TFA9879HN/N1,157 NXP Semiconductors, TFA9879HN/N1,157 Datasheet - Page 21

• Manufacturer Part Number: TFA9879HN/N1,157
• Description: IC AMP AUDIO DGTL MONO D 24HVQFN
• Manufacturer: NXP Semiconductors
• Type: Class Dr

Specifications of TFA9879HN/N1,157

• Output Type: 1-Channel (Mono)
• Package / Case: 24-VFQFN Exposed Pad
• Max Output Power X Channels @ Load: 2.75W x 1 @ 4 Ohm
• Voltage - Supply: 2.5 V ~ 5.5 V
• Features: Depop, Digital Inputs, I²C, I²S, Mute, Short-Circuit and Thermal Protection, Tone and Volume Control
• Mounting Type: Surface Mount
• Product: Class-D
• Output Power: 2.75 W
• Thd Plus Noise: 0.02 %
• Operating Supply Voltage: 3.7 V
• Supply Current: 5.7 mA
• Mounting Style: SMD/SMT
• Audio - Load Impedance: 4 Ohms, 8 Ohms
• Audio Load Resistance: 4 Ohms, 8 Ohms
• Input Signal Type: Serial
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

NXP Semiconductors
TFA9879
Product data sheet
9.2.11 Power limiter
Table 12.
[1]
[2]
[3]
The power limiter controls the maximum output voltage in Amplifier mode. This feature
makes it possible to limit the output voltage across a peripheral (speaker) when
necessary.
The TFA9879 output voltage is dependent on:
The bass/treble output signal is connected to the power limiter input and is relative to the
Fraction of Full Scale (FFS), from −1 to +1.
Equation 10
between pins OUTA and OUTB in the audio bandwidth:
Equation 10
control and the R
The power limiter gain can be reduced in 249 steps of 0.5 dB in the range 0 dB to
−124 dB.
V
Control value:
attack rate
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
•
•
•
o
=
The control value is selected via bits AT_RATE in the DRC control register (see
The control value is selected via bits RL_RATE in the DRC control register (see
Default value.
The analog supply voltage on pin V
The gain of the power limiter (G)
The power limiter input signal (X
[3]
⎛
⎜
⎝
X
V
i
DDP
×
[1]
DRC attack and release rates
G
shows the relationship between these settings and the output voltage
only applies with no load and with clip control off (see
×
5.91
All information provided in this document is subject to legal disclaimers.
DSon
Attack rate (dB/ms)
3
2.7
2.25
1.8
1.35
0.9
0.45
0.225
0.15
0.11
0.09
0.075
0.065
0.06
0.055
0.05
Rev. 02 — 15 October 2010
of the power switches reduce the maximum clipped output signal.
X
X
i
I
×
×
G
G
×
×
5.91
5.91
Mono BTL class-D audio amplifier with digital input
i
)
<
≥
DDP
V
V
DDP
DDP
Control value:
release rate
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
(V)
[3]
[2]
Release rate (dB/ms)
0.5
0.137
0.075
0.05
0.036
0.03
0.026
0.021
0.020
0.017
0.015
0.014
0.013
0.012
0.011
0.01
Section
Table
Table
TFA9879
© NXP B.V. 2010. All rights reserved.
28).
28).
9.3). Clip
21 of 60
(10)