New PWM controller ICs for power supply in multiple industrial applications

Supports a wide range of power transistors from Si MOSFETs and IGBTs to SiC MOSFETs, with built-in high-accuracy undervoltage prevention malfunction

ROHM has developed external FET-type controller ICs using PWM current control mode optimised for AC/DC power supply in various industrial applications. Mass production has begun for four variants created to drive a wide range of power semiconductors: the BD28C55FJ-LB for low-voltage MOSFETs, BD28C54FJ-LB for medium to high-voltage MOSFETs, BD28C57LFJ-LB for IGBTs, and BD28C57HFJ-LB for SiC MOSFETs.

Although the global semiconductor shortage is starting to ease, the supply of semiconductor components for power supplies in industrial applications continues to lag behind demand. This is especially true for PWM controller ICs, where the limited number of manufacturers has created chronic shortages, leading to multiple requests for product development.

In response, the company has developed PWM controller ICs that meet the ongoing supply issue by fulfilling the industrial market's stringent package and performance necessities. Depending upon the application's input AC voltage range, a wide variety of semiconductors are employed for the power supply circuit. Each of these semiconductors demands different undervoltage lockout levels to prevent thermal runaway in case of supply/gate voltage drop. To solve this issue, the company has developed four variants with different undervoltage lockout levels.

The new products feature an input voltage range of 6.9V to 28V, circuit current up to 2mA, maximum startup current of 75µA, and a maximum duty cycle of 50%, offered in the standard SOP-J8 package (equivalent to the JEDEC SOIC8). The products are pin-to-pin compatible with standard products commonly used in power supply circuits, therefore, reducing re-design and modification efforts. All variants are equipped with a self-recovery-type undervoltage lockout function with voltage hysteresis. This greatly improves application reliability by lowering the threshold voltage error to ±5%, compared to the typical ±10% of standard products.

At the same time, these ICs are designated for long-term supply, ensuring continuous operation of long-life industrial equipment. Going forward, the lineup will be further expanded to include products suitable for driving high-voltage MOSFETs and GaN devices. More variants to support a maximum duty cycle of 100% are also being planned.

Application Examples

Industrial equipment.