u2740b ETC-unknow, u2740b Datasheet - Page 8

• Manufacturer Part Number: u2740b
• Description: Am/fm Transmitter
• Manufacturer: ETC-unknow

Application Circuit (FSK Modulation)
Principle of Operation (FSK Modulation)
U2740B
8 (10)
(data/power)
(power-up)
AM_in
XTO_out
V
CS
RFout
S
FM_in
(data)
R
LD
4
1/fxtal
L
osc
2.2 pF
2.7 pF
I
4/fxtal
4
Data
Lock detect
1
2
3
4
5
6
7
8
Preliminary Information
VCO
f
:128
V
S
C
Figure 7.
Figure 8.
XTO
Power–
PA
V
I
up
Ref
Ref
locked
16
15
14
13
12
11
10
9
Clock
Power–up
Output power
I
I
I
I
I
I
39 pF
16
14
13
11
10
S
TELEFUNKEN Semiconductors
12 pF
R
16
1 nF
R
10
C
Loop antenna
10,
C
11
= 4.7 pF
Rev. A3, 24-Feb-97
10 k
R
10 nF
14
13327
Time
V
S
13328