FM Radio Tuner with VCO Using the SVC704 Application Note Overview This application note explains about ON Semiconductor’s SVC704 which is used as a Voltage Controlled Oscillator (VCO) for FM Radio Tuner. www.onsemi.com The SVC704 is used to adjust the oscillation frequency of a tuning circuit of Radio since its capacitance value can be changed depending on the DC voltage applied. The evaluation board is adjusted to Intermediate Frequency of 10.7MHz. A standard material FR4 is used for the printed circuit board (PCB). © Semiconductor Components Industries, LLC, 2015 March 2015- Rev. 0 1 Publication Order Number: ANDSVC704_1/D FM Radio Tuner with VCO Using the SVC704 ■Summary of Data Ta = 25 ºC, Vctl = 0 V to 8 V, Zo = 50 Ω Parameter Symbol DC Voltage DC Current Oscillating Power Condition Result Unit Vcc 8.0 V Idd 20.5 mA Posc f = 86.7 MHz 6.07 f = 102.7 MHz 6.00 f = 118.7 MHz 5.57 dBm ■Circuit Design Vctl Vcc= 8V C7 R4 R5 C6 R1 TR1 C3 C1 C4 L1 VD1 OUTPUT R2 C2 ■Evaluation Board www.onsemi.com 2 C5 R3 FM Radio Tuner with VCO Using the SVC704 ■Bill of Materials Item Symbol Value Manufacture Size Bipolar-Tr. TR1 55GN01CA ON Semiconductor SC-59 Varactor Diode VD1 SVC704 ON Semiconductor SC-70 C1 68 pF Murata GRM155 1608 C2 68 pF Murata GRM155 1608 C3 68 pF Murata GRM155 1005 C4 1000 pF Murata GRM155 1005 C5,C6,C7 2200 pF Murata GRM155 1608 R1 2.2 kΩ Various 1005 R2 2.2 kΩ Various 1005 R3 100 Ω Various 1005 R4 100 Ω Various 1005 R5 30 kΩ Various 1005 L1 56 nH TDK GLQ1005 1005 Capacitor Resistor Inductor Material FR-4 www.onsemi.com 3 25 x 13 mm FM Radio Tuner with VCO Using the SVC704 ■Measurement Results 150 Oscillating Frequency ‐MHz 140 130 120 110 100 90 80 70 60 Vctl = 0V to 8V 50 0 1 2 3 4 5 6 7 Reveres Voltage ‐ V 8 9 10 Figure 1 Oscillating Frequency vs. Reveres Voltage www.onsemi.com 4 Figure 2 Oscillating Power vs. Frequency FM Radio Tuner with VCO Using the SVC704 ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC) or its subsidiaries in the United States and/or other countries. SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf . SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. www.onsemi.com 5