A2B Converter modules

Clockworks’ A²B Converter modules can be used to convert between the two power schemes and the three connector types found on Analog Device’s hardware. With an easily made adapter cable the appropriate module can convert pretty much “any to any”.

All modules galvanically isolate input to output, including power if the module supports input to output power generation. No software changes are needed when using these modules except if the converter module will provide downstream power; then the upstream AD243x device must provide CFG4 power as always on (versus the normal software probe).

Module have jumpers to enable the power options. The details are best understood by looking at the schematic for the module(s) of interest.

This is important when mixing CFG4 (24V) and CFG0 (9V) parts, as applying CFG4 power to a CFG0 device will let the magic smoke out.

ADI Power schemes

CFG0: Supplies 9V at up to 300 mA. Used on AD242x and AD2433 devices. Typically used with 2 wire A²B connections, i.e. the bus power is sent over the same wires and the A²B data. Typically used with (tan) DuraClik connectors on the standard Clockwork A²B modules.

CFG4: Supplies 24V at up to 2 amps. Used with AD243x devices, except for the AD2433. There are three different ways this is implemented by ADI:

• 2 Wire: On Clockworks AD2437 based modules a red DuraClik connector is used. No checking of downstream devices is done.
• XLR: A 3 pin XLR connector is used. The scheme is very similar to how phantom power is used for active microphones. Software must first probe the downstream device to make sure it’s an A²B device that will accept 24V. This is done by first providing a power limited 5V to enable the downstream transceiver to respond to the upstream queries.
• RJ45: A standard 8 pin RG45 jack is used. One pair carries A²B and the other three pairs carry 24V. Like with the XLR scheme, software must probe the downstream device to make sure it as an A²B system and not some other device that might be damaged by 24V. Please note this is not a PoE like system.

Five different modules for conversion

To provide flexibility and out of the box solutions for many common needs Clockworks offers 5 different modules. While based on ADI’s standard connectors, adapter cables can allow use with any system. As with Clockworks other A²B products, custom versions are available on a fast-turn prototype/fixed NRE basis.

The AB0400 module accepts a CFG4 upstream connection and provides a downstream CFG0 connection. If power is available from the upstream node then the module will provide 9V at up to 300 mA to power downstream AD242x nodes.

The AB0401 module accepts a CFG4 upstream connection and provides a downstream CFG0 connection.

It does not have any power options, which really makes this a universal module for galvanically isolating A²B bus segments and protecting downstream nodes from CFG4 power.

Likewise IN and OUT are actually arbitrary as that concept mostly applies to cases where bus power is being used; data in an A²B system is bidirectional. Therefor this module could be used between two CFG4 systems, two CFG0 systems, or pretty much any other A²B system that can be imagined.

The AB0402 module accepts a CFG4 upstream XLR connection and provides a downstream CFG0 connection. If power is available from the upstream node then the module will provide 9V at up to 300 mA to power downstream AD242x nodes.

The AB0403 module accepts a CFG4 upstream RJ45 connection and provides a downstream CFG0 connection. If power is available from the upstream node then the module will provide 9V at up to 300 mA to power downstream AD242x nodes.

The AB0404 module is a little different than the other modules. It accepts a CFG4 upstream or CFG0 connection and provides a downstream CFG4 XLR connection. An external 24V 2 amp power input is used to power downstream devices.

This modules allows upstream AD242x CFG0 nodes to be used with downstream bus powered AD2437 nodes without needing to add a locally powered AD2437 node.

The external 24V input is polarity and power protected. There is no direct connection between the 24V/XLR output and the 2 wire Duraclik input.

A2B Converter modules datasheet

Module schematics and 3D pdfs

A²B is a trademark of Analog Devices Inc.