AS1701_1 AMSCO [austriamicrosystems AG], AS1701_1 Datasheet - Page 12

• Manufacturer Part Number: AS1701_1
• Description: 1.6W Audio Power Amplifiers
• Manufacturer: AMSCO [austriamicrosystems AG]

AS1701, AS1706
Data Sheet
If the internal power dissipation exceeds the maximum allowed for a given package, power dissipation can be reduced
by increasing the ground plane heat-sinking capabilities and increasing the size of the traces to the device
and Grounding Considerations on page
ambient temperature can reduce device power dissipation.
The integrated thermal-overload protection circuitry limits the total device power dissipation. Note that if the junction
temperature is ≥ +145°C, the integrated thermal-overload protection circuitry will disable the amplifier output stage. If
the junction temperature is reduced by 9ºC, the amplifiers will be re-enabled.
Note: A pulsing output under continuous thermal overload results as the device heats and cools.
Efficiency
Efficiency of the AS1701/AS1706 is calculated by taking the ratio of the power delivered to the load, to the power con-
sumed from the power supply. Output power is calculated by:
where V
full-wave rectified sinusoid with the magnitude proportional to the peak output voltage and load.
Calculate the supply current and power drawn from the power supply by:
The efficiency of the AS1701/AS1706 is:
Component Selection
Gain-Setting Resistors
External feedback resistors R
Optimum output offset is achieved when R
If used in a high-gain configuration (greater than 8V/V), a feedback capacitor may be required to maintain stability
Figure 1 on page
Note: Ensure that the pole created by C
www.austriamicrosystems.com
PEAK
- A p p l i c a t i o n I n f o r m a t i o n
is half the peak-to-peak output voltage. In BTL amplifier configurations, the supply current waveform is a
1). C
F
and R
F
F
and R
limit the bandwidth of the device, preventing high-frequency oscillations.
IN
(see Figure 1 on page 1)
14). Additionally, reducing V
F
F
and R
= 20k Ω . Device gain can be varied by changing the value of R
η =
F
P
P
I
P
is not within the frequency band of interest.
R
DD
OUT
IN
OUT
Revision 1.52
IN
A
= V
=
VD
=
2V
= 2 x
DD
=
V
π
π
PEAK
π
PEAK
R
2
2V
L
R
R
R
π
L
set the gain of the device as:
2
PEAK
IN
F
R
P
L
2V
OUT
DD
2
DD
, increasing load impedance, and decreasing
R
L
(see Layout
IN
.
(EQ 10)
(EQ 11)
(EQ 7)
(EQ 8)
(EQ 9)
12 - 17
(see