tea5761uk NXP Semiconductors, tea5761uk Datasheet - Page 9

• Manufacturer Part Number: tea5761uk
• Description: Tea5761uk Low-voltage Single Chip Fm-stereo Radio
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 4:
9397 750 13451
Product data sheet
Mute mode
Audio frequency mute
Hard mute
Left hard mute
Right hard mute
Standby mute
Soft mute
Specification of Mute modes
8.13.2 Hard mute
8.13.3 Audio frequency mute
8.14 MPX decoder
8.15 Signal dependent mono/stereo blend (stereo noise cancellation)
8.16 Software programmable port
The audio outputs VAFL and VAFR can be hard muted by bit MU in byte TNCTRL2 which
means they are put into 3-state. This can also be done by setting bits Left Hard Mute
(LHM) or Right Hard Mute (RHM) in byte TESTBITS, which allows either one or both
channels to be muted and forces the TEA5761UK to Mono mode. When the TEA5761UK
is in Standby mode the audio outputs are hard muted.
The audio signal is muted by setting bit AFM of the TNCTRL1 register to logic 1. In the
soft mute attenuator the audio signal is blocked and so pins VAFL and VAFR will be at
their DC biasing point with no signal.
The audio is automatically muted during a preset as shown in the flowchart of
When the audio must be muted during Search mode, it is done by setting bit AFM to
logic 1 before the search action and resetting it to logic 0 afterwards.
The PLL stereo decoder is adjustment free. It can be switched to mono via the I
If the RF input level decreases, the MPX decoder blends from stereo to mono to limit the
output noise. The continuous mono-to-stereo blend can also be programmed via the
I
cancellation can be switched off via the I
The software programmable port (CMOS output) can be addressed via the I
In Test mode, the software port outputs signals according to
selected by setting bit TM of byte TESTMODE to logic 1.
The programmed output status of the software port remains, independent of bit PUPD;
see
Bit
AFM = 1
MU = 1
LHM = 1
RHM = 1
PUPD = 0
SMUTE = 1
2
C-bus to an RF level dependent switched mono-to-stereo transition. Stereo noise
•
•
Bit SWPM = 1: port functions as the output for bit FRRFLAG.
Bit SWPM = 0: port outputs the level corresponding to bit SWP.
Section
8.17.
MPX output
Impedance State
500
500
500
500
3-state
RF level sensitive audio level; has no influence on mute or output impedance
Rev. 01 — 2 August 2006
muted
muted
audio
audio
muted
VAFL output (left)
Impedance State
50
3-state
3-state
50
3-state
2
C-bus by bit SNC.
Low voltage single-chip FM stereo radio
muted
muted
muted
mono audio 3-state
muted
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Table
TEA5761UK
VAFR output (right)
Impedance State
50
3-state
50
3-state
23. Test mode is
2
muted
muted
mono audio
muted
muted
C-bus:
Figure
2
C-bus.
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3.