Car audio amplifiers usually applied boost converter born 18 V ~ 28 V or higher battery output voltage. 100W and 100W high power use more need big boost inductor, multiple levels of output capacitor parallel MOSFET and the diode,www.12vgridtiepowerinverters.com. The power stage is divided into a plurality of parallel phase to reduce a lot of the power component stress, accelerating the load change, such as the response of the bass notes and advances the system effectiveness.
find a pulse width modulation (PWM) controller for 2-phase boost converter is definitely compared easily. Most dual-channel interleaving the offline controller or push-pull controller can be used to directly drive two boost MOSFET of phase. However, in the 4-phase solution, the scale of the controller's choice is more limited. Honored, multiphase buck controller can be easily converted to 4-phase boost converter.
Figure 1 shows the
using TI's TPS40090 multiphase buck moderation 4 a boost-phase, 300W power supply, the converter is designed to dispose of individual will be presented in audio using 500W peak burst. Typically, the in multiphase buck construct, the uniform current through the inductance of the inductive output of the gripper to equalize the electric power of each phase. In contrast, in a multiphase boost configuration, the current sensing is carried out in the device in each FET source resistor. The peak current through each FET equalizer,Grid tie inverter, multiphase grippers average deployment of power at all in the boost phase. From the grasp the gate drive signal to a logic level, and thus each phase request exists a MOSFET driver. In this design, the application of a dual-channel MOSFET driver, such as the UCC27324 to reduce the number of components.
Figure 1 for car audio amplifier 300W 4-phase boost converter
protected against a current limit applied to each phase and multiphase mastered cover temperance uploaded premise of the infringement. Audio utilization have a lot higher than the uniform output power transient peak power needs. Necessary for the flow limit is set high enough to satisfied with the peak power request. External undervoltage lockout (UVLO) circuit also supply another level maintenance, which can avoid the system running in the low battery voltage conditions. Boost power supply when the battery voltage drops, will attempt to supply as many as possible of the input current, this will lead to the dramatic landing of the battery voltage when the battery is running out of power. This situation causes the battery is damaged, the worst case even make battery scrap. Brief and low-cost the UVLO circuit by a reference circuit, a dual-channel analogy with several resistance.
the design, the four phases are 500 kHz switch, and the resolution of 90 degrees synchronization. Figure 2 shows all four phases of the drain - source voltage waveform. Qijiang from each phase of the ripple current in the input terminal and an output terminal, while they at the input and output terminal partially canceling each other. This at the same time reduce the input and output capacitor AC ripple current. In addition, the integrated ripple current to 2 MHz, the phase frequency is four times the frequency of a single phase. Because the lower the ripple current and a higher frequency,power inverter, and the single-phase solutions comparable input and output power capacity in the multiphase solution is much smaller. A more efficient switching frequency also allows the converter more swiftly, to respond to the change of the load current.
power level is divided into a plurality of phase and decrease the stress of each power module. The lower current and additional power to provide a wider spot supply inductance, FET with diode choice areas. Single-phase solution plan unmatched power loss less and wider spread area, thus simplifying the cooling governance. In the case of driving a 300W load, such a four-phase design is to obtain a 94% of the effect, thus achieving the loss of less than 20W.
looking for a can drive more than two-phase boost controller will bring a certain design provocation. The TPS40090 multiphase boost converter is very practical in the use of high-power audio.
interleaved 4-phase boost settlement plan
the Figure 2 2MHz efficient ripple current run results
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