MAX221EEUE-T Maxim Integrated, MAX221EEUE-T Datasheet - Page 7

• Manufacturer Part Number: MAX221EEUE-T
• Description: RS-232 Interface IC
• Manufacturer: Maxim Integrated
• Series: MAX221Er

Specifications of MAX221EEUE-T

• Data Rate: 250 Kbps
• Operating Supply Voltage: 5 V
• Supply Current: 10 mA
• Operating Temperature Range: 0 C to + 70 C
• Mounting Style: SMD/SMT
• Function: Transceiver
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Number Of Drivers: 1
• Number Of I/os: 4
• Number Of Receivers: 1
• Propagation Delay Time Ns: 0.15 us
• Shutdown: Yes

Figure 3. AutoShutdown Trip Levels
Figure 4. AutoShutdown with Initial Turn-On to Wake Up a
Mouse or Another System
RECEIVER
VOLTAGE
INVALID
OUTPUT
INPUT
±15kV ESD-Protected, +5V, 1µA, Single RS-232
MANAGEMENT
a)
b)
(V)
(V)
POWER-
+2.7V
+0.3V
-0.3V
-2.7V
UNIT
V
V
V+
CC
CC
V-
0
0
0
AUTOSHUTDOWN, TRANSMITTER DISABLED,
TRANSMITTER ENABLED, INVALID HIGH
TRANSMITTER ENABLED, INVALID HIGH
1 A SUPPLY CURRENT, INVALID LOW
MASTER SHDN LINE
_______________________________________________________________________________________
t
INVL
INDETERMINATE
INDETERMINATE
FORCEOFF
MAX221E
0.1µF
FORCEON
Transceiver with AutoShutdown
1M
t
INVH
INVALID
REGION
t
WU
For direct software control, use INVALID to indicate a
DTR or Ring Indicator signal. Connect FORCEOFF and
FORCEON together to disable AutoShutdown so the
line acts like a SHDN input.
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges encountered during handling and
assembly. The driver output and receiver input of the
MAX221E have extra protection against static electrici-
ty. Maxim’s engineers have developed state-of-the-art
structures to protect these pins against ESD of ±15kV
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
keep working without latchup, whereas competing
RS-232 products can latch and must be powered down
to remove latchup.
ESD protection can be tested in various ways; the trans-
mitter output and receiver input of the MAX221E are
characterized for protection to the following limits:
1) ±15kV using the Human Body Model
2) ±8kV using the Contact-Discharge Method
3) ±15kV using IEC 1000-4-2’s Air-Gap Method
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Figure 5a shows the Human Body Model, and Figure
5b shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the test device
through a 1.5k resistor.
The IEC 1000-4-2 standard covers ESD testing and
performance of finished equipment; it does not specifi-
cally refer to integrated circuits. The MAX221E helps
you design equipment that meets Level 4 (the highest
level) of IEC 1000-4-2, without the need for additional
ESD-protection components.
The major difference between tests done using the
Human Body Model and IEC 1000-4-2 (Figure 6) is
higher peak current in the IEC 1000-4-2 because series
resistance is lower in the IEC 1000-4-2 model. Hence,
specified in IEC 1000-4-2
Software-Controlled Shutdown
±15kV ESD Protection
ESD Test Conditions
Human Body Model
IEC 1000-4-2
7