Texas Instruments TRF4900, Руководство пользователя, Страница: 9 / 45

Purpose
1-2
1.1 Purpose
The TRF4900 evaluation module (EVM) provides a platform for lab prototype
evaluation of the Texas Instruments TRF4900.
The TRF4900 EVM board evaluates the RF performance of the TRF4900. It
contains a PC parallel port interface and operates from 850 MHz to 950 MHz
from 2.2 V to 3.6 V. The TRF4900 EVM contains two SMA connectors that
allow the user to observe transmitted data, to test the VCO tuning range, or
to feed in an external RF input. The transmitted data can be viewed on a
spectrum analyzer as either a single output frequency or in FSK mode at data
rates up to 30 kbps. Although higher data rates are achievable with the
TRF4900, the TRF4900 EVM is designed to operate at data rates up to 30
kbps at room temperature.
1.2 EVM Setup
The 3.5-inch diskette supplied with the TRF4900 contains the software
required to demonstrate the TRF4900. Complete the following steps to set up
the TRF4900 for evaluation.
Step 1: Place the 3.5-inch diskette into the floppy disk drive of the computer
being used to evaluate the TRF4900.
Step 2: Copy the TRF4900.exe file to the hard drive.
Step 3: Connect a DB25 female to a DB25 male cable between the TRF4900
evaluation board and the PC parallel port. The DB25 female end of
the cable is connected to the TRF4900. The DB25 male end of the
cable is connected to the desired LPT port of the PC (LPT1 or LPT2).
Step 4: Connect a dc power supply capable of 10 V 200 mA between the red
power supply pin and ground on the TRF4900 evaluation board.
Step 5: Verify that the power supply output is set to 8 V.
Step 6: Turn the power supply on.
Step 7: If the jumper at JP4 is installed, verify that LED3 (the red power on
LED) is illuminated.
Step 8: Run the TRF4900.exe file on the PC.
Step 9: Press the Send Words Now (F12) button located on the main
program screen.
Step 10: Verify that LED1 (the green lock detect LED) is illuminated. When the
lock detect LED is illuminated, the PLL is locked on frequency.
Note:
The actual icons/windows on the computer screen may differ from those
shown in the user’s guide, due to software version upgrades.
The schematics shown in this user’s guide may not match the current
revision, due to PCB and component upgrades.
Always check the TI website for the latest schematics and software.