LMP90100EB/NOPB National Semiconductor, LMP90100EB/NOPB Datasheet - Page 9

• Manufacturer Part Number: LMP90100EB/NOPB
• Description: EVAL BOARD FOR LMP90100
• Manufacturer: National Semiconductor

Specifications of LMP90100EB/NOPB

• Main Purpose: Interface, Analog Front End (AFE)
• Embedded: No
• Utilized Ic / Part: LMP90100
• Primary Attributes: 8 Programmable Output Data Rates Per Channel
• Secondary Attributes: SPI Interface
• Silicon Manufacturer: National
• Silicon Core Number: LMP90100
• Kit Application Type: Data Converter
• Application Sub Type: ADC
• Kit Contents: LMP90100 Evaluation Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

© 2009 National Semiconductor Corporation
H. Connecting and Powering the Boards
I.
1.
2.
3.
Configuring the Device Using the Sensor AFE Software
1.
Connect the LMP90100EB’s JP12 to SPIO-4 Board’s J6 (pins 1-16) as seen in Figure 3.
Connect SPIO-4 Board to a PC via USB.
Use a multimeter to measure LMP90100EB’s JP6, JP7, and JP14.P2; they should all be approximately
5V. If they are not, check your power supplies and jumpers.
Follow the step-by-step instructions under the “HelpBar” mini-tab to configure the device. The
recommended configuration can be seen in Figure 7.
a.
b.
c.
d.
e.
f.
g.
h.
i.
Step 1: Select a Sensor - select “DC”  “DC” since the input source is a DC voltage
Step 2: Configure Inputs – click on the “INPUT MUX” block to set “VINP = 000: VIN0” and
“VINN = 000: VIN0”. Since VINP = VINN, a reading of approximately 0V should be read.
Step 3: Select Reference – click on the “VREF MUX” block to choose “VREF_SEL = 0: VREF1”.
On the left hand side of the GUI, change the VREF1 value to 5.0V as seen below.
Step 4: Source IB1/IB2? – this step can be ignored because neither IB1 nor IB2 is connected to the
inputs.
Step 5: Set Gain – since VIN = 0V, the maximum gain that can be set is 128x. Click on the “FGA”
block, “PGA” block, or the “Gain” slider to select the gain.
Step 6: Set Buffer – click on the “BUFF” block to include or exclude the buffer from the signal path.
Step 7: Set Calibration - the purpose of this example is to show how the LMP90100 removes the
offset error using background calibration. Initially, disable the calibration by selecting “000: No
Calibration” under the “No Calibration” block.
Refer to the LMP90100 datasheet to more information on the LMP90100’s background calibration
types and modes.
Step 8: Int/Ext CLK? – click on the “CLK MUX” block and make sure the internal clock is selected.
Step 9: Performance - click on the “Performance” mini-tab. This tab displays the Estimated
Device Performance base on the block diagram that you’ve configured, as well as the Measured
System Performance if you’ve connected a board and ran the LMP90100.
Page 9 of 30
with Sensor AFE Software User’s Guide
lmp90100eb_usersguide_20101227_v23.doc
LMP90100 Evaluation Board