SP3232EEP-L Exar Corporation, SP3232EEP-L Datasheet - Page 8

• Manufacturer Part Number: SP3232EEP-L
• Description: IC TXRX RS232 ESD TRUE 16PDIP
• Manufacturer: Exar Corporation
• Type: Transceiverr

Specifications of SP3232EEP-L

• Package / Case: 16-DIP (0.300", 7.62mm)
• Number Of Drivers/receivers: 2/2
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5.5 V
• Mounting Type: Through Hole
• On Resistance (max): 5 KOhms
• Propagation Delay Time: 1 us
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Function: Transceiver
• Mounting Style: Through Hole
• Supply Current: 1 mA
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Logic Type: RS-232 Transceivers
• Number Of Circuits: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

The
meet the EIA/TIA-232 and ITU-T V.28/V.24
communication protocols and can be imple-
mented in battery-powered, portable, or
hand-held applications such as notebook or
palmtop computers. The SP3222E/SP3232E
devices feature Exar's proprietary on-board
charge pump circuitry that generates ±5.5V
for RS-232 voltage levels from a single
+3.0V to +5.5V power supply. This series is
ideal for +3.3V-only systems, mixed +3.3V
to +5.5V systems, or +5.0V-only systems
that require true RS-232 performance. The
SP3222E/SP3232E devices can operate
at a typical data rate of 235kbps when fully
loaded.
The SP3222E and SP3232E are 2-driver/2-
receiver devices ideal for portable or hand-
held applications. The SP3222E features a
1µA shutdown mode that reduces power
consumption and extends battery life in por-
table systems. Its receivers remain active in
shutdown mode, allowing external devices
such as modems to be monitored using only
1µA supply current.
THEORY OF OPERATION
The SP3222E/SP3232E series is made up
of three basic circuit blocks:
1. Drivers
2. Receivers
3. The Exar proprietary charge pump
Drivers
The drivers are inverting level transmitters
that convert TTL or CMOS logic levels to
+5.0V EIA/TIA-232 levels with an inverted
sense relative to the input logic levels.
Typically, the RS-232 output voltage swing
is +5.4V with no load and +5V minimum fully
loaded. The driver outputs are protected
against infinite short-circuits to ground with-
out degradation in reliability. Driver outputs
will meet EIA/TIA-562 levels of +/-3.7V with
supply voltages as low as 2.7V.
SP3222E/SP3232E transceivers
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
8
The drivers can guarantee a data rate of
120kbps fully loaded with 3kΩ in parallel
with 1000pF, ensuring compatability with
PC-to-PC communication software.
The slew rate of the driver is internally limited
to a maximum of 30V/µs in order to meet the
EIA standards (EIA RS-232D 2.1.7, Para-
graph 5). The transition of the loaded output
from HIGH to LOW also meet the monotonic-
ity requirements of the standard.
Figure 8 shows a loopback test circuit
used to test the RS-232 Drivers. Figure
9 shows the test results of the loopback
circuit with all drivers active at 120kbps
with RS-232 loads in parallel with a
1000pF capacitor. Figure 10 shows the
test results where one driver was active
at 235kbps and all drivers loaded with an
RS-232 receiver in parallel with 1000pF
capacitors. A solid RS-232 data transmis-
sion rate of 120kbps provides compatibility
with many designs in personal computer
peripherals and LAN applications.
The SP3222E driver's output stages are
turned off (tri-state) when the device is in
shutdown mode. When the power is off, the
SP3222E device permits the outputs to be
driven up to +/-12V. The driver's inputs do
not have pull-up resistors. Designers should
connect unused inputs to Vcc or GND.
In the shutdown mode, the supply current
falls to less than 1µA, where SHDN = LOW.
When the SP3222E device is shut down,
the device's driver outputs are disabled (tri-
stated) and the charge pumps are turned off
with V+ pulled down to Vcc and V- pulled to
GND. The time required to exit shutdown is
typically 100µs. Connect SHDN to Vcc if the
shutdown mode is not used.
SP3222E/SP3232E_100_120810
DESCRIPTION