TDA7575B STMicroelectronics, TDA7575B Datasheet - Page 26

• Manufacturer Part Number: TDA7575B
• Description: IC AMP DUAL BRIDGE FLEXIWATT27
• Manufacturer: STMicroelectronics
• Type: Class ABr

Specifications of TDA7575B

• Output Type: 1-Channel (Mono) or 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 150W x 1 @ 1 Ohm; 75W x 2 @ 2 Ohm
• Voltage - Supply: 8 V ~ 18 V
• Features: Differential Inputs, I²C, Mute, Short-Circuit and Thermal Protection, Standby
• Mounting Type: Through Hole
• Package / Case: 27-Flexiwatt (bent and staggered leads)
• Operational Class: Class-AB
• Audio Amplifier Output Configuration: 1-Channel Mono/2-Channel Stereo
• Output Power (typ): 150x1@1Ohm/75x2@2OhmW
• Audio Amplifier Function: Speaker
• Input Offset Voltage: 45@14.4VmV
• Total Harmonic Distortion: 0.02@4Ohm@30W%
• Single Supply Voltage (typ): 9/12/15V
• Dual Supply Voltage (typ): Not RequiredV
• Power Supply Requirement: Single
• Power Dissipation: 86W
• Rail/rail I/o Type: No
• Single Supply Voltage (min): 8V
• Single Supply Voltage (max): 18V
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temp Range: -55C to 150C
• Operating Temperature Classification: Military
• Mounting: Through Hole
• Pin Count: 27
• Package Type: FLEXIWATT(Vertical)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Diagnostics functional description
7.3
7.4
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Output DC offset detection
Any DC output offset exceeding ± 2 V are signalled out. This inconvenient might occur as a
consequence of initially defective or aged and worn-out input capacitors feeding a DC
component to the inputs, so putting the speakers at risk of overheating.
This diagnostic has to be performed with low-level output AC signal (or Vin = 0).
The test is run with selectable time duration by microprocessor (from a "start" to a "stop"
command):
●
●
Excess offset is signalled out if persistent throughout the assigned testing time. This feature
is disabled if any overloads leading to activation of the short-circuit protection occurs in the
process.
AC diagnostic
It is targeted at detecting accidental disconnection of tweeters in 2-way speaker and, more
in general, presence of capacitively (AC) coupled loads.
This diagnostic is based on the notion that the overall speaker's impedance (woofer +
parallel tweeter) will tend to increase towards high frequencies if the tweeter gets
disconnected, because the remaining speaker (woofer) would be out of its operating range
(high impedance). The diagnostic decision is made according to peak output current
thresholds, and it is enabled by setting (IB2-D2) = 1. Two different detection levels are
available:
●
●
To correctly implement this feature, it is necessary to briefly provide a signal tone (with the
amplifier in "play") whose frequency and magnitude are such to determine an output current
higher than 500mApk with IB2(D7)=0 (higher than 250mApk with IB2(D7)=1) in normal
conditions and lower than 250 mApk with IB2(D7)=0 (lower than 125 mApk with IB2(D7)=1)
should the parallel tweeter be missing.
The test has to last for a minimum number of 3 sine cycles starting from the activation of the
AC diagnostic function IB2<D2>) up to the I
confirm presence of tweeter, it is necessary to find at least 3 current pulses over the above
threholds over all the measuring period, else an "open tweeter" message will be issued.
The frequency / magnitude setting of the test tone depends on the impedance
characteristics of each specific speaker being used, with or without the tweeter connected
(to be calculated case by case). High-frequency tones (> 10 kHz) or even ultrasonic signals
are recommended for their negligible acoustic impact and also to maximize the impedance
module's ratio between with tweeter-on and tweeter-off.
Start = Last reading operation or setting IB1 - D5 - (OFFSET enable) to 1
Stop = Actual reading operation
HIgh current threshold IB2 (D7) = 0
–
–
Low current threshold IB2 (D7) = 1
–
–
Iout > 500 mApk = normal status
Iout < 250 mApk = open tweeter
Iout > 250 mApk = normal status
Iout < 125 mApk = open tweeter
Doc ID 14103 Rev 2
2
C reading of the results (measuring period). To
TDA7575B