APA2613A Datasheet, PDF (14/25 Pages) Anpec Electronics Coropration – 8W Stereo Class-D Audio Power Amplifier

APA2613A
Function Description
Class-D Operation
Output = 0
V_OUTP
V_OUTN
V_OUT
(V_OUTP-V_OUTN)
I_OUT
Output > 0
V_OUTP
V_OUTN
V_OUT
(V_OUTP-V_OUTN)
I_OUT
Output < 0
V_OUTP
V_OUTN
V_OUT
(V_OUTP-V_OUTN)
I_OUT
Figure1. The APA2613A Output Waveform
The APA2613A uses a modulation scheme that allows
operation without the classic LC reconstruction filter when
the amp is driving an inductive load. Each output is switch-
ing from 0 volts to the supply voltage. The V and V
OUTP
OUTN
are in phase with each other with no input so that there is
little or no current in the speaker. The duty cycle of V_OUTP is
greater than 50% and V_OUTN is less than 50% for positive
output voltages. The duty cycle of V_OUTP is less than 50%
and V_OUTN is greater than 50% for negative output voltages.
The voltage across the load sits at 0V throughout most of
the switching period, reducing the switching current, which
reduces any I²R losses in the load.
Gain Setting Operation
GAIN1
GAIN0
Gain
Ri(Ω)
0
0
20dB
60k
0
1
26dB
30k
1
0
32dB
15k
1
1
36dB
9k
Table 1 : The Gain Setting
The APA2613A’s gain can be set by GAIN0, GAIN1. The
detail gain setting value is list at table 1.
Shutdown Operation
In order to reduce power consumption while not in use,
the APA2613A contains a shutdown function to externally
turn off the amplifier bias circuitry. This shutdown feature
turns the amplifier off when logic low is placed on the SD
pin for APA2613A. The trigger point between a logic high
and logic low level is typically 2.2V. It is best to switch
between ground and the supply voltage VDD to provide
maximum device performance. By switching the SD pin
to low level, the amplifier enters a low-consumption- cur-
rent state, I for APA2613A is in shutdown mode. On nor-
DD
mal operating, APA2613A’s SD pin should pull to high
level to keeping the IC out of the shutdown mode. The SD
pin should be tied to a definite voltage to avoid unwanted
state changes.
Power Limit Operation
The voltage at pin 10 can used to limit the power to levels
below that which is possible based on the supply rail.
Add a resistor divider from Vclamp to ground to set the
voltage at the PLIMIT pin. An external reference may also
be used if tighter tolerance is required. Also add a 1µF
capacitor from pin 10 to ground.
Copyright © ANPEC Electronics Corp.
14
Rev. A.1 - Jan., 2013
www.anpec.com.tw