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File name NJU7505.pdf

NJU7505 PPRELIMINARY BAND PASS FILTER FOR AUDIO SPECTRUM ANALYZER DISPLAY s GENERAL DESCRIPTION The NJU7505 is a band pass filter for audio spectrum analyzer display. It consists of high and low band pass filters, CR oscillation circuit, control circuit and DC transfer circuit. Each band pass filter using the switched capacitor filter technology operates at the shared time by 5 bands which filter constant is switched by the internal clock. Therefore, the audio signal shared of 5 bands is output from a serial output terminal. The 10 band version using the double by the cascade connection is prepared. s PACKAGE OUTLINE NJU7505XD NJU7505XM s FEATURES q BPF for the audio spectrum analyzer display of the 5 bands q 10 bands extension is available by the cascade connection (Version of A: For 5-band application by the single) (Version of B: For 10-band application by the double) q BPF using the switched capacitor filter technology q CR oscillation circuit on chip (External clock input is available) q Power-on initialization circuit on chip (External reset input is available) q C-MOS Technology q Package Outline DIP8, DMP8 s PIN CONFIGURATION OSC1 OSC2 RST/CLKO RD 1 2 3 4 5 6 7 8 VDD AIN AOUT VSS s BLOCK DIAGRAM Audi o Signal RST/CLKO RD Control Signa Crock Signal OSC1 OSC2 OSC f OSC f OSC/16 Control Circuit f OSC/4 iH iL RL RH Power-on Initialize H L BPF High Band AIN High Band Peak Detector Lev el Shifter & Out Put BUF AOUT Input BUF LPF BPF Low Band Low Band Peak Detector VDD VDD AGND VSS VSS - 1 -A NJU7505 s TERMINAL DESCRIPTION NO. 1 2 3 4 5 8 6 7 FUNCTION External Resistor connecting terminal. External Resistor connecting terminal or External clock input terminal. Both as Reset input terminal RST/CLKO and the clock of (2/3)*fosc output terminal. RD Trigger signal for reading-out the AOUT of each band output terminal. VSS GND 0V Positive power supply +5.0 V VDD AOUT Peak voltage of each band output terminal. AIN Audio signal input terminal. SYMBOL OSC1 OSC2 s VERSION LINEUP AND PEAK FREQUENCY The NJU7505 prepares two version of A and B which are different of the peak frequency of each bands. The version of A is recommended for the 5 bands application using the single and the version of B is recommended for the 10 bands using the double by the cascade connection, however, the version of A can be used for the 10 bands using the double and the version of B can be used for the 5 bands using the single. Peak Frequency ( Hz ) Using the single Using the double Version of A Version of B Version of A Version of B 12k 18k 12k 18k 8k 12k 3.5k 5.3k 3.5k 5.3k 2.3k 3.5k 1k 1.5k 1k 1.5k 670 1k 250 375 250 375 165 250 63 95 63 95 * 63 42 Band f1a f1b f2a f2b f3a f3b f4a f4b f5a f5b Note) The bands of f1a, f2a, ... f5a correspond to the master side and the bands of f1b, f2b, ... f5b correspond to the slave side at the cascade connection of the double. Note) It may not be output along the expectation at the peak frequency of * marking, sinc