|
|
PDF U4311B-FS Data sheet ( Hoja de datos )
| Número de pieza | U4311B-FS | |
| Descripción | Low-Current Superhet Remote Control Receiver | |
| Fabricantes | ATMEL Corporation | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de U4311B-FS (archivo pdf) en la parte inferior de esta página. Total 13 Páginas | ||
|
No Preview Available !
U4311B-FS
Low-Current Superhet Remote Control Receiver
Description
The U4311B-FS is a monolithic integrated circuit in
bipolar technology for low-current UHF remote control
super-heterodyne receivers in amplitude- or frequency-
modulated mode. Typical applications are keyless car
lock-, alarm- or tele-control remote indication systems.
Especially for automotive applications, it supports a
superhet design with about 1 mA total current
consumption as required by the car manufacturers.
Features
D Usable for amplitude- and frequency-modulated
transmission systems
D Extremely low quiescent current (approximately
1 mA in standby mode due to wake-up concept)
D Wide power supply voltage range 3 to 13 V
D Sensitive IF amplifier for 10.7-MHz operating
frequency
Block Diagram
D Logarithmic AM demodulator
D FM demodulator
D Monoflop output to wake up a microcontroller
D High-performance operational amplifier to realize a
data recovering filter
D Non-inverting clamping comparator with amplitude-
depending hysteresis for data regeneration
Wake-up out
VRef = 2.4V 17
VS
19
Bandgap
15
Internal
VRef = 2.4 V
13 3 9 7
Monoflop
RF
Level
Wake up
Non – invert.
clamping
comparator
6 Data out
10.7 MHz
12
IF
amplifier
Quadrature
detector
Operational
amplifier
2
5 11 16
log AM out
–
18 20
FM out
+
1
12648
10.7 MHz
Data
filter
Figure 1. Block diagram
Ordering Information
Extended Type Number
U4311B-MFSG3
Package
SSO20
Remarks
Ambient temperature up to +105°C
Rev. A3, 28-Sep-00
1 (13)
Free Datasheet http://www.datasheet-pdf.com/
1 page  
U4311B-FS
Circuit Description
General Functions
The integrated circuit U4311B-FS includes the following
functions: IF amplifier, FM demodulator, wake-up circuit
with monoflop, operational amplifier, non-inverting data
comparator and voltage regulator.
The 10.7-MHz IF signal from the front end passes the
integrated IF amplifier which operates for amplitude- or
frequency-modulated signals to either a logarithmic AM
demodulator which was implemented to avoid settling-
time problems effected by use of an automatic gain
control system or a quadrature detector for FM. A data-
shaping filter * advantageously realized with the
internal high-performance operational amplifier *
reduces system bandwidth to an optimized compromise
regarding transmission distance and data recognition.
Thus, an optimal bit-error rate can be achieved without
any further active component.
The comparator connected to the output of the filter has
a level-dependent hysteresis and clamps its reference
voltage to the signal’s minimum and maximum peaks as
described later.
Without IF-input signal * in normal mode * only the IF
amplifier and the AM demodulator which operates as a
level-strength indicator are activated. If the level of the IF
signal increases, the entire circuitry is turned on by the
wake-up circuit. This signal is externally available at
Pin 13 and can be used to wake up a microcontroller.
After an adjustable reset time, determined by the mono-
flop time constant, the integrated circuit returns to sleep
mode. In this case, typically 1-mA supply current is re-
quired. An external resistor matched at Pin 3 to ground
blocks the wake-up circuit and enables the complete func-
tionally at lower IF level as can be seen in figures 24
and 27, but supply current increases up to typically
2.8 mA.
Function of the Clamping Comparator
The output signal of the operational amplifier is fed to the
input of the non-inverting comparator and two peak
detectors (Q1 and Q2, figure 3). Their time constants are
distinguished by RC+ and RC–. The component’s value
must be adapted to the transmission code. The time
constant should be large compared to the bit rate for opti-
mized noise and hum suppression. To compensate the
input transistor’s base-emitter-voltage differences, these
two signals are buffered by Q3 and Q4. The mean value
is used as comparator threshold, the difference of the peak
values controls the hysteresis. This clamping comparator
operates as a data regenerator.
VRef
1
2
3 456
78
9
10
12650
Q1 Q3
Op. amp.
+–
to Pin 20
Comparator
Hysteresis
Comp. threshold
Figure 3. Principle function of the clamping comparator
Q4
Q2
Rev. A3, 28-Sep-00
5 (13)
Free Datasheet http://www.datasheet-pdf.com/
5 Page 
U4311B-FS
C2
100 nF
R1
8.2 kW
R15
22 kW
VS
C7
10 mF
R14
22 kW
C8
100 nF
C9
10 mF
20 19 18 17
Filter TOKO A119ACS-19000Z
(L = 2.2 mH, C = 100 pF)
C10
22 pF
16 15
R9
56 W
R10
300 W
R8
100 kW
IF input
C11
10 nF
Wake-up
out
14 13 12
11
R11
10 kW
C1
10 nF
R2
30 kW
C3
1.5 nF
R6
100 kW
R5
100 kW
12345678
C4
100 nF
R12 C12
Wake up
100 kW 220 nF
Data filter
output
22Rk7W
R3
220 kW
C5
220 nF
R13
10 kW
R4
100 kW
Figure 26. FM test circuit with 2-kHz Bessel lowpass data filter
9 10
Comparator
output
C6
220 nF
10
0
–10
–20
–30
–40
–50
–60
–70
0
95 10291
S+N
N
20 40 60 80
IF-input level ( dmBV )
100
Figure 27. Signal-to-noise ratio FM; deviation 22.5 kHz
2.5
C10 = 22 pF
2.0
1.5
1.0 C10 = 47 pF
0.5
0.0
10.3
95 10290
10.5 10.7 10.9
Frequency ( MHz )
11.1
Figure 28. FM-discriminator characteristic
Rev. A3, 28-Sep-00
11 (13)
Free Datasheet http://www.datasheet-pdf.com/
11 Page | ||
| Páginas | Total 13 Páginas | |
| PDF Descargar | [ Datasheet U4311B-FS.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| U4311B-FS | Low-Current Superhet Remote Control Receiver | ATMEL Corporation |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |