U2740B Datasheet, PDF (8/10 Pages) TEMIC Semiconductors – UHF AM/FM Transmitter

U2740B
Application Circuit (FSK Modulation)
L_osc 2.2 pF
1
2.7 pF
V_S
2
VCO
3
f
R₄
I₄
:128
PA
4
V_Ref
5
I_Ref
6
Power–
up
7
8
XTO
Data
Lock detect
V_S
µC
Figure 7.
I₁₆
R₁₆
16
15
I₁₄
14
I₁₃
13
I_S
12
I₁₁
11
I₁₀
10
9
Loop antenna
R₁₄
10 k Ω
C_10, C₁₁= 4.7 pF
V_S
1 nF
10 nF
R₁₀
12 pF
39 pF
Clock
Power–up
Output power
13327
Principle of Operation (FSK Modulation)
CS
(power-up)
XTO_out
1/fxtal
LD
AM_in
(data/power)
FM_in
(data)
4/fxtal
locked
RFout
Figure 8.
Time
13328
8 (10)
TELEFUNKEN Semiconductors
Preliminary Information
Rev. A3, 24-Feb-97