UNISONIC TECHNOLOGIES CO., LTD
LM1875
20W AUDIO POWER AMPLIFIER
DESCRIPTION
The UTC LM1875 is a monolithic power amplifier offering very
low distortion and high quality performance for consumer audio
applications. It delivers 20W into a 4Ω or 8Ω load on
±25V
supplies.
Using an 8Ω load and +30V supplies, over 30W of power may be
delivered. The amplifier is designed to operate with a minimum of
external components. Device overload protection consists of both
internal current limit and thermal shutdown.
The UTC LM1875 design utilizes advanced circuit techniques
and processing to achieve extremely low distortion levels even at
high output power levels. Other outstanding features include high
gain, fast slew rate and a wide power bandwidth, large output
voltage swing, high current capability, and a very wide supply range.
The amplifier is internally compensated and stable for gains of 10 or
greater.
1
LINEAR INTEGRATED CIRCUIT
TO-220-5
1
TO-220B
*Pb-free plating product number: LM1875L
FEATURES
*Up to 30W output power
*Avo typically 90 dB
*Low distortion: 0.015%,1kHz,20W
*Wide power bandwidth: 70kHz
*Protection for AC and DC short circuits to ground
*Thermal protection with parole circuit
*High current capability: 4A
*Wide supply range 16V-60V
*Internal output protection diodes
*94 dB ripple rejection
APPLICATIONS
*High performance audio systems
*Bridge amplifiers
*Stereo phonographs
*Servo amplifiers
*Instrument systems
ORDERING INFORMATION
Order Number
Normal
Lead Free Plating
LM1875-TA5-T
LM1875L-TA5-T
LM1875-TB5-T
LM1875L-TB5-T
L M 1 8 7 5 L -T A5 -T
(1)Packing Type
(2)Package Type
(3)Lead Plating
(1) T: Tube
(2) TA5: TO-220-5, TB5: TO-220B
(3) L: Lead Free Plating Blank: Pb/Sn
,
Package
TO-220-5
TO-220B
Pin Assignment
1
2
3
4
5
+IN -IN -V
EE
OUT V
CC
+IN -IN -V
EE
OUT V
CC
Packing
Tube
Tube
www.unisonic.com.tw
Copyright © 2005 Unisonic Technologies Co., Ltd
1 of 7
QW-R107-019,D
LM1875
ABSOLUTE MAXIMUM RATINGS
(Ta=25
℃
)
PARAMETER
LINEAR INTEGRATED CIRCUIT
SYMBOL
RATING
UNIT
Supply Voltage
V
CC
60
V
Input Voltage
V
IN
-V
EE
~ V
CC
V
Junction Temperature
T
J
+150
℃
Storage Temperature
T
STG
-40 ~ +150
℃
Note Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
ELECTRICAL CHARACTERISTICS
(V
CC
=+25V,-V
EE
=-25V,Ta=25
℃
,R
L
=8
Ω
,Av=20(26dB),fo=1kHz,unless otherwise specified.)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Supply Current
I
CC
P
OUT
=0W
70
100
mA
Output Power(Note)
P
OUT
THD=1%
25
W
P
OUT
=20W,fo=1kHz
0.015
Total Harmonic Distortion
P
OUT
=20W, fo =20kHz
0.05
0.4
THD
%
(Note)
P
OUT
=20W,R
L
=4Ω,fo=1kHz
0.022
P
OUT
=20W,R
L
=4Ω,fo=20kHz
0.07
0.6
Offset Voltage
V
O(OFF)
±1
±15
mV
Input Bias Current
I
I(BIAS)
±0.2
±2
µA
Input Offset Current
I
I(OFF)
0
±0.5
µA
Gain-Bandwidth Product
GB
W
Fo=20kHz
5.5
MHz
Open Loop Gain
Gv
DC
90
dB
V
CC
,1kHz,1 Vrms
52
95
Power Supply Rejection Ratio
RR
dB
V
EE
,1kHz,1 Vrms
52
83
Max Slew Rate
SR
20W,8Ω,70kHz BW
8
V/µs
Current Limit
I
LIMIT
V
OUT
=V
SUPPLY
–10V
3
4
A
Equivalent Input Noise Voltage
eN
Rs=600Ω,CCIR
3
µVrms
Note: Assumes the use of a heat sink having a thermal resistance of 1
℃
/W and no insulator with an Ta=25
℃
.
Because the output limiting circuitry has a negative temperature coefficient, the maximum output power
delivered to a 4Ω load may be slightly reduced when the tab temperature exceeds 55
℃
.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
2 of 7
QW-R107-019,D
LM1875
TYPICAL APPLICATION CIRCUIT
+Vcc
C3
0.1μF
C1
2.2μF
V
IN
R1
1M
R2
22k
2 _
-V
EE
C4
0.1μF
1
+
LINEAR INTEGRATED CIRCUIT
C7 100μF
4Ω~8Ω
+
5
LM1875
3
C6
+ 100μF
4
R5
1
C5
0.22μF
R4
20k
R3 1K
+
C2
22μF
TYPICAL SINGLE SUPPLY OPERATION
R1
22k
+
C2
10μF
R2 +Vcc C4
0.1μF
22k
C1
1.0μF
V
IN
R4
1M
R3
22k
1
+
5
C7
+ 100μF
C6
2200μF
+
4Ω~
8Ω
LM1875
2 _
3
4
R7
1
C5
0.22μF
R6
200k
C3
R5
10μF 10k
+
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3 of 7
QW-R107-019,D
LM1875
TYPICAL CHARACTERISTICS
THD vs Power Output
1.0
Total Harmonic Distortion (%)
0.1
LINEAR INTEGRATED CIRCUIT
THD vs Supply Voltage
Vs=+25V
0.09 P
D
=10W
0.08
0.07
THD(%)
0.06
0.05
0.04
0.03
0.02
0.01
0
20
R
L
=4Ω
R
L
=8Ω
0.1
0.01
0.1
1.0
10
100
50 100 200 500 1K 2K
Frequency (Hz)
5K 10K 20K
Power Output (W)
35
30
Power Output (W)
25
20
15
10
5
0
0
Power Output vs Supply Voltage
R
L
=8Ω
THD=1%
Supply Current (mA)
100
80
60
40
20
0
5
10
15
20
Supply Voltage (+V)
25
30
Supply Current vs Supply Voltage
0
5
10
15
20
25
30
Supply Voltage (±V)
RR vs Frequency
100
90
Device Dissipation (W)
80 POSITIVE SUPPLY
70
RR (dB)
60
50
40
30
20
10
0
20
50 100 200 500 1K 2K
Frequency (Hz)
5K 10K 20K
INPUT REFERRED
R
S
=0
R
L
=4
1 Vrms
NEGATIVE SUPPLY
Device Dissipation vs Ambient Temperature
45
40
35
30
25
20
15
10
5
0
10℃/W HEAT SINK
0
20
40 60 80 100 120 140 160
Ta - Ambient Temperture (℃)
Interface=1℃/W
See Application Hints .
5℃/W
HEAT SINK
INFINITE HEAT SINK
1℃/W HEAT SINK
2℃/W
HEAT SINK
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
4 of 7
QW-R107-019,D
LM1875
TYPICAL CHARACTERISTICS (Cont.)
Power Disipation vs Power Output
50
45
Vs=+30V
50
45
40
35
30
25
20
15
10
5
0
LINEAR INTEGRATED CIRCUIT
Power Disipation vs Power Output
R
L
=8Ω
fo=1kHz
Power Dissipation (W)
35
30
25
20
15
10
5
0
Vs=+25V
Power Dissipation (W)
40
Vs=+30V
Vs=+25V
Vs=+20V
Vs=+15V
R
L
=4Ω
fo=1kHz
0
5
10
15
20
25
30
Vs=+20V
Vs=+15V
0
5
10
15
20
25
30
Power Output (W)
Power Output (W)
I
OUT
vs V
OUT
-Current Limit/
Safe Operating Area Boundary
6
30
25
20
15
Open Loop Gain and Phase vs
Frequency
Output Current (A)
4
180
135
90
45
0
-45
-90
-135
1M
-180
10M
Gain (dB)
2
0
-2
-4
-6
-25 -20 -15 -10 -5
0
5 10 15 20 25
10
5
0
-5
-10
-15
-20
100k
Output Voltage (V)
Frequency (Hz)
Input Bias Current vs Supply Volage
300
T
A
=70℃
Input Bias Current (nA)
250
T
A
=
25
℃
200
150
100
0
T
A
=0℃
0
5
10
Supply Voltage
(+V)
15
20
25
30
* Thermal shutdown with infinite heat sink
**Thermal shutdown with 1℃/ W heat sink
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
5 of 7
QW-R107-019,D
Ohase Lag (Degrees)
嵌入式系统
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