Overview
The LA7357 can be used as a PAL/SECAM
discrimination IC. Since no ceramic resonator or tank
circuit is required, only a small number of external
components are used, and the LA7357 can contribute to
reduced mounting areas and lower system costs.
Package Dimension
unit: mm
3098B-DIP10S
Monolithic Linear IC
Ordering number : EN5654
73097HA(OT) No. 5654-1/6
SANYO: DIP10S
[LA7357]
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
PAL/SECAM Discrimination Circuit for VHS VCRs
LA7357
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
V
CC
max
7.0
V
Allowable power dissipation
Pd max
Ta
65 C
120
mW
Operating temperature
Topr
10 to +65
C
Storage temperature
Tstg
40 to +125
C
Parameter
Symbol
Conditions
Ratings
Unit
Supply voltage
V
CC
5.0
V
Operating voltage range
V
CC
op
4.8 to 5.5
V
Operating Conditions
at Ta = 25C
Specifications
Maximum Ratings
at Ta = 25C
No. 5654-2/6
LA7357
Parameter
Symbol
Conditions
Ratings
Unit
min
typ
max
Current drain
I
CC
1
Pin 5 = ground, pin 7 influx current: T4 output
7.0
10.0
13.0
mA
I
CC
2
Pin 5 = V
CC
, pin 7 influx current: T4 output
7.5
10.5
13.5
mA
The pin 5 voltage when the pin 2 output
appears when slowly raising the voltage
BGP threshold level
BTH
applied to pin 5 from 0 V.
2.2
2.5
2.8
V
The input signal should be 300 mVp-p:
T2 output
The pin 5 voltage when the pin 2 output
appears when slowly lowering the voltage
SYNC threshold level
STH
applied to pin 5 from 5 V.
0.6
0.8
1.0
V
The input signal should be 300 mVp-p:
T2 output
Stipulated as the output ratio when a
Input limiter amplifier gain
LIMG
10 mVp-p amplitude sine wave is input to
9
12
15
dB
pin 1: T2 output
Measure the output amplitude when a
Input limiter amplifier level
LIMD
300 mVp-p amplitude sine wave is input to
150
190
230
mVp-p
pin 1: T2 output
The V1 level when T1 switches from low to
Comparator hysteresis high-level voltage
Comp H
high when slowly raising V1 from 0 V: T1
2.7
3.0
3.3
V
output
The V1 level when T1 switches from high to
Comparator hysteresis low-level voltage
Comp L
low when slowly lowering V1 from 5 V: T1
2.0
2.3
2.6
V
output
DET-OUT output high-level voltage
DETH
With a 2-k
load: T1 output
3.6
4.0
4.4
V
DET-OUT output low-level voltage
DETL
With a 2-k
load: T1 output
0
0.2
0.4
V
Operating Characteristics
at Ta = 25C, V
CC
= 5 V
Switching Conditions
Symbol
Input signal
Input pulse
Applied voltage
Switch states
S1
S2
S3
S4
V1
V2
SW1
SW2
SW3
SW4
SW5
I
CC
1
No signal
No signal
0 V
0 V
Off
Off
Off
Off
Off
I
CC
2
No signal
No signal
5 V
5 V
Off
Off
Off
Off
Off
BTH
Sig.1
No signal1
0 V
0 V
Variable DC level
On
Off
On
Off
Off
STH
No signal
Sig.1
0 V
0 V
Variable DC level
On
Off
On
Off
Off
LIMG
Sig.1
No signal
5 V
0 V
On
Off
Off
Off
Off
LIMD
Sig.1
No signal
5 V
0 V
On
Off
Off
Off
On
Comp H
No signal
No signal
No signal
No signal
Variable DC level
Off
On
Off
Off
On
Comp L
No signal
No signal
No signal
No signal
Variable DC level
Off
On
Off
Off
On
DETH
Sig.2
Sig.1
P2
P1
Off
Off
Off
Off
On
DETL
Sig.3
Sig.1
P2
P1
Off
Off
Off
Off
On
Block Diagram
Test Circuit
No. 5654-3/6
LA7357
Pin No.
Pin
Pin Functions
Equivalent circuit
No. 5654-4/6
LA7357
Pin Functions
1
CHROMA-IN
Chrominance signal input. This pin can handle burst (or unmodulated
carrier for SECAM input) signal amplitudes of between 50 and 800 mVp-p.
2
HPF.MONI
High-pass filter output monitor
To avoid interference between pin 1 and pin 3, this pin should be
connected to V
CC
during normal operation.
3
FILTER
Phase comparator output
This signal is smoothed with an external capacitor.
The smoothed level will be:
2.0 V or lower for PAL
3.5 V or higher for SECAM or MESECAM.
4
GND
5
SYNC+BGP
BGP + SYNC input
The input level is a 1.0- to 2.0-V rising pulse ( ) during the SYNC period,
and a 3.0- to 4.5-V rising pulse ( ) during the BGP period. Note that since
a combined BGP and C.SYNC pulse ( ) is output from the Y/C IC when
the LA7357 is used in combination with a Sanyo single-chip Y/C IC (any
one of the LA7430, LA7435, or LA71520) no external component will be
required on pin 5.
6
DET-ADJ
7
V
CC
Discrimination sensitivity adjustment pin
The discrimination is shifted towards PAL as the pin voltage is increased,
and towards SECAM as the pin voltage is lowered.
This pin is normally left open.
Continued on next page.
No. 5654-5/6
LA7357
Continued from preceding page.
Pin No.
Pin
Pin Functions
Equivalent circuit
8
FSC-IN
PAL fsc (4.43 MHZ) input
This pin can handle inputs with amplitude between about 300 and 800
mVp-p.
9
AFP.MONI
APF output monitor
This pin must be connected to V
CC
to prevent interference between pins 8
and 10.
10
DET-OUT
Discrimination output
This pin outputs a high level (4.2 V) for SECAM or MESECAM inputs, and a
low level (close to 0 V) for PAL inputs.
Test Input Signals and Pulses
No. 5654-6/6
LA7357
fsc sine wave
SECAM color bar signal
PAL color bar signal
This catalog provides information as of July, 1997. Specifications and information herein are subject to change
without notice.
s
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.
s
Anyone purchasing any products described or contained herein for an above-mentioned use shall:
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:
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.
s
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.
PDF 
ZIP