MAX3226EAAE+T Maxim Integrated, MAX3226EAAE+T Datasheet - Page 8

• Manufacturer Part Number: MAX3226EAAE+T
• Description: RS-232 Interface IC
• Manufacturer: Maxim Integrated
• Series: MAX3224E, MAX3225E, MAX3226E, MAX3227E, MAX3244E, MAX3245Er

Specifications of MAX3226EAAE+T

• Data Rate: 250 Kbps
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 1 mA
• Operating Temperature Range: 0 C to + 70 C
• Function: Transceiver
• Number Of Drivers: 1
• Number Of I/os: 4
• Number Of Receivers: 1
• Propagation Delay Time Ns: 0.15 us
• Shutdown: Yes

±15kV ESD-Protected +2.5V to +5.5V
RS-232 Transceivers in UCSP and WLP
MAX3231E/AE are active. If the other system transmits
valid RS-232 signals within that time, the RS-232 ports
on both systems remain enabled.
When shut down, the device’s charge pumps are off,
V+ is pulled to V
transmitter outputs are high impedance. The time
required to exit shutdown is typically 100µs (Figure 3b).
Unlike other RS-232 interface devices, where the receiv-
er outputs swing between 0 and V
and MAX3231E/AE feature a separate logic supply input
(V
ter inputs (T_IN), FORCEON, and FORCEOFF, are also
referred to V
interfacing to different systems and logic levels.
Connect V
to +5.5V), and bypass it with a 0.1µF capacitor to GND.
If the logic supply is the same as V
V
V
If direct software control is desired, connect FORCEOFF
and FORCEON together to disable AutoShutdown. The
Figure 2a. MAX323_E Entering 1µA Supply Mode with
AutoShutdown
Figure 2b. MAX323_E with Transmitters Enabled Using
AutoShutdown
8
CC
CC
L
+2.7V
+0.3V
-0.3V
-2.7V
) that sets V
R_IN
R_IN
TRANSMITTERS ARE ENABLED IF:
_______________________________________________________________________________________
ANY RECEIVER INPUT IS GREATER THAN +2.7V OR LESS THAN -2.7V.
ANY RECEIVER INPUT HAS BEEN BETWEEN +0.3V AND -0.3V FOR LESS THAN 30μs.
. Always enable V
TRANSMITTERS ARE DISABLED, REDUCING SUPPLY CURRENT TO 1μA IF
must be greater than or equal to the V
ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR AT LEAST 30μs.
L
to the system’s logic supply voltage (+1.65V
L
. This feature allows maximum flexibility in
OH
Software-Controlled Shutdown
CC
for the receiver outputs. The transmit-
, V- is pulled to ground, and the
CC
before enabling the V
V
L
Logic Supply Input
CC
COUNTER
COUNTER
, the MAX3230E/AE
30μs
30μs
CC
R
R
, connect V
AND TRANSMITTERS
L
supply.
POWER SUPPLY
POWER SUPPLY
INVALID
INVALID
TO MAX323 _E
TO MAX323 _E
L
supply.
L
to
microcontroller (µC) then drives FORCEOFF and
FORCEON like a SHDN input. INVALID can be used to
alert the µC to indicate serial data activity.
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 outputs and receiver inputs of the
MAX3230E/AE and MAX3231E/AE have extra protec-
tion against static electricity. 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 power-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 outputs and receiver inputs of this product family
are characterized for protection to the following limits:
1) ±15kV using the Human Body Model
3) ±15kV using the IEC 1000-4-2 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. 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 interest,
2) ±8kV using the Contact Discharge method specified
Figure 2c. MAX323_E AutoShutdown Logic
in IEC 1000-4-2
V
INVALID IS AN INTERNALLY GENERATED SIGNAL
THAT IS USED BY THE AutoShutdown LOGIC
AND APPEARS AS AN OUTPUT OF THE DEVICE.
POWER DOWN IS ONLY AN INTERNAL SIGNAL.
IT CONTROLS THE OPERATIONAL STATUS OF
THE TRANSMITTERS AND THE POWER SUPPLIES.
CC
FORCEOFF
FORCEON
INVALID
±15kV ESD Protection
ESD Test Conditions
Human Body Model
POWER DOWN