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參數(shù)資料
| 型號： | U4221B-BFP |
| 英文描述： | Radio Controlled Clock Receiver |
| 中文描述： | 電波鐘接收器 |
| 文件頁數(shù)： | 3/12頁 |
| 文件大?。?/td> | 169K |
| 代理商： | U4221B-BFP |
U4221B
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 15-May-96
3 (12)
TCO
The digitized serial signal of the time code transmitter can
be directly decoded by a microcomputer. Details about
the time code format of several transmitters are described
separately.
The output consists of a PNP current source and a NPN
switching transistor T
S
. The guaranteed source output
current is 0.2
μ
A (TCO = high) and the sink current is
1
μ
A (TCO = low). Considering these output currents, the
supply voltage and the switching levels of the following
μ
C, the lowest load resistance is defined. The maximum
load capacitance is 100 pF.
In order to improve the driving capability an external
pull-up resistor can be used. The value of the resistor
should be 4.7 M . To prevent an undefined output vol-
tage in the power-down state of the U4221B, the use of
this pull-up resistor is recommended.
An additional improvement of the driving capability may
be achieved by using a CMOS driver circuit or a NPN
transistor with pull-up resistor connected to the collector
(see figure 2). Using a CMOS driver this circuit must be
connected to V
CCD
.
pin 9
100 k
V
CCD
pin13
TCO
4.7 M
TCO
TS
I
SOURCE
0.2 A
I
SINK
1 A
93 7689 e
Figure 2.
Functional Description
The following description gives you some additional
information and hints in order to facilitate your design, in
particular the problems of the antenna.
Figure 3 shows the principal function of the receiver
(simplified consideration).
res
R
Demodulator
Comparator
CF
A1
93 7521 e
A 2 and
Figure 3.
R
res
: resonant resistance, A1: preamplifier,
A2: amplifier 2, CF: crystal filter
Condition for signal reception:
S/N
≈
4 at comparator input.
Important parameters are:
V
NA
= (4 k T R
res
)
1/2
BW
A
= f
res
/Q
A
input noise voltage density of preamplifier:
V
NA1
: 40 nV/Hz
1/2
(typ)
bandwidth of preamplifier:
BW
A1
: 60 kHz (typ)
bandwidth of crystal filter:
BW
CF
: 16 Hz (typ)
ultimate attenuation of crystal filter:
D
CF
: –35 dB (typ)
whereas:
V
NA
k
T
BW
A
bandwidth of antenna
f
res
resonant frequency
Q
A
Q antenna
antenna noise voltage density
1.38 10
–23
Ws/K (Boltzmann constant)
absolute temperature
The equivalent input noise voltage at the preamplifier in-
put is:
V
N
V
NA
BW
CF
2
V
NA
BW
A
D
CF
2
V
NA1
BW
CF
2
V
NA1
BW
A1
D
CF
2
whereas:
R
res
= 300 k , BW
A
= 1 kHz then V
N
≈
0.4 V
The condition for signal reception is:
S/N
≈
4
sensitivity
≈
1.6 V
That means that the noise voltage of antenna within the
bandwidth of the crystal filter dominates and the
bandwidth of antenna is uncritical for the sensitivity
aspect.
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| U4221B | Radio Controlled Clock Receiver |
| U4222B-CFP | Voltage comparators |
| U4222B | Radio Controlled Clock Receiver |
| U4222B-CFPG1 | Radio Controlled Clock Receiver |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| U4221B-BFPG1 | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:Radio Controlled Clock Receiver |
| U4222B | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:Radio Controlled Clock Receiver |
| U4222B-CFP | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:Radio Controlled Clock Receiver |
| U4222B-CFPG1 | 制造商:TEMIC 制造商全稱:TEMIC Semiconductors 功能描述:Radio Controlled Clock Receiver |
| U4223B | 制造商:ATMEL 制造商全稱:ATMEL Corporation 功能描述:Time-Code Receiver with A/D Converter |
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