AM Radio Amplifier with Filter Using the NSVJ3557SA3 Application Note Overview This application note explains about ON Semiconductor’s NSVJ3557SA3 which is used as a Low Noise Amplifier (LNA) for AM Radio. www.onsemi.com The NSVJ3557SA3 is a silicon junction field effect transistor best suited for high-frequency applications which is assembled in the 3-pin surface mount package. For information about the performance, please refer to the datasheet of this product. The evaluation board is adjusted to provide +9.5dB gain in AM band (520 to 1720 kHz) and reduce gain to −80dB in FM band (76 to 108 MHz). A standard material FR4 is used for the printed circuit board (PCB). © Semiconductor Components Industries, LLC, 2015 May 2015- Rev. 0 1 Publication Order Number: ANDNSVJ3557SA3_1/D AM Radio Amplifier with Filter Using the NSVJ3557SA3 ■Summary of Performance Ta = 25ºC, Input Power = -40 dBm, Zo = 50 Ω Parameter Symbol DC Voltage DC Current Result Unit Vdd 5.0 V Idd 16.8 mA Gp1 Condition f = 520 kHz 9.42 f = 1120 kHz 9.70 f = 1720 kHz 9.51 f = 76 MHz -89.0 f = 90 MHz -91.0 f = 108 MHz -88.3 f = 520 kHz -0.03 f = 1120 kHz -0.22 f = 1720 kHz -0.55 f = 520 kHz -0.35 f = 1120 kHz -0.66 f = 1720 kHz -1.35 f = 520 kHz -46.3 f = 1120 kHz -39.8 f = 1720 kHz -36.1 Power Gain dB Gp2 Input Return Loss Output Return Loss Isolation RLin RLout ISL www.onsemi.com 2 dB dB dB AM Radio Amplifier with Filter Using the NSVJ3557SA3 ■Circuit Diagram Vdd = 5V L4 C2 INPUT C4 L1 L2 R7 R2 R4 FET1 R1 C1 ■Evaluation Board www.onsemi.com 3 L3 C5 OUTPUT R5 R3 R6 C7 C3 C6 AM Radio Amplifier with Filter Using the NSVJ3557SA3 ■Bill of Materials Item Symbol Value Manufacture Size J-FET FET1 NSVJ3557SA3 ON Semiconductor SC-59 C1 10 pF Murata GRM155 1005 C2 12 pF Murata GQM188 1608 C3 120 pF Murata GRM155 1005 C4,C5,C6,C7 0.1 uF ROHM MCH182CN 1608 R1 22 kΩ Various 1608 R2 270 Ω Various 1608 R3 100 kΩ Various 1608 R4 150 Ω Various 1608 R5 100 kΩ Various 1608 R6 10 Ω Various 1608 R7 120 Ω Various 1608 L1,L2,L3 3.3 uH TDK NLV25T 2520 L4 330 uH TDK NLCV32T 3225 Capacitor Resistor Inductor Material FR-4 www.onsemi.com 4 25 x 13 mm AM Radio Amplifier with Filter Using the NSVJ3557SA3 12 0 10 ‐10 ‐20 8 Isolation ‐ dB Power Gain ‐ dB ■Measurement Results 6 4 ‐30 ‐40 ‐50 2 ‐60 0 ‐70 0.1 1 Frequency ‐ MH z 10 0.1 10 Figure 2 Isolation vs. Frequency 2 2 0 0 Output Return Loss ‐ dB Input Return Loss ‐ dB Figure 1 Power Gain vs. Frequency 1 Frequency ‐ MH z ‐2 ‐4 ‐6 ‐2 ‐4 ‐6 ‐8 ‐8 ‐10 ‐10 0.1 1 Frequency ‐ MHz 10 Figure 3 Input Return Loss vs. Frequency 0.1 1 Frequency ‐ MHz Figure 4 Output Return Loss vs. Frequency 520 kHz to 1720 KHz 520 kHz to 1720 kHz Figure 5 Smith Chart S11 Figure 6 Smith Chart S22 www.onsemi.com 5 10 AM Radio Amplifier with Filter Using the NSVJ3557SA3 20 10 0 ‐10 ‐20 ‐30 ‐40 ‐50 ‐60 ‐70 ‐80 ‐90 ‐100 12 S21 S11 ↓ 8V ↓ 4V ↓ ↑ 3V 10 ↑ S22 Power Gain ‐ dB S11,S21,S12,S22 ‐ dB ■Measurement Results S12 8 6 4 2 0 0.1 1 10 Frequency ‐ MHz 100 1000 0.1 Figure 7 S11,S21,S12,S22 Wide Span 1 Frequency ‐ MHz Figure 8 Voltage Dependency www.onsemi.com 6 10 AM Radio Amplifier with Filter Using the NSVJ3557SA3 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. 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