What is it?

This is a breakout board for the TI ISOW7841 digital isolator with a built-in DC/DC from TI.

The board provides breakout pins for the 4 isolated channels, plus a voltage select pin, and solder jumper pads, on the output side for 3.3 or 5 volts DC/DC output.

By default the solder bridges are not soldered, thus the VCC on the output side is set to 3.3V.

The board comes with the "FA" variant, meaning the output state will be logic LOW.

The ISOW7841 IC from TI can be used with an input voltage range of 3 to 5.5 5.5 Volts (making it perfect for both 3.3V and 5V systems). It is very robust with an isolation voltage of 5kVRMS and can operating at up to 100Mbps. The IC features 3/1 configuration (please see IC block picture).

The built-in DC/DC can output 3.3V or 5V, depending on the state of the SEL pin. The output current can be used to provide power to external circuitry like an MCU and/or sensor. The output current limit are as follows (with a power limit of 650mW):

• 5V to 5V --> 130mA
• 5V to 3.3V --> 130mA
• 3.3V to 3.3V --> 75mA
• 3.3V to 5V --> 40mA

The DC/DC also has the following features:

• Soft-start to limit the inrush current
• Overload and short circuit protection

This is a great module for those looking to isolate grounds or communicate between high and low voltage zones. This makes an excellent isolator for SPI or UART communication. It needs no power supply with the built in DC/DC.

All components used are able to be used with an operating temperature range of -40 degC to + 85 degC.

The header pins will need to be soldered by the customer.

Why did you make it? I didn't see any board on the market that has the features of the ISOW7841 IC with reliable, high quality parts. Also, the dual row headers help in development because you can probe one pin while the other one can be connected to a signal.

What makes it special? We use parts from reputable distributors and resellers. Board designed and built in the USA!