– 11 –

CXA1100/CXA1101/CXA1102/CXA1163

be usefull.

The operation voltage range are

CXA1100

11.5 to 16V (±5.75 to ±8V)

CXA1101

8.5 to 16V (±4.25 to ±8V)

CXA1102

6.5 to 16V (±3.25 to ±8V)

CXA1163

5.0 to 16V (±2.5 to ±8V)

Fig. a-1.

The devices will satisfy the signal handling of 12dB specified by Dolby Laboratories on above voltage range.

2) Operation mode control

The CXA1100 series provide fully electronic switching circuits. The functions are controlled by DC voltages

of the two control pins of REC/PB (pin 12) and ON/OFF (pin 5). The switching truth tables are shown in Fig. a-2.

(a) Single ended supply operation

0.5V

(b) Split supply operation

Fig. a-2.

It is desirable to provide CR time constant circuits at the mode control pins with time constant from

100msec to 1sec, which will reduce switching clicks effectively.

3) Reference levels

Characteristics and specifications of the Dolby noise reduction processor are defined as the levels and

measured with reference to the Dolby level. This particular level in these devices is –10dBm (245mVrms),

and is measured at the recording output (REC OUT) in the NR off mode.

The reference levels of the recording input (REC IN), play back input (PB IN) and line output (LINE OUT)

are defined the levels which provide the Dolby level at the recording output in the NR off mode.

The CXA1100 series has a common silicon die, and has different internal connection. The series provides

four different line output levels for various applications. Other reference levels, recording input level,

playback input level and recording output level (= Dolby level) are identical in all devices.

The reference levels are as follows

Recording output level (= Dolby level)

–10dBm (245mVrms)

Recording input level

–30dBm (24.5mVrms)

Play back input level

–30dBm (24.5mVrms)

Line output level

CXA1100

0dBm (775mVrms)

CXA1101

–3dBm (548mVrms)

CXA1102

–6dBm (388mVrms)

CXA1163

–10dBm (245mVrms)

13

14

15

R1

43k

47

100 to 470µF

CXA1100

Series

REC/PB

Function

PB (Decode)

REC (Encode)

ON/OFF

Function

NR off

NR on