TDF8591TH_1

© NXP B.V. 2008. All rights reserved.

Product data sheet

Rev. 01 — 5 March 2008

15 of 34

NXP Semiconductors

TDF8591TH

2

× 100 W SE (4 Ω) or 1 × 310 W BTL (4 Ω) class-D amplifier

11. Switching characteristics

12. Application information

12.1 BTL application

When using the power amplifier in a mono BTL application the inputs of both channels

must be connected in parallel and the phase of one of the inputs must be inverted (see

Figure 8). The loudspeaker is connected between the outputs of the two single-ended

demodulation filters.

12.2 Output power estimation

The achievable output powers in SE and BTL applications can be estimated using the

following expressions:

SE:

W

BTL:

W

Table 10.

Switching characteristics

Symbol

Parameter

Conditions

Min

Typ

Max

Unit

Internal oscillator

oscillator frequency

290

310

344

kHz

-

560

-

kHz

-

200

-

kHz

External oscillator or frequency tracking

referred to SGND

4

-

6

V

referred to SGND

0

-

1

V

tracking frequency range

210

-

600

kHz

Drain source on-state resistance of the output transistors

low-side drain-source on-state resistance

-

185

205

m

Ω

-

140

155

m

Ω

high-side drain-source on-state resistance

-

220

245

m

Ω

-

160

175

m

Ω

P

o 0.5%

()

R

L

R

L

R

DSon hs

()

R

sL

()

++

------------------------------------------------------

V

P

×

1t

w min

()

–

f

osc

2

----------

×





×





2

2R

L

×

----------------------------------------------------------------------------------------------------------------------------------

=

P

o 0.5%

()

R

L

R

L

R

DSon hs

()

R

DSon ls

()

+

() 2R

sL

()

++

-------------------------------------------------------------------------------------------

2V

P

×

1t

wmin

()

–

f

osc

2

----------

×





×





2

2R

L

×

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------

=