TS4997IQT STMicroelectronics, TS4997IQT Datasheet - Page 26

• Manufacturer Part Number: TS4997IQT
• Description: IC AMP AUDIO 1W STER AB 16QFN
• Manufacturer: STMicroelectronics
• Type: Class ABr

Specifications of TS4997IQT

• Output Type: 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 1W x 2 @ 8 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Features: 3D, Depop, Differential Inputs, Standby, Thermal Protection
• Mounting Type: Surface Mount
• Package / Case: 16-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-5995-2

Application information
4.10
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The C
and an indirect influence on power supply disturbances. With a value for C
expect THD+N performance similar to that shown in the datasheet.
In the high frequency region, if C
disturbances on the power supply rail are less filtered.
On the other hand, if C
rail are more filtered.
The C
PSRR performance (with grounded input and in the lower frequency region).
Standby control and wake-up time t
The TS4997 has two dedicated standby pins (STBYL, STBYR). These pins allow to put
each channel in standby mode or active mode independently. The amplifier is designed to
reach close to zero pop when switching from one mode to the other.
When both channels are in standby (V
mode. When at least one of the two standby pins is released to put the device ON, the
bypass capacitor C
amplifier, the bias will not work properly until the C
voltage is called the wake-up time or t
During the wake-up phase, the TS4997 gain is close to zero. After the wake-up time, the
gain is released and set to its nominal value. If C
to the graph in
When a channel is set to standby mode, the outputs of this channel are in high impedance
state.
Figure 66. Typical startup time vs. bypass capacitor
S
b
capacitor has an influence on the THD+N at lower frequencies, but also impacts
capacitor has particular influence on the THD+N at high frequencies (above 7kHz)
Figure 66
100
b
90
80
70
60
50
40
30
starts to be charged. Because C
0.0
S
Tamb=25
is greater than 1µF, then those disturbances on the power supply
to establish the corresponding wake-up time.
0.5
°
1.0
S
C
is lower than 1µF, then THD+N increases and
Bypass Capacitor Cb (
WU
1.5
STBYL
Vcc=3.3V
and is specified in
2.0
= V
STBYR
b
2.5
b
Vcc=2.7V
has a value different from 1µF, then refer
voltage is correct. The time to reach this
b
WU
3.0
= GND), the circuit is in shutdown
is directly linked to the bias of the
μ
F)
3.5
Table 4 on page
4.0
Vcc=5V
4.5
S
of 1µF, one can
5, with C
TS4997
b
=1µF.