ak4373 ETC-unknow, ak4373 Datasheet - Page 65

• Manufacturer Part Number: ak4373
• Description: Low Power Stereo Dac With Hp/spk-amp
• Manufacturer: ETC-unknow

<ALC Operation Example of Speaker Playback>
<Caution for using Piezo Speaker>
When a piezo speaker is used, two resistances more than 20Ω should be connected between SPP/SPN pins and speaker in
series, respectively, as shown in
56, in order to protect SPK-Amp of the AK4373 from the power that the piezo speaker outputs when the speaker is
pressured. Zener diodes of the following zener voltage should be used.
MS0991-E-00
0.92 x HVDD ≤ Zener voltage of zener diodo (ZD in
Ex) In case of HVDD = 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.
Register Name
LMTH1-0
ZELMN
ZTM1-0
WTM2-0
REF7-0
AVL7-0,
AVR7-0
LMAT1-0
RGAIN1-0
ALC
Figure 56. Speaker Output Circuit (Load Capacitance > 30pF)
SPK-Amp
Table 44. ALC Operation Example of Speaker Playback
Figure
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
56. Zener diodes should be inserted between speaker and GND as shown in
SPP
SPN
- 65 -
≥20Ω
Figure
≥20Ω
ZD
56) ≤ HVDD+0.3V
ZD
Data
C1H
91H
011
00
10
00
00
0
1
fs=44.1kHz
−2.5dBFS
Operation
11.6ms
23.2ms
Enable
+18dB
Enable
1 step
1 step
0dB
[AK4373]
2008/09
Figure