SP213EHCA Datasheet, PDF (8/19 Pages) Exar Corporation – Low Power, High ESD +5V RS-232 Transceivers

SHUTDOWN MODE
SP211E and SP213E feature a control input
which will shut down the device and reduce
the power supply current to less than 10µA,
making the parts ideal for battery–powered
systems. In shutdown mode the transmitters
will be tri–stated, the V⁺ output of the charge
pump will discharge to VCC, and the V^– output
will discharge to ground. Shutdown will tri-
state all receiver outputs of the SP211E.
SP213E WAKEUP FUNCTION
On the SP213E, shutdown will tri-state re-
ceivers 1-3. Receivers 4 and 5 remain active
to provide a “wake-up” function and may be
used to monitor handshaking and control
inputs for activity.With only two receivers
active during shutdown, the SP213E draws
only 5–10µA of supply current.
Many standard UART devices may be con-
figured to generate an interrupt signal based
on changes to the Ring Indicate (RI) or other
inputs. A typical application of this function
would be to detect modem activity with the
computer in a power–down mode. The ring
indicator signal from the modem could be
passed through an active receiver in the
SP213E that is itself in the shutdown mode.
The ring indicator signal would propagate
through the SP213E to the power manage-
ment circuitry of the computer to power up
the microprocessor and the SP213E driv-
ers. After the supply voltage to the SP213E
reaches +5.0V, the SHUTDOWN pin can
be disabled, taking the SP213E out of the
shutdown mode.
All receivers that are active during shutdown
maintain 500mV (typ.) of hysteresis. All
receivers on the SP213E may be put into
tri-state using the ENABLE pin.
SHUTDOWN CONDITIONS
For complete shutdown to occur and the
10µA power drain to be realized, the follow-
ing conditions must be met:
SP211E:
• +5V must be applied to the SD pin
• ENABLE must be either Ground, +5.0V or
not connected
• the transmitter inputs must be either +5.0V
or not connected
• VCC must be +5V
• Receiver inputs must be >0V and <+5V
SP213E:
• 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
• VCC must be +5V
• Receiver inputs must be >0V and <+5V
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com

SP207E_100_072309