Toshiba TA8266HQ, Руководство по описанию и применению

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TA8266HQ
2006-04-28
3
Caution and Application Method
(Description is made only on the single channel.)
1. Voltage Gain Adjustment
This IC has no NF (negative feedback) terminals. Therefore, the voltage gain can’t adjusted, but it makes
the device a space and total costs saver.
The voltage gain of Amp.1 : G
V1
=
8dB
The voltage gain of Amp.2A, B : G
V2
=
20dB
The voltage gain of BLT Connection : G
V (BTL)
=
6dB
Therefore, the total voltage gain is decided by expression below.
G
V
= G
V1
+ G
V2
+ G
V (BTL)
= 8 + 20 + 6 = 34dB
2. Stand-by SW Function
(pin 4)
By means of controlling pin 4 (stand-by terminal) to
high and low, the power supply can be set to ON and
OFF. The threshold voltage of pin 4 is set at about
3V
BE
(typ.), and the power supply current is about 2
µ A (typ.) at the stand-by state.
Control Voltage of pin 4: V
SB
Stand-by Power V
SB
(V)
ON OFF 0~1.5
OFF ON 3~V
CC
Adjustage of Stand-by SW
(1) Since VCC can directly be controlled to ON or OFF by the microcomputer, the switching relay can be
omitted.
(2) Since the control current is microscopic, the switching relay of small current capacity is satisfactory
for switching
Amp. 1
Input
Amp. 2A
Amp. 2B
Figure 1 Block Diagram
Figure 2 With pin 4 set to High,
Power is turned ON
ON
4
OFF
10 k
Ω
to BIAS
CUTTING CIRCUIT
≈
2V
BE
V
CC
Power