User manual

Hardware Description

 2010 Microchip Technology Inc. DS51845B-page 13

1.4 ANALOG INPUT STRUCTURE

Two differential input paths allow external signal sources to be easily connected to the

MCP3901 input. Edge connectors JP1 and JP2 are 3-pin connectors that act both as

crew type and clip on post connectors.

JP1 and JP2 can be used to force either channel from a differential to single-ended

configuration. R3 and R4 (on CH0), and R1 and R2 (on CH2) act as locations for

burden resistor connectors for any current transformer inputs.

1.5 UNIVERSAL SERIAL BUS (USB)

The MCP3901 ADC Evaluation Board for 16-Bit MCUs also contains a USB connection

for higher speed sampling and data collection. The circuit includes a 512x8 SRAM for

data collection. Figure 1-5 summarizes the connections between the ADC, the two

microcontrollers and memory.

FIGURE 1-5: USB Block Diagram.

Note: To use an edge connector as a post connector, pull up the blue plastic top

to access posts.

Note: For the MCP3901 ADC Evaluation Board for 16-Bit MCUs release, no USB

firmware is supplied. The PIC18F86J55 is blank and only included for

development purposes.

SCK2/RG6

SDI2/RG7

SDO2/RG8

2/RG9

USB

RD6/SCK2

RD4/SDO2

RD5/SDI2

PIC18F86J55

RD7/SS

ADC

MCP3901

RF6/SCK1

RF7/SDI1

RF8/SDO1

SCK

SDO

SDI

USB

SERIAL

512x8

SRAM