LA7775M [SANYO]
Wideband FSK Receiver; 宽带FSK接收器
| 型号： | LA7775M |
| 厂家： | 
SANYO SEMICON DEVICE |
| 描述： | Wideband FSK Receiver |
| 文件： | 总5页 (文件大小：77K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Ordering number : EN5736
Monolithic Linear Integrated Circuit
LA7775M
Wideband FSK Receiver
Overview
Package Dimensions
The LA7775M is an FM receiver for CATV or FM
communications equipment. In addition to functions for
FM demodulation (oscillator, mixer, limiting IF amplifier,
and quadrature detection circuits) it also includes on chip
an FSK data shaper circuit, an RF amplifier, and a local
oscillator frequency switching circuit.
unit: mm
3045B-MFP24
[LA7775M]
Functions
• RF amplifier
• Mixer
• Oscillator
• Oscillator switching
• Limiting IF amplifier
• Quadrature detection
• Data shaper
SANYO: MFP24
Features
• Wideband RF input
• On-chip RF amplifier
• On-chip oscillator frequency switching circuit
Specifications
Maximum Ratings at Ta = 25°C
Parameter
Maximum supply voltage
Symbol
Conditions
Ratings
Unit
V
V
CC max
Pd max
Topr
7
350
Allowable power dissipation
Operating temperature
Storage temperature
mW
°C
–20 to +75
–55 to +125
Tstg
°C
Operating Conditions at Ta = 25°C
Parameter
Recommended supply voltage
Operating supply voltage range
Symbol
VCC
Conditions
Ratings
5
Unit
V
VCCop
4.5 to 5.5
40 to 350
V
Input frequency
fin21, fin24
MHz
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
63097HA(OT) No. 5736-1/5
LA7775M
Operating Characteristics at Ta = 25°C (V = 5 V, f = 106.5 MHz, fIF = 10.7 MHz)
CC
o
Ratings
typ
20
Parameter
Symbol
Conditions
Unit
min
max
26
Current drain
ICCO
Ci21
Ri21
Gp
mA
pF
Preamplifier input capacitance
Preamplifier input resistance
Preamplifier voltage gain
Mixer input capacitance
Mixer input resistance
Mixer conversion gain
–3 dB limiting sensitivity
Demodulation output
100 MHz
100 MHz
350 MHz
100 MHz
100 MHz
350 MHz
7
1
kΩ
15
dB
Ci24
Ri24
Gc
7
pF
1
kΩ
25
dB
Vi
∆F = 75 kHz dev, at 1 kHz
∆F = 75 kHz dev, at 1 kHz
10
16
1.65
0.5
dBµ
mVrms
V
Vo
180
250
1.50
SAW switching threshold level
Data output high level
Data output low level
V19TH
V18H
V18L
V2
1.35
4.5
V
V
Oscillator output
117.2 MHz
0.35
Vp-p
Equivalent Circuit Block Diagram and Test Circuit
RF
INPUT
V
0.1 µF
CC
2 kΩ 10 kΩ
LO
SELECT
DATA
470 pF
220 pF
OUTPUT
5 pF
10 kΩ
24
23
22
21
20
19
18
17
16
15
14
13
GND
V
CC
PREAMP
DATA
SHAPER
MIXER
FMDET
330 Ω
OSC
390 Ω
LIM.AMP
1 kΩ
10
510 Ω
RFGND
1
2
3
4
5
6
7
8
9
11
12
6 pF
20 pF
1000 pF
SFE10.7MS2
1 µH
20 pF
V
OSC
OUTPUT
CC
T00078
No. 5736-2/5
LA7775M
Pin Functions
Pin No.
1
Pin
Pin voltage(V)
Notes
Equivalent circuit
RFGND
Oscillator output after the limiting amplifier. This pin is used
when constructing a PLL synthesizer or related circuit. A 1-
kΩ external resistor is required when using this pin.
2
LOOUT
3.3
2
3
100 mA
T00079
3
4
LOCOM
LORES1
1.2
4
5
When pin 19 is low, pin 4 is selected, when high, pin 5 is
selected.
Switching
circuit
19
1.9
0.8
3
5
6
LORES2
RFVCC
T00080
4 pF
1 kΩ 1 kΩ
330 Ω
7
7
IFOUT
4.1
A matching resistor for the SAW filter is built in.
8 pF
0.5 mA
T00081
VCC
8
9
LIMITER
INPUT1
1.5
1.5
1.5
9
10
330 Ω
1kΩ
50kΩ
LIMITER
INPUT2
Insert a 510-Ω resistor between pins 9 and 11 when using
this circuit.
10
11
11
50kΩ
LMITER
BIAS
T00082
VCC
390 Ω
12
LIMITER
OUTPUT
12
4.2
LIMITER AMP
T00083
Continued on next page.
No. 5736-3/5
LA7775M
Continued from preceding page.
Pin No.
Pin
Pin voltage(V)
Notes
Equivalent circuit
13
QUAD
INPUT
4 kΩ
13
4.3
T00084
FILTER
INPUT
14
15
2.5
1.8
15
14
0.7 mA
DET.
OUTPUT
T00085
DATA-
SHAPER
INPUT1
16
17
18
10 kΩ
18
DATA-
SHAPER
INPUT2
16
17
DATA
OUTPUT
T00086
When pin 19 is low, pin 4 is selected, when high, pin 5 is
selected.
19
LOSELECT
19
40 kΩ
1.5 V
T00087
20
21
GND
VCC
RF AMP
INPUT
1.6
0.6
6.7 kΩ
23
22
3.3 kΩ
RF AMP
BIAS
22
23
The optimal collector current is between 1.5 and 2 mA.
1 kΩ
5 kΩ
21
RF AMP
OUTPUT
T00088
2.5 V
3 kΩ
2 kΩ
MIXER
1.5 kΩ
24
MIX INPUT
1.9
24
T00089
No. 5736-4/5
LA7775M
Design Notes
C1
C2
24
1. RF amplifier
This circuit is formed as a two-transistor cascode amplifier and takes an LC tank
circuit as its load. The operating current is set by the external resistor connected to
pin 22. The optimal operating current is between 1.5 and 2 mA. The capacitor
(C2) connected between pins 23 and 24 is related to the tank circuit Q, and must
not be too large.
23
22
21
2. Oscillator circuit
T00090
This is a grounded collector oscillator circuit, and supports using either an LC, a crystal, or a SAW resonator. Care is
required when constructing this circuit, since the input sensitivity may be suppressed if the oscillator circuit output
leaks into the IF limiting amplifier. It is extremely important to use a capacitor (e.g. a ceramic capacitor) with
excellent high-frequency characteristics for the 1000 pF bypass capacitor inserted between the oscillator circuit power
supply pin (pin 6) and the ground pin (pin 1). In addition, this capacitor must be located as close as possible to pins 1
and 6. When forming an oscillator circuit using a SAW resonator, the optimal values for C1 through C3 will vary
with the oscillator frequency. Thus this circuit must be adjusted for optimal
performance. Since the capacitor C3 between pin 3 and ground will be shared if a
circuit that switches between two SAW resonators is used, the difference between
the frequencies must be held to under 10 MHz. If a large frequency difference is
required, design a circuit that also switches the capacitance between pin 3 and
ground.
3
4
5
C1
C2
C3
T00091
3. IF limiting amplifier
This circuit consists of a six-stage direct coupled differential amplifier to which DC feedback is applied. Since an
internal 1-kΩ resistor is built in between the IF input pin (pin 9) and pin 11, the input and output impedance of the
330-Ω IF filter can be matched with an external 510-Ω resistor. No external matching resistor is required for the IF
output (pin 7), since a 330-Ω resistor is built in.
4. Quadrature detection circuit
An external phase shifting circuit is formed from an LC tuning circuit and a ceramic discriminator.
12
13
12
13
390 W
4 kW
T00092
T00093
■ No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace
equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of
which may directly or indirectly cause injury, death or property loss.
■ Anyone purchasing any products described or contained herein for an above-mentioned use shall:
➀ Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and
distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all
damages, cost and expenses associated with such use:
➁ Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on
SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees
jointly or severally.
■ Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for
volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied
regarding its use or any infringements of intellectual property rights or other rights of third parties.
This catalog provides information as of June, 1997. Specifications and information herein are subject to change
without notice.
No. 5736-5/5
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