (Page 25)

25
4920A–GPS–01/06
ATR0630 [Preliminary]
5. Crystals
The ATR0630 only needs a GPS crystal (XTAL), but supports also TCXOs. The reference fre-
quency is 23.104 MHz. By connecting an optional RTC crystal, different power modes are
available. The reference frequency is 32.768 kHz.
5.1 GPS XTAL
Figure 5-1. Application Example Using a GPS Crystal with ESR Typically = 12
Ω
(See Table 5-1 on page 27 )
Figure 5-2. Application Example Using a GPS Crystal With ESR Typically
≠
12
Ω
(See Table 5-2 on page 27 )
Note: The external series resistor R1 has to be selected depending on the typical value of the crystal
ESR. Refer to the application note “ATR0601: Crystal and TXCO Selection”.
X1
27
47 pF
47 pF
82 pF
B2
A2
B3
A1
X
NX
XTO
NXTO
X1
R1
47 pF
47 pF
82 pF
B2
A2
B3
A1
X
NX
XTO
NXTO