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GAMMA
instabus
Release: February 2012
KNX EIB TP-UART 2-IC
Siemens AG
pages 42
Technical Manual
Infrastructure and Cities Sector,
Building Technologies
Control Products and Systems
© Siemens AG 2012
page 11
P. O. Box 10 09 53,
Subject to change without further notice.
D-93009 Regensburg
Symbol Parameter
Min
Max
Unit
Note
V
VSP
energy buffer voltage
V
VB+
- V
VDIF
45
V
1)
V
VDIF
voltage difference between V
VB+
and V
VSP
0.5
2
V
C
VSP
external storage capacitance
264
µF
2) 6)
ESR
VSP1
ESR of external storage capacitance evaluated @
120Hz
0.70
ESR
VSP2
ESR of external storage capacitance evaluated @
100kz
0.20
1) DC voltage of bus is 20V to 30V.
2) recommended 330 µF; must be larger than the capacitor at VCC
6) It is highly recommended, but not mandatory, that an additional capacitor C
VDDH
is included in any
application configuration where capacitors C
VSP
is present. When present it is recommended that C
VDDH
be
placed as close as possible to pin VDDH.
Table 7 Buffer Voltage Pin VSP
Figure 2 VCC supply external connections
2.2.6 Supply Pin VCC
Pin VCC delivers the internally generated supply voltage to external loads. The supply is generated by
a switched mode power supply (with an internal oscillator, softstart function), current source and shunt
regulator. The voltage of VCC depends on the level of pin SVCC. Internal input voltage for VCC
(switched mode power supply) is VDDH. VCC supply generation is disabled during softstart.
The I
VCC
maximum current can be greater than 30mA if the maximum I
V20
current is reduced.