SANYO LA7975

Ordering number: EN3994B
Monolithic Linear IC
LA7975
PAL SIF Converter Circuit
for TV and VCR Multi-system
Overview
Package Dimensions
The LA7975 is an IC that converts PAL SIF signals (5.5 MHz,
6 MHz, and 6.5 MHz) to 6 MHz. For the sake of high sound
quality, this IC uses a unique mixer technique to supress
interference from NICAM signals.
unit : mm
3042C-SIP5
[LA7975]
Functions
. Mixer, amplifier, oscillator, oscillator mute
Features
. Resistant to interference by NICAM signals
. Small SIP-5 package
. Wide range of usage voltage (5 V to 12 V)
SANYO : SIP5
Specifications
Maximum Ratings at Ta = 25°C
Parameter
Maximum supply voltage
Maximum feed current
Allowable power dissipation
Symbol
Conditions
VCC max
Ratings
I5 max
3
I4 max
Pd max
Unit
13.2
Ta % 70°C
V
mA
1
mA
200
mW
Operating temperature
Topr
–20 to +70
°C
Storage temperature
Tstg
–40 to +150
°C
Ratings
Unit
Operating Conditions at Ta = 25°C
Parameter
Recommended supply voltage
Operating voltage range
Symbol
VCC
VCC op
Conditions
9
V
5 to 12
V
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73096HA(II)/8282TS No.3994-1/6
LA7975
Operating Characteristics at Ta = 25°C, VCC = 9 V
Parameter
Current drain
Conversion gain
5.5 MHz
6.5 MHz
Symbol
ICC
G5.5
G6.5
6.0 MHz
G6.0
Oscillation level
Maximum output level
Input impedance
Pin voltages
500 kHz level difference
relative to 6 MHz
Maximum input level
Oscillation stop current
Test point
Pin 2
Pin 5
Pin 5
min
5
10
10
typ
6.5
13.5
13.5
max
9
17
17
Unit
mA
dB
dB
Pin 5
18.5
22
25.5
dB
Pin 4
Pin 5
15
109
80
115
Pin 1
Pin 4
Pin 5
2.6
7.6
7.2
36
112
4.8
3
8
7.6
mVp-p
dB/µV
kΩ
V
V
V
OSC leak
Pin 5
30
44
VIN max
I4
Pin 4
VOSC
VO max
Ri
V1
V4
V5
Conditions
80 dB/µV input
80 dB/µV input
80 dB/µV input, Pin 4
grounded with 10 kΩ
5.5 MHz 100 dB/µV input
5.5 MHz input
3.4
8.4
8
dB
90
300
dB/µV
µA
Sample Application Circuit
Oscillator
500 kHz CSB503E5
Murata Industries, Ltd.
1.5 MHz CSA1.500MK2 Murata Industries, Ltd.
500 kHz EFOA500K04S Matsushita Electric, Ltd.
Unit (resistance: Ω, capacitance: F)
No.3994-2/6
LA7975
Reference Example 1
Reference Example 2
Unit (resistance: Ω, capacitance: F)
No.3994-3/6
LA7975
. Pin 1 is the SIF input pin.
The filter in Figure 2 can be connected to the input section
to improve the buzz characteristic.
Figure 3 shows the characteristics for the filter in Figure 2.
If C1 is too small, the buzz characteristic improves for
normal input, but the filter cuts into the sound carrier and the
buzz characteristic deteriorates for the P/S (picture/sound
carrier) ratio.
Use C1 6 20 pF to 47 pF.
Filter characteristic
Figure 1
Attenuation – dB
Unit (resistance: Ω, capacitance: F)
From video
output section
Figure 2
Unit (resistance: Ω, capacitance: F)
Frequency – Hz
Figure 3
. Pin 4 is the ceramic oscillator pin.
To make the oscillation waveform approach a sine wave,the
oscillation level is controlled internally.
Oscillation levels of 15 to 80 mVp-p at Pin 4 give the
waveform shown in Figure 5.
To stop oscillation, attach an external resistor as in Figure 6
and switch S1 on.
Here are the conditions for handling multiple systems.
Figure 4
Unit (resistance: Ω)
Figure 5
(Pin 4 oscillation waveform)
Input frequency
5.5 MHz
6.0 MHz
Oscillator
500 kHz
Oscillation stop
6.5 MHz
4.5 MHz
500 kHz
1.5 MHz
Pin 5 output
6 MHz
6 MHz
(pass through)
6 MHz
6 MHz
Figure 7
Figure 8 shows a proposed multi-system
(Multi-system implementation)
Figure 6
Figure 8
Unit (resistance: Ω)
Unit (resistance: Ω)
No.3994-4/6
LA7975
. Pin 5 is the output pin. The output from Pin 5 is input to the
SIF via a 6 MHz bandpass filter (BPF).
When 5.5 MHz is input to Pin 1, the spectrum shown in
Figure 10 is obtained at Pin 5. Even if there is a 5.85 MHz
NICAM signal, the D/U (desirable/undesirable) ratio at Pin 5
increases and the buzz characteristic does not deteriorate.
When 6 MHz is input at Pin 1 and there is a 6.552 MHz
NICAM signal, then 6.552 MHz is mixed with 500 kHz to
make 6.052 MHz. This becomes an interference signal and is
within the band for 6 MHz. Therefore,for 6 MHz input, Pin 4
is grounded with 10 kΩ to stop the oscillation and pass
through the input signal 6 MHz as is.
Figure 9
Unit (resistance: Ω)
Output level
Ceramic BPF
chracteristic
D/U ratio
Figure 10 (5.5 MHz input)
Output level
Interference obtained with LA7975 mixer
6.552 MHz – 500 kHz = 6.052 MHz
D/U
ratio
Figure 11 (6 MHz input)
Reference Characteristic Diagram
* S1 on for 6 MHz
measurement
Unit (resistance: Ω, capacitance: F)
Input level – dB/µV
VO – VCC
Output level, VO – dB/µV
Output level, VO – dB/µV
Input/output characteristic
* Input level 80 dB/µV S1 on
for 6 MHz measurement
Supply voltage, VCC – V
No.3994-5/6
LA7975
Oscillation level – VCC
Oscillation level – mVp-p
Oscillation frequency, f – kHz
f – VCC
Oscillation stop voltage 3.7 V
Supply voltage, VCC – V
Supply voltage, VCC – V
Oscollation level – mVp-p
Oscillation level – R
FET probe
Series resistance, R – Ω
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:
1 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:
2 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 July, 1996. Specifications and information herein are subject to change without notice.
No.3994-6/6