Ordering number : EN6038A
Monolithic Linear IC
LA1781M
Overview
For Car Radios
Single-Chip Tuner IC
The LA1781M integrates all six blocks required in a car radio tuner on a single chip.
Features
•
Improved noise reduction methods
The FM front end provides excellent 3-signal characteristics equivalent to those of the LA1193M.
Superlative listenability due to improved medium and weak field noise canceller characteristics.
Improved separation characteristics.
Anti-birdie filter.
Improved AM and FM thermal characteristics.
Excellent FM signal meter linearity.
Modified N.C. circuit for improved noise rejection.
•
Double conversion AM tuner (up conversion)
Reduces the number of external components required as compared to earlier double conversion tuners, in particular,
no crystal is required (when used in conjunction with the LC72144).
•
Sample-to-sample variation reduction circuit built into the FM IF circuit.
(Fixed resistors are used for the SD, keyed AGC, mute on adjustment, ATT, SNC, and HCC functions.)
•
The LA1781 inherits the block arrangement of the LA1780M and supports pin-compatible designs.
Functions
•
FM front end
•
Multiplex
•
FM IF
•
AM up-conversion
•
Noise canceller
•
FM/AM switch
•
MRC
Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to
"standard application", intended for the use as general electronics equipment (home appliances, AV equipment,
communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be
intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace
instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety
equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case
of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee
thereof. If you should intend to use our products for applications outside the standard applications of our
customer who is considering such use and/or outside the scope of our intended standard applications, please
consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our
customer shall be solely responsible for the use.
Specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein stipulate
the performance, characteristics, and functions of the described products in the independent state, and are not
guarantees of the performance, characteristics, and functions of the described products as mounted in the
customer
'
s products or equipment. To verify symptoms and states that cannot be evaluated in an independent
device, the customer should always evaluate and test devices mounted in the customer
'
s products or
equipment.
71509 SY PC/32301TN (OT) No.6038-1/48
LA1781M
Specifications
Maximum Ratings
at Ta = 25°C
Parameter
Maximum supply voltage
Symbol
VCC1 max
VCC2 max
Allowable power dissipation
Operating temperature
Storage temperature
Pd max
Topr
Tstg
Pins 6, 40, and 61
Pins 7, 45, 54, 59, and 60
Ta
≤
55°C
Conditions
Ratings
9
12
950
-40 to +85
-40 to +150
Unit
V
V
mW
°C
°C
Operating Conditions
at Ta = 25°C
Parameter
Recommended supply voltage
Symbol
VCC
VCCST IND
Operating supply voltage range
VCC op
Conditions
Pins 6, 7, 40, 45, 54, 59, 60, and 61
Pin 26
Ratings
8
5
7.5 to 9.0
Unit
V
V
V
Electrical Characteristics
at Ta = 25°C, VCC = 8V, in the specified test circuit for the FM IF input
Parameter
Symbol
Conditions
min
FM characteristics
At the FM IF input
Current drain
Demodulation output
Pin 31 demodulation output
Channel balance
Total harmonic distortion
Signal-to-noise ratio : IF
AM suppression ratio: IF
Muting attenuation
ICCO-FM
VO-FM
VO-FM31
CB
THD-FM mono
S/N-FM IF
AMR IF
Att-1
Att-2
Att-3
Separation
Stereo on level
Stereo off level
Main total harmonic distortion
Pilot cancellation
SNC output attenuation
HCC output attenuation
Sep
ST-ON
ST-OFF
THD-Main L
PCAN
AttSNC
AttHCC-1
AttHCC-2
Input limiting voltage
Muting sensitivity
SD sensitivity
VIN-LIM
VIN-MUTE
SD-sen1 FM
SD-sen2 FM
IF counter buffer output
Signal meter output
VIFBUFF-FM
VSMFM-1
VSMFM-2
VSMFM-3
VSMFM-4
Muting bandwidth
Mute drive output
BW-MUTE
VMUTE-100
10.7MHz, 100dBμ, unmodulated. The pin 23 output
No input. The pin 24 DC output, unmodulated
50dBμ. The pin 24 DC output, unmodulated
70dBμ. The pin 24 DC output, unmodulated
100dBμ. The pin 24 DC output, unmodulated
100dBμ. The bandwidth when V33 = 2V, unmodulated
100dBμ, 0dBμ. The pin 33 DC output, unmodulated
No input, I40 + I45 + I54 + I59 + I60 + I61
10.7MHz, 100dBμ, 1kHz, 100%mod, The pin 15 output
10.7MHz, 100dBμ, 1kHz, 100%mod, The pin 31 output
The ratio between pins 15 and 16 at 10.7MHz, 100dBμ, 1kHz
10.7MHz, 100dBμ, 1kHz, 100% mod, pin 15
10.7MHz, 100dBμ, 1kHz, 100% mod, pin 15
10.7MHz, 100dBμ, 1kHz, fm = 1kHz, 30% AM, pin 15
10.7MHz, 100 dBμ, 1kHz. The pin 15
attenuation when V33 goes from 0 to 2V
10.7MHz, 100 dBμ, 1kHz. The pin 15
attenuation when V33 goes from 0 to 2V*
1
10.7MHz, 100 dBμ, 1kHz. The pin 15
attenuation when V33 goes from 0 to 2V*
2
10.7MHz, 100dBμ, L + R = 90%, pilot = 10%. The pin 15 output
ratio
The pilot modulation such that V26
<
0.5V
The pilot modulation such that V26
>
3.5V
10.7MHz, 100dBμ, L + R = 90%, pilot = 10%. The pin 15 signal
10.7MHz, 100dBμ, pilot = 10%.
The pin 15 signal/the pilot level leakage. DIN audio
10.7MHz, 100dBμ, L - R = 90%, pilot = 10%.
V28 = 3V
→
0.6V, pin 15
10.7MHz, 100dBμ, 10kHz, L + R = 90%, pilot = 10%.
V29 = 3V
→
0.6V, pin 15
10.7MHz, 100dBμ, 10kHz, L + R = 90%, pilot = 10%.
V29 = 3V
→
0.1V, pin 15
100dBμ, 10.7MHz, 30% modulation. The IF input such that the
input reference output goes down by 3dB
The IF input level (unmodulated) when V33 = 2V
The IF input level (unmodulated) (over 100mV rms)
such that the IF counter buffer output goes on
20
1
0.5
6
33
27
54
54
130
0.0
0.4
2.0
4.7
150
0.00
2.1
1.2
4.1
3.1
0.3
30
5
4.5
10
40
35
62
62
200
0.1
1.0
2.7
5.5
220
0.03
9
8.5
14
47
43
70
70
270
0.3
1.5
3.5
6.2
290
0.20
1.2
6.5
%
%
%
dB
dB
dB
dB
dBμ
dBμ
dBμ
dBμ
mVrms
V
V
V
V
kHz
V
75
55
5
15
28
30
60
205
190
-1
94
310
295
0
0.3
82
68
10
20
33
40
15
25
38
110
415
380
+1
1.0
mA
mVrms
mVrms
dB
%
dB
dB
dB
dB
dB
dB
Ratings
typ
max
Unit
Continued on next page.
No.6038-2/48
LA1781M
Continued from preceding page.
Parameter
FM FE Mixer input
N-AGC on input
W-AGC on input
Conversion gain
Oscillator buffer output
NC Block
NC input (pin 30)
Gate time
Noise sensitivity
NC effect
TGATE
SN
SN-NC
f = 1kHz, for a 1μs, 100-mVp-o pulse
The level of a 1kHz, 1μs pulse input that starts
noise canceller operation. Measured at pin 30.
The pulse rejection effect provided by the noise canceller.
For a repeated 1μs wide pulse, frequency = 10kHz,
150mVp-o. The ratio of the FM mode pin 15 output
referenced to the AM mode pin 15 output (effective value)
Multipath rejection circuit
MRC input (pin 27)
MRC output
MRC operating level
VMRC
MRC-ON
V24 = 5V
The pin 32 input level at f = 70kHz such that
pin 24 goes to 5V and pin 27 goes to 2V
2.2
10
2.3
15
2.4
20
V
mVrms
5
55
40
μs
mVp-o
VNAGC
VWAGC
A. V
VOSCBUFF-FM
83MHz, unmodulated.
The input such that the pin 2 voltage is 2.0V or below
83MHz, unmodulated. The input such that the pin 2
voltage is 2.0V or below. (When the keyed AGC is set to 4.0V.)
83MHz, 80dBμ, unmodulated. The FE CF output
No input
81
104
19
85
88
110
30
110
95
116
48
165
dBμ
dBμ
mVrms
mVrms
Symbol
Conditions
min
Ratings
typ
max
Unit
AM characteristics
AM ANT input
Practical sensitivity
Detector output
Pin 31 detector output
AGC F.O.M.
Signal-to-noise ratio
Total harmonic distortion
Signal meter output
S/N-30
VO-AM
VO-AM31
VAGC-FOM
S/N-AM
THD-AM
VSMAM-1
VSMAM-2
Oscillator buffer output
Wide band AGC sensitivity
1MHz, 30dBμ, fm = 1kHz, 30% modulation, pin 15
1MHz, 74dBμ, fm = 1kHz, 30% modulation, pin 15
1MHz, 74dBμ, fm = 1kHz, 30% modulation, pin 31
1MHz, 74dBμ, referenced to the output, the input amplitude
such that the output falls by 10dB. Pin 15
1MHz, 74dBμ, fm = 1kHz, 30% modulation
1MHz, 74dBμ, fm = 1kHz, 80% modulation
No input
1MHz, 130dBμ, unmodulated
0.0
3.5
185
92
83
24
24
200
20
130
110
59
47
195
175
64
52
0.3
0.2
4.4
230
98
89
30
30
290
104
95
36
36
1
0.5
6.1
270
230
69
dB
mVrms
mVrms
dB
dB
%
V
V
mVrms
dBμ
dBμ
dBμ
dBμ
mVrms
VOSCBUFF-AM1 No input, the pin 15 output
W-AGCsen1
W-AGCsen2
1.4MHz, the input when V46 = 0.7V
1.4MHz, the input when V46 = 0.7V (seek mode)
1MHz, the ANT input level such that the IF counter output turns
on.
SD-sen2AM
1MHz, the ANT input level such that the SD pin goes to the on
state.
1MHz, 74dBμ, unmodulated. The pin 23 output
SD sensitivity
SD-sen1AM
IF buffer output
VIFBUFF-AM
Note : These measurements must be made using the either the IC-51-0644-824 or KS8277 IC socket (manufactured by Yamaichi Electronics).
*1. When the resistor between pin 58 and ground is 200kΩ.
*2. When the resistor between pin 58 and ground is 30kΩ.
No.6038-3/48
LA1781M
Package Dimensions
unit : mm (typ)
3159A
Allowable power dissipation, Pd max -- mW
17.2
14.0
48
49
33
32
1000
950
900
800
700
600
500
400
300
200
100
0
--40
--20
0
20
40
60
80
100
Pd max -- Ta
Mounted on a specified board :
40
×
80
×
1.3mm
3
glass epoxy board
Independent IC
14.0
64
1
0.8
(1.0)
(2.7)
17
16
0.35
0.15
17.2
0.8
Ambient temperature, Ta --
°C
3.0max
0.1
SANYO : QIP64E(14X14)
Function List
1. FM Front End (Equivalent to the Sanyo LA1193)
(1) Double input type double balanced mixer
(2) Pin diode drive AGC output
(3) MOSFET second gate drive AGC output
(4) Keyed AGC adjustment pin
(5) Differential IF amplifier
(6) Wide band AGC sensitivity setting pin, and narrow
band AGC sensitivity setting pin
(7) Local oscillator
2. FM IF
(1) IF limiter amplifier
(2) S-meter output (also used for AM) 6-stage pickup
(3) Multipath detection pin (shared FM signal meter)
(4) Quadrature detection
(5) AF preamplifier
(6) AGC output
(7) Band muting
(8) Weak input muting
(9) Soft muting adjustment pin
(10) Muting attenuation adjustment pin
(11) IF counter buffer output (also used for AM)
(12) SD (IF counter buffer on level) adjustment pin
(13) SD output (active high) (also used for AM)
3. Noise Canceller
(1) High-pass filter (first order)
(2) Delay circuit based low-pass filter (fourth order)
(3) Noise AGC
(4) Pilot signal compensation circuit
(5) Noise sensitivity setting pin
(6) Function for disabling the noise canceller in AM
mode
4. Multiplex Functions
(1) Adjustment-free VCO circuit
(2) Level follower type pilot canceller circuit
(3) HCC (high cut control)
(4) Automatic stereo/mono switching
(5) VCO oscillation stop function (AM mode)
(6) Forced monaural
(7) SNC (stereo noise controller)
(8) Stereo display pin
(9) Anti-birdie filter
5. AM
(1) Double balanced mixer (1st, 2nd)
(2) IF amplifier
(3) Detection
(4) RF AGC (narrow/wide)
(5) Pin diode drive pin
(6) IF AGC
(7) Signal meter output (also used for FM)
(8) Local oscillator circuits (first and second)
(9) Local oscillator buffer output
(10) IF counter buffer output (also used by the FM IF)
(11) SD (IF counter buffer on level) adjustment pin
(12) SD output (active high) (also used for AM)
(13) Wide AGC
(14) Detection output frequency characteristics
adjustment pin (low cut, high deemphasis)
(15) AM stereo buffer
6. MRC (multipath noise rejection circuit)
7. AM/FM switching output (linked to the FM VCC)
No.6038-4/48
LA1781M
Operating Characteristics and Symbols Used in the Test Circuit Diagrams
(1) Switches (SW)
Switch on = 1, SW off = 0
There are two switches that use signal transfer.
1) SW2 : switches between the mixer input and the IF input.
2) SW4 : switches between noise canceler input and IF output + noise canceler input.
(2) Types of SG used
PG1 (AC1)
AC2
AC3
AC4
AC5
Used for noise canceler testing. A pulse generator and an AF oscillator are required.
Used for FM front end testing. Outputs an 83MHz signal.
Used for FM IF, noise canceler, and MPX testing. Outputs a 10.7MHz signal. Stereo modulation must be possible.
Used for AM testing. Outputs 1 MHz and 1.4MHz signals.
Used with the MRC. Can also be used for AF and OSC.
(3) Power supply
VCC
VCC1
VCC2
VCC3
8V
5V
0.1V/0.7V/2V/4V
0.1V/0.6V/2V
These levels must be
variable.
SD, stereo, seek/stop
Keyed AGC, Mute ATT
HCC, SNC, SASC (MRC)
(4) (a) Switches
Parameter
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
SW9
SW10
AM/FM switching. The FE VCC is supplied to pin 62.
FM IF switching. Pin 51/FE output
For conversion gain testing
For switching between noise canceler input and IF output + noise
canceler.
High-speed SD
SEEK/STOP (IF BUFF ON/OFF)
MUTE ATT 200kΩ
MUTE ATT 30kΩ
For pilot cancellation testing
Mute off (pin 33)
High-speed SD
STOP
MUTE 200kΩ
MUTE 30kΩ
When pilot cancellation is used
MUTE OFF
Other/purposes
Seek (IF buffer output)
OFF
OFF
When pilot cancellation is not used
MUTE ON
ON
FM
FE IF OUT (A)
Conversion gain measurement (A)
AC1 (A)
OFF
AM
AC3 (B)
Other/purposes
Other/purposes
(b) Trimmers (variable resistors)
VR1
VR2
Separation adjustment
Pilot cancellation adjustment
(5) Test Points
(a) DC voltages
VD1
VD2
VD3
VD4
VD5
VD6
VD7
FM RF AGC voltage
AM/FM SD, AM Tweet, FM stereo indicator
AM/FM S-meter
MRC output
Mute drive output
AM antenna damping voltage
N.C. Gate time
Pin 2
Pin 26
Pin 24
Pin 27
Pin 33
Pin 46
Pin 8
(b) AC voltages
VA1
VA2
VA3
VA4
VA5
AM/FM OSC Buff
First IF output
IF counter buffer
MPX OUT Left ch
MPX OUT Right ch
Pin 4
Pin 53
→
CF
→
pin 51 load level (10.7MHz)
Pin 23 (10.7MHz/450kHz)
Pin 15 (AF)
Pin 16 (AF)
No.6038-5/48
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
