TS4994EIKJT STMICROELECTRONICS [STMicroelectronics], TS4994EIKJT Datasheet - Page 30

• Manufacturer Part Number: TS4994EIKJT
• Description: 1.2 W differential input/output audio power amplifier with selectable standby
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Application information
4.8
4.9
30/35
To calculate the maximum ambient temperature T
●
●
●
Example: V
Using the power dissipation formula given above in
T
Equation 5
Therefore, the maximum allowable value for T
Decoupling of the circuit
Two capacitors are needed to correctly bypass the TS4994. A power supply bypass
capacitor C
C
indirect influence on power supply disturbances. With a value for C
similar THD+N performance to that shown in the datasheet.
In the high frequency region, if C
on the power supply rail are less filtered.
On the other hand, if C
more filtered.
C
result of PSRR (with input grounded and in the lower frequency region).
Wake-up time: t
When the standby is released to put the device ON, the bypass capacitor C
immediately. As C
properly until the C
time or t
TS4994 gain is close to zero. After the wake-up time, the gain is released and set to its
nominal value.
If C
wake-up time.
amb
s
b
has particular influence on the THD+N in the high frequency region (above 7kHz) and an
has an influence on THD+N at lower frequencies, but its function is critical to the final
b
The value of the power supply voltage, V
The value of the load resistor, R
The R
P
T
has a value other than 1µF, refer to the graph in
is calculated as follows:
amb
dissmax
WU
= 125-80x0.633=62°C
thja
s
and is specified in
CC
and a bias voltage bypass capacitor
= 633mW
value for the package type
= 5V, R
b
b
is directly linked to the bias of the amplifier, the bias will not work
voltage is correct. The time to reach this voltage is called the wake-up
L
s
WU
= 8Ω, R
is higher than 1µF, the disturbances on the power supply rail are
T
Table 3 on page
amb
thja-flipchip
s
is lower than 1µF, it increases THD+N, and disturbances
=
L
125° C R
= 100°C/W (100mm² copper heatsink)
–
amb
CC
5, with C
TJHA
amb
C
is:
b
Equation 3
×
.
Figure 88 on page 22
allowable, you need to know:
P
dissmax
b
=1µF. During the wake-up time, the
this gives a result of:
s
of 1µF, you can expect
b
to establish the
is not charged
TS4994FC