TS4994IST STMicroelectronics, TS4994IST Datasheet - Page 28

• Manufacturer Part Number: TS4994IST
• Description: IC AMP AUDIO PWR 1W MONO 8MSOP
• Manufacturer: STMicroelectronics
• Type: Class ABr

Specifications of TS4994IST

• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 1W x 1 @ 8 Ohm
• Voltage - Supply: 2.5 V ~ 5.5 V
• Features: Depop, Differential Inputs, Short-Circuit and Thermal Protection, Standby
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• For Use With: 497-6396 - BOARD EVAL FOR LV TS4984IQT497-6395 - BOARD EVAL FOR LP DIFF TS4994IQT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-4452-2

Application information
4.8
4.9
28/35
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=74°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
s
is lower than 1µF, it increases THD+N, and disturbances
=
= 80°C/W
L
125° C R
–
amb
CC
6, with C
TJHA
amb
C
is:
b
Equation 3
×
.
Figure 69 on page 20
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
TS4994