SP213ECA-L-TR Datasheet, PDF (9/17 Pages) Exar Corporation – High Speed +5V High Performance RS232 Transceivers

WAKEUP FUNCTION
The SP213EH has a wake–up feature that keeps
two receivers (R and R ) in an enabled state
4
5
when the device is in the shutdown mode. With
only the receivers active during shutdown, the
devices draw 5–10µA of supply current.
A typical application of this function would be
where a modem is interfaced to a computer in a
power–down mode. The ring indicator signal
from the modem could be passed through an
active receiver in the SP213EH that is itself in
the shutdown mode. The ring indicator signal
would propagate through the SP213EH to the
power management circuitry of the computer to
power up the microprocessor and the SP213EH
drivers. After the supply voltage to the SP213EH
reaches +5.0V, the SHUTDOWN pin can be
disabled, taking the SP213EH out of the
shutdown mode.
All receivers that are active during shutdown
maintain 500mV (typical) of hysteresis.
ESD TOLERANCE
The SP207EH Family incorporates ruggedized
ESD cells on all driver output and receiver input
pins. The ESD structure is improved over our
previous family for more rugged applications
and environments sensitive to electro-static dis-
charges and associated transients. The improved
ESD tolerance is at least +15kV without damage
nor latch-up.
There are different methods of ESD testing
applied:
a) MIL-STD-883, Method 3015.7
b) IEC1000-4-2 Air-Discharge
c) IEC1000-4-2 Direct Contact
The Human Body Model has been the generally
accepted ESD testing method for semiconductors.
This method is also specified in MIL-STD-883,
Method 3015.7 for ESD testing. The premise of
this ESD test is to simulate the human body’s
potential to store electro-static energy and discharge
it to an integrated circuit. The simulation is
performed by using a test model as shown
in Figure 7. This method will test the IC’s
capability to withstand an ESD transient during
normal handling such as in manufacturing areas
where the ICs tend to be handled frequently.
The IEC-1000-4-2, formerly IEC801-2, is generally
used for testing ESD on equipment and systems.
For system manufacturers, they must guarantee a
certain amount of ESD protection since the system
itself is exposed to the outside environment and
human presence. The premise with IEC1000-4-2
is that the system is required to withstand an
amount of static electricity when ESD is applied to
points and surfaces of the equipment that are
accessible to personnel during normal usage. The
transceiver IC receives most of the ESD current
when the ESD source is applied to the connector
pins. The test circuit for IEC1000-4-2 is shown
on Figure 8. There are two methods within
IEC1000-4-2, the Air Discharge method and the
Contact Discharge method.
RR_CC
DC Power
Source
SSWW11
RR_SS
CC_SS
SSWW22
Device
Under
Test
Figure 7. ESD Test Circuit for Human Body Model
SP207EHDS/08
SP207EH Series High Performance Transceivers
9
© Copyright 2000 Sipex Corporation