PA4201-PUNK POP-UP NOISE KILLER
FEATURES
Extremely low supply current (<1µA)
>45dB mute attenuation
Shunt operation.
SOFT mute during normal operation.
Built-in expansion capability. Soft Mute out for driving additional channels.
Instant Power UP and Power DOWN muting.
ESD protected outputs.
2.7V to 5.5V supply operation.
Compact 2 x 2 x 0.6mm 8 lead DFN and SO-8 Package
APPLICATIONS
DFN-8
Cell phones
PDAs
Portable DVD Players
Portable MP3 Players
Notebook Audio
Set-top boxes
Digital Video Recorders
LCD TVs
Home Theater systems
GENERAL DESCRIPTION
PA4201 (PUNK) is a low power (ICC < 1µA) monolithic CMOS mixed signal device. PUNK’s primary function is
to control power supply transition noise in audio circuits and systems.
PUNK boasts several features that make it a “one of a kind” product on the market. Most prominent is the
feature that allows the designer to implement SOFT mute on an audio line during normal operation. PUNK is an
exceptional product for multi-channel devices as it is capable of expanding the SOFT mute operation into
(Dolby 5.1 DTS
TM
) systems .
PUNK requires few external components for its operation, working from low to medium power supply voltages
of 2.7V to 5.5V. As soon as a change in the power supply is detected, PUNK ensures that audio inputs to
succeeding amplifiers are switched to a convenient low impedance voltage rail. This causes the amplifiers to
remain silent as the power supply changes state.
PUNK operates as a passive shunt device. So the designer does not have to worry about PUNK introducing
any kind of noise or distortion into the system.
While consuming less than 1µA of supply current PUNK provides more than 45dB of mute attenuation at the
audio lines.
PUNK is equipped with ESD (Human Body Model) protection circuitry on the outputs.
PUNK is available as an 8L low profile 0.6mm DFN as well as the SO-8 package and is specified for operation
over the -40 to +85 deg. C temperature range.
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95020 REV.0 08/07
PA4201-PUNK POP-UP NOISE KILLER-ABSOLUTE MAXIMUM RATINGS
Sustained operation at or above the following ratings is not recommended. Catastrophic and irre
versible damage will occur to the device at or above these ratings.
Symbol
V
X
I
X
T
A
T
S
T
SOL
Description
Voltage at any pin
Current at any pin
Ambient Temperature
Storage Temperature
Soldering Temperature
Rating
-0.3 to 7.0+0.3V
500mA
150 deg. C
200 deg. C
260 deg. C
Recommended Operating Conditions:
Unless otherwise specified, VDD=3 +/- 10%, TA = Ambient Temperature = 25 deg. C.
DC OPERATING CONDITIONS
Limit
Symbol
V
DDa
I
DD
T
A
V
OH
V
OL
V
IH
V
IL
R
ON
Parameter
Positive Power Supply
VDD Current
Ambient Temperature
Logic High O/P Voltage
Logic Low O/P Voltage
Logic High I/P Voltage
Logic Low I/P Voltage
FET ON Resistance
Condition
Min
Normal Operation
Normal Operation
Normal Operation
IOH=100µA
IOL=-100µA
IIH= 1µA
IIL=1µA
VDD=2.7V, VDFET=0.4V
VCC=5.5V, VDFET=0.4V
0.7
0.5
VDD-0.3
0.3
1
1
-40
VDD-0.1
0.2
2.7
Typ
Max
5.5
1
85
Unit
V
µA
O
C
V
V
V
ohm
95020 REV.0 08/07
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NOT FOR USE IN LIFE SUPPORT SYSTEMS
PA4201-PUNK POP-UP NOISE KILLER
Symbol
Parameter
Condition
Min
Limit
Typ
Max
300
300
5
12
Unit
M
OFFDb
M
STDb
M
PDEL
NFETV
c
Mute release delay
Soft mute fall/rise time
Mute ON Delay
NFET open drain volt
Mute Control=VIL
10
Set by ext. RC network at RCS pin
Mute Control transitions to VIH.
Set by ext. capacitor CEXT
Power drops by 10%
1
ms
ms
µS
V
Notes:
a. Power supply stabilization times have been assumed to range from 20ms to 200ms
b. Two external capacitors (C1 and C2) set the delay time for mute release and soft mute
c. Output switches are open drain N channel MOSFETS
PIN OUT
Pin
1
2
3
4
5
6
7
8
Name
VCC
RCS
CEXT
SMUTEOUT
MUTE1
MUTE2
GND
MUTECONT
Function
Positive power supply. 2.7V tp 5.5V +/-10%
Power On mute delay resistor-capacitor connection
Soft mute delay capacitor
Soft Mute OUT for multiple channels
Open Drain output of NFET 1
Open Drain output of NFET 2
Ground
Mute control signal from microprocessor
TYPICAL APPLICATION BLOCK DIAGRAM
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NOT FOR USE IN LIFE SUPPORT SYSTEMS
PA4201-PUNK POP-UP NOISE KILLER -THEORY OF OPERATION
Startup
During Startup, the power supply ramps from 0V to VCC. This time is usually in excess of 20ms. As
soon as this change in voltage is sensed, PUNK latches the Mute Controller outputs to HIGH, thus
“muting” the lines. This is the Startup Operation (figure 1). The duration for which for which the
controller outputs are latched HIGH can be controlled by an external RC circuit. When the voltage
this RC pin reaches a certain threshold, the mute controller releases the lines (Gate voltage is LOW)
and Normal Operation starts.
Shutdown
During Shutdown, the reverse process happens. As the power supply reaches the threshold on its
way down, the mute controller again latches the outputs to HIGH, thus “muting” the lines (figure 2).
This muting prevents unwanted signal spikes from getting the power amplifiers. However, for optimal
performance, it is suggested to mute the lines using the MUTECONT signal before power down. This
process will ensure that the pop noise involved during shutdown is diminished.
SOFT Mute
During normal operation, PUNK is in OFF state. But if there arises a situation when the audio lines
need to be muted, the designer can do this by asserting the MUTECONT signal to HIGH. This will
initiate a SOFT mute sequence (figure 3). When the MUTECONT signal is asserted, the mute
controller gradually ramps, the control voltages in a “SOFT” fashion so as to provide a soft mute
operation.
The mute delay is fully controllable by the designer by using an external capacitor at CEXT.
Typical values of CEXT are between 0.1 micro F and 0.5 µF. The reverse happens when the
MUTECONT signal is released. This operation is explained in detail in the Application Circuit section.
95020 REV.0 08/07
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4
NOT FOR USE IN LIFE SUPPORT SYSTEMS
PA4201-PUNK POP-UP NOISE KILLER
95020 REV.0 08/07
www.protekdevices.com
5
NOT FOR USE IN LIFE SUPPORT SYSTEMS
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