TDA8933BTW/N2,118 NXP Semiconductors, TDA8933BTW/N2,118 Datasheet - Page 16

• Manufacturer Part Number: TDA8933BTW/N2,118
• Description: IC AMP AUDIO CLASS D 32HTSSOP
• Manufacturer: NXP Semiconductors
• Type: Class Dr

Specifications of TDA8933BTW/N2,118

• Output Type: 1-Channel (Mono) or 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 20.6W x 1 @ 16 Ohm; 10.3W x 2 @ 8 Ohm
• Voltage - Supply: 10 V ~ 36 V, ±5 V ~ 18 V
• Features: Depop, Differential Inputs, Mute, Short-Circuit and Thermal Protection
• Mounting Type: Surface Mount
• Package / Case: 32-TSSOP Exposed Pad, 32-eTSSOP, 32-HTSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 935285222118

NXP Semiconductors
2.
3.
4.
UBA2074(A)
Preliminary data sheet
Presuming that the effective full bridge load impedance is in inductive region.
The OC comparator is behind the double side rectifier at the IFB-pin
Provided that the current sensing circuit is simple sense resistor only.
7.10.1 Over voltage protection
7.10.2 Over current detection
7.10.3 Arcing detection
7.10.4 Hard switching protection
The over voltage protection circuit is intended to prevent the transformer output voltage
from exceeding its maximum rating. It can also be used to regulate the output voltage to
the required lamp ignition voltage.
When the voltage on the VFB-pin exceeds the OV reference level V
is detected. As result PWM dimming and synchronisation are disabled and the fault timer
is started. Also the capacitor connected to the CVFB-pin is discharged (by I
When the voltage at the VFB-pin drops below the OV reference level, the CVFB capacitor
is charged (by I
again. Because the charging and discharging of the CVFB capacitor follows the ripple on
the VFB voltage, the feedback gain of the voltage control loop is set by the ripple on the
feedback signal.
If CVFB is more discharged then charged (over a hf cycle) then the CVFB voltage will
drop, and the switching frequency increase. As a result the output voltage of the
transformer will decrease
S1 of
changed by the current regulation loop) in order to prevent the frequency increase being
compensated by a phase shift difference increase by the current control.
An internal latch makes the OV fault signal continuesly high even if the voltage at the
VFB-pin only exceeds VVFB(ovref) during part of the output period. So the peak of the
voltage on the VFB-pin determines if an over voltage fault condition is seen.In order to
avoid that OV fault condition at the nominal switching frequency (with the lamps operating
normally), the voltage ripple on the VFB-pin must not be too large.
The voltage at CVFB is limited by the oscillator circuit to V
switching frequency F
capability at over voltage detection.
When the absolute value
the IFB-pin) exceeds the OC reference level V
PWM dimming and synchronisation are disabled and the fault timer is started.
If arcing occurs, for instance due to a bad lamp connection, it causes repetitive short
current spikes that can be seen as voltage spikes at the IFB input
circuit is directly connected to the IFB-pin, so it can only see spikes with a positive polarity.
Usually that will be sufficient. It can detect spikes with amplitude above V
duration longer then T
to the control circuits that arcing has been detected. If this happens PWM dimming and
synchronisation are disabled, and the fault timer is started.
The hard switching protection is not present in the A-version.
Figure 9
is opened (non-conducting), so the regulation level stored in C1 cannot be
CVFB(charge)
s(min)
SPIKE(min)
Rev. 02.0 — February 2007
3
2
) again.and the output voltage of the transformer will increase
. When this happens the current control loop is froozen (switch
of the voltage across the current sense resistor (connected to
is reached. This ensures an immediate frequency increase
High Voltage Full-bridge control IC for CCFL backlighting
. Each spike will trigger an internal one-shot, which signals
IFB(ocref)
, over-current is detected. As result
CVFB(range)
UBA2074(A)
4
. The arcing detection
VFB(ovref)
when the minimum
© NXP B.V. 2007. All rights reserved.
IFB(arcref)
CVFB(ov)
, over voltage
and a
).
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