TDA7374BV STMicroelectronics, TDA7374BV Datasheet - Page 11

• Manufacturer Part Number: TDA7374BV
• Description: IC AMP AUDIO PWR 21W MULTIWATT15
• Manufacturer: STMicroelectronics
• Type: Class ABr

Specifications of TDA7374BV

• Output Type: 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 21W x 2 @ 4 Ohm
• Voltage - Supply: 8 V ~ 18 V
• Features: Depop, Short-Circuit and Thermal Protection, Standby
• Mounting Type: Through Hole
• Package / Case: Multiwatt-15 (Vertical, Bent and Staggered Leads)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TDA7374
3
3.1
3.2
Output stage
The fully complementary output stage was made possible by the development of a new
component: the ST exclusive power ICV PNP.
A novel design based upon the connection shown in
exploitation of its possibilities.
Figure 17. The new output stage
The clear advantages this new approach has over classical output stages are as follows:
Rail-to-rail output voltage swing with no need of bootstrap
capacitors
The output swing is limited only by the V
of 0.6 Ω each.
Classical solutions adopting composite PNP-NPN for the upper output stage have higher
saturation loss on the top side of the waveform. This unbalanced saturation causes a
significant power reduction. The only way to recover power consists of the addition of
expensive bootstrap capacitors.
Absolute stability without any external compensation
Referring to the circuit of
R2/R1. The DC Output (V
By controlling the amount of this local feedback it is possible to force the loop gain (A * β) to
less than unity at frequency for which the phase shift is 180°C. This means that the output
buffer is intrinsically stable and not prone to oscillation.
Most remarkably, the above feature has been achieved in spite of the very low closed loop
gain of the amplifier.
In contrast, with the classical PNP-NPN stage, the solution adopted for reducing the gain at
high frequencies makes use of external RC networks, namely the Boucherot cells.
Figure 17
CC
/2) is fixed by an auxiliary amplifier common to all the channels).
the gain V
cesat
of the output transistors, which are in the range
OUT
/V
IN
Figure 17
is greater than unity, approximately 1 +
has then allowed the full
Output stage
11/19