Toshiba TA 8246 AHQ Service Manual
TOSHIBA Bipolar Linear Integrated Circuit Silicon Monolithic
TA8246AHQ
Dual Audio Power Amplifier 6 W × 2 Ch
TA8246AHQ is dual power amplifier for Consumer applications.
This IC provides an output power of 6 watts per channel
(at V
It is suitable for power amplifier of TV and home Stereo.
Features
= 20 V, f = 1 kHz, THD = 10%, RL = 8 Ω).
CC
TA8246AHQ
• : High output power: P
(V
• Built-in audio muting circuit.
• NF terminal capacitor less
: Fixed gain (G
• Protectors
: Thermal shut down protection circuit, over voltage protection circuit
• Low poping noise
• High THD ratio
• High input dynamic range
• Available for using same PCB layout with 3 channel IC: TA8256BHQ
• Operating supply voltage range
: V
= 20 V, RL = 8 Ω, f = 1 kHz, THD = 10%)
CC
= 34dB), needless external capacitor.
v
CC (opr)
= 10~30 V (Ta = 25°C)
= 6 W (Typ.)
out
Weight: 4.04 g (typ.)
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Block Diagram
INPUT1
RIPPLE FILTER
4 kΩ
4
6 9
Amp 1
30 kΩ
OUT1
TA8246AHQ
V
CC
8
R
L
R
L
INPUT2
3
2
350 Ω
350 Ω
4 kΩ
30 kΩ
20 kΩ
V
18
20 kΩ
Amp 2
MUTE SW
PW-GNDPre-GND
2.1 V
OUT2
75
MUTE T.C.
10
12
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Terminal Explanation
A
TA8246AHQ
Terminal
No.
2 IN2
4 IN1
3 Pre-GND GND terminal ⎯
5 MUTE SW
Symbol Function Equivalent Circuit
4 kΩ
30 kΩ
Input
2/4
7
MUTE control terminal
5
10 kΩ
V
CC
NF へ
to MUTE
20 kΩ
350 Ω
GND
V
CC
mplifier
OUT
7 MUTE T.C.
10 kΩ
6 R/F Ripple filter
6
5.1 kΩ
8 OUT1
Output
12 OUT2
9 V
10 PW-GND GND terminal ⎯
CC
Supply voltage terminal ⎯
GND
to POP-NOIZE
preventive circuit
to Bias circuit
V
CC
8/12
2.2 kΩ
GND
1, 11: NC
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TA8246AHQ
Cautions
This IC is not proof enough against a strong E-M field by CRT which may cause malfunction such as leak.
Please set the IC keeping the distance from CRT.
Maximum Ratings
Characteristic Symbol Rating Unit
(Ta = 25°C)
Supply voltage V
Output current (peak/ch) I
Power dissipation PD (Note) 25 W
Operating temperature T
Storage temperature T
CC
O (peak)
opr
stg
30 V
2 A
−20~75 °C
−55~150 °C
Note: Derated above Ta = 25°C in the proportion of 200 mW/°C.
Electrical Characteristics
(Unless otherwise specified, VCC = 20 V, RL = 8 Ω, Rg = 620 Ω, f = 1 kHz, Ta = 25°C)
Characteristic Symbol
Quiescent current I
Output power
Total harmonic distortion
Voltage gain G
Input resistance R
Ripple rejection ratio R.R. ⎯ f = 100 Hz −40 −47 ⎯ dB
Output noise voltage V
Cross talk C.T. ⎯
Mute control voltage
Mute attenuation level ATT ⎯ V
CCQ
P
(1) ⎯ THD = 10% 5 6 ⎯
out
(2) ⎯ THD = 1% ⎯ 4.5 ⎯
P
out
THD (1) ⎯ P
THD (2) ⎯ P
v
IN
no
V
th (ON)
V
th (OFF)
Test
Circuit
⎯ Vin = 0 50 85 130 mA
⎯ V
⎯ ⎯ ⎯ 34 ⎯ kΩ
Rg = 10 kΩ,
⎯
BW = 20 Hz~20 kHz
Rg = 10 kΩ,
V
⎯ MUTE ON 3.1 ⎯ V
⎯ MUTE OFF 0 ⎯ 2.5
Test Condition Min. Typ. Max Unit
= 2 W ⎯ 0.04 0.2
out
= 2 W, f = 10 kHz, ⎯ 0.1 0.6
out
= 0.775 Vrms 32.5 34 35.5 dB
out
⎯ 0.14 0.3 mVrms
= 0.775 Vrms
out
= 0.775 Vrms → Mute −52 −60 ⎯ dB
out
⎯ −60 ⎯ dB
CC
W
%
V
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