HA12134A

HA12134A, HA12135A, HA12136A Dolby B-Type Noise Reduction System ADE-207-016B (Z) 3rd Edition Jun. 1999 Description The HA12134A, HA12135A, HA12136A are silicon monolithic bipolar IC series providing dual channel Dolby B-type noise reduction system* in one chip. The circuit is used primarily to reduce the level of background noise introduced during recording and playback of audio signals on magnetic tape. HA12134A series provide the following functions and features. Functions Dual Dolby B-type NR processor NR ON/OFF control switch. Record (encode)/playback (decode) control switch. Features Separate record/playback input and output. Unprocessed signal output available in the encode and decode modes. Reduction of external components count. Small capacitor value for the reference voltage. NR ON/OFF switching and REC/PB switching are provided internally. 2-type package (DP-16, FP-16DA) Wide range of operating supply voltage. * Dolby is a trademark of Dolby Laboratories Licensing Corporation. A license from Dolby Laboratories Licensing Corporation is required for the use of this IC. HA12134A, HA12135A, HA12136A Ordering Information Type No HA12134A HA12134AF HA12135A HA12135AF HA12136A HA12136AF 580 450 Dolby Level (mVrms) 300 Package DP-16 FP-16DA DP-16 FP-16DA DP-16 FP-16DA Block Diagram REC IN GND PB IN BIAS 18 k 22 k REC/PB PB OUT DET REC OUT 0.22 µ 16 15 14 13 12 11 10 9 SW BIAS SW BUF AMP SIDE CHAIN BUF AMP SIDE CHAIN 1 2 3 4 + 1...