AK7844 Datasheet | Asahi Kasei Microdevices

DESCRIPTION THE AK7844 is Stereo Class-D amplifier for driving Piezo-Electric Speakers. Built-in Boost DCDC converter generates adequate high voltage for driving Piezo Speakers from Li-Ion battery. AKM state-of-the-art filter-less solution eliminates LC-filters, which are normally required at Class-D outputs. That contributes to total space saving. Class-D operation ensures higher power efficiency, and couple with Piezo Speaker that is low-powerconsumption and low-profile figure. The AK7844 is very applicable for cellular phones with piezo speakers. FEATURES - Class-D Amplifier ： - Piezo-Electric Speaker Driver - Single-ended analog Input - BTL output - Output voltage = 8Vrms @VDD1=8.75V - Filter-less solution - Stereo mode - Pop noise suppressor - Output short protection - Boost DCDC Converter ： - Input voltage (Battery) = 2.7V ∼ 4.5V Æ Boosted voltage will be 8.75V - Over-current protection - Over-voltage protection - Control function ： - Pre-gain amplifier - 6d B ∼ +15d B, 3d B step - Built-in Second order lowpass filter at Input. - Cutoff Frequency (4k Hz,8k Hz,16k Hz) - Power-on/off control - Over-temperature protection - Operational voltage - Adjustable by Pin (PG0, PG1 and PG2) control - Adjustable by Pin (PG0, PG1 and PG2) control ： VBAT=2.7V ∼ 4.5V、DVDDI=1.65V ∼ 4.5V ： - 30°C ∼ 85°C - Operational temperature - Package ： 31pin WL-CSP (3.0mm × 3.0mm, 0.5mm pitch) Rev.00 －1- 2007/08 AKEMD AKEMD CONFIDENTIAL [AK7844] .. BLOCK DIAGRAM FC１ FC0 PG 2 PG 1 PG 0 DVDDI...