AK4343EN AKM [Asahi Kasei Microsystems], AK4343EN Datasheet - Page 61

• Manufacturer Part Number: AK4343EN
• Description: Stereo DAC with HP/RCV/SPK-AMP
• Manufacturer: AKM [Asahi Kasei Microsystems]

ASAHI KASEI
<ALC Operation Example of Speaker Playback>
<Caution for using Piezo Speaker>
When a piezo speaker is used, resistances more than 10Ω should be inserted between SPP/SPN pins and speaker in series,
respectively, as shown in Figure 58. Zener diodes should be inserted between speaker and GND as shown in Figure 58, in
order to protect SPK-Amp of AK4343 from the power that the piezo speaker outputs when the speaker is pressured. Zener
diodes of the following zener voltage should be used.
MS0478-E-01
0.92 x HVDD ≤ Zener voltage of zener diodo (ZD in Figure 58) ≤ HVDD+0.3V
Ex) In case of HVDD = 5.0V: 4.6V ≤ ZD ≤ 5.3V
Register Name
LMTH1-0
ZELMN
ZTM1-0
WTM2-0
REF7-0
AVL7-0,
AVR7-0
LMAT1-0
RGAIN1-0
ALC
For example, zener diode which zener voltage is 5.1V(Min: 4.97V, Max: 5.24V) can be used.
Figure 58. Speaker Output Circuit (Load Capacitance > 30pF)
SPK-Amp
Table 55. ALC Operation Example of Speaker Playback
Comment
Limiter detection Level
Limiter zero crossing detection
Zero crossing timeout period
Recovery waiting period
*WTM2-0 bits should be the same or
Maximum gain at recovery operation
Gain of AVOL
Limiter ATT step
Recovery GAIN step
ALC enable
longer data as ZTM1-0 bits
SPP
SPN
- 61 -
≥10Ω
≥10Ω
ZD
ZD
Data
C1H
91H
11
00
00
10
00
0
1
fs=44.1kHz
−2.5dBFS
Operation
23.2ms
11.6ms
Enable
+18dB
Enable
1 step
1 step
0dB
[AK4343]
2006/10