sta335ml STMicroelectronics, sta335ml Datasheet - Page 12

• Manufacturer Part Number: sta335ml
• Description: 2-channel Microless High-efficiency Digital Audio System Sound Terminaltm
• Manufacturer: STMicroelectronics

Applications
5
5.1
5.2
5.3
12/20
Applications
Applications schematic
Figure 10
Concerning the power supplies, take care when designing the PCB layout. In particular, the
3.3-Ω resistors on the digital supplies (VDD_DIG) must be placed as close as possible to
the device. This helps to prevent parasitic oscillation in the digital part of the device due to
the inductive tracks of the PCB. The same rule applies for all the decoupling capacitors in
order to limit any spikes on the supply pins.
Internal voltage reference
An embedded voltage regulator produces the reference voltages for the DMOS bridge
driver. It requires two 100 nF capacitors to keep the regulator stable. The capacitors should
be place close to the pins.
Figure 8.
PLL filter schematic
It is recommended to use the circuit in
best performance from the device in general application. Note that the ground of this filter
scheme has to be connected to the ground of the PLL without any resistive path.
Concerning the component values, please take into account that the greater is the filter
bandwidth, the less is the lock time but the higher is the PLL output jitter.
Figure 9.
on the next page shows the schematic of a typical application for the STA335ML.
GND_REG
VCC_REG
VDD_REG
VSS_REG
Reference voltage block diagram
PLL applications schematic
FILTER_PLL
GND_DIG
100 nF
100 nF
Regulator
I
Input
level
shifter
interface
Ferrite bead
2
S
Doc ID 17638 Rev 3
Figure 9
4.7 nF
below for the PLL loop filter to achieve the
2k2
Driver P
Driver N
100 pF
PLL_GND
GND
680 pF
VCC
STA335ML