Texas Instruments TRF1500 manual Low-Band LNA Turn on Time

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SWRA004A

Low-Band LNA

In a typical down-conversion receiver, the LNA is usually placed directly after the antenna and a band-select filter. The purpose of the LNA is to amplify the desired signal being received while adding as little undesired noise and distortion as possible. The TRF1500 LNA is a common emitter amplifier, designed to operate on a single 3.75 volt supply. The LNA has two selectable gain states, normal state or strong signal state, which are controlled with the digital CMOS control lines. The strong signal state, which disables the LNA, is provided for operation in a high signal environment such as near the base station. Operating near the base station in the normal state could cause an increase in the intermodulation product levels and thus cause undesired noise and distortion in the receiver. Stand-alone LNA performance can be ascertained by reconfiguring the evaluation board as noted on the datasheet.

Low-Band LNA Turn on Time

The turn on time can be adjusted by changing the values of C10, R6 and R7, as shown in Figure 3 and Figure 4. The resistors form a voltage-divider network across the supply, Vcc. The function of this network is to provide a bias condition near the ideal operating region at the base of the common emitter amplifier. By providing this bias condition, the charge time of the series capacitor, C10, can be adjusted. Changing the value of resistors should not affect gain, IIP3 or noise figure (NF) performance.

Figure 3. Voltage Divider at Low-Band LNA Input

TRF1500 Integrated Dual-Band RF Receiver User’s Guide

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Contents TRF1500 Integrated Dual-Band RF Receiver User’s Guide Important Notice Trademarks PIC Telephone Contents Appendix a Test Bench Configuration Figures TablesTRF1500 Integrated Dual-Band RF Receiver User’s Guide AbstractProduct Support Ingl E Chip Anal OG AS E BRelated Documentation World Wide WebIntroduction Design Considerations External ComponentsBoard Design and Impedance Matching TRF1500 Dual-Band Receiver Block Diagram TRF 1500 Dual-Band ReceiverPin Descriptions Pin Number Name DescriptionStrong Signal TRF1500 Control State Control State and the Corresponding Active CircuitsCascaded Block Diagram of the Low-Band Receiver Section Low-Band LNA Low-Band LNA Turn on TimeLow-Band LNA Input Low-Band LNA OutputLow-Band LNA Output Configuration Surface Acoustic Wave SAW FilterLow-Band Mixer Low-Band Mixer RF InputLow-Band Mixer LO Input Low-Band if OutputLow-Band if Output Configuration Low-Band LO Buffer Amplifier OutputLow-Band Buffer Amplifier Output Configuration LOW-Band Cascaded Power Conversion Gain Low-Band Cascaded Test GuideLB LNA, LB Mixer, SAW Filter, and LB if Amp Parameters Low-Band Cascaded Power Conversion Gain Reduction Low-Band Cascaded Noise Figure TRF1500 Integrated Dual-Band RF Receiver User’s Guide Low-Band Cascaded RF Input Return Loss Low-Band Cascaded LO Input Return LossLOW Band LO Buffer Output Power Low-Band Power Leakage LO In to RFLow-Band Cascaded Third Order Input Intercept Point IIP3 Low-Band Cascaded 1dB RF Input Compression Point Low-Band Cascaded 1dB Blocking Point Block Diagram of the High-Band Receiver Section High-Band RF Input High-Band LO InputHigh-Band LO Frequency Doubler Driven Configuration High-Band if Output Configuration High-Band if OutputHigh-Band LO Buffer Amplifier Output Configuration High-Band LO Buffer Amplifier OutputHigh-Band Cascaded Power Conversion Gain High-Band Cascaded Test GuideHB LNA, HB mixer, HB if amp High-Band Cascaded Power Conversion Gain Reduction High-Band Cascaded Image Rejection High-Band Cascaded Noise Figure High-Band Cascaded RF Input Return Loss High-Band LO Buffer Output Power High-Band Cascaded Power Leakage LO In to RF High-Band Cascaded Third Order Input Intercept Point IIP3High-Band Cascaded 1dB Input Compression Point High-Band Cascaded 2X2 Spur Performance High Band 3X3 Spur Performance Low-Band and High-Band Transmit Low- and High-Band Transmit MixerLow-Band and High-Band Transmit Mixer RF Input Low- and High-Band Transmit Mixer RF Input Configuration Low- and High-Band Transmit Mixer if Output ConfigurationLow-Band Transmit Mixer Power Conversion Gain Low-Band Transmit Mixer Test GuideLow-Band Transmit Performance Parameters Low-Band Transmit Mixer Noise Figure Low-Band Transmit Mixer Input Return Loss Low-Band Transmit Mixer Power Leakage LO In to TX Low-Band Transmit Mixer Power Leakage TX In to LOLow-Band Transmit Mixer 1dB Input Compression Point See Appendix a Test Bench Setups See Appendix a Test Bench Setups High-Band Transmit Mixer Test Guide High-Band Transmit Mixer Performance ParametersLow-Band LNA Input Return Loss Low-Band LNA Stand-Alone Test GuideLow-Band LNA Gain Low-Band LNA ParametersLow-Band LNA Output Return Loss Low-Band LNA IsolationLow-Band LNA 1dB Input Compression Point Low-Band LNA Noise Figure Low-Band LNA Third Order Input Intercept Point IIP3 TRF1500 Integrated Dual-Band RF Receiver User’s Guide Low-Band Receiver Mixer Power Conversion Gain Low-Band Receiver Mixer Stand-Alone Test GuideLow-Band Receiver Mixer Parameters Low-Band Receiver Mixer Input Return Loss Low-Band Receiver Mixer Power Leakage LO In to RF Low-Band Receiver Mixer Noise FigureTRF1500 Integrated Dual-Band RF Receiver User’s Guide Low-Band Receiver Mixer 1dB RF Input Compression Point 12.2 11.4 10.4 ←1dB Compression Point TRF1500 Integrated Dual-Band RF Receiver User’s Guide Appendix a Test Bench Configuration Test Bench Setup Noise Figure Test Bench Setup Power Leakage RF In to LO In Measurements Test Bench Setup LNA 1dB Input Compression Point