NJM2760 Band Pass Filter for Spectrum Analyzer Display ■ GENERAL DESCRIPTION The NJM2760 is a band pass filter for spectrum analyzer display. It includes 4-band BPF amplifier, 4-band detector and recording level indicator output. It is suitable for mini-components, CD radio cassette and other audio components. ■ PACKAGE OUTLINE NJM2760V ■ FEATURES ● Operating Voltage +2.7V to +9V ● 4 Band Pass Filters & Detector ● Recording Level Indicator Output ● Low Offset Voltage 5mV typ. ● Adjustable Input Sensitivity ● Bipolar Technology ● Package Outline SSOP20 ■ PIN CONFIGURATION 1 20 2 19 3 18 4 17 5 16 6 15 7 14 8 13 9 12 10 11 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. IN1 IN2 BUF1OUT BPF2IN1 BPF2IN2 BPF3IN1 BPF3IN2 BPF4IN1 BPF4IN2 GND 20. BUF2OUT 19. BPF1IN2 18. BPF1IN1 17. RECOUT 16. BPF1OUT 15. BPF2OUT 14. BPF3OUT 13. BPF4OUT 12. N.C. 11. V+ ■ BLOCK DIAGRAM 5.6kΩ 10kΩ 22nF V+ 6.8kΩ 47nF BPF 4.7nF BPF4 out DET 1µF 1µF BPF BPF3 out DET 1µF 200kΩ L in R in 200kΩ BPF BPF2 out DET 1µF 1µF BPF BPF1 out DET 1µF 200kΩ 200kΩ REC out DET 1µF 1µF GND 470pF –1– NJM2760 ■ ABSOLUTE MAXIMUM RATING (Ta=25°C) PARAMETER SYMBOL + RATINGS UNIT 14 V Supply Voltage V Power Dissipation PD 300 mW Operating Temperature Range Topr -20 to +75 °C Storage Temperature Range Tstg -40 to +125 °C ■ ELECTRICAL CHARACTERISTICS (Ta=25°C, V+=3.3V, VIN=1VPEAK unless otherwise specified) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT - 2.7 3.3 9.0 V - 1.4 3.0 mA 0.7 1.0 1.42 V 2.1 3.0 - V ◆Power Supply + Operating Voltage V Operating Current Icc No Signal ◆ AC CHARACTERISTICS Typical Output Voltage VOT Maximum Output Voltage VOM Vin=1Vpeak, f=Center Frequency of BPF Vin=3Vpeak, f=Center Frequency of BPF BPF1 Center Frequency Level GVBPF1 f=8kHz -3 0 +3 dB BPF2 Center Frequency Level GVBPF2 f=1.2kHz -3 0 +3 dB BPF3 Center Frequency Level GVBPF3 f=300Hz -3 0 +3 dB BPF4 Center Frequency Level GVBPF4 f=80Hz -3 0 +3 dB No Signal - 5 30 mV DC Offset Voltage VOS ◆ TEST CIRCUIT C1 1µF R2 100kΩ C2 1µF IN1 IN2 1 IN1 2 IN2 3 BUF1OUT 4 BPF2IN1 5 BPF2IN2 6 BPF3IN1 7 BPF3IN2 8 BPF4IN1 9 BPF4IN2 10 GND C3 4.7nF R3 6.8kΩ C4 4.7nF C5 22nF R4 5.6kΩ C6 22nF C7 47nF R5 10kΩ C8 47nF NJM2760 R1 100kΩ BUF2OUT 20 BPF1IN2 19 BPF1IN1 18 RECOUT 17 C14 1µF RECOUT BPF1OUT 16 C13 1µF BPF1OUT BPF2OUT 15 C12 1µF BPF2OUT BPF3OUT 14 C11 1µF BPF3OUT BPF4OUT 13 C10 1µF BPF4OUT NC 12 V+ 11 C16 470pF C15 470pF + –2– C9 1µF V+ NJM2760 ■ TERMINAL DESCRIPTION No. SYMBOL FUNCTION 1 2 5 7 9 19 IN1 IN2 BPF2IN2 BPF3IN2 BPF4IN2 BPF1IN2 Input for BPF1-4 Input for recording level detector Capacitor terminal for BPF2 Capacitor terminal for BPF3 Capacitor terminal for BPF4 Capacitor terminal for BPF1 3 20 BUF1OUT BUF2OUT Buffer output Buffer output 4 6 8 18 BPF2IN1 BPF3IN1 BPF4IN1 BPF1IN1 Capacitor terminal for BPF2 Capacitor terminal for BPF3 Capacitor terminal for BPF4 Capacitor terminal for BPF1 13 14 15 16 17 BPF4OUT BPF3OUT BPF2OUT BPF1OUT RECOUT BPF4 output BPF3 output BPF2 output BPF1 output Recording level detector output EQUIVALENT CIRCUIT 1.4V 680Ω FB VOLTAGE 680Ω 1.4V 1.4V 680Ω 0V 90kΩ FB 30kΩ 10 GND Ground terminal - 11 V+ Power supply terminal - –3– NJM2760 ■ APPLICATION CIRCUIT LIN RIN R11 200kΩ R12 200kΩ R21 200kΩ 1 IN1 2 IN2 C2 1µF 3 BUF1OUT 4 BPF2IN1 5 BPF2IN2 6 BPF3IN1 7 BPF3IN2 8 BPF4IN1 9 BPF4IN2 10 GND C3 4.7nF R3 6.8kΩ C4 4.7nF C5 22nF R4 5.6kΩ C6 22nF C7 47nF R5 10kΩ C8 47nF NJM2760 R22 200kΩ C1 1µF BUF2OUT 20 BPF1IN2 19 C16 470pF C15 470pF BPF1IN1 18 RECOUT 17 C14 1µF RECOUT BPF1OUT 16 C13 1µF BPF1OUT BPF2OUT 15 C12 1µF BPF2OUT BPF3OUT 14 C11 1µF BPF3OUT BPF4OUT 13 C10 1µF BPF4OUT NC 12 V+ 11 + –4– C9 1µF V+ NJM2760 ■ APPLICATION NOTE 1. Center Frequency Setting for Band Pass Filters Band pass filters equivalent circuits as follows. External Circuit Internal Circuit External Circuit Internal Circuit C C Rb Rb to Detector C Ra Ra to Detector C from Input Buffer Fig.1-a. BPF1's Equivalent Circuit from Input Buffer Fig.1-b. BPF2-4 's Equivalent Circuit Center Frequency (fo) can be formulated as follows. Table 1. Center frequency setting example f0 = 2Q 2πCR b [Hz], Q=2 BPF1 (8kHz) BPF2 (1.2kHz) BPF3 (300Hz) BPF4 (80Hz) Ra ) 10 kΩ* 6.8 kΩ 5.6 kΩ 10 kΩ Rb ) 169 kΩ* ) 113 kΩ* ) 96.5 kΩ* ) 169 kΩ* C 470pF 4.7nF 22nF 47nF *) As regards the BPF1, the values of Ra and Rb are fixed. Also as regards the BPF2-4, the values of Rb is fixed. 2. Output Gain Setting for RECout. Output Voltage of RECout is adjustable by external resistor: R2 Voltage Gain (Gv) is defined as follows. R [kΩ] Vout[ Vdc ] = Gv = 2 100[kΩ] Vin[ Vpeak ] –5– NJM2760 ■ TYPICAL CHARACTERISTICS Supply Current vs. Temperature V+=3.3V 3 3 2.5 2.5 2 2 25,75°C Icc[mA] Icc[mA] Supply Current vs. Supply Voltage Ta=-40, 25, 75°C 1.5 1 1.5 1 Ta=-20°C 0.5 0.5 0 0 0 1 2 3 4 5 6 7 8 9 10 -50 -30 -10 10 Vcc[V] 8 RECout R2=80kΩ 7 Vos [mV] Vout[VDC] 110 130 150 9 RECout R2=100kΩ 2.5 2 1.5 RECout R2=120kΩ 1 6 5 RECout BPF1out BPF2out 4 3 2 0.5 BPF3out BPF4out 1 0 0 0 0.5 1 1.5 2 2.5 3 Output vs. Frequency V+=3.3V, Vin=1VPEAK 5 75°C BPF4 BPF3 BPF2 BPF1 25°C -20°C -10 -15 -20 -25 -30 10 100 1000 f[Hz] -50 0 50 Ta[°C] Vin[VPEAK] Vout[dB] 90 10 3 –6– 70 DC Offset Voltage vs. Temperature V+=3.3V 3.5 -5 50 Ta[°C] INPUT vs. OUTPUT Vcc=3.3V, Ta=25°C, f=8kHz, R2=R21/ /R22 0 30 10000 100000 100 150 NJM2760 ■ TYPICAL CHARACTERISTICS Input vs. Output Level V+=3.3V, Vout=BPFout1, fo=8kHz Input vs. Output Level V+=3.3V, Vout=BPFout2, fo=1.2kHz 4 4 3 3 75°C 75°C 25°C Vout[VDC] Vout[VDC] 25°C -20°C 2 1 2 -20°C 1 0 0 0 0.5 1 1.5 2 2.5 3 0 0.5 1 Vin[VPEAK] 1.5 2 3 Vin[VPEAK] Input vs. Output Level V+=3.3V, Vout=BPF3out, fo=300Hz Input vs. Output Level V+=3.3V, Vout=BPF4out, fo=80Hz 4 4 75°C 75°C 3 3 25℃ 25°C Vout[VDC] Vout[VDC] 2.5 2 -20° 1 2 -20°C 1 0 0 0 0.5 1 1.5 2 2.5 3 Vin[VPEAK] 0 0.5 1 1.5 Vin[VPEAK] 2 2.5 3 Input vs. Output Level V+=3.3V, Vout=RECout, fo=8kHz 4 75°C 3 Vout[VDC] 25°C 2 -20°C 1 0 0 0.5 1 1.5 2 2.5 3 [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. Vin[VPEAK] –7–