PowerNavigator Software GUI: Designing a System with the ISL68200
Hi, my name is Brandon Howell, Product Marketing Manager for Intersil digital power products. In this video, we are talking about the development platforms available for our new ISL68200 and ISL68201 hybrid digital controllers. We have three demo boards available to support these products. The ISL68200 includes the ISL68200 with the 5mm by 6mm FET power stage.
The ISL68201DEMO1Z includes our ISL99140 6x6 DrMOS. We also have a compact ISL68201 featuring 5x5mm DrMOS power stage in a 13x13mm area. After you selected your demo board platform of choice, our PowerNavigator software can be downloaded from our website and used to interface with the demo board.
In this video I'll run through an example of PowerNavigator when used with our ISL68200DEMO1Z board.
On the screen here, I'm showing our PowerNavigator software connected to our ISL68200DEMO board. The software has gone through and scanned in from the demo board on our PM bus interface.
By clicking the start button it'll take us to the PowerNavigator launch page. On the launch page we have the power map which shows the ISL68200 demo board, the monitor view which shows the real time telemetry including output voltage, the input voltage, the switching frequency, the temperature and the output current.
If I double click on the ISL68200 icon on the power map, it'll launch me into the device rail inspector window. Rail inspector is used as both the design tool and a configuration tool for our 68200DEMO board platform. On the left hand side is a navigation window that guides you through the design of an ISL68200 controller.
The design requirements tab will ask you for the main requirements for design. This includes the input voltage, the output voltage in a load current. And this is an example we have a 12-volt input with a one-volt output, the Vout tolerance is 5%, the Vout ripple tolerance is 1% or 10 millivolts, and the max load current is 30 amps.
The max load step is assumed to be one half of the max load current or 15 amps and the over current trip point is one 125% of the max load current or 37.5 amps.
On the next screen, we walk you through component selection. This screen shows the power stage that is used with the ISL68200DEMO board. By clicking on each component you can enter the device name, the quantity and all the device parasitics that are associated with it. In this case this is the upper mosfet, I can click through and look at the lower mosfet the output inductor and the output capacitors.
You can also select the switching frequency for your design, in this case 400 kilohertz, as you make design decisions, the inductor ripple current and the peak full load current are automatically calculated for you. On the next page we generate a full efficiency curve based on the components you selected in the input voltage, the output voltage and switching frequency.
In this design case we have a 12 volt in to one volt out with a peak efficiency of 91.4% and a full load efficiency of 89.3%. You can make on the fly design decisions such as changing the switching frequency and see what effect that has on the overall efficiency. For example, if I adjust the switching frequency from 400 kilohertz to 300 kilohertz I'll notice an improvement in my peak and full load efficiency at the cost of overall design size in Vout ripple.
The next page walks you through the over current settings for the device. In this case we have desired over current trip point of 37.5 amps, PowerNavigator automatically calculates the correct resistor values to use to set this over current trip point as displayed here.
On this page we look at the four configuration pins that are used to set up the ISL68200, the program one pin is used to set the output voltage, the program two is use a set PFM or light load efficiency operation on or off, temperature compensation in your PMBus address. Program three, sets your over current retry or latch off option, your switching frequency, your R4 control loop gain and an optional 25 kilohertz clamp for light load efficiency. Program four sets up your soft start rate another R4 gain parameter and your AV multiplier. As I make changes in real time, PowerNavigator automatically calculates what the correct resistors are needed to set those values on each pin.
The next page is a design verification page, and this page which generate a bode plot and output impedance plot of your design. The bode plot can be used to check for regulator stability and the output impedance plot can be used check for overall design goals with respect to transiting performance.
The final page shows a schematic that is fully generated for your design. The schematic includes the mosfets, the output inductor and output capacitors you've selected, as well as the resistor values needed for each of the four configuration pins. This schematic matches our demo board of reference schematic and can be used to start your design.
So the process of five minutes, we've gone through and made a full design for ISL68200 controller using our PowerNavigator design software. This showcases the ease of use and just how simple it is to go from design requirements to a full design with our new controller family.