tel: 886-2-66296288 fax: 886-2-29174598 url: http://www.princeton.com.tw pt2325 v1.1 - 1 - august, 2007 6 channel volume control pt2325 description the volume controller is a basic function in an audio system, in a modern mu lti-channel system always needs a main volume that can adjust volume of all channels in synchronously. in traditional multi-channel design mostly utilizi ng a multi-gang potentiometer, but it ?s so expensive and not easy to achieved well volume attenuation matching between each channel. now a better solution is uses the pt2325 to repl ace the multi-gang potent iometer. the pt2325 is designed for multi-channel audio purpose, the chip has 6 groups built-in 48 steps volume attenuator for each channel and running in synchronous, it only needs an external dc voltage to setting volume attenuation. in general application, a cheap single-gang potentiometer is work well to control whole channel?s volume. the dc volume setting also can be controlled by a pwm sig nal from the mcu and support 3.3v mcu bus voltage. the performance of the pt2325 is excellent for t he high cost/performance multi-channel audio system, its wide attenuation range (down to -100db), high channel separation char acteristics is also suite for other high quality audio purpose. features ? 6 channels, volume control range 0 ~ -100db/per channel ? operating voltage range: 5 ~ 10v (volume buffer) 3.3 ~ 10v (volume controller) ? low noise, high snr: greater than 100db (a-weighted) ? high channel separation > 100db ? built-in mute function ? dc controlled volume attenuation applications ? av surround system ? car audio ? mini combo ? pc multimedia speaker ? other audio applications
tel: 886-2-66296288 fax: 886-2-29174598 url: http://www.princeton.com.tw pt2325 v1.1 - 2 - august, 2007 6 channel volume control pt2325 pin configuration in2 in3 out4 out2 out5 out3 gnda gndv mute vccv freq_ad j ref volume 1 20 219 318 4 17 8 13 7 14 912 615 5 16 pt2325 in4 in5 out6 10 11 in6 out1 pin description pin name i/o description pin no. in1 i channel.1 input, ac coupling to audio source 1 in2 i channel.2 input, ac coupling to audio source 2 in3 i channel.3 input, ac coupling to audio source 3 vcca - power supply for internal amplifier 4 ref - 1/2 vcca reference bypassing, connect a capacitor to ground 5 gnda - ground pin for amplifier 6 mute i mute pin. connect to the vcca active the mute function 7 in4 i channel.4 input, ac coupling to audio source 8 in5 i channel.5 input, ac coupling to audio source 9 in6 i channel.6 input, ac coupling to audio source 10 out6 o channel.6 output, ac coupling to next stage 11 out5 o channel.5 output, ac coupling to next stage 12 out4 o channel.4 output, ac coupling to next stage 13 freq_adj - oscillator frequency adjustment for the volume controller 14 gndv - ground pin for the volume controller 15 volume i dc voltage input for the volume controller 16 vccv - power supply input for the volume controller 17 out3 o channel.3 output, ac coupling to next stage 18 out2 o channel.2 output, ac coupling to next stage 19 out1 o channel.1 output, ac coupling to next stage 20
tel: 886-2-66296288 fax: 886-2-29174598 url: http://www.princeton.com.tw pt2325 v1.1 - 3 - august, 2007 6 channel volume control pt2325 application circuit notes: 1. cadj is for volume controller calibration pur pose, the osc frequency is 1mhz when cadj=100pf. 2. the dc block coupling capacitor (1 f) placed in every input and output pi n must care the polarity, the positive polarity side of cap mu st toward the higher potential for proper operation. if not may cause abnormal pop noise during volume is changed.
tel: 886-2-66296288 fax: 886-2-29174598 url: http://www.princeton.com.tw pt2325 v1.1 - 4 - august, 2007 6 channel volume control pt2325 order information valid part number package type top code pt2325-d (l) 20 pin, dip, 300mil pt2325-d notes: 1. (l), (c) or (s) = lead free. 2. the lead free mark is put in front of the date code.
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