The SZG-DBG-STD is a pass-thru debug and development accessory for SYZYGY carriers and peripherals. Each board has two SYZYGY connectors, both the carrier connector and the peripheral connector. With them, it can breakout signals from either a carrier or a peripheral, or it can be placed between a carrier and a peripheral and be used to sense the signals that pass between them.

It also has multiple options for powering peripherals to aid in new hardware testing and debugging. Power can pass from the carrier to the peripheral, power can be supplied from an external power supply, or power can be supplied from onboard linear regulators connected to an external power supply via the barrel jack connector. The power connection for each SYZYGY rail (5V, 3.3V and VIO) can be selected independently using jumpers.

SYZYGY Pass-Thru Device

Note that the SZG-DBG-STD is not a SYZYGY-compliant device because it does not contain the SYZYGY DNA. It is intended for use with a compliant peripheral to allow convenient access to the signals for development purposes.




All of the SYZYGY I/O signals that pass between the SYZYGY carrier and peripheral connectors on the SZG-DBG-STD can be accessed via 0.1″ headers. The headers are labeled according to the standard SYZYGY signal names.

There are additional headers with access to the SYZYGY DNA I2C bus wires, as well as the SYZYGY global address resistor wire.


There are three different options for providing power to the connected SYZYGY peripheral. Each option can be selected for each power rail independently using a jumper placed on the Peripheral Power Selection header block. The silk screen indicates the jumper position for each power source option. A single jumper should be placed for each row, to select the peripheral power source for the indicated power rail.

Carrier Pass Through Power

Power can be passed through the SZG-DBG-STD from the carrier to the peripheral. All onboard or external power sources for the rail will be disconnected from both the SYZYGY carrier and peripheral for the select rail when using the carrier power connection option.

Onboard Regulator Power

The SZG-DBG-STD has three onboard linear regulators that can supply power to the SYZYGY peripheral. These regulators take a DC input voltage of 7V to 15V supplied via the DC barrel jack. Alternatively, input power can be connected to the 2 pin header P8. The switch S1 controls the input power flow to the onboard regulators and can be used to turn the supplied peripheral power on and off.

The onboard linear regulators are the Diodes Incorporated part AZ2117H-ADJTRG1.

RailVoltageRegulator Designator

By default, the VIO rail regulator is configured to supply 1.8V. This can be customized by changing the feedback resistors for the regulator. See the regulator part datasheet for information on calculating the feedback resistor values. R7 is the top side VIO regulator feedback resistor, and R6 is the bottom side (connected to ground).

External Power

Test point loops are provided in the External Power Input PCB area to allow for one or more external power supplies to be clipped to the SZG-DBG-STD. These external rail connections make it easy to use bench top power supplies to apply custom voltages or enable current limiting features for prototype peripheral testing.

Power Status LEDs

There are included power LEDs for each SYZYGY power rail. The LEDs will light when the peripheral rail has power applied.

The VIO rails LED may be dim or off depending on the operating voltage of the rail.

SYZYGY Compliance

The SZG-DBG-STD is not a SYZYGY compliant device in its own right. It does not have its own SYZYGY DNA. When used as an interposer between a SYZYGY carrier and peripheral, the peripheral’s DNA is presented to the carrier as if it were directly connected.