AK7841

ASAHI KASEI [AK7841] www.DataSheet4U.com 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. AK7841 □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 -1- 2008/3 ASAHI KASEI [AK7841] www.DataSheet4U.com BLOCK DIAGRAM DVDDI PDN VBAT PD C ont Pow er Booster VCO IL VFB ERRO VSS2 PG 0 PG 1 PG 2 Gain C ontrol...