Ordering number : ENN6655
LA1787M
Monolithic Linear IC
Single-Chip Tuner IC
for Car Radios
Overview
The LA1787M integrates all six blocks required in a car radio tuner on a single chip.
http://onsemi.com
Functions
• FM front end
• AM up-conversion
• FM IF
• FM/AM switch
• Noise canceller
• MRC
• Multiple
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
• Improved AM adjacent channel interference characteristics (40 kHz)
• 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.)
• Improved FM separation temperature characteristics
• The LA1787 inherits the block arrangement of the LA1780M and supports pin-compatible designs.
Package Dimensions
unit : mm (typ)
QIP64E(14X14)
1.0
1.6
1.0
48
49
0.8
33
32
0.15
Allowable power dissipation,
Pd max mW
17.2
14.0
0.35
1.6
1.0
Mounted on a 40 x 80 x 1.3 mm
glass epoxy printed circuit board
Independent IC
17.2
14.0
0.8
17
1.0
64
1
16
3.0max
0.1
2.7
15.6
0.8
Ambient temperature, Ta
C
Semiconductor Components Industries, LLC, 2011
January, 2011
72602RM (OT) No. 6655-1/54
LA1787M
Specifications
Maximum Ratings
at Ta = 25°C
Parameter
Maximum supply voltage
Allowable power dissipation
Operating temperature
Storage temperature
Symbol
V
CC
1 max
V
CC
2 max
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
Operating supply voltage range
Symbol
V
CC
V
CC
ST IND
V
CC
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
Operating Characteristics
at Ta = 25°C, V
CC
= 8.0V, in the specified test cricuit for the FM IF input
Ratings
Parameter
Symbol
Conditions
min
60
205
190
–1
typ
94
310
295
0
0.3
75
55
5
15
28
30
1.2
0.6
82
68
10
20
33
40
2.4
1.6
0.3
20
1
0.5
6
33
27
54
54
10.7 MHz, 100 dBµ, unmodulated. The pin 23 output
No input. The pin 24 DC output, unmodulated
50 dBµ. The pin 24 DC output, unmodulated
70 dBµ. The pin 24 DC output, unmodulated
100 dBµ. The pin 24 DC output, unmodulated
100 dBµ. The bandwidth when V33 = 2 V, unmodulated
100 dBµ, 0 dBµ. The pin 33 DC output, unmodulated
130
0.0
0.4
2.0
4.7
150
0.00
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
4.4
15
25
38
max
110
415
380
+1
1
[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
I
CCO
-FM
V
O
-FM
V
O
-FM31
CB
THD-FM mono
S/N-FM IF
AMR IF
Att-1
Muting attenuation
Att-2
Att-3
Separation
Stereo on level
Stereo off level
Main total harmonic distortion
Pilot cancellation
SNC output attenuation
Separation
ST-ON
ST-OFF
THD-Main L
PCAN
AttSNC
AttHCC-1
HCC output attenuation
AttHCC-2
Input limiting voltage
Muting sensitivity
SD sensitivity
IF counter buffer output
Vi-lim
Vi-mute
SD-sen1 FM
SD-sen2 FM
V
IFBUFF-FM
V
SM
FM-1
Signal meter output
V
SM
FM-2
V
SM
FM-3
V
SM
FM-4
Muting bandwidth
Mute drive output
BW-mute
V
MUTE-100
No input,
I40
+
I45
+
I54
+
I59
+
I60
+
I61
10.7 MHz, 100dBµ, 1 kHz, 100%mod, The pin 15 output
10.7 MHz, 100dBµ, 1 kHz, 100%mod, The pin 31 output
The ratio between pins 15 and 16 at 10.7 MHz, 100 dBµ, 1 kHz
10.7 MHz, 100 dBµ, 1 kHz, 100% mod, pin 15
10.7 MHz, 100 dBµ, 1 kHz, 100% mod, pin 15
10.7 MHz, 100 dBµ, 1 kHz, f
m
= 1 kHz, 30% AM, pin 15
10.7 MHz, 100 dBµ, 1 kHz. The pin 15
attenuation when V33 goes from 0 to 2 V
10.7 MHz, 100 dBµ, 1 kHz. The pin 15
attenuation when V33 goes from 0 to 2 V
*1
10.7 MHz, 100 dBµ, 1 kHz. The pin 15
attenuation when V33 goes from 0 to 2 V
*2
10.7 MHz, 100 dBµ, L+R = 90%, pilot = 10%. The pin 15 output
ratio
The pilot modulation such that V26 < 0.5 V
The pilot modulation such that V26 > 3.5 V
10.7 MHz, 100 dBµ, L+R = 90%, pilot = 10%. The pin 15 signal
10.7 MHz, 100 dBµ, pilot = 10%.
The pin 15 signal/the pilot level leakage. DIN audio
10.7 MHz, 100 dBµ, L-R = 90%, pilot = 10%.
V28 = 3 V
→
0.6 V, pin 15
10.7 MHz, 100 dBµ, 10 kHz, L+R = 90%, pilot = 10%.
V29 = 3 V
→
0.6 V, pin 15
10.7 MHz, 100 dBµ, 10 kHz, L+R = 90%,
pilot = 10%. V29 = 3 V
→
0.1 V, pin 15
100 dBµ, 10.7 MHz, 30% modulation. The IF input such
that the input reference output goes down by 3 dB
The IF input level (unmodulated) when V33 = 2 V
The IF input level (unmodulated) (over 100 mV rms)
such that the IF counter buffer output goes on
mA
mVrms
mVrms
dB
%
dB
dB
dB
dB
dB
dB
%
%
%
dB
dB
dB
dB
dBµ
dBµ
dBµ
dBµ
mVrms
V
V
V
V
kHz
V
unit
Continued on next page.
No. 6655-2/54
LA1787M
Continued from preceding page.
Ratings
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
τGATE1
SN
f = 1 kHz, for a 1-µs, 100-mV p-o pulse
The level of a 1 = kHz, 1-µs pulse input that starts
noise canceller operation. Measured at pin 30.
The pulse rejection effect provided by the noise canceller.
For a repeated 1-µs wide pulse, frequency = 10 kHz,
150 mV p-o. The ratio of the FM mode pin 15 output
referenced to the AM mode pin 15 output (effective value)
55
40
µs
mVp-o
V
N
-AGC
V
W
AGC
A.V
V
OSCBUFFFM
83 MHz, unmodulated.
The input such that the pin 2 voltage is 2.0 V or below
83 MHz, unmodulated. The input such that the pin 2
voltage is 2.0 V or below. (When the keyed AGC is set to 4.0 V.)
83 MHz, 80 dBµ, 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
typ
max
unit
NC effect
SN-NC
5
[Multipath Rejection Circuit] MRC input (pin 27)
MRC output
MRC operating level
VMRC
MRC-ON
V24 = 5 V
The pin 32 input level at f = 70 kHz such that
pin 24 goes to 5 V and pin 27 goes to 2 V
2.2
10
2.3
15
2.4
20
V
mVrms
[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
Oscillator buffer output
Wide band AGC sensitivity
S/N-30
V
O
-AM
V
O
-AM31
V
AGC-FOM
S/N-AM
THD-AM
V
SM
AM-1
V
SM
AM-2
V
OSCBUFF AM1
W-AGCsen1
W-AGCsen2
SD sensitivity
IF buffer output
SD-sen1 AM
SD-sen2 AM
V
IFBUFF-AM
1 MHz, 30 dBµ, f
m
= 1 kHz, 30% modulation, pin 15
1 MHz, 74 dBµ, f
m
= 1 kHz, 30% modulation, pin 15
1 MHz, 74 dBµ, f
m
= 1 kHz, 30% modulation, pin 31
1 MHz, 74 dBµ, referenced to the output, the input amplitude
such that the output falls by 10 dB. Pin 15
1 MHz, 74 dBµ, f
m
= 1 kHz, 30% modulation
1 MHz, 74 dBµ, f
m
= 1 kHz, 80% modulation
No input
1 MHz, 130 dBµ, unmodulated
No input, the pin 15 output
1.4 MHz, the input when V46 = 0.7 V
1.4 MHz, the input when V46 = 0.7 V (seek mode)
1 MHz, the ANT input level such that the IF counter output turns on.
1 MHz, the ANT input level such that the SD pin goes to the on state.
1 MHz, 74 dBµ, unmodulated. The pin 23 output
0.0
4.8
185
92
83
24
24
200
20
130
110
51
47
195
175
56
52
0.3
0.2
6
230
98
89
30
30
290
104
95
36
36
1
0.5
7.3
270
230
61
dB
mVrms
mVms
dB
dB
%
V
V
mVrms
dBµ
dBµ
dBµ
dBµ
mVrms
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 200 kΩ.
*
2. When the resistor between pin 58 and ground is 30 kΩ.
No. 6655-3/54
LA1787M
Function List
FM Front End (Equivalent to the Sanyo LA1193)
• Double input type double balanced mixer
• Pin diode drive AGC output
• MOSFET second gate drive AGC output
• Keyed AGC adjustment pin
• Differential IF amplifier
• Wide band AGC sensitivity setting pin, and narrow
band AGC sensitivity setting pin
• Local oscillator
FM IF
• IF limiter amplifier
• S-meter output (also used for AM) 6-stage pickup
• Multipath detection pin (shared FM signal meter)
• Quadrature detection
• AF preamplifier
• AGC output
• Band muting
• Weak input muting
• Soft muting adjustment pin
• Muting attenuation adjustment pin
• IF counter buffer output (also used for AM)
• SD (IF counter buffer on level) adjustment pin
• SD output (active high) (also used for AM)
Noise Canceller
• High-pass filter (first order)
• Delay circuit based low-pass filter (fourth order)
• Noise AGC
• Pilot signal compensation circuit
• Noise sensitivity setting pin
• Function for disabling the noise canceller in AM
mode
Multiplex Functions
• Adjustment-free VCO circuit
• Level follower type pilot canceller circuit
• HCC (high cut control)
• Automatic stereo/mono switching
• VCO oscillation stop function (AM mode)
• Forced monaural
• SNC (stereo noise controller)
• Stereo display pin
• Anti-birdie filter
AM
• Double balanced mixer (1st, 2nd)
• IF amplifier
• Detection
• RF AGC (narrow/wide)
• Pin diode drive pin
• IF AGC
• Signal meter output (also used for FM)
• Local oscillator circuits (first and second)
• Local oscillator buffer output
• IF counter buffer output (also used by the FM IF)
• SD (IF counter buffer on level) adjustment pin
• SD output (active high) (also used for AM)
• Wide AGC
• Detection output frequency characteristics
adjustment pin (low cut, high deemphasis)
• AM stereo buffer
MRC (multipath noise rejection circuit)
AM/FM switching output (linked to the FM V
CC
)
No. 6655-4/54
LA1787M
Operating Characteristics and Symbols Used in the Test Circuit Diagrams
Switches (SW)
Switch on = 1, SW off = 0
There are two switches that use signal transfer.
— SW2: switches between the mixer input and the IF input.
— SW4: switches between noise canceler input and IF output + noise canceler input.
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 83 MHz signal.
Used for FM IF, noise canceler, and MPX testing. Outputs a 10.7 MHz signal. Stereo modulation must be possible.
Used for AM testing. Outputs 1 MHz and 1.4 MHz signals.
Used with the MRC. Can also be used for AF and OSC.
Power supply
V
CC
V
CC
1
V
CC
2
V
CC
3
8V
5V
0.1 V / 0.7 V / 2 V / 4 V
0.1 V / 0.6 V / 2 V
These levels
must be variable.
SD, stereo, seek/stop
Keyed AGC, Mute ATT
HCC, SNC, SASC (MRC)
• Switches
Parameter
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
SW9
SW10
AM/FM switching. The FE V
CC
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 200 kΩ
MUTE ATT 30 kΩ
For pilot cancellation testing
Mute off (pin 33)
ON
FM
FE IF OUT (A)
Conversion gain measurement (A)
AC1 (A)
High-speed SD
STOP
MUTE 200 kΩ
MUTE 30 kΩ
When pilot cancellation is used
MUTE OFF
OFF
AM
AC3 (B)
Other/purposes
Other/purposes
Other/purposes
Seek (IF buffer output)
OFF
OFF
When pilot cancellation is not used
MUTE ON
• Trimmers (variable resistors)
VR1
VR2
Separation adjustment
Pilot cancellation adjustment
Test Points
• 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
• 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 (10.7 MHz)
Pin 23 (10.7 MHz/450 kHz)
Pin 15 (AF)
Pin 16 (AF)
No. 6655-5/54
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