Overview

These modules are carrier boards or breakout boards for the ISO654x general purpose functional isolators from Texas Instruments; we therefore recommend referring to the ISO654x datasheet for detailed specifications. The ISO654x features four digital channels that enable communication between two galvanically (electrically) isolated devices at up to 50 Mbps per channel. This isolation means that current cannot flow from one side to the other, and incorrect connections or bad voltages on one side cannot propagate through to damage the device on the other side. It also means the logic voltage can be at different levels on the two sides, allowing these carrier boards to function as level shifters.

The six IC versions feature different combinations of channel directions and default output behavior as shown in the table below:

	Pololu Item #	IC part number	Default output	Channels	Max data rate	Working voltage 1	Min PCB Creepage 2	Size	Price
ISO654x carrier	#5740	ISO6540	high	4 forward, 0 reverse	50 Mbps	400 VRMS	5.3 mm	0.6″×0.7″	$2.75
	#5741	ISO6540F	low
	#5742	ISO6541	high	3 forward, 1 reverse
	#5743	ISO6541F	low
	#5744	ISO6542	high	2 forward, 2 reverse
	#5745	ISO6542F	low
Note 1: IC component functional isolation rating per manufacturer datasheet.
Note 2: Minimum creepage along PCB surface based on layout design only. Other creepage distances, e.g. along the body of the component, may be lower.

Pinouts of the ISO654x 4-Channel Digital Isolator Carrier series.

Details for item #5740

This is the version features the ISO6540, which has all four channels in the forward direction and defaults to high in the event of input power or signal loss. It can be differentiated from the other versions by the “6540” marking on the IC, and there is also a blank white rectangle on the bottom silkscreen for adding your own distinguishing marks.

Pinout of the ISO6540/ISO6540F 4-Channel Digital Isolator Carrier.

Each side must be powered separately across its respective VCCx and GNDx pins, and the voltages on the two sides can be at different levels. The two sides are galvanically isolated (GND1 is NOT connected to GND2).

Schematic diagram of the ISO654x 4-Channel Digital Isolator Carrier.

Isolation rating and board creepage considerations

The ISO654x provides functional isolation with a manufacturer-rated working voltage of 400 V_RMS. The IC package has a clearance and creepage of >3.7 mm, and our carrier PCB has a routed slot under the IC that increases the PCB creepage to 5.3 mm. A rough rule of thumb is that uncontaminated FR4 PCBs should have roughly 1 mm of creepage per 100 V_RMS of isolation. Please note that these carrier boards are not certified to any particular safety standard.