PRELIMINARY
PCT1789W DATA SHEET
PIN COMPARISON OF PCT301L AND PCT303W
!!
PCT303W Pin Descriptions
Table 6 PCT303W Pin Descriptions
Name
Number I/O Description
Line Interface
FILT
15
Filter. Sets the time constant for the DC termination circuit.
Filter 2. Sets the time constant for the DC termination circuit.
Receive input. Serves as the receive side input from the telephone network.
DC termination. Provides DC termination to the telephone network.
External resistor. Sets the real AC termination impedance.
FILT2
RX
16
14
2
DCT
REXT
REXT2
RNG1
13
12
5
External resistor 2. Sets the complex AC termination impedance.
Ring 1. Connects through a 680pF capacitor to the “Tip” lead of the telephone line. Pro-
vides the ring and caller ID signals to the PCT303DW.
RNG2
6
Ring 2. Connects through a 680pF capacitor to the “Ring” lead of the telephone line.
Provides the ring and caller ID signals to the PCT303DW.
QB
7
8
Transistor base. Connects to the base of transistor Q3.
Transistor emitter. Connects to the emitter of transistor Q3.
Transistor emitter 2. Connects to the emitter of transistor Q4.
QE
QE2
REF
1
11
Reference. Connects to an external resistor to provide a high-accuracy reference cur-
rent.
Isolation
C1B
4
3
Isolation capacitor 1B. Connects to one side of isolation capacitor C1.
IGND
Isolated ground. Connects to ground on the line-side interface. Also connects to capac-
itor C2.
Miscellaneous Signals
VREG
9
Voltage regulator. Connects to an external capacitor to provide bypassing for an inter-
nal power supply.
VREG2
10
Voltage regulator 2. Connects to an external capacitor to provide bypassing for an
internal power supply.
PIN COMPARISON OF PCT301L AND PCT303W
Table 7 PCT301L/PCT303W Pin Comparison
Pin Name
Pin Name
PCT301L
Pin Number
Pin Number
PCT301L
TSTA
TSTB
IGND
C1B
PCT303W
QE2
PCT303W
VREG
VREG2
REF
1
2
3
4
5
6
7
8
9
VREG
NC
DCT
10
11
12
13
14
15
16
IGND
C1B
NC
DCT
REXT
RX
REXT2
REXT
RX
RNG1
RNG2
QB
RNG1
RNG2
QB
NC
FILT
QE
QE
TX
FILT2
PRELIMINARY
PC-TEL, Inc.
16
1789W0DOCDAT06A-0299
ETC [ ETC ]
