PEB2025 Datasheet, PDF (3/21 Pages) Siemens Semiconductor Group – ISDN Exchange Power Controller

PEB 2025
Pin Definitions and Functions
Pin No.
P-DIP-22
Pin No.
Symbol
P-LCC-28
17
21, 22, 23 V _BAT
22
1
V _CC
11
14
GND
19, 18, 16,
15
12
25, 24, 20,
19
15
aF0 - aF3
R _Imax
21, 20, 14, 28, 26, 18, CLC0 -
13
16
CLC3
1
3
2
6, 5, 4
8, 7
10
2
CS
4
WR
3
RD
8, 7, 5
D0 - D2
11, 9
A0, A1
13
RES
Input (I)
Output (O)
I
I
I
O
I
I
I
I
I
I/O
I
I
Function
Supply Voltage: This pin has to be
connected to the negative supply
voltage. V _BAT supplies power to all line
drivers.
Digital Supply Voltage: + 5V
Ground: Digital
Note: GND has to be connected to
ground battery (positive supply
voltage)
a-Line Feeding: aF_i are the line driver
outputs
Current Limit: Using an external resistor
connected between R _Imax and GND, the
maximum limit is the same to all line
drivers.
Current Limit Characteristic: By
connecting external capacitors between
CLC_i and GND, the time-dependent turn
off-characteristics of the line drivers are
defined.
Chip Select: A logic low on CS enables
RD and WR communication between the
processor and the IEPC.
Write: A logic low on this pin, while CS is
low, enables the IEPC to accept
command words from the processor.
Read: A low on this pin (while CS is low)
enables the IEPC to release status onto
the data bus for the processor.
Data Bus: Control, status and command
information are transferred via this bus
between IEPC and processor.
Address Bus: These inputs select the
internal registers while chip select is
active.
Reset: A logic high on the RES input sets
the device into the initial state.
Semiconductor Group
3