AK7844 Datasheet, PDF (1/21 Pages) Asahi Kasei Microsystems – Stereo Audio Class-D Amp with Power Booster for Piezo Speakers

AKEMD
AKEMD CONFIDENTIAL
[AK7844]
AK7844
Stereo Audio Class-D Amp with Power Booster for Piezo Speakers
GENERAL 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-power-
consumption 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 −6dB ∼ +15dB, 3dB step
• Built-in Second order lowpass filter at Input.
• Cutoff Frequency (4kHz,8kHz,16kHz)
• Power-on/off control
• Over-temperature protection
* Adjustable by Pin (PG0, PG1 and PG2) control
* Adjustable by Pin (PG0, PG1 and PG2) control
□ Operational voltage ： VBAT=2.7V ∼ 4.5V、DVDDI=1.65V ∼ 4.5V
□ Operational temperature ： −30°C ∼ 85°C
□ Package ： 31pin WL-CSP (3.0mm × 3.0mm, 0.5mm pitch)
Rev.00
－1–
2007/08