Document
TOSHIBA Bipolar Linear Integrated Circuit Silicon Monolithic
TA7376P
Audio Power Amplifier
TA7376P
The TA7376P is dual audio power amplifier for portable products.
Features
· Low operating supply voltage: VCC = 1.8~6V (Ta = 25°C) · Low quiescent current: ICCQ = 5.3mA
(VCC = 4.5V) · Including ripple filter circuit: RR = −42dB
(CRIP = 10µF, fr = 100Hz) · Voltage gain: GV = 39.5dB (typ.) · Very few external parts and small package. (SIP−9pin)
Weight: 0.92g (typ.)
Output Power Table (THD = 10%, f = 1kHz, Stereo, Typ. value)
VCC
3V 4.5V 6V
Load
RL = 32Ω
21mW 56mW 120mW
RL = 16Ω
38mW 100mW 230mW
RL = 8Ω
65mW 180mW 400mW
RL = 4Ω
100mW 300mW
―
Block Diagram
Vin 1 Vin 2
IN1
1
2 NF1 IN2
9
8
NF2
VCC 4 RF
RF 7
CH - 1
OUT1
3
GND
5
CH - 2
OUT2
6
VCC
RL RL
1 2002-10-30
TA7376P
Application Note
1. Input stage The input stage of power amplifier (equivalent circuit) is comprised of a PNP differential pair (Q2 and Q3) preceded by a PNP emitter follower (Q1) which allows DC referencing of the source signal to ground. This eliminates the need for an input coupling condenser. However, in case the brush noise of volume becomes a problem, provide serially a coupling condenser to the input side.
2. Adjustment of voltage gain
The voltage gain is fixed at GV≒40dB by the resistors (R1 and R2) in IC, however, its reduction is possible through adding Rf as shown in Fig.2. In this case, the voltage gain is obtained by the following equation.
GV
≒
20log
R1 + R2 + R1 + Rf
Rf
It is recommended to use this IC with the voltage gain of GV≒30dB or over.
3. Ripple rejection ratio (RR)
If the TA7376P does not have the ripple filter
condenser (CRIP), the ripple rejection ratio is as follow. RR = -25dB (typ.) (CNF = 22µF, fr = 100Hz) RR = -34dB (typ.) (CNF = 100µF, fr = 100Hz)
If the ripple filter condenser is connected to the pin(7), the ripple rejection
ratio is improved as following the DATA (RR-fr).
VCC 4
Vin 1 / 9 GND 5
30 kΩ
Q2 Q3
R2 R1
Q1 Q4
Q5
Fig.1
2/8
NF
Vin 1 / 9
Rf R1
2/8 510 Ω
R2
51 kΩ
Fig.2
VCC
4
4. Pop sound
It must be connected the condenser (CRIP) from pin(7) to GND, if the "Pop" sound is harshness.
In this case, the value is 10µF something.
CRIP
7 RF
1/9
2/8
CNF
Fig.3
2 2002-10-30
5. Phase-compensation The purpose of condenser C1 is to prevent oscillation. These condenser need to be small temperature coefficient and excellent frequency characteristic. So ceramic condenser is unsuitable. Condenser C2 is rather large value than 10µF and GND line is better to short and wide lay-out so that the some common impedance are decreased.
Maximum Ratings (Ta = 25°C)
TA7376P
4
VCC
C2
3/6
OUT GND 5
C1
VCC RL
Characteristic
Symbol
Rating
Unit
Supply voltage Power dissipation Operation temperature Storage temperature
VCC PD (Note) Topr Tstg
8 950 -25~75 -55~150
V mW °C °C
(Note) Derated above Ta = 25°C in the proportion of 7.6mW / °C.
Fig.4
Electrical Characteristics (unless otherwise specified, VCC = 4.5V, f = 1kHz, Rg = 600Ω, RL = 4Ω, Ta = 25°C)
Characteristic Quiescent current
Output power
Total harmonic distortion
Symbol ICCQ
Pout THD
Test Circuit
Test Condition
Min. Typ.
Vin = 0, VCC = 3V
― 4.9
― Vin = 0
― 5.3
Vin = 0, VCC = 6V
― 5.7
VCC = 3V, RL = 4Ω, THD = 10%
84 100
VCC = 3V, RL = 32Ω, THD = 10%
―
21
― VCC = 4.5V, RL = 4Ω, THD = 10% 250 300
VCC = 4.5V, RL = 8Ω, THD = 10% ―
180
VCC = 6V, RL = 8Ω, THD = 10%
― 400
― Pout = 100mW
― 0.11
Voltage gain Output noise voltage
Ripple rejection ratio
Cross talk Input resistance
GV ― Vout = 0.775Vrms
37.5 39.5
Vno ― Rg = 10Ω, BPF = 20Hz~20kHz ― 0.21
CRIP = 10µF, CNF = 22µF RR ― fr = 100Hz, Vr = 0.38Vrms
CRIP = OPEN, CNF = 100µF fr = 100Hz, Vr = 0.38Vrms
― -42 ― -34
CT ― Vout = 0.775 Vrms
― -60
RIN ―
―
― 30
Max. Unit
8.0 10.0 mA 14.0 ― ― ― mW ― ―
1.0 %
41.5 0.7
dB mVrms
-30 dB
―
-40 dB ― kΩ
Quiescent Terminal DC Voltage (VCC = 4.5V, Ta = 25°C, typ. value)
[Unit: V]
Terminal Voltage (V)
1 0.003
2 0.59
3 1.98
4 4.5
56789
0
1.98
1.28
0.59 0.003
3 2002-10-30
Test circuit
Vin 1 Vin 2
22 µF
IN1
1
2 NF1 IN2
9
8
NF2
30 kΩ
30 kΩ
VCC 4
RF
RF
7
CH − 1
OUT1
3
GND
5
CH − 2
OUT2
6
2.2 Ω 2.2 Ω 0.1 µF 0.1µF
CRIP 10 µF 10 µF
VCC
(Note)
470 µF
RL
470 µF
RL
22 µF
(Note) CRIP is shown in item 3 and 4 of Application Note.
TA7376P
Output DC voltage V3 , V6 (V) Quiescent current ICCQ (mA)
7 14 6 12
ICCQ , V3 , V6 – VCC
Ta = 25 °C
5 10
48
36 24
ICCQ
V3 , V6
12
00 1 2 3 4 5 67 Supply voltage VCC (V)
Quiescent current ICCQ (mA) Output DC voltage V3 , V6 (V)
ICCQ , V3 , V6 – Ta
6 ICCQ
5
4
3
V3 , V6
2
1
VCC = 4.5 V RL = 4 Ω
0 −20
0
20 40
60
Ambient temperature Ta (°C)
80
4 2002-10-30
Total harmonic distortion THD (%)
50
30
VCC = 3 V f = 1 kHz
Ta = 25 °C 10
5 3
RL = 32 Ω 1
0.5 0.3
THD – Pout
16 8
4
0.1 0.05
0.005
0.01
0.03 0.05
0.1
Output power Pout (W)
0.3
Total harmonic distortion THD (%)
TA7376P
50 30
10
5 3 RL = 32 Ω
THD – Pout
16 8
4
1 0.