MCP355XDM-TAS Microchip Technology, MCP355XDM-TAS Datasheet - Page 12

• Manufacturer Part Number: MCP355XDM-TAS
• Description: BOARD DEMO TINY APP SNSR MCP355X
• Manufacturer: Microchip Technology

Specifications of MCP355XDM-TAS

• Number Of Adc's: 1
• Number Of Bits: 22
• Data Interface: Serial
• Inputs Per Adc: 1 Single Ended
• Input Range: ±3 V
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 125°C
• Utilized Ic / Part: MCP355x
• Processor To Be Evaluated: MCP355x
• Interface Type: USB
• Silicon Manufacturer: Microchip
• Silicon Core Number: MCP3551, MCP3553, MCP3550-50, MCP3550-60
• Kit Application Type: Data Converter
• Application Sub Type: ADC
• Kit Contents: Board Cable Docs
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Not applicable / Not applicable

MCP355X Tiny Application Sensor Demo Board User’s Guide
2.3
DS51598A-page 8
FUNCTIONAL BLOCK DESCRIPTIONS
Ground
Analog
Plane
SM5420
Power Supply
Filtering
FIGURE 2-2:
2.3.1
The SM5420 device is an absolute pressure sensor in a surface mount SOIC package.
The device is a piezo resistive silicon device available from Silicon Microstructure.
With a constant excitation voltage, the output changes linearly with pressure. The zero
scale error of the device is rated at ±10 mV/V and the full scale output is rated at
60 mV/V ±20 mV. These large errors require an overall system calibration, as well as
temperature compensation for a working absolute pressure sensor design. This board
demonstrates the overall system resolution and noise performance of the ADC and
sensor with no voltage reference.
2.3.2
The MCP3551 is a 22-bit Delta-Sigma A/D converter. The device includes a third-order
modulator, fourth-order digital SINC filter, internal oscillator for oversampling clock and
digital logic for a simple SPI interface.
Digital SINC Filter
The MCP3551 device includes a digital decimation filter, which is a fourth-order modi-
fied SINC filter. This filter averages the incoming bitstream from the modulator and out-
puts a 22-bit conversion word in binary two's complement. When all bits have been
processed by the filter, the output code is ready for SPI communication, the RDY flag
is set on the SDO/RDY pin and all the internal registers are reset in order to process
the next conversion. This filter achieves greater than -80 dB of rejection at both 50 and
60 Hz. For improved performance, the MCP3550 device is available which gives
greater than -120 dB of rejection at either 50 or 60 Hz.
U3
SM5420
MCP3551
USB Power (Digital)
Analog Power & Reference
PIC18F4550
Block Diagram.
U2
Digital Ground
Plane
MCP3551
USB Connector
JP1
U4
© 2006 Microchip Technology Inc.
USB Power & Data