Philips TFA9843AJ 8. Functional description

TFA9843AJ_1 © Koninklijke Philips Electronics N.V. 2006. All rights reserved.

Preliminary data sheet Rev. 01 — 28 April 2006 4 of 19

Philips Semiconductors TFA9843AJ

20 W stereo power ampliﬁer with volume control

7.2 Pin description

8. Functional description

8.1 Input conﬁguration

The input cut-off frequency is as follows:

(1)

Single-ended application: Ri=60kΩand Ci= 220 nF:

(2)

As shown in Equation 2, large capacitor values for the inputs are not necessary; therefore

switch-on delay during charging of the input capacitors can be minimized. This results in a

good low frequency response and good switch-on behavior.

The TFA9843AJ has clamps on the inputs. In Standby mode the voltage on the input pins

is clamped for voltages lower than −0.1 V. When the TFA9843AJ is in Mute, Volume

control or Operating mode (maximum gain) the input clamp voltage is 1 V (RMS).

8.2 Power ampliﬁer

The power ampliﬁer is a single-ended ampliﬁer with an all NPN output stage, capable of

delivering a peak output current of 4 A.

8.2.1 Output power measurement

The output power as a function of the supply voltage is measured on the output pins at

THD=10%;seeFigure 7. The maximum output power is limited by the supply voltage of

26 V and the maximum available output current is 4 A repetitive peak current. A minimum

load of 3 Ω is required for supply voltages > 22 V; see Figure 4. The output power is

measured with one channel driven.

Table 3. Pin description

Symbol Pin Description

IN2 1 input 2

OUT2 2 loudspeaker terminal 2

CIV 3 common input voltage decoupling

IN1 4 input 1

GND 5 ground

SVR 6 half supply voltage decoupling (ripple rejection)

VC 7 volume control input (standby, mute and volume control)

OUT1 8 loudspeaker terminal 1

VCC 9 supply voltage

fi3dB–() 1

2πRiCi

×()

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

=

fi3dB–() 1

2π60 103

×220×10 9–

×()

-----------------------------------------------------------------12 Hz==

Contents

Main 1. General description 2. Features 3. Applications TFA9843AJ Rev. 01 28 April 2006 Preliminary data sheet 20 W stereo power amplier with volume control 20 W stereo power amplier with volume control 4. Quick reference data =25 5. Ordering information =18V; T = 0 V; measured in test circuit of Figure 11; 6. Block diagram TFA9843AJ Fig 2. Pin conguration TFA9843AJ Fig 1. Block diagram 8. Functional description 8.1 Input conguration 8.2 Power amplier 8.2.1 Output power measurement 8.2.2 Headroom 8.3 Mode selection 8.4 Supply voltage ripple rejection 8.5 Built-in protection circuits 9. Limiting values 10. Thermal characteristics 11. Static characteristics =25 12. Dynamic characteristics =18V; T = 0 V; measured in test circuit of Figure 11; Philips Semiconductors TFA9843AJ 4 function of frequency 24 16 20 Philips Semiconductors TFA9843AJ THD = 10 %; RL = 4 ; f = 1 kHz VCC = 18 V; RL = 4 frequency 13. Application information 13.1 Application diagrams TFA9843AJ Fig 11. SE application diagram 13.1.1 Single-ended application 13.1.2 Volume control drive options VC V VC 001aae339 13.2 Printed-circuit board 13.2.1 Layout and grounding 13.2.2 Power supply decoupling 13.3 Thermal behavior and heatsink calculation 14. Test information Fig 16. Junction temperature as a function of supply voltage 14.1 Quality information is applicable. General Quality Specication for Integrated Circuits, SNW-FQ-611 15. Package outline Fig 17. Package outline SOT523-1 (DBS9P) DBS9P: plastic DIL-bent-SIL power package; 9 leads (lead length 12/11 mm); exposed die pad SOT523-1 16. Soldering 16.1 Introduction to soldering through-hole mount packages Data Handbook IC26; Integrated Circuit Packages 16.2 Soldering by dipping or by solder wave 16.3 Manual soldering Page 18. Legal information 18.1 Data sheet status 18.2 Denitions 18.3 Disclaimers 18.4 Trademarks 20. Contents