High-Power single-channel class D Audio Powered Amplifier using IRS2092S dedicated Class D amplifier IC. IRS400SMPS is specially designed for plate amplifiers used for powered speakers and very compact all-on-board single channel Class D Power Amplifiers. Output power is 400W on 4R at less than 0.1% THD and up to 480W on 4R at 1% THD. Output power on 8R with 0.1% THD or less is 225W and up to 270W at 1% THD. IRS400SMPS can be powered from 120V (100-127V) or 230V (210-245V) mains voltage It has on-board fully-regulated, high-efficiency resonant power supply which ensure constant supply voltage for IRS400SMPS Amplifier power stage independent on the mains supply voltage value. It also has on-board auxiliary differential supply +-18V 300mA which can be used to supply pre-amplifier and other house-keeping circuits. The regulated power supply has class II insulation, without protective earth connection required for easier implementation and lowest noise. Amplifier gain is 26.67, Input sensitivity 1.5V RMS for 400W on 4R output power. Input Impedance is 3.6K. Frequency response from 24Hz to 18KHz has better than 1.4dB linearity and 3dB from 16Hz to 22KHz.
Idle power consumption during operation is 10W and when the amplifier is muted the power consumption drops to 2W (with no load on Aux. Supply output). Amplifier stage efficiency is 94% at 480W 4R 1% THD and up to 96% with output power 270W on 8R load and 1% THD. Power supply alone has better than 93% efficiency from 20% to 70% load, thus the maximum total efficiency from Mains to speaker can reach 90% with IRS400SMPS Powered Amplifier Module supplied at 230V AC and output power 270W on 8R. Average efficiency measured on 4R loads from 100W to 400W output power and mains voltage both 120V and 230V exceed 87%
IRS400SMPS Powered Amplifier Module has full protection set implemented: output short-circuit protection, over-current, over-temperature with mute/release when temperature reach 90/85*C, under-voltage, over-voltage (if excessive bus pumping is experienced due to high amplitude low frequency content or DC component at input) mains voltage presence/absence which will activate the IRS400SMPS powered amplifier module only when is supplied with mains voltage within required range. And the most important, DC fault protection, latched shut-down protection which will disable the power supply section once a DC component with value over 10V is detected on speaker output for more than 60ms, protecting the speakers if DC component on speaker output is detected. It has Mute control pin (3-6V=active, default mode – active, pull to GND for Mute) two LED’s which indicate the mode, ON – normal operation and Mute. 6.3mm fast-on blade connectors are used for mains supply and speaker output, one 4 pins 2.54mm connector is used for singnal Input, Mute control and one 3 pins 2.54mm connector is used for Aux. voltage Output. The size of the amplifier is 180mm long, 60mm wide and 31mm tall from the board base, and total height 38mm including 5mm spacers under PCB. With a weight of the board alone of about 300 grams, it can reach a power density of 1.33W/gram and an overall volume of just 18 cub. inch has a power density of 15W/cu.inch, being the most compact powered amplifier in it’s class, available on the market.
All the power devices are installed under the PCB at equal distance from the board. For proper operation IRS400SMPS requires a heatsink (aluminium plate or amplifier enclosure can be used as heatsink) with a thermal resistance of 2.4*C/W or better. In case of plate amplifier applications, an aluminium plate with the min size of 200x100mm and min 3mm thick can be used as a heatsink if will be installed outside the speaker enclosure allowing cooling by convection.