LM4952TSBD National Semiconductor, LM4952TSBD Datasheet - Page 16

• Manufacturer Part Number: LM4952TSBD
• Description: BOARD EVALUATION LM4952TS
• Manufacturer: National Semiconductor
• Series: Boomer®r

Specifications of LM4952TSBD

• Amplifier Type: Class AB
• Output Type: 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 3.8W x 2 @ 4 Ohm
• Voltage - Supply: 9.6 V ~ 16 V
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: LM4952
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Application Information
manner, the ground lead of the capacitor connected between
the BYPASS pin and GND should also be connected to the
package’s grounded tab.
OPTIMIZING CLICK AND POP REDUCTION
PERFORMANCE
The LM4952 contains circuitry that eliminates turn-on and
shutdown transients ("clicks and pops"). For this discussion,
turn-on refers to either applying the power supply voltage or
when the micro-power shutdown mode is deactivated.
As the V
final value, the LM4952’s internal amplifiers are muted. Once
the voltage at the BYPASS pin reaches V
are unmuted.
The gain of the internal amplifiers remains unity until the
voltage on the bypass pin reaches V
voltage on the bypass pin is stable, the device becomes fully
operational and the amplifier outputs are reconnected to
their respective output pins.
DD
/4 voltage present at the BYPASS pin ramps to its
DD
/4. As soon as the
DD
(Continued)
/4, the amplifiers
16
In order eliminate "clicks and pops", all capacitors must be
discharged before turn-on. Rapidly switching V
allow the capacitors to fully discharge, which may cause
"clicks and pops".
There is a relationship between the value of C
C
is applied or the shutdown mode is deactivated. Best perfor-
mance is achieved by selecting a C
greater than twelve times C
RECOMMENDED PRINTED CIRCUIT BOARD LAYOUT
Figure 9 through Figure 11 show the recommended two-
layer PC board layout that is optimized for the TO263-
packaged, SE-configured LM4952 and associated external
components. These circuits are designed for use with an
external 12V supply and 4Ω(min)(SE) speakers.
These circuit boards are easy to use. Apply 12V and ground
to the board’s V
speaker between the board’s OUT
respective GND pins.
BYPASS
that ensures minimum output transient when power
DD
and GND pads, respectively. Connect a
IN
’s value.
A
and OUT
BYPASS
B
value that is
DD
outputs and
may not
IN
and