SP385E Datasheet, PDF (7/11 Pages) Sipex Corporation – Enhanced +3V or +5V RS-232 Line Driver/Receiver

V_CC = +5V
+
C_{1 –}
–5V
+5V
+
C_{2 –}
–5V
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
Figure 4. Charge Pump — Phase 3
V_CC = +5V
+
C_{1 –}
+10V
+
C_{2 –}
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
Figure 5. Charge Pump — Phase 4
Shutdown (ON/OFF)
The SP385E has a shut-down/standby mode to
conserve power in battery-powered systems. To
activate the shutdown mode, which stops the
operation of the charge pump, a logic "0" is
applied to the appropriate control line. The
shutdown mode is controlled on the SP385E by
a logic "0" on the ON/OFF control line (pin 18
for the SOIC and pin 20 for the SSOP packages);
this puts the transmitter outputs in a tri-state mode.
ESD Tolerance
The SP385E device 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
discharges and associated transients. The
improved ESD tolerance is at least ±15KV with-
out 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 6. 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 7. There are
two methods within IEC1000-4-2, the Air
Discharge method and the Contact Discharge
method.
R_CC
DC Power
Source
SSWW11
R_SS
CC_SS
SSWW22
Device
Under
Test
Figure 6. ESD Test Circuit for Human Body Model
R_CC
DC Power
Source
SW1
Contact-Discharge Module
R_SS
R_V
SW2
Device
C_SS
Under
Test
RS and RV add up to 330Ω for IEC1000-4-2.
Figure 7. ESD Test Circuit for IEC1000-4-2
Rev. 10/22/01
SP385E Enhanced +3V to +5V RS-232 Line Driver/Receiver
7
© Copyright 2001 Sipex Corporation