DB315A Datasheet, PDF (5/11 Pages) CML Microcircuits – Low Distortion Sinewave Output

CTCSS Encoder
5
3. External Components
MX315A
MICROPHONE
VOICE BAND
FILTER
SUMMING
AMPLIFIER
TO
MODULATOR
V_SS
X1
1MHz
33pF
4 32 1 56
8
D0 D1 D2 D3 D4 D5
1M
XTAL/CLOCK
9 _{XTAL MX315AJ}
12
TX ENABLE
PTT
11
TX TONE OUT
Figure 2: External Components
R1 Note 1
1M
20%
C1
33pF 20%
X1 Note 2, 3 1MHz 0.19%
Table 2: Recommended External Components
Notes:
1. The 1M resistor is used to bias the internal CMOS inverter into its linear mode. A tolerance of ±20%
is acceptable.
2. “X1” is a parallel resonant crystal. A reference frequency of 1MHz ±0.19% is required to maintain a
tone accuracy within 0.5%.
3. For best results, a crystal oscillator design should drive the clock inverter input with signal levels of at
least 40% of V_DD, peak to peak. Tuning fork crystals generally cannot meet this requirement. To
obtain crystal oscillator design assistance, consult your crystal manufacturer.

1998 MXCOM, INC.
www.mxcom.com tel: [phone] 744 5050 fax: [phone]
Doc. # 20480054.006
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All Trademarks and service marks are held by there respective companies.