Texas Instruments TRF3705, Руководство пользователя

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EVM Test Procedure
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3 EVM Test Procedure
3.1 Single-Tone Output Power Test
1. Connect power supplies:
• Set V
CC
supply to 3.3 V and set the current limit to 500 mA.
•
Connect the V
CC
supply to header TP2. Connect the ground to TP1.
2. Use a suitable 50- Ω output signal generator to supply the LO signal with 0 dBm with the cable loss
compensated and the desired frequency f
LO
= 1 GHz to J1; terminate J2 with 50 Ω to ground.
3. Use a digital-to-analog converter or an arbitrary waveform generator to provide I/Q input signals. A
typical setup is as follows: a 1-Vpp sinusoidal wave in differential mode for both I and Q signals with a
frequency of f
1
, a dc offset of 0.25 V, and an output impedance of 50 Ω . Use an Agilent E4438C vector
signal generator to provide I/Q signals in the following example.
• Press Preset.
• Press Mode → More (1 of 2) → Multitone.
• Press Initialize Table → Number of Tones → 12 → Enter.
• Press Freq Spacing → 1 → MHz.
• Press Done.
• Highlight each row of the first 11 rows, and press Toggle State to turn the selected tone off; keep
only the last row with the BB frequency of 5.5 MHz. Now, 5.5-MHz, single-tone, BB I/Q signals are
configured for E4438C.
• Press Multitone Off/On until On is highlighted to generate the multitone waveform.
•
Connect I signals to J4 (I+) and J3 (I
–
), and the Q signals to J5 (Q
–
) and J6 (Q+).
• Adjust the differential I or Q voltage level to be 1 Vpp by pressing Mode → I/Q → I/Q Output
Control → I/Q Output Atten → enter 9 → Press dB. The voltage can be measured by an
oscilloscope. Note that the differential voltage is twice the single-ended voltage.
• Set the common-mode voltage (CMV) of E4438A to 0.25 V by pressing Mode → I/Q → I/Q Output
Control → Common Mode I/Q Offset → 250 → mV. Use a dc voltage meter to monitor the dc
common voltage at the inputs of I and Q, and fine-tune the CMV setting until it is measured to be
250 mV.
4. Verify that jumper connection of pin 2 and pin 3 on JP2 to set device in low gain mode
5. Verify that jumper connection of pin 2 and pin 3 at JP1 to ensure that power down is not engaged.
6. Monitor Vcc at TP1 to ensure that Vcc is 3.3 V. Verify that the current draw is about 305 mA
±
15 mA.
7. Connect a spectrum analyzer to the SMA connector marked RFOUT (J7), and measure the TRF3705
output power at f
LO
+ f
1
= 1005.5 MHz. The RF power must be 3.5 dBm ± 1 dBm after the RF cable
loss is compensated.
4 TRF3705EVM Evaluation Module SLWU073 – October 2011
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