New BD7F series of isolated flyback-type DC/DC converters
Conventionally, in order to stabilize the output voltage of isolated power supplies methods using limited life components such as Optocouplers and/or auxiliary winding are employed.
In contrast, ROHM has developed isolated flyback DC/DC converter controllers that eliminate the need for these types of feedback circuits.
The simple, efficient design is ideal for industrial power supplies (i.e. FA equipment), power storage systems, and high power inverters.
In addition to samples of the BD7F100xxx-LB and BD7F200xxx-LB, an evaluation board integrating the BD7F100HFN-LB will be available for purchase through online distributors.
The BD7F100HFN-EVK-001 evaluation board makes it easy to evaluate and verify operation of ROHM's isolated flyback DC/DC converter controller (24V input, 5V/800mA output).
|Part No.||Data sheet||Package|| Output |
| Max. |
| Input |
| Over |
| Switching |
| Operating |
|BD7F100HFN-LB|| HSON8 |
| 1W |
|45V||3.0~40V||1.25A||400kHz (Typ.)||-40°C ～ +125°C|| Enable Soft Start |
Load Mode UVLO
|BD7F100EFJ-LB|| HSOP-J8 |
|BD7F200HFN-LB|| HSON8 |
| 10W |
|BD7F200EFJ-LB|| HSOP-J8 |
Feature 1：No Optocoupler or auxiliary winding required contributes to greater miniaturization
Applying feedback at the primary side in order to detect the voltage and current at the secondary side eliminates the need for a Optocoupler or auxiliary winding along with other necessary components. This simplifies design considerably, resulting in improved reliability, greater energy savings, and increased miniaturization. Stable output voltage is achieved using just a single resistor.
Feature 2：Adaptive ON time control improves load response characteristics
Conventional isolated power supply control ICs are susceptible to large variations in output voltage with instantaneous load current fluctuations. In response, ROHM developed an adaptive ON time control method based on the market-proven ON time control design utilized for non-isolated power supply control ICs.
This new method significantly improves response characteristics against instantaneous load current fluctuations, reducing output voltage variations by more than 65% - to less than 200mV (at a load current of 1A and rise time of 100µs) - resulting in improved reliability.