1000 Base-T, ±15kV ESD Protection LAN Switches

_______________________________________________________________________________________

7

Digital Control Inputs

The MAX4890E/MAX4892E provide a single digital con-

trol SEL. SEL controls the switches as well as the LED

switches as shown in Table 1.

Analog Signal Levels

The on-resistance of the MAX4890E/MAX4892E is very

low and stable as the analog input signals are swept

from ground to V+ (see the Typical Operating

Characteristics). The switches are bidirectional, allow-

ing A_ and _B_ to be configured as either inputs or out-

puts.

ESD Protection

The MAX4890E/MAX4892E are characterized using the

Human Body Model for ±15kV of ESD protection. Figure 5

shows the Human Body Model. This model consists of a

100pF capacitor charged to the ESD voltage of interest

which is then discharged into the test device through a

1.5k

Ω resistor. All signal and control pins are ESD pro-

tected to ±15kV HBM (Human Body Model).

Applications Information

Typical Operating Circuit

The Typical Operating Circuit shows the MAX4890E/

MAX4892E in a 1000 Base-T docking station application.

Power-Supply Sequencing and

Overvoltage Protection

Caution: Do not exceed the absolute maximum ratings.

Stresses beyond the listed ratings may cause perma-

nent damage to the device.

Proper power-supply sequencing is recommended for

all CMOS devices. Always apply V+ before applying

analog signals, especially if the analog signal is not

current limited.

Layout

High-speed switches require proper layout and design

procedures for optimum performance. Keep design-con-

trolled-impedance pc board traces as short as possible.

Ensure that bypass capacitors are as close as possible

to the device. Use large ground planes where possible.

Chip Information

PROCESS: BiCMOS

SEL

CONNECTION

0

A_ to _B1, LED_ to _LED1

1

A_ to _B2, LED_ to _LED2

Table 1. Truth Table