STMicroelectronics

The device is a highly integrated solution for SMPS applications, with an LED pilot-lamp requiring a dual control loop to perform CV (constant voltage) and CC (constant current) regulation. The IC allows very efficient LED pilot-lamp driving which helps to reduce the standby consumption of the SMPS. It integrates a voltage reference, two op-amps (with OR-ed open-drain outputs), a low-side current sensing circuit and an LED pilot-lamp driver pin implemented with an open-drain mosfet driven by square waveform with 12.5% duty cycle at 1 kHz that allows reducing LED consumption. The voltage reference, along with one op-amp, is the core of the voltage control loop. The current sensing circuit and the other op-amp make up the current control loop. The external components needed to complete the two control loops are: - a resistor divider that senses the output of the power supply and fixes the voltage regulation setpoint at the specified value - a sense resistor that feeds the current sensing circuit with a voltage proportional to the DC output current; this resistor determines the current regulation setpoint and must be adequately rated in terms of power dissipation - the frequency compensation components (R-C networks) for both loops. The device is ideal for space-critical applications.

The SG3525A series of pulse width modulator integrated circuits are designed to offer improved performance and lowered external parts count when used in designing all types of switching power supplies. The on-chip + 5.1 V reference is trimmed to ±1 % and the input common-mode range of the error amplifier includes the reference voltage eliminating external resistors. A sync input to the oscillator allows multiple units to be slaved or a single unit to be synchronized to an external system clock. A single resistor between the CTand the discharge terminals provide a wide range of dead time ad- justment.These devices also feature built-in soft-start circuitry with only an external timing capacitor required. A shutdown terminal controls both the soft-start circuity and the output stages, providing instantaneous turn off through the PWM latch with pulsed shutdown,as well as soft-start recycle with longer shutdown commands. These functions are also controlled by an undervoltage lockout which keeps the outputs off and the soft-start capacitor discharged for sub-normal input voltages. This lockout circuitry includes approximately 500 mV of hysteresis for jitter-free operation. Another feature of these PWM circuits is a latch following the comparator. Once a PWM pulses has been terminated for any reason,the outputs will remain off for the duration of the period. The latch is reset with each clock pulse. The output stages are totem-pole designs capable of sourcing or sinking in excess of 200 mA. The SG3525A output stage features NOR logic, giving a LOW output for an OFF state.

The SGT65R65AL is a 650 V, 25 A e-mode PowerGaN transistor combined with a well established packaging technology. The resulting G-HEMT device provides extremely low conduction losses, high current capability and ultra fast switching operation to enable high power density and unbeatable efficiency performances.

This device combines two MOSFETs in a half-bridge topology. The ACEPACK SMIT is a very compact and rugged power module in a surface mount package for easy assembly. Thanks to the DBC substrate, the ACEPACK SMIT package offers low thermal resistance coupled with an isolated top-side thermal pad. The high design flexibility of the package enables several configurations, including phase legs, boost, and single switch through different combinations of the internal power switches.