Silicon Laboratories Si5350/51-B20QFN-EVB, User Manual

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Si535x-B20QFN-EVB
4 Rev. 0.3
2. Jumpers
The following jumpers are available on the evaluation board:

VDD— Connects the Si5350/51 pin to the VDD voltage regulator (normally installed).

VDD VOLT_SEL —Allows user to select a VDD voltage of 2.5 V or 3.3 V (default 3.3 V).

VDDOA —Connects the Si5350/51 pin to the VDDOA voltage regulator (normally installed).

VDDOA VOLT_SEL —Allows user to select a VDDOA voltage of 1.8 (jumper removed), 2.5, or 3.3 V
(default).

VDDOB —Connects the Si5350/51 pin to the VDDOB voltage regulator (normally installed).

VDDOB VOLT_SEL —Allows user to select a VDDOB voltage of 1.8 (jumper removed), 2.5, or 3.3 V
(default).

VDDOC —Connects the Si5350/51 pin to the VDDOC voltage regulator (normally installed).

VDDOC VOLT_SEL —Allows user to select a VDDOC voltage of 1.8 (jumper removed), 2.5, or 3.3 V
(default).

VDDOD —Connects the Si5350/51 pin to the VDDOD voltage regulator (normally installed).

VDDOD VOLT_SEL —Allows user to select a VDDOD voltage of 1.8 (jumper removed), 2.5, or 3.3 V
(default).

SCL —Connects the Si5350/51 SCL pin to the I
2
C bus from the MCU. Removing the jumper breaks the
connection to the MCU and allows the user to feed in an external I
2
C signal to the device.

SDA —Connects the Si5350/51 SDA pin to the I
2
C bus from the MCU. Removing the jumper breaks the
connection to the MCU and allows the user to feed in an external I
2
C signal to the device.

EXT POWER —Allows user to select between 5 V USB supply and 5 V external supply on J17. See
Figure 1 for jumper locations.
3. Status LEDs
There are three status LEDs on the evaluation board:

RDY (Green)—Indicates that the EVB is operating normally. This LED should always be on.

BUSY (Green)—Indicates that the on-board MCU is communicating with the device and/or the USB host.

INTR (Red)—Indicates device or EVB fault condition (also on when DUT hasn't been programmed).
4. Clock Inputs
The EVB can operate in asynchronous mode using the onboard 27 MHz crystal, synchronous mode using an
external CMOS clock source, or both modes. An SMA connector and test points are provided to interface an
external clock source to CLKIN. Additionally, in the Si5350/51B mode, V
C
input can be applied to either the V
C
test
point or SMA connection.
5. Clock Outputs
Outputs can be measured using either SMA cables attached directly to an oscilloscope (recommended) or with
high impedance probes at the output clock test loops (TP53-TP60).
Clock voltage levels can be 1.8, 2.5, or 3.3 V depending on the VDDOx VOLT_SEL jumper selection.