TA8221AHQ Toshiba, TA8221AHQ Datasheet - Page 3

• Manufacturer Part Number: TA8221AHQ
• Manufacturer: Toshiba

Specifications of TA8221AHQ

• No. Of Channels: 2
• Package: HZIP 17-P-2.00
• Recommended Vcc (v): 13.2
• Rl=2 Ohm: 26W x 2
• Rl=4 Ohm: 19W x 2
• Rl=8 Ohm: -
• Features/built-in Functions: 2 BTL channels, standby switch
• Operating Voltage (v): 9 to 18

2. Stand−by SW function
The total closed loop gain G
amp 1 is G
The closed loop voltage gain of power amp, amp 3
and amp 4 is fixed at G
Therefore, the total closed circuit voltage gain G
obtained through BTL connection by the expression
below.
For example, when Rf = 0Ω, G
expressions (1) and (2) as shown below.
The voltage gain is reduced when R
With the voltage gain reduced, since (1) the oscillation
stability is reduced, and (2) the pop noise changes when
V
By means of controlling pin(4) (stand−by terminal) to high
and low, the power suply can be set to on and off.
The threshold voltage of pin(4) is set at 2.1V (3V
and the power supply current is about 100µA (typ.) at the
stand−by state.
Control voltage of pin(4): V
Advantage of stand−by SW
(1) Since V
(2) Since the control current is microscopic, the switching relay of small current capacity is satisfactory for
CC
Stand − by
is set to on, refer to the items 3 and 4.
switching.
On
Off
G
G
G
V
V
V1
V1
≒24 + 20 + 6 = 50dB
= G
=
CC
.
20
V1
can directly be controlled to on / off by the microcomputer, the switching relay can be omitted.
l
og
+ G
Power
R1
Off
On
V3
+
f R
V3
(R
+ 6 (dB) ............... (2)
+
f
≒G
R2
+
(SB)
V
R2)
V4
of this IC can be obtained by expression below when the closed loop voltage gain of
V
(dB)
is obtained by the
V
= 20dB.
3~V
(SB)
0~2
f
is increased. (Fig.2)
CC
(V)
..... (1)
V
BE
is
.),
3
TA8221AHQ / ALQ
2004-09-28