U2740B Datasheet, PDF (7/10 Pages) TEMIC Semiconductors – UHF AM/FM Transmitter

U2740B
Application Circuit (ASK 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
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
V_S
Lock detect
µC
Clock
Power–up
Data
13325
Figure 5.
Principle of Operation (ASK Modulation)
CS
(power-up)
XTO_out
1/fxtal
LD
AM_in
(data/power)
4/fxtal
locked
RFout
Figure 6.
TELEFUNKEN Semiconductors
Rev. A3, 24-Feb-97
Preliminary Information
Time
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