80
Circuit Descriptions
TM8100/TM8200 Service Manual
© Tait Electronics Limited
June 2006
Auxiliary Audio
Output
The source for the auxiliary audio output signal
CDC
AUD
TAP
OUT
is provided
by IC204 (
RAMPDAC
ball). The DAC output of IC204 is low-pass filtered to
remove high-frequency artefacts. The low-pass filter, formed by IC201
(pins 1 to 3), R219, R220, R221, R224, C206, C208 and C210, is a third-
order Butterworth type with a cut frequency of approximately 12kHz.
The output of the low-pass filter is amplified by 6dB by a buffer amplifier,
IC201 (pins 5 to 7), and fed via R207 and R208 to drive the
CDC
AUD
TAP
OUT
interface line. The DC bias for this signal path is provided by IC204 and
is approximately 1.2V when operational. The offset at
CDC
AUD
TAP
OUT
is
approximately 2.4V owing to the gain of the buffer amplifier.
Summary of Contents for TM8235
Page 1: ...TM8100 mobiles TM8200 mobiles Service Manual MMA 00005 04 Issue 4 June 2006...
Page 10: ...10 TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 62: ...62 Description TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 148: ...148 Disassembly and Reassembly TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 162: ...162 Servicing Procedures TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 178: ...178 Interface Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 258: ...258 Receiver Fault Finding TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...
Page 446: ...446 Spare Parts TM8100 TM8200 Service Manual Tait Electronics Limited June 2006...