tda8592j NXP Semiconductors, tda8592j Datasheet - Page 6

• Manufacturer Part Number: tda8592j
• Description: I?c-bus Controlled 4 X 50 W Power Amplifier
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 13007
Preliminary data sheet
7.2 Start-up and shut-down timing
7.3 Power-on reset and supply voltage spikes
7.4 Diagnostic output
7.5 Muting
7.6 Temperature protection
7.7 Offset detection
A capacitor connected to pin SVR enables smooth start-up and shut-down, preventing the
amplifier from producing audible clicks at switch-on or switch-off. The start-up and
shut-down times can be extended by increasing the capacitor value.
If the amplifier is shut-down using pin STB, the amplifier is muted, and the capacitor
connected to pin SVR discharges. The low current standby mode is activated 2 seconds
after pin STB goes LOW; see
If the supply voltage drops too low to guarantee the integrity of the data in the I
latches, the power-on reset cycle will start. All latches will be set to a pre-defined state, pin
DIAG will be pulled LOW to indicate that a power-on reset has occurred, and bit D7 of
data byte 2 is also set for the same reason. When D0 of instruction byte 1 is set, the
power-on flag resets, pin DIAG is released and the amplifier will then enter its start-up
cycle; see
Pin DIAG indicates clipping, thermal protection pre-warning, short-circuit protection, low
and high battery voltage. Pin DIAG is an open-drain output, is active LOW, and must be
connected to an external voltage via an external pull-up resistor. If a failure occurs, pin
DIAG remains LOW during the failure and no clipping information is available. The
microcontroller can read the failure information via the I
A hard mute and a soft mute can both be performed via the I
the amplifier within 0.5 ms. A soft mute mutes the amplifier within 20 ms and is less
audible. A hard mute is also activated if a voltage of 8 V is applied to pin STB.
If the average junction temperature rises to a temperature value that has been set via the
I
temperature continues to rise, all four channels will be muted to reduce the output power
(soft thermal clipping). The value at which the temperature mute control activates is fixed:
only the temperature at which the thermal protection pre-warning signal occurs can be
specified by bit D4 in instruction byte 3. If the temperature mute control does not reduce
the average junction temperature, all the power stages will be switched off (muted) at the
absolute maximum temperature T
Offset detection can only be performed when there is no input signal to the amplifiers, for
instance when the external digital signal processor is muted after a start-up. The output
voltage of each channel is measured and compared with a reference voltage. If the output
voltage of a channel is greater than the reference voltage, bit D2 of the associated data
byte is set and read by the microcontroller during a read instruction. Note that the value of
this bit is only meaningful when there is no input signal and the amplifier is not muted.
Offset detection is always enabled.
2
C-bus, a thermal protection pre-warning is activated making pin DIAG LOW. If the
Figure 9
and see
Rev. 01 — 8 June 2004
Figure
Figure
j(max)
10.
8.
.
TDA8592J; TDA8592Q
I
2
C-bus controlled 4
2
C-bus.
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
2
C-bus. A hard mute mutes
50 W power amplifier
2
C-bus
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