SX1441EVK Semtech, SX1441EVK Datasheet - Page 69

• Manufacturer Part Number: SX1441EVK
• Description: KIT DEV FOR SX1441
• Manufacturer: Semtech
• Series: EasyBlue™r
• Type: Bluetoothr

Specifications of SX1441EVK

• For Use With/related Products: SX1441
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Contents: -
• Other names: SX1441DVK; SX1441DVK

Personal Area Network
Figure 34 shows the typical configuration of the speaker and power amplifier. VDD_PA may be connected to
VREGD or any voltage lesser or equal to 1.8V.
The output filter is a balanced 2-pole filter. Equation 5 gives a raw estimation of the values of the external inductors
and capacitors as a function of the speaker impedance Z
kHz, as defined by the Bluetooth audio specifications. Z
© Semtech 2006
VDD_PA
VSS_PA
C
Equation 5 – Typical L and C values for the speaker output filter
=
VREGD
VSSIO_DIG
2
⋅
SX1441
Z
2
PWM bitstream
L
Figure 33 - Power Amplifier (PA) structure
⋅
ω
0
Figure 34 - Typical output filter
PA_OUTP
PA_OUTN
,
VDD_PA
VSS_PA
L
=
PA_OUTP
2
2
L
⋅
69
ω
⋅
may be very dependant on the speaker.
Z
L
0
L
and the cut-off frequency f
PA_OUTN
L
L
where
C
C
ω
0
=
2
⋅
π
SX1441 – Bluetooth® 1.2 SoC
⋅
f
0
0
of the filter. f
www.semtech.com
0
Data Sheet
is usually 4