The ISL85413DEMO3Z demonstration board is used to demonstrate the performance of the ISL85413 wide VIN low quiescent current, high-efficiency, synchronous buck regulator to produce a positive primary output and a negative isolated secondary output.

The ISL85413DEMO3Z uses the ISL85413 synchronous buck regulator in an isolated buck configuration. It replaces the filter inductor with a coupled inductor (or transformer) to produce a primary output and an inverting secondary output.

The ISL85413 is offered in a 3mm x 3mm 8 Ld TDFN package with a 1mm maximum height. The converter occupies 3.3cm² area.


  • Wide input voltage range of 3.5V to 40V
  • Synchronous operation for high efficiency
  • Integrated high-side and low-side NMOS devices
  • Internal switching frequency (700kHz)
  • Continuous output current up to 150mA
  • Internal soft-start
  • No compensation required
  • Minimal external components required
  • Power-good and enable functions available for primary output



  • Industrial control
  • Medical devices
  • Portable instrumentation
  • Distributed power supplies
  • Cloud infrastructure


Type Title Date
Manual - Development Tools PDF 909 KB
Datasheet PDF 1.36 MB
2 items

Design & Development

Software & Tools

Software Downloads

Type Title Date
PCB Design Files ZIP 2.12 MB
1 item
Designing with the ISL8541x

See how easy it is to design with Intersil's new pin-for-pin compatible synchronous buck regulators with a wide input voltage range. With three different output current options, these highly efficient sync buck regulators simplify power circuit design and enable reuse of circuit board design across a wide range of end applications.


Hi, my name is Paul Orfanu, I'm an application engineer for Intersil. I'm going to introduce ISL85415 that will help you simplify your design while maintaining similar efficiency or better than standard buck regulators. This one is a synchronous buck regulator, and let me show how this topology works. This is the block diagram that you may find on the datasheet. We have the two upper and lower FET integrated, which eliminates the the needs for external drivers. And also, we have integrated the compensation. It could be internal compensation or external compensation. That also eliminates the need for components.

In order to have performance optimization, we also have the frequency that also can be adjustable. By looking at the performance of efficiency, we have optimized the curves that indicates at light load our efficiency can go up to 95%. And in heavy load, it's also maintaining to reduce oscillation of the output FETs, integrated FETs. So while I'm integrating them, we'll also ensure a very good performance, by minimizing their oscillation. Going back to the topology, because of the peak current mode control pulse with modulation architecture, there is also a fast transient response that this part can have, can ensure. Also, the part has synchronization, as a sync pin. If the sync pin is tied high, that can ensure PWM, forced PWM operation. If the sync pin is tied low, then there will be a forced PFM.

However, the part will have a very good transition, PFM to PWM, because of this architecture. Also, in PWM mode the frequency can be internal, D4 500kHz, while external selectable from 300kHz to 2MHz optimized component inefficiency. And also output voltage is selectable from 0.6V all the way to 95% of the input voltage. Quiescent current is also very low on the part, as well as shutdown current. Enable and power-good are also additional added features. That is also explained in the data sheet. All these features and calculations are explained in the application note and data sheet. You might refer to them.

Because of its wired input voltage range, eight out of ten design engineers would have a need to use this part in their application, from consumer devices to industrial markets.