Toshiba TA8266HQ Description And Application Manual page 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
The voltage gain of Amp.2A, B
The voltage gain of BLT Connection : G
Therefore, the total voltage gain is decided by expression below.
G = G + G
V V1
2. Stand-by SW Function
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 (typ.), and the power supply current is about 2
BE
µA (typ.) at the stand-by state.
Control Voltage of pin 4: V
Stand-by Power
ON OFF
OFF ON
Adjustage of Stand-by SW
(1) Since V can directly be controlled to ON or OFF by the microcomputer, the switching relay can be
CC
omitted.
(2) Since the control current is microscopic, the switching relay of small current capacity is satisfactory
for switching
Amp. 1
Input
Figure 1 Block Diagram
: G
V1
: G
V2
V (BTL)
+ G = 8 + 20 + 6 = 34dB
V2 V (BTL)
(pin 4)
SB
V (V)
SB
0~1.5
3~V
CC
Amp. 2A
Amp. 2B
= 8dB
= 20dB
= 6dB
ON
Power 10 kΩ
4
OFF
Figure 2 With pin 4 set to High,
Power is turned ON
3
TA8266HQ
V
CC
≈ 2V
BE
to BIAS
CUTTING CIRCUIT
2006-04-28