SP3243EET-L Exar Corporation, SP3243EET-L Datasheet - Page 11

• Manufacturer Part Number: SP3243EET-L
• Description: IC TXRX RS232 INTELLIGNT 28WSOIC
• Manufacturer: Exar Corporation
• Type: Transceiverr

Specifications of SP3243EET-L

• Package / Case: 28-SOIC (0.300", 7.50mm Width)
• Number Of Drivers/receivers: 3/5
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5.5 V
• Mounting Type: Surface Mount
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Function: Transceiver
• Mounting Style: SMD/SMT
• Supply Current: 1 uA
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Logic Type: RS-232 Transceivers
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 1016-1122-5

Date: 2/05/06
The Sipex-patented charge pumps are designed
to operate reliably with a range of low cost
capacitors. Either polarized or non polarized
capacitors may be used. If polarized capacitors
are used they should be oriented as shown in the
Typical Operating Circuit. The V+ capacitor
may be connected to either ground or Vcc.
The charge pump operates with 0.1μF capacitors
for 3.3V operation. For other supply voltages,
see the table for required capacitor values. Do
not use values smaller than those listed. Increasing
the capacitor values (e.g., by doubling in value)
The SP3243 devices have a patent pending AUTO
ON-LINE
in applications such as laptop computers, palmtop
(PDA) computers and other portable systems.
The SP3243 devices incorporate an AUTO ON-
LINE
when the external transmitters are enabled and
the cable is connected. Conversely, the AUTO
ON-LINE
internal circuitry when the device is not being
used and goes into a standby mode where the
device typically draws 1mA. This function can
also be externally controlled by the ONLINE
pin. When this pin is tied to a logic LOW, the
AUTO ON-LINE
tive, the device is enabled until there is no
activity on the receiver inputs. The receiver
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circuit that automatically enables itself
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circuitry on board that saves power
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circuit also disables most of the
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SP3243 +3.0V to +5.5V RS-232 Transceivers
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g r
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reduces ripple on the transmitter outputs and
may slightly reduce power consumption. C2,
C3, and C4 can be increased without changing
C1’s value.
For best charge pump efficiency locate the charge
pump and bypass capacitors as close as possible
to the IC. Surface mount capacitors are best for
this purpose. Using capacitors with lower
equivalent series resistance (ESR) and self-
inductance, along with minimizing parasitic PCB
trace inductance will optimize charge pump
operation. Designers are also advised to consider
that capacitor values may shift over time and
operating temperature.
input typically sees at least +3V, which are
generated from the transmitters at the other end
of the cable with a +5V minimum. When the
external transmitters are disabled or the cable is
disconnected, the receiver inputs will be pulled
down by their internal 5kΩ resistors to ground.
When this occurs over a period of time, the
internal transmitters will be disabled and the
device goes into a shutdown or standy mode.
When ONLINE is HIGH, the AUTO ON-LINE
mode is disabled.
The AUTO ON-LINE
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1) Inactive Detection
2) Accumulated Delay
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AUTO ONLINE CIRCUITRY
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© Copyright 2006 Sipex Corporation
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