TS4998IQT STMicroelectronics, TS4998IQT Datasheet - Page 25

• 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

TS4998
4.7
4.8
Footprint recommendation
Footprint soldering pad dimensions are given in
previous section, the maximum allowable value for ambient temperature is dependent on
the thermal resistance junction to ambient R
power dissipation.
Based on best thermal performance, it is recommended to use 4-layer PCBs with vias to
effectively remove heat from the device. It is also recommended to use vias for 2-layer PCBs
to connect the package exposed pad to heatsink cooper areas placed on another layer.
For proper thermal conductivity, the vias must be plated through and solder-filled. Typical
thermal vias have the following dimensions: 1.2mm pitch, 0.3mm diameter.
Figure 65. QFN16 footprint recommendation
Decoupling of the circuit
Two capacitors are needed to correctly bypass the TS4998: a power supply bypass
capacitor C
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).
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)
S
and a bias voltage bypass capacitor C
S
is greater than 1µF, then those disturbances on the power supply
S
is lower than 1µF, then THD+N increases and
THJA
Figure 72 on page
. Decreasing the R
b
.
Application information
THJA
30. As discussed in the
value causes better
S
of 1µF, one can
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