MAX2608中文资料

General Description

The MAX2605–MAX2609 evaluation kits (EV kits) simplify evaluation of this family of voltage-controlled oscillators (VCOs). These kits enable testing of the devices’ per-formance and require no additional support circuitry.Both signal outputs use SMA connectors to facilitate connection to RF test equipment.

These EV kits are fully assembled and tested. Their oscil-lation frequencies are set to approximately the midrange of the respective VCOs.

Features

o Easy Evaluation

o Complete, Tunable VCO Test Board with Tank Circuit o Low Phase Noise

o Fully Assembled and Tested

Evaluate: MAX2605–MAX2609

MAX2605–MAX2609 Evaluation Kits

19-1673 Rev 0; 9/00

Ordering Information

Component Suppliers

For free samples and the latest literature, visit https://www.wendangku.net/doc/f36217357.html, or phone 1-800-998-8800.For small orders, phone 1-800-835-8769.

MAX2606 Component List

MAX2605 Component List

E v a l u a t e : M A X 2605–M A X 2609

MAX2605–MAX2609 Evaluation Kits 2

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Quick Start

The MAX2605–MAX2609 evaluation kits are fully assembled and factory tested. Follow the instructions in the Connections a nd Setup section for proper device evaluation.

Test Equipment Required

?Low-noise power supplies (these are recommended for oscillator noise measurement). Noise or ripple will frequency-modulate the oscillator and cause spectral spreading. Batteries can be used in place of power supplies, if necessary.

– Use a DC power supply capable of supplying +2.7V to +5.5V. Alternatively, use two or three 1.5V batteries.

– Use a DC power supply capable of supplying +0.4V to +2.4V, continuously variable, for TUNE.Alternatively, use two 1.5V batteries with a resistive voltage divider or potentiometer.

?An RF spectrum analyzer that covers the operating frequency range of the MAX2605–MAX2609? A 50?coaxial cable with SMA connectors ?An ammeter (optional)

Connections and Setup

1)Connect a DC supply (preset to +3V) to the V CC and GND terminals (through an ammeter, if desired) on the EV kit.

2)Turn on the DC supply. If used, the ammeter reading

MAX2607 Component List

MAX2608 Component List

Evaluate: MAX2605–MAX2609

MAX2605–MAX2609 Evaluation Kits

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3

approximates the typical operating current specified in the MAX2605–MAX2609 data sheet.

3)Connect the VCO output (OUT+ or OUT-) to a spec-trum analyzer with a 50?coaxial cable.4)Apply a positive variable DC voltage between 0.4V and 2.4V to TUNE.

5)Check the tuning bandwidth on the spectrum analyz-er by varying the tuning voltage (+0.4V to +2.4V).

Layout Considerations

The EV kit PC board can serve as a guide for laying out a board using the MAX2605–MAX2609. Generally, the VCC pin on the PC board should have a decoupling capacitor placed close to the IC. This minimizes noise

coupling from the supply. Also, place the VCO as far away as possible from the noisy section of a larger sys-tem, such as a switching regulator or digital circuits.The VCO ’s performance is strongly dependent on the availability of the external tuning inductor. For best per-formance, use high-Q components and choose their val-ues carefully. To minimize the effects of parasitic ele-ments, which degrade circuit performance, place the tuning inductor and C BYP close to the VCO. For higher-frequency versions, include the parasitic PC board inductance and capacitance when calculating the oscillation frequency. In addition, remove the ground plane around and under the tuning inductor to minimize the effect of parasitic capacitance.

Noise on TUNE translates into FM noise on the outputs;therefore, keep the trace between TUNE and the control circuitry as short as possible. If necessary, use an RC filter to further suppress noise, as done on the EV kits.

E v a l u a t e : M A X 2605–M A X 2609

MAX2605–MAX2609 Evaluation Kits 4_______________________________________________________________________________________

Figure 2. MAX2608/MAX2609 EV Kits Schematic

Figure 1. MAX2605/MAX2606/MAX2607 EV Kits Schematic

Evaluate: MAX2605–MAX2609

MAX2605–MAX2609 Evaluation Kits

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Figure 3. MAX2605/MAX2606/MAX2607 EV Kits Component

Placement Guide—Top Silk Screen

Figure 4. MAX2608/MAX2609 EV Kits Component Placement

Guide—Top Silk Screen

Figure 5. MAX2605/MAX2606/MAX2607 EV Kits PC Board

Layout—Component Side

Figure 6. MAX2608/MAX2609 EV Kits PC Board Layout—

Component Side

Ma xim ca nnot a ssume responsibility for use of a ny circuitry other tha n circuitry entirely embodied in a Ma xim product. No circuit pa tent licenses a re implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

6_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600?2000 Maxim Integrated Products

Printed USA

is a registered trademark of Maxim Integrated Products.

E v a l u a t e : M A X 2605–M A X 2609

MAX2605–MAX2609 Evaluation Kits Figure 7. MAX2605/MAX2606/MAX2607/MAX2608/MAX2609

EV Kits PC Board Layout—Ground Plane