Preamplifier + Power Amplifier
for 1.5 V Headphone Stereos
Overview
The LA4587M is a system IC that includes all of the necessary
functions for a playback set on a single chip, reducing the
number of external components needed.
Functions
.
Stereo preamplifier (supports auto reverse function,
switchable between metal and normal tape)
.
Stereo power amplifier (OCL, mute function)
.
Ripple filter
.
Low boost function (BTL operation in low-frequency range)
.
AMSS (Automatic Music Select System)
.
Power switch
Features
.
Preamplifier has a high open-loop gain (VG
O
= 73 dB).
.
Preamplifier requires no NF capacitor.
.
Virtual ground capacitor can be 1 F or less. (Lower
impedance is achieved by having a V
REF
amplifier built in.)
.
Ripple filter requires no capacitor for preventing oscillation.
.
Powerful output is obtained in low boost output
(Po = 21 mW/V
CC
= 1.2 V, f = 100 Hz).
.
A high-frequency cutoff capacitor is built into the
preamplifier and power amplifier inputs; anti-buzz provision.
Package Dimensions
unit : mm
3102-QFP48D
[LA4587M]
SANYO : QIP48D
Specifications
Maximum Ratings
at Ta = 25 C
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
V
CC
max
3.0
V
Allowable power dissipation
Pd max
635
mW
Operating temperature
Topr
10 to +60
C
Storage temperature
Tstg
40 to +125
C
Allowable
power
dissipation,
Pd
max
-
m
W
Ambient temperature, Ta - C
Ordering number: EN5204A
Monolithic Linear IC
LA4587M
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
13097HA(II)/N3095HA(II) No.5204-1/18
Operating Conditions
at Ta = 25 C
Parameter
Symbol
Conditions
Ratings
Unit
Recommended supply voltage
V
CC
1.5
V
Operating supply voltage range
V
CC
op
0.95 to 2.2
V
Operation Characteristics
at Ta = 25 C, V
CC
= 1.2 V, f = 1 kHz, 0.775 V = 0 dBm,
R
L
= 10 k
(preamplifier), R
L
= 16
(power amplifier)
Parameter
Symbol
Conditions
min
typ
max
Unit
[Preamplifier + Power Amplifier]
Quiescent current
I
CCO
1
Rg = 2.2 k
, Rv = 0
8
15
24
mA
I
CCO
2
When power switch is off
0.1
5
A
Voltage gain (closed)
VG
T
V
O
= 20 dBm, R
V
= 10 k
54
57
60
dB
[Preamplifier]
Voltage gain (open)
VG
0
V
O
= 20 dBm
60
73
dB
Voltage gain (closed)
VG
1
V
O
= 20 dBm
34
35.5
37
dB
VG
2
V
O
= 20 dBm, f = 10 kHz, metal on
25.5
28
30.5
dB
Maximum output voltage
V
O
max
THD = 1 %
100
210
mV
Total harmonic distortion
THD
1
VG = 35.5 dB/NAB, V
O
= 100 mV
0.1
0.5
%
Equivalent input noise voltage
V
NI
Rg = 2.2 k
, BPF: 20 Hz to 20 kHz
1.3
3.0
V
Interchannel crosstalk
CT
1
Rg = 2.2 k
, 1 kHz TUNE, V
O
= 20 dBm
45
56
dB
Interchannel crosstalk between
F and R
CT
2
Rg = 2.2 k
, 1 kHz TUNE, V
O
= 20 dBm
65
78
dB
Ripple rejection ratio
Rr1
Rg = 2.2 k
, Vr = 30 dBm,
fr = 100 Hz, 100 Hz TUNE
45
52
dB
[Low Boost + Power Amplifier]
Voltage gain (closed)
VG
3
V
O
= 20 dBm
20.5
23
25.5
dB
VG
4
V
O
= 20 dBm, L.B. = on
20.5
23
25.5
dB
VG
5
V
O
= 20 dBm, L.B. = on, f = 10 kHz
24.5
27.5
30.5
dB
VG
6
V
O
= 20 dBm, L.B. = on, f = 100 Hz
30
34
38
dB
Output power
P
O1
THD = 10 %
5
9
mW
P
O2
THD = 10 %, f = 100 Hz, L.B. = on
13
21
mW
Total harmonic distortion
THD
2
P
O
= 1 mW
0.5
1.5
%
Interchannel crosstalk
CT
3
V
O
= 20 dBm, R
V
= 0
38
43
dB
Output noise voltage
V
NO
R
V
= 0
, BPF: 20 Hz to 20 kHz
35
48
V
Ripple rejection ratio
Rr
2
R
V
= 0
, Vr = 30 dBm,
fr = 100 Hz, 100 Hz TUNE
50
74
dB
Output mute voltage
V
M
V
IN
= 30 dBm, 1 KHz TUNE, mute on
85
dBm
Input resistance
Ri
8
10
12
k
Voltage gain difference
VG
3
0
+1.5
dB
[Ripple Filter ]
Ripple rejection ratio
Rr
3
fr = 100 Hz, Vr = 30 dBm, V
CC
= 1.0 V,
I
RF
= 25 mA, 2SB1295, h
FE
6 rank used
33
39
dB
Output voltage
V
RF
V
CC
= 1.0 V, I
RF
= 25 mA
0.89
0.93
V
[AMSS]
Operating output voltage
V
OAMSS
Preout voltage when AMSS V
O
= 0.6 Vp-p
Pin 34 is short-circuited through 270 k
.
1.80
2.55
3.60
mV
Note: L.B. = Low boost
LA4587M
No.5204-2/18
Block Diagram
Test Circuit Diagram
Unit (resistance:
)
Unit (resistance:
, capacitance: F)
LA4587M
No.5204-3/18
Sample Application Circuit
Note 1: Transistors equivalent to the 2SB1295 with h
FE
6 rank and upward are recommended.
Note 2: C18, C23, and C26 are oscillation prevention capacitors; a polyester film or ceramic capacitor (which can guarantee the
specified capacitance at operating temperatures) is recommended.
Unit (resistance:
, capacitance: F)
LA4587M
No.5204-4/18
Pin Functions
Unit (resistance:
, capacitance: F)
* Pin voltage is when V
CC
= 1.2 V
Pin No.
Pin name
Pin voltage
[V]
Internal equivalent circuit
Remarks
45
R.F OUT
1.13
2
7
13
POWER OUT1
POWER OUTC
POWER OUT2
0.6
c
A 160
resistor is connected
between individual outputs
(between pins 2 and 7, and
between pins 13 and 7).
3
9
12
POWER NF REF1
POWER NF REFC
POWER NF REF2
0.75
c
Each power NF connection
4
8
11
POWER NF1
POWER NFC
POWER NF2
0.75
c
Each power NF connection.
5
10
POWER H.P1
POWER H.P2
0.75
c
Grounded to V
REF
through a
1 k
resistor when low boost
is on (pin 41: floating).
14
L.P2
0.75
c
Low boost secondary LP
connection.
Continued on next page.
LA4587M
No.5204-5/18
Continued from preceding page.
Unit (resistance:
, capacitance: F)
Pin No.
Pin name
Pin voltage
[V]
Internal equivalent circuit
Remarks
15
Low Boost NF
0.75
c
Low boost amplifier NF
connection.
16
18
POWER IN2
POWER IN1
0.75
c
Each power input connection.
c
The input resistance is
10 k
.
c
An anti-buzz capacitor is built
in.
17
L.P1
0.75
c
Low boost primary LP.
connection.
19
20
NFC2
NFC1
0.75
21
28
PRE NF1
PRE NF2
0.75
c
Each preamplifier NF
connection.
c
NF requires no capacitor.
22
27
PRE OUT1
PRE OUT2
0.45
c
200 k
is connected
between each output pin and
NF pin.
Continued on next page.
LA4587M
No.5204-6/18
Continued from preceding page.
Unit (resistance:
, capacitance: F)
Pin No.
Pin name
Pin voltage
[V]
Internal equivalent circuit
Remarks
23
26
METAL1
METAL2
0
c
Connected to GND through
3.9 k
in metal on mode (pin
40: floating)
24
25
AMSS IN1
AMSS IN2
0.75
c
AMSS inverting input
connection.
c
An external input resistor is
required.
29
30
31
32
PRE REV IN1
PRE REV IN2
PRE FWD IN2
PRE FWD IN1
0.75
b
Pins 29 and 30 turn on in
REV mode (pin 39: GND).
c
Pins 31 and 32 turn on in
FWD mode (pin 39: floating)
c
When not using the head, a
bias resistor (2.2 k
) is
required between these pins
and V
REF
(pin 33).
c
An anti-buzz capacitor is built
in.
33
V
REF
0.75
c
V
REF
amplifier output. Low
impedance is achieved due
to the output resistor (ro =
10
).
c
Inflow/outflow current:
200 A max.
34
REF
0.75
c
The V
REF
amplifier is
referenced hereto.
36
AMSS OUT
c
Outputs a pulse waveform in
accordance with the AMSS
IN (pins 24 and 25) input
level.
Continued on next page.
LA4587M
No.5204-7/18
Continued from preceding page.
Unit (resistance:
, capacitance: F)
Pin No.
Pin name
Pin voltage
[V]
Internal equivalent circuit
Remarks
37
41
POWER MUTE SW
Low Boost SW
c
When pin 37 is grounded,
mute is on.
c
When pin 41 is floating, low
boost is on.
38
POWER SW
c
Power on when grounded.
39
40
FWD/REV SW
METAL SW
c
When pin 39 is floating: FWD
mode; when grounded: REV
mode.
c
When pin 40 is in FL mode:
metal on.
44
R.F REF
1.13
c
RF is referenced hereto. An
external capacitor can be
used to vary RF SVRR.
46
R.F BASE
0.5
c
Used for external PNP
transistor base drive.
LA4587M
No.5204-8/18
Description of External Components
.
C
1
(1.0 to 10 F):
V
REF
amplifier is referenced to this decoupling capacitor.
The V
REF
SVRR depends on the value of this capacitor.
Note that if the capacitance is reduced, the SVRR worsens.
.
C
2
, C
10
:
Playback preamplifier EQ constant.
.
C
3
, C
9
(0.47 to 3.3 F):
Preamplifier output capacitor.
.
C
4
, C
8
:
AMSS input HPF capacitor.
.
C
5
, C
7
:
EQ constant for metal (built-in resistance 3.9 k
15%).
.
C
6
(0.1 to 22 F):
V
REF
decoupling capacitor.
For high-frequency noise rejection.
.
C
11
, C
12
(3.3 to 10 F):
NFC decoupling capacitor.
Note that if the capacitance is reduced, the preamplifier low-frequency gain decreases.
.
C
13
, C
15
(1.0 to 3.3 F):
Power amplifier input capacitor (Input resistance: 10 k
).
.
C
14
, C
17
:
Capacitor for low boost LPF.
The low boost gain depends on the capacitance.
.
C
16
(1.0 to 4.7 F):
Boost amplifier NF capacitator.
Note that if the capacitance is reduced, the low boost low-frequency gain decreases.
.
C
18
, C
23
, C
26
(0.1 to 1.0 F):
Oscillation blocking capacitator.
.
C
19
, C
22
, C
25
(3.3 to 10 F):
Power amplifier NF capacitor.
Note that if the capacitance is reduced, the power amplifier low-frequency gain decreases.
.
C
20
, C
24
:
Bass high boost capacitor.
The high gain depends on the capacitance.
.
C
21
(100 to 2200 pF):
Oscillation blocking capacitator.
.
C
29
(4.7 to 10 F):
RF output decoupling capacitor. (Also serves as the power supply capacitor and the
oscillation blocking capacitor.)
.
C
28
(22 to 220 F):
Power supply capacitor.
.
C
30
(2.2 to 10 F):
RF is referenced to this LPF capacitor.
The RF SVRR depends on the capacitance.
.
C
31
, C
32
(0.047 to 0.22 F):
Switching circuit smoothing capacitor. Must be adjusted according to the set timing.
.
R
1
, R
10
:
For preamplifier gain adjustment.
.
R
2
, R
9
:
Playback preamplifier EQ constant.
.
R
3
, R
8
:
EQ constant for metal.
.
R
4
, R
7
:
10 k
volume control.
.
R
5
, R
6
:
For AMSS gain adjustment and HPF.
.
R
11
, R
12
, R
13
:
For oscillation blocking.
.
R
14
, R
15
(100 to 430 k
):
For switching circuit smoothing (discharge resistors).
LA4587M
No.5204-9/18
Operation Descprition
.
Low boost system
.
Note on low boost
The signals that are applied to each power input are mixed and then passed through a two-stage LPF. Because the signal levels
are attenuated by the LPF, level compensation is accomplished by amplifying the signals through a low boost amplifier located
in between. The phase of signals that pass through the secondary LPF is inverted relative to the input signal; these signals are
then input to each power amplifier.
.
Note on channels 1 and 2
The positive phase signals that were input from the positive (``+'') input pins and the reverse phase signals that were input from
the negative (``'') input pins and then were passed through the secondary LPF are all input, amplified, and then output.
.
Note on the common amplifier
The phase of the signals that passed through the secondary LPF is inverted by the inverting amplifier; the signals (with reversed
phases relative to channels 1 and 2) are then input to the negative (``'') inputs. The positive (``+'') input signals are grounded
to V
REF
, amplified by the inverting amplifier and then output.
The phase of the channel 1 and 2 amplifier outputs and the common amplifier outputs are made to oscillate with inverted
phases, making it possible to obtain the dynamic range efficiently.
Low-frequency region amplification: 12 dB/oct, high-frequency region amplification: 6 dB/oct.
Phase 90
Phase 180
LA4587M
No.5204-10/18
Sample Application Circuits for Low Boost Switching
In the above circuits, MID and MAX are switched by changing the gain of the boost amplifier.
The AMSS comparator
Block Diagram
Sample 1
Sample 2
LA4587M
No.5204-11/18
Operation Description
.
The input amplifiers are inverting amplifiers. The gain and HPF characteristics can be adjusted through an external C-R
(input impedance).
.
The AMSS comparator outputs pulses for an input waveform that satisfies certain set conditions (frequency and voltage
level).
.
When AMSS is not used, the input pins (pins 24 and 25) are connected to V
REF
(pin 33).
Notes on the ripple filter
.
The RF SVRR can be adjusted by an external capacitor connected to pin 44.
3.3 F
39 dB
4.7 F
42 dB
10 F
47 dB
.
It is recommended that external transistors be equivalent to the 2SB1295 with h
FE
6 rank and upward.
Note on power output
.
The power amplifier output and the common amplifier output are connected by a resistor of approximately 160
.
Notes on power mute
.
Power mute turns off the fixed current that is supplied to the power section.
.
The output DC when power mute is on is the V
REF
electric potential (0.75 V).
.
The output impedance when power mute is on is approximately 10 k
.
Input
Output
LA4587M
No.5204-12/18
SW Pin Equivalent Circuit Diagram
1. Power switch
On when power switch is grounded
I
O
= V
CC
/200 k + V
CC
0.7 V/22 k
Pin 38
V
S
= 100 mV or less
2. Power mute and low boost switch
On when pin 37 power mute is grounded
On in pin 41 low boost switch floating mode
I
O
= 0.1 A or less
V
S
= 80 mV or less
* The discharge resistance for
smoothing is 430 k
max.
3. FWD/REV, METAL switch
REV when pin 39 FWD/REV is grounded
On in pin 40 metal floating mode
I
O
= 7 A or less
V
S
= 0.5 V or less
LA4587M
No.5204-13/18
Quiescent
current,
I
CCO
--m
A
Supply voltage, V
CC
-- V
VG, VG
O
V
CC
On
On
Open
loop
gain,
VG
o
--d
B
Closed
loop
gain,
VG
--
d
B
Frequency, f
i
-- Hz
THD V
O
Preamplifier
DIN AUDIO used
Normal
Metal
Open-loop
gain,
VG
o
--d
B
Closed-loop
gain,
VG
--
d
B
Supply voltage, V
CC
-- V
Interchannel CT - f
i
Preamplifier
T
otal
harmonic
distortion,
THD
--
%
Supply voltage, V
O
-- mV
CT - f
i
between FWD/REV
Preamplifier
Crosstalk,
CT
--
d
B
Frequency, f
i
-- Hz
Preamplifier
used
Crosstalk,
CT
--
d
B
Frequency, f
i
-- Hz
Preamplifier
used
Crosstalk,
CT
--
d
B
Supply voltage, V
CC
-- V
Between FWD/REV
Interchannel CT
Preamplifier
Output
noise
voltage,
V
NO
--
V
Supply voltage, V
CC
-- V
Preamplifier
to
to
VG,VG
O
f
i
CVREF
LA4587M
No.5204-14/18
V
ODC
--%
V
REF
--%
Supply voltage, V
CC
-- V
V
OUT
-- f
i
Preamplifier
Ripple
rejection
ratio,
SVRR
--
d
B
Supply voltage, V
CC
-- V
V
OUT
-- V
CC
Pre + V
REF
FWD/REV
equivalent
Output,
V
OUT
--
dBm
Frequency, f
i
-- Hz
Output,
V
OUT
--
dBm
Supply voltage, V
CC
-- V
V
REF
-- IV
REF
ro
--
Supply voltage, V
CC
-- V
V
O
V
REF
--V
IV
REF
-- A
V
O
Operating
output
voltage,
V
o
AMSS
--
m
V
Pre-output -- Hz
Pre out. = 6 mV
Input H.P.
Input on both channels
Input on one channel
Operating
output
voltage,
V
o
AMSS
--
m
V
Supply voltage, V
CC
-- V
Pre out. = 6 mV
Input on both channels
Input on one channel
V
REF
V
REF
C
VREF
V
REF
C
VREF
V
REF
C
VREF
V
REF
VREF
V
REF
LA4587M
No.5204-15/18
Operating
output
voltage,
V
o
AMSS
--
m
V
Pre-output -- mV
Input on both channels
Input on one channel
Output
ripple
voltage,
V
RFO
--V
Supply voltage, V
CC
-- V
Ripple
rejection
ratio,
SVRR
--
d
B
Supply voltage, V
CC
-- V
I
RFO
Output
ripple
voltage,
V
RFO
--V
Supply voltage, V
CC
-- V
I
RFO
Ripple
rejection
ratio,
SVRR
--
d
B
Output
ripple
voltage,
V
RFO
--V
Output ripple current, IRFO
-- mA
Ripple
rejection
ratio,
SVRR
--
d
B
Output
ripple
voltage,
V
RFO
--V
Output ripple current, IRFO
-- mA
V
RFO
,
Ripple
rejection
ratio,
SVRR
--
d
B
Ripple
rejection
ratio,
SVRR
--
d
B
Frequency, f
R
-- Hz
Output
ripple
voltage,
V
RFO
--V
Ripple voltage, V
R
-- mV
Ripple
rejection
ratio,
SVRR
--
d
B
Input H.P
LA4587M
No.5204-16/18
V
oltage
gain,
VG
--
d
B
Frequency, f
i
-- Hz
V
O
When low boost is on
When low boost is off
Output on both
channels
V
oltage
gain,
VG
--
d
B
Supply voltage, V
CC
-- V
P
O
on
on
on
off
Output on both channels
Output
voltage,
V
O
m
a
x--V
on
Input on both channels
Output
power
,
P
O
--m
W
on
Input on both
channels
Supply voltage, V
CC
-- V
P
O
-- f
i
Output
voltage,
V
O
m
a
x--V
Frequency, f
i
-- Hz
L.B.= on
Input on both channels,
Load on both channels
L.B. + Power
Output
power
,
P
O
--m
W
Frequency, f
i
-- Hz
THD -- f
i
L.B. = on
Input on both chanels,
Load on both channels
V
ODC
--V
Supply voltage, V
CC
-- V
T
otal
harmonic
distortion,
THD
--
%
Frequency, f
i
-- Hz
on
off
Input on both
channels No filter
Supply voltage, V
CC
-- V
V
O
max -- f
i
f
i
V
O
LA4587M
No.5204-17/18
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 January 1997. Specifications and information herein are subject to change without notice.
Crosstalk,
CT
--
d
B
Frequency, f
i
-- Hz
off
on
Output
noise
voltage,
V
NO
--
V
Supply voltage, V
CC
-- V
on
off
Ripple
rejection
ratio,
SVRR
--
d
B
Supply voltage, V
CC
-- V
off
on
f
i
LA4587M
No.5204-18/18
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