AK7841 Datasheet, PDF (1/21 Pages) Asahi Kasei Microsystems – Monaural Audio Class-D Amp with Power Booster for PiezoSpeaker

ASAHI KASEI
[AK7841]
AK7841
Monaural Audio Class-D Amp with Power Booster for
PiezoSpeaker
GENERAL DESCRIPTION
The AK7841 is a Monaural Class-D amplifier for driving Piezo-Electric Speakers. Its built-in power boost
DCDC converter generates adequate high voltage for driving Piezo Speaker from a Li-Ion battery.
Output filter-less solution eliminates post LC-filters, which are normally required at Class-D outputs, and
contributes to total space savings. Class-D operation ensures higher power efficiency. The AK7841 is
the most appropriate for Cellular Phones with a piezo speaker.
FEATURES
□ Class-D Amplifier :
• Piezo-Electric Speaker Driver
• Analog Monaural signal input for both single and Differential-ended
• Monaural BTL output
• Output voltage = 12Vpp @VDD1=8.75V
• Filter-less solution
• Pop noise free architecture during power up or down.
• Output short protection
□ Boost DCDC Converter ：
• Input voltage = 2.7V ∼ 4.5V Æ Output voltage = 8.75V
• Over-current protection
• Over-voltage protection
□Control function ：
• Pre-gain amplifier −3dB ∼ +18dB, 3dB step.
• Power-own control
• Over-temperature protection
Controlled by pin setting.
□Operational voltage ：VBAT=2.7V ∼ 4.5V、DVDDI=1.65V ∼ 4.5V
□Operational temperature： −30°C ∼ 85°C
□Package： 24pin WL-CSP (2.5mm × 2.5mm, 0.5mm pitch)
Rev.08
2008/3
-1-