TS4998IQT STMicroelectronics, TS4998IQT Datasheet - Page 26

• Manufacturer Part Number: TS4998IQT
• Description: IC AMP AUDIO PWR 1W STER 16QFN
• Manufacturer: STMicroelectronics
• Type: Class ABr

Specifications of TS4998IQT

• 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: Depop, Differential Inputs, Standby, Thermal Protection
• Mounting Type: Surface Mount
• Package / Case: 16-QFN
• Operational Class: Class-AB
• Audio Amplifier Output Configuration: 2-Channel Stereo
• Output Power (typ): 1x2@8OhmW
• Audio Amplifier Function: Speaker
• Total Harmonic Distortion: 0.5@8Ohm@700mW%
• Single Supply Voltage (typ): 3/5V
• Dual Supply Voltage (typ): Not RequiredV
• Power Supply Requirement: Single
• Unity Gain Bandwidth Product (typ): 1.5MHz
• Rail/rail I/o Type: No
• Power Supply Rejection Ratio: 80dB
• Single Supply Voltage (min): 2.7V
• Single Supply Voltage (max): 5.5V
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 16
• Package Type: QFN EP
• For Use With: 497-8259 - BOARD EVAL BASED ON TS4998
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6842-2

Application information
4.9
4.10
Note:
4.11
26/33
Standby control and wake-up time t
The TS4998 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 TS4998 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
Shutdown time
When the standby command is activated (both channels put into standby mode), the time
required to put the two output stages of each channel in high impedance and the internal
circuitry in shutdown mode is a few microseconds.
In shutdown mode when both channels are in standby, the Bypass pin and L
R
C
Pop performance
Due to its fully differential structure, the pop performance of the TS4998 is close to perfect.
However, due to mismatching between internal resistors R
IN
IN
- pins are shorted to ground by internal switches. This allows a quick discharge of C
capacitors.
Figure 66
100
b
90
80
70
60
50
40
30
starts to be charged. Because C
0.0
Tamb=25
to establish the corresponding wake-up time.
0.5
°
1.0
C
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)
feed
3.5
Table 4 on page
, external resistors R
4.0
Vcc=5V
4.5
IN
5, with C
+, L
IN
IN
TS4998
-, R
and
b
b
=1µF.
IN
and
+,