AK4634EN Datasheet, PDF (54/94 Pages) Asahi Kasei Microsystems – 16-Bit Mono CODEC with ALC & MIC/SPK -AMP

[AK4634]
<Caution for using Piezo Speaker>
When a piezo speaker is used, resistances more than 10 should be connected between the SPP/SPN pins and speaker in
series respectively as shown in Figure 44. Zener diodes should be connected between speaker and GND as shown in Figure
44, in order to protect SPK-Amp of the AK4634 from the power that is the piezo speaker output when the speaker is
pressured. Zener diodes of the following Zener voltage should be used.
92% of SVDD ≤ Zener voltage of Zener diodo(ZD of Figure 44) ≤ SVDD+0.3V
Ex) In case of SVDD = 3.8V :3.5V ≤ ZD ≤ 4.1V
For example, Zener diode which Zener voltage is 3.9V(Min 3.7V, Max 4.1V) can be used.
SPK-Amp
ZD
10
SPP
SPN
10
ZD
Figure 44. Circuit of Speaker Output (using a piezo speaker)
MS0686-E-03
- 54 -
2014/10