MAX13331EVKIT+: Headphone 125mW x2 @ 32Ω, 5V in

The MAX13331 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that evaluates the MAX13331 DirectDrive® stereo headphone amplifier. DirectDrive eliminates the two large DCblocking capacitors typically required between the output of the amplifier and the headphones. The MAX13331 EV kit includes two RCA phono jacks on the input and a 3.5mm headphone jack on the output to facilitate easy connections to the circuit board.

The MAX13331 EV kit can also evaluate the MAX13330 IC. This requires the IC replacement of U1.

The MAX13330/MAX13331 stereo headphone amplifiers are designed for automotive applications requiring output short-circuit and ESD protection to battery/ground with diagnostics. These devices use Maxim’s unique DirectDrive® architecture to produce a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving board space and component height. The gain of the amplifier is set internally (-1.5V/V) on the MAX13330 or adjusted externally with resistors on the MAX13331.

The MAX13330/MAX13331 deliver 120mW per channel into a 16Ω load or 135mW into a 32Ω load and have a low 0.01% THD+N. Low output impedance and the efficient integrated charge pump allows the device to drive loads as low as 8Ω, enabling the use of small loudspeakers. An 80dB at 217Hz PSRR allows these devices to operate from noisy digital supplies without an additional linear regulator. These devices include ±15kV Human Body Model ESD protection and short circuit protection up to +45V at the headphone outputs. Comprehensive click-and-pop circuitry suppresses audible clicks and pops on startup and shutdown. A low-power shutdown mode reduces the supply current to 3μA (typ).