AK4213 Datasheet, PDF (15/38 Pages) Asahi Kasei Microsystems – Mono Class-D SPK-Amp with Stereo Cap-less HP-Amp

[AK4213]
■ Class-D Speaker-Amp
The output signal from ALC block is converted by PWM and is outputted from the SPP/SPN pins by BTL. The signal of
ALC block is inputted from the SPIN pin. The BPF (Band Pass Filter) is made by inserting the capacitor and resistor
between the MIXO pin and the SPIN pin. A 0.1uF capacitor must be connected between the MIXO pin and the SPIN pin
in order to cancel DC offset of Mixing & Selector circuit, if the BPF is not needed.
MIXO pin
SPIN pin
Mixing & Selector
AK4213
1kΩ ^0.015μF
0.033μF
SPGA5-0bits
typ.26kΩ
-
+
ALC
Figure 9. Example of Band-Pass-Filter for Speaker (BPF = typ. 442Hz to 4.83kHz @ -3dB)
MIXO pin
SPIN pin
Mixing & Selector
AK4213
0.1μF
SPGA5-0bits
typ.26kΩ
-
+
ALC
Figure 10. Example of normal connection for Speaker (fc = typ. 66Hz @ -3dB)
When the input signal level is 0.7Vrms in single-ended mode, the speaker-amp outputs 0.6W at ALC=OFF and
SPGA=0dB. When the stereo signal is input to the AK4213 in single-ended mode, the input volume of left and right
channels should be set to “-6dB” and left and speaker mixer path of left and right channels should be ON. In this case, the
speaker outputs the signal level of “(L +R)/2”.
The default internal gain is +9.82dB.When ALC is ON (ALC bit = “1”), ALC output level is automatically adjusted to
−7.5dBV ∼ −9.5dBV at LMTH bit = “0” and −11.5dBV ∼ −13.5dBV at LMTH bit = “1”. The reference level is set by
REF5-0 bits. The internal gain of Class-D SPK-amp is fixed to +11.76dB
Input
Input Volume
(-1.94dB @ Vol=0dB)
Mixing & Selector
(0dB)
ALC OFF: SPGA5-0 bits
ALC ON: REF5-0 bits
Class-D
(+11.76dB)
Figure 11. Speaker-Amp Path Level Diagram
MS0949-E-01
- 15 -
2008/07