1ꢀ5k EꢁD-ꢂrotected, +ꢀk Rꢁ-232 Transceivers
The MAX213E’s receiver propagation delay is typically
0.ꢀµs in normal operation. In shutdown mode,
propagation delay increases to 4µs for both rising and
falling transitions. The MAX213E’s receiver inputs have
approximately 0.ꢀV hysteresis, except in shutdown,
when receivers R4 and Rꢀ have no hysteresis.
MAX211E
3V
0V
SHDN
V+
10V
5V
When entering shutdown with receivers active, R4 and
Rꢀ are not valid until 80µs after SHDN is driven low.
When coming out of shutdown, all receiver outputs are
invalid until the charge pumps reach nominal voltage
levels (less than 2ms when using 0.1µF capacitors).
0V
V-
-5V
-10V
1ꢀ5k EꢁD ꢂrotection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against
electrostatic discharges encountered during handling
and assembly. The driver outputs and receiver inputs
have extra protection against static electricity. Maxim’s
engineers developed state-of-the-art structures to
protect these pins against ESD of 1ꢀ5V without
damage. The ESD structures withstand high ESD in all
states: normal operation, shutdown, and powered
down. After an ESD event, Maxim’s E versions 5eep
wor5ing without latchup, whereas competing RS-232
products can latch and must be powered down to
remove latchup.
200µs/div
Figure 5. MAX211E V+ and V- when Exiting Shutdown (0.1µF
capacitors)
Table 1a. MAX205E/MAX206E/MAX211E/
MAX241E Control Pin Configurations
OPERATION
SHDN EN
Tx
Rx
All Active
All High-Z
All High-Z
STATUS
Normal
Operation
ESD protection can be tested in various waysꢁ the
transmitter outputs and receiver inputs of this product
family are characterized for protection to the following
limits:
0
0
1
0
1
X
All Active
All Active
All High-Z
Normal
Operation
1) 1ꢀ5V using the Human Body Model
Shutdown
2) 85V using the contact-discharge method specified
in IEC1000-4-2
X = Don't Care
3) 1ꢀ5V using IEC1000-4-2’s air-gap method.
Table 1b. MAX213E Control Pin
Configurations
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test set-up, test methodology, and test results.
Rx
OPERATION
SHDN EN
Tx 1–4
STATUS
Shutdown
Shutdown
1–3
4, 5
Human Body Model
Figure 6a shows the Human Body Model, and Figure
6b shows the current waveform it generates when
discharged into a low impedance. 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.ꢀ5Ω resistor.
0
0
1
1
0
1
0
1
All High-Z
All High-Z
All Active
All Active
High-Z
High-Z
High-Z
High-Z
Active
Active*
High-Z
Active
Normal
Operation
Normal
Operation
*Active = active with reduced performance
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