TDA8926 Datasheet, PDF (15/32 Pages) NXP Semiconductors – Power stage 2 x 50 W class-D audio amplifier

Philips Semiconductors
Power stage 2 × 50 W class-D audio
amplifier
Preliminary specification
TDA8926
15.1 BTL application
When using the system in a mono BTL application (for more output power), the inputs of both channels of the PWM
modulator must be connected in parallel; the phase of one of the inputs must be inverted. In principle the loudspeaker
can be connected between the outputs of the two single-ended demodulation filters.
15.2 Package ground connection
The heatsink of the TDA8926J is connected internally to V_SS.
15.3 Output power
The output power in single-ended applications can be estimated using the formula
P_o(1%) = ---^{(------R---------L}--------⁺---------R----------^dR-----s-----^{(L--o------n----)------+----------R----------s-----)}----2^×-----_×^V----P_R-----^×_L----⁽---1-----^–----t--^W----⁽--^m----ⁱ-ⁿ--⁾---^×-----f--^o--^s---^c--⁾-----²-
The maximum current I_O(max) = ^[---V----^P----R-^×---_L--⁽--1₊-----^–_R----t-d-^W-_s---₍₍-_o-^m--_n--ⁱ⁾-ⁿ--₊-⁾---^×-R---f--_so---^s--^c---⁾--^] should not exceed 5 A.
The output power in BTL applications can be estimated using the formula
P_o(1%) = ----R---------^{L--------+----------2----------×----------(----RR----------dL----s----(----o----n------)------+----------R--------s-------)}-2---^×-_×---2--R--V---_L--^P----^×-----⁽--1-----^–-----t--^W----⁽-^m----ⁱ-ⁿ---⁾---^×----f--^o---^s--^c--⁾-----²-
The maximum current I_O(max) = -^[--2---R-V---_L-^P---₊--^×---2-⁽---1-_×----^–-₍--R-t--^W--_d--^(s--^m-₍-_o--ⁱ-_nn--₎₎---₊^×-----Rf--^o---_ss--₎-^c--⁾---^] should not exceed 5 A.
Where:
R_L = load impedance
R_s = series resistance of filter coil
P_o(1%) = output power just at clipping
The output power at THD = 10%: P_o(10%) = 1.25 × P_o(1%).
15.4 Reference design
The reference design for a two-chip class-D audio amplifier for TDA8926J and controller TDA8929T is shown in Fig.7.
The Printed-Circuit Board (PCB) layout is shown in Fig.8. The bill of materials is given in Table 1.
2002 Oct 10
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