Class D stereo amplifier in a 20-ball UCSP
The MAX9701EBP+G45 is a 2-channel (stereo) Class D audio power amplifier from Analog Devices, delivering 2.2W per channel into a 4Ω load from a 2.5V to 5.5V supply rail. Class D switching topology means the output stage operates as a PWM bridge, achieving higher efficiency than linear Class AB amplifiers — less heat dissipation in a compact 20-ball CSPBGA package (20-UCSP, 2.03x2.54 mm). The industrial temperature range (-40°C to 85°C) qualifies it for equipment enclosures, portable instruments, and automotive cabin applications where ambient temperatures stay within that band.
Output power and supply flexibility
Rated 2.2W x 2 at 4Ω — the per-channel power into a 4Ω speaker determines the loudspeaker impedance the amplifier can drive to full output. Into higher impedances (8Ω), the output power drops roughly by half, so the 4Ω figure is the load the design should target for the rated SPL. The output power scales with supply voltage — at 5.5V the amplifier reaches its maximum swing into the load. Surface-mount assembly in the 20-WFBGA/CSPBGA footprint — the 0.5 mm ball pitch and 2.03x2.54 mm body demand a controlled solder-paste stencil and reflow profile per JEDEC J-STD-020 for the CSP package.
The Bulk package option (non-tape-and-reel) is the ordering code for engineering samples or small-lot production.