Class AB stereo line driver in 8-SOP
The BA3121F-E2: The BA3121F- is a Class AB stereo audio amplifier IC with two output channels in an 8-SOP surface-mount package. It operates from a 4 V to 18 V supply rail.
Supply range and thermal headroom
Class AB topology means linear dissipation: at 18 V supply and moderate output current, the 8-SOP package's thermal impedance limits continuous power. The wide 4 V to 18 V window lets a single BOM line serve 5 V and 12 V product variants — no separate regulator needed. For higher output power (9 W class), the BD28412MUV- Class D alternative trades linearity for efficiency.