ISL94203 Highly Integrated Battery Pack Monitor Protects and Extends Life of Mulit-Cell Li-ion Batteries
Hello, my name is Dan Goodhew, and I'm an Applications Engineer for Intersil. Today I'd like to talk to you about the ISL94203 Battery Management IC.
OEMs today don't use lead-acid battery or nickel-cadmium battery, but instead they've embraced the more environmentally friendly lithium-ion chemistries.
Lithium-ion batteries have a high energy density, allowing them to be small in size and weight. However, they also have a drawback. Lithium-ion cells are only operable safely within a small window, and operating outside of this window can be very serious because the high energy density causes catastrophic effects. Hence the need for a battery management system. The ISL94203 is a complete standalone system with the ability to support three to eight lithium-ion cells in a battery pack.
The device has monitors to protect the battery pack and also has the circuitry to drive high side N-channel FETs to turn the battery pack on and off in the case of a fault condition. It also allows the ability to balance cells for increased on time of the battery and increased battery life expectancy.
The ISL94203 also has an eval board for sale. The eval board includes three boards, as well as the user software. The boards are the device on a test board, a board to simulate a battery pack and also allows you to attach a load such as this LED pack that is currently attached, and also an interface board. The interface board allows the computer to talk to the device via I2C and the user interface software.
So, let's take a look at the software. Upon startup, the GUI displays the pack settings, which allows the user to select the threshold levels for all of the monitors that are monitoring the battery cells.
Clicking on the AD button also brings up another form that allows the user to have a visual graph of one of the monitored conditions. Selecting "Current," we can see the current through the system due to the flashing LED pack.
To see an example of how changing a threshold will affect the system, let's go back to the main menu and under the "Disharge over current" condition, we will change the setting from 32 mV to 8 mV. We'll write the pack setting, and now we're going back to the AD form. We see that while the high-frequency pulses are still here, the low-frequency pulse goes away. The reason for this is because the system detects the over current condition, and due to the delay period being exceeded, it shuts down the battery pack. Similarly, if we change the discharge short circuit current to 60 mV and the timing to 40 ms, and write that to the pack settings, we will see that now there is a solitary pulse. A short circuit is detected and so the pack is shut down.
In summary, the ISL94203 is a complete battery management solution that gives you the ability for the user to safely use lithium ion battery packs, and also provides an extended battery life.
For samples or to download the datasheet, please visit www.intersil.com/products/isl94203
Thank you for watching!