SP213ECA-L-TR Datasheet, PDF (7/17 Pages) Exar Corporation – High Speed +5V High Performance RS232 Transceivers

V_CC = +5V
+
C_{1 –}
–5V
+5V
+
C_{2 –}
–5V
Figure 4. Charge Pump — Phase 3
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
V_CC = +5V
+
C_{1 –}
+10V
+
C_{2 –}
C₄
+ – _{VDD Storage Capacitor}
– + _{VSS Storage Capacitor}
C₃
Figure 5. Charge Pump — Phase 4
Receivers
The high performance receivers of the SP207EH
Series can accept input signals at a typical data
rate of 500Kbps. The receivers convert RS-232
input signals to inverted TTL signals. The
receivers convert RS-232 input signals to
inverted TTL signals. Since the input is usually
from a transmission line where long cable lengths
and system interference can degrade the signal,
the inputs have a typical hysteresis margin of
500mV. This ensures that the receiver is
virtually immune to noisy transmission lines.
Should an input be left unconnected, a 5kΩ
pulldown resistor to ground will commit the
output of the receiver to a high state.
SHUTDOWN MODE
The SP211EH, and SP213EH all feature a
control input which will disable the device and
reduce the power supply current to less than
10µA, making the parts ideal for battery–
powered systems. In the “shutdown” mode the
receivers and transmitters will both be tri–stated.
The V⁺ output of the charge pump will discharge
to V_CC, and the V^– output will discharge to
ground. Products with the Wake-Up function
can enable or disable the receivers during
shutdown.
For complete shutdown to occur and the 10µA
power drain to be realized, the following
conditions must be met:
SP211EH:
• +5V must be applied to the SD pin
• ENABLE must be either 0V, +5.0V or not
connected
• the transmitter inputs must be either +5.0V
or not connected
• V_CC must be +5V
• Receiver inputs must be >0V and <+5V
SP213EH:
• 0V must be applied to the SD pin
• ENABLE must be either 0V, +5.0V or not
connected
• the transmitter inputs must be either +5.0V
or not connected
• V_CC must be +5V
• Receiver inputs must be >0V and <+5V
SP207EHDS/08
SP207EH Series High Performance Transceivers
7
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