TA8205ALQ Ver la hoja de datos (PDF) - Toshiba
Número de pieza
componentes Descripción
Fabricante
TA8205ALQ Datasheet PDF : 14 Pages
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TA8205AHQ/ALQ
The total closed loop gain GV of this IC can be obtained by expression below when the closed loop voltage gain of
Amp 1 is GV1.
GV1
=
20log
R1+ (Rf + R2)
Rf + R2
(dB)
..... (1)
The closed loop voltage gain of power Amp, Amp 3
and Amp 4 is fixed at GV3 ≒ GV4 = 20dB.
Therefore, the total closed circuit voltage gain GV is
obtained through BTL connection by the expression
below.
GV = GV1 + GV3 + 6 (dB) ............... (2)
For example, when Rf = 0Ω, GV is obtained by the
expressions (1) and (2) as shown below.
GV ≒ 24 + 20 + 6 = 50dB
The voltage gain is reduced when Rf is increased. (Fig.2)
With the voltage gain reduced, since (1) the oscillation
stability is reduced, and (2) the pop noise changes when
VCC is set to on, refer to the items 3 and 4.
Fig.2
2. Stand−by SW function
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 about 3V (typ.),
and the power supply current is about 1µA (typ.) at the
stand−by state.
Pin(4) control voltage : V (SB)
Stand−by
Power
V (SB) (V)
On
Off
0~2
Off
On
3~VCC
Fig.3 With pin(4) set to high, power is turened on.
Advantage of stand−by SW
(1) Since VCC can directly be controlled to on / off by the microcomuter, the switching relay can be omitted.
(2) Since the control current is microscopic, the switching relay of small current capacity is satisfactory for
switching.
3
2006-04-28
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