PEF2256 INFINEON [Infineon Technologies AG], PEF2256 Datasheet - Page 60

• Manufacturer Part Number: PEF2256
• Description: E1/T1/J1 Framer and Line Interface Component for Long- and Short-Haul Applications
• Manufacturer: INFINEON [Infineon Technologies AG]

3.4
3.4.1
The FALC
For compatibility reasons, it is possible to operate the device off a single 3.3 V power
supply. In this operation mode, the 1.8-V core voltage is generated internally using an
on-chip voltage regulator. In order to minimize the power consumption it is also possible
to operate the device using separate external 3.3-V and 1.8-V supplies. Suppl y voltage
selection is done by using control pin VSEL (Voltage SELect). See
Figure 12
Note: The 1.8 V power supply requires de-coupling in either operation mode.
Figure 12
User’s Manual
Hardware Description
The voltage levels of V
level, even during device power-up and power-down. Otherwise cross currents
through ESD protection diodes will occur.
®
for more detail.
Power Supply
Power Supply Configuration
56 uses two different supply voltages internally, which are 3.3 V and 1.8 V.
Single Voltage Power Supply Mode
3.3 V
DD
, V
DDP
V
V
V
V
V
V
V
V
V
DD
DDX
DDR
DDP
DDC
SS
SSP
SSX
SSR
, V
FALC
DDX
60
, and V
®
56
VSEL
DDR
Functional Description E1/T1/J1
(can be left
open)
3.3 V
must always be above the V
F56V2_power_supply_single
DS1.1, 2003-10-23
PEF 2256 H/E
Figure 11
FALC
®
and
DDC
56