Microchip Technology TSSOP20EV Data Sheet

DS51875A-page 18

© 2009 Microchip Technology Inc.

The 20-Pin TSSOP and SSOP Evaluation Board PCB is designed to be flexible in the 
type of device evaluation that can be implemented.

The following sections describe each element of this evaluation board in further detail. 

The 20-Pin TSSOP and SSOP Evaluation Board has a VDD pad and a VSS pad. These 
pads can have connection posts installed that allows easy connection to the power 
(V

DD

) and ground (V

SS

) planes. The layout allows either through-hole or surface-mount 

connectors.

The power and ground planes are connected to the appropriate passive components 
on the PCB (such as power plane to RXU and ground plane to RXD components).

For each package pin (pins 1 to 8), there is a PCB pad (pads 1 to 8). The device will 
have some power pins (V

DD

) and some ground pins (V

SS

). To ease connections on the 

PCB, vias to the power and ground plane have been installed close to each PCB pad. 
This allows any pad to be connected to the power or ground plane, so when power is 
connected to the VDD and VSS pads, the power is connected to the appropriate device 
pin (see Figure 2-4).

The footprints for these components are present to allow maximum flexibility in the use 
of this PCB to evaluate a wide range of devices. The purpose of these components may 
vary depending on the device under evaluation and how it is to be used in the desired 
circuit. Refer to the device data sheet for the recommended components that should 
be used when evaluating that device.

• Component RXU allows a pull-up resistor to be installed for the device pin

• Component RXD allows a pull-down resistor or a a capacitive load/filter to be 

installed for the device pin

• Component C1 and C2 allows power supply filtering capacitors to be installed

Jumpering to VDD   

or   

or   

Ω 

Ω