Texas Instruments TRF370 Series, User Manual

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User's Guide
SLWU062 – March 2010
TRF370x Quadrature Modulator Evaluation Module
1 Overview
This document relates to the TRF370x direct quadrature modulator for applications in the transmit path of
base stations and communications equipment. The quadrature modulator is used for upconversion of
signals from the transmit chain DAC to the RF power amplifier device. Evaluating modulator complex
performance involves careful bias-voltage setup, an LO signal, and two differential (I/Q) signals at the
input of the modulator. This document describes the wide range of test options available and the factors
that must be considered in using this EVM.
1.1 Purpose
The TRF370x evaluation module (EVM) is intended for the evaluation of the TRF370333, TRF370317,
TRF370315, and TRF370417 direct-launch quadrature modulators. Unless otherwise stated, the
functionality described in this manual applies to all the TRF370x devices.
1.2 EVM Circuit Overview
The EVM comes configured for differential I/Q input signals via four SMA connectors as shown in the
schematic,
Figure 14 , and in Table 1 .
For the upper sideband, the I signals are connected to J4 (I+) and J3 (I–). The Q signals are connected to
J5 (Q–) and J6 (Q+). The LO signal is fed to SMA connector J1, whereas J2 must be terminated with 50
Ω
to ground. SMA connector J7 is used to monitor the RF output signal from the quadrature modulator (U1).
The quadrature modulator requires a supply voltage of 4.5 V–5.5V from a regulated power supply through
headers TP2 and TP4.
The TRF370x quadrature modulators require a dc common-mode bias voltage (3.3 VDC, 1.7 VDC, or 1.5
VDC, corresponding to the last two digits of the part number) on all four input pins.
1.3 Power Requirements
The TRF370x EVM requires two 5-V V
CC
dc power-supply connectors through headers TP2 and TP4.
Header TP4 supplies 5 V to the LO circuitry, and TP2 supplies 5 V to the modulator circuitry.
CAUTION
Voltage Limits
Exceeding 5.6 V may damage the TRF370x.
5 SLWU062 – March 2010 TRF370x Quadrature Modulator Evaluation Module
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