Cypress Semiconductor Cy8CKIT-050 Cy8CKIT-050B ユーザーズマニュアル

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CY8CKIT-050 PSoC® 5LP Development Kit Guide, Doc. # 001-65816 Rev. *E

Hardware

Two jumpers govern the power rails on the board. J10 is responsible for the selection of Vddd (digital
power) and J11 selects the VADJ of Vdda (analog power). 

The jumper settings for each power scheme are as follows.

Warning: 

■

The PSoC device performance is guaranteed when Vdda is greater than or equal to Vddd. Fail-
ure to meet this condition can have implications on the silicon performance.

■

When USB power is used, ensure a 3.3 V setting on both analog and digital supplies. This is 
because, the 5-V rail of the USB power is not accurate and is not recommended.

The board is designed considering analog designs as major target applications. Therefore, the
grounding scheme in the board is unique to ensure precision analog performance. 

This ground has three types of ground:

■

GND - This is the universal ground where all the regulators are referred. Both Vssd and Vssa 
connect to this ground through a star connection.

■

Vssd - This is the digital ground and covers the digital circuitry on the board, such as RS-232 and 
LCD. 

■

Vssa - This is the analog ground and covers the grounding for analog circuitry present on the 
board, such as the reference block.

When creating custom circuitry in the prototyping area provided on the board, remember to use the
Vssa for the sensitive analog circuits and Vssd for the digital ones. 

Port E on the board is the designated analog expansion connector. This connector brings out
ports 0, 3, and 4, which are the best performing analog ports on PSoC 3 and PSoC 5 devices. The
expansion connector, port E, has two types of grounds. One is the analog ground (GND_A in silk
screen, Vssa in the schematic), which connects directly to the analog ground on the board. The
other ground, known as GND, is used for the digital and high current circuitry on the expansion
board. This differentiation on the connector grounds helps the expansion board designer to separate
the analog and digital ground on any high precision analog boards being designed for port E. 

The kit also facilitates application development, which requires low power consumption. Low-power
functions require a power measurement capability, also available in this kit. 

The analog supply is connected to the device through the zero-ohm resistor (R23). By removing this
resistor and connecting an ammeter in series using the test points, Vdda_p and Vdda, you can
measure the analog power used by the system. 

The digital supply can be monitored by removing connection on the jumper J10 and connecting an
ammeter in place of the short. This allows to measure the digital power used by the system. 

Vdda = 5 V, Vddd = 5 V

J10 in 5 V setting and J11 in 5 V setting.

Vdda = 3.3 V, Vddd = 3.3 V

J10 in 3.3 V setting and J11 in 3.3 V setting.

Vdda = 5 V, Vddd = 3.3 V

J10 in 3.3 V setting and J11 in 5 V setting.

Vdda = 3.3 V, Vddd = 5 V

Can be achieved, but is an invalid condition because the PSoC 5LP silicon 
performance cannot be guaranteed.