NEC Barracuda Service Manual page 32

Barracuda PDA Maintenance
1.2.2.9 RS-232 Transceivers: SP3243E
DESCRIPTION
The SP3223E and 3243E products are RS-232 transceiver solutions intended for portable or hand-held
applications such as notebook and palmtop computers. The SP3223E and 3243E Use an internal high-efficiency,
charge-pump power supply that requiresonly0.1mFcapacitors in 3.3V operation. This charge pump and Sipex's
driver architecture allow the SP3223E/ 3243E series to deliver compliant RS-232 performance from a single power
supply ranging from +3.3V to +5.0V. The SP3223E is a 2-driver/2-receiver device, and the SP3243E is a
3-driver/5-receiver device ideal for laptop/notebook computer and PDA applications.
The SP3243E includes one complementary receiver that remains alert to monitor an external device's Ring
Indicate signal while the device is shutdown.
The Auto-Online feature allows the device to automatically "wake-up" during a shutdown state when an
RS-232 cable is connected and a connected peripheral is turned on. Otherwise, the device automatically shuts itself
down drawing less than 1mA.
Features
Meets true EIA/TIA-232-F Standards from a +3.0V to +5.5V power supply
Interoperable with EIA/TIA-232 and adheres to EIA/TIA-562 down to a +2.7V power source
Auto-Online ?circuitry automatically wakes up from a 1mA shutdown
Minimum 120Kbps data rate under load
Regulated Charge Pump Yields Stable RS-232 Outputs Regardless of VCC Variations
Enhanced ESD Specifications:
+15KV Human Body Model
+15KV IEC1000-4-2 Air Discharge
+8KV IEC1000-4-2 Contact Discharge
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