pi5l100 Pericom Semiconductor Corporation, pi5l100 Datasheet - Page 7

• Manufacturer Part Number: pi5l100
• Description: Lan Switch Quad 2 1 Mux 6.2v Supply
• Manufacturer: Pericom Semiconductor Corporation

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2
1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 1 2 3 4 5 6 7 8 9 0 1 2
LAN Switch Applications
The PI5L100 was designed to switch between various standards
such as 10Base-T, 100Base-T, 100VG-AnyLAN, and Token Ring.
Also general purpose applications such as loopback, line termina-
tion, and line clamps that might normally use mechanical relays are
also ideal uses for this LAN Switch (see Figure 11 applications).
Generally speaking, this LAN Switch can be used for data rates to
200 Mbps and data signal levels from 0V to 4.5V.
Differential Crosstalk . . . X
Adjacent pins cause the most crosstalk because of the interlead
package capacitance which is generally in the order of 0.5pF (pin-
to-pin). It can be seen in Figure 11 that this Evaluation (EV) Board
schematic uses four pairs of switches. Pair 1B/2B are RX1 that
connect to YA and YB. The second pair, 3B/4B, are TX1 and connect
to YC and YB. Pairs 3 and 4 are grounded for this differential
crosstalk test. The purpose of this EV board is to determine the
amount of crosstalk between the transmit and receive pairs in a full
duplex application. Figure 15 shows the scope waveforms. Traces
LAN Standards
10Base-T
100Base-T
100VG-AnyLAN
–100dB
–10dB
–20dB
–40dB
–50dB
–60dB
–70dB
–80dB
–90dB
–30db
0dB
Data Rate per twisted pair (UTP)
10 Mbps
100 Mbps
25 Mbps
RBW: 10 kHz
PI5L100
NETWORK
A: REF
0.000
[dB]
TALK
10.00
DIV
(DIF)
2
XTALK 10 MHz, RL = 50 Ohm
ST: 4.05 sec
B: REF
180.0
[deg]
4
Figure 7. Crosstalk vs Frequency
36.00
DIV
6
RANGE: R = 0, T = 0dBm
8
Applications
1
7
2
1 and 2 are single ended inputs to the differential inputs of the DUT.
Trace 3 is the differential X
V
the effective input frequency is equal to 0.3/t
So the approximate Differential Crosstalk at 150 MHz is –44dB.
Because pins measured are not adjacent, the differential crosstalk
is typically > 60 dB at 10 MHz. The load resistor (R
( to match the UTP impedance). Increasing the data rate or R
also increase differential crosstalk.
V
To keep R
be increased to a voltage between +6.0V and +6.5V (see Figure 13).
The R
voltage which is exponential. Ideally an input voltage between 0.2V
and 3.6V will keep R
is ~2 ohms).
Signal Distortion
Distortion of the input signal is equated to 20LOG R
keeping R
distortion. Also, increasing the data rate increases harmonic distor-
tion which also effects the signal amplitude.
Evaluation Board
Figure 14 shows the layout for an EV board that can be used for
evaluation. This is a 2-layer board and is one-inch square.
OUT
CC
Bias Voltage vs R
MAGNITUDE
/V
ON
PHASE
IN
4
vs. V
ON
START
ON
= 20LOG 30 mV/5V = –44dB. Since the edge rate is 2ns,
STOP
MKR 10 074 746.057 Hz
T/R
to a minimum, it is recommended that the V
IN
flat as data signal level varies is critical to low
6
curve shows the effect of on-resistance and input
–90.2501
519.486m
8
300 000 000 . 000 Hz
ON
1 000 000 . 000 Hz
1
in the flat part of the curve ( R
LanSwitch Quad 2:1 Mux/Demux
ON
Wide-Bandwidth, Low-Voltage
TALK
dB
deg
2
output which equates to 20LOG
+180˚
+144˚
+108˚
+72˚
+36˚
0¡
–36˚
–72˚
–108˚
–144˚
–180˚
R
which is ~150 MHz.
L
PS7031F
) used was 100
ON
ON
PI5L100
CC
or flatness
/ R
voltage
09/17/04
L
L
. So
will