TDA8931 View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

TDA8931

Power comparator 1×20 W

Philips Electronics 

Philips Semiconductors

TDA8931

Power comparator 1 × 20 W

14.1 Output power estimation

The output power, just before clipping, can be estimated using the following equation:

Po(1%) = ----R--------L--------+----------R-------D--------S------o----n--------R+------8--L--R-----×---c----o---R---i---l-L----+----------R--------E------S------R-----×-----V----P------2

(2)

Where:

Po(1%) = output power just before clipping at THD = 1 %

RL = load impedance

RDSon = on-resistance power switch

Rcoil = series resistance output coil

RESR = ESR of the single-ended capacitor

VP = supply voltage (VDDP − VSSP)

Example: Substituting RL = 4 Ω, RDSon = 0.22 Ω (at Tj = 25 °C), Rcoil = 0.045 Ω,

RESR = 0.06 Ω and VP = 22 V results in output power Po = 12.9 W.

The output power at THD = 10 % can be estimated by:

Po(10%) = 1.25 × Po(1%)

(3)

Figure 6 shows the estimated output power as a function of the supply voltage for different

load impedances.

30

PO

(W)

20

10

001aac236

4Ω

6Ω

8Ω

RL = 3 Ω

10 Ω

30

PO

(W)

20

10

001aac237

RL = 3 Ω

4Ω

6Ω 8Ω

10 Ω

0

10

15

20

25

30

35

VP (V)

a. THD = 1 %.

Fig 6. Output power as a function of supply voltage

0

10

15

20

25

30

35

VP (V)

b. THD = 10 %.

9397 750 13847

Preliminary data sheet

Rev. 01 — 14 January 2004

© Koninklijke Philips Electronics N.V. 2005. All rights reserved.

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