STC3232E Datasheet, PDF (5/7 Pages) List of Unclassifed Manufacturers – High ESD-Protected, Low Power, 3.3V to 5.5V, True RS-232 Transceivers

STC International Limited
Typical Operating Circuits
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Detailed Description
Dual Charge-Pump Voltage Converter
The STC3232E’s internal power supply consists of a regulated dual charge pump that provides output voltages of +5.5V
(doubling charge pump) and -5.5V (inverting charge pump) over the +3.0V to +5.5V VCC range. The charge pump
operates in discontinuous mode; if the output voltages are less than 5.5V, the charge pump is enabled, and if the output
voltages exceed 5.5V, the charge pump is disabled. Each charge pump requires a flying capacitor (C1, C2) and a storage
capacitor (C3, C4) to generate the V+ and V- supplies.
RS-232 Transmitters
The transmitters are inverting level translators that convert TTL/CMOS-logic levels to ±5V EIA/TIA-232 compliant
levels. The STC3232E transmitter guarantees a 250kbps data rate with worst-case loads of 3KO parallel with 1000pF.
Transmitters can be paralleled to drive multiple receivers. The STC3232E permits the outputs to be driven up to ±12V in
shutdown.
RS-232 Receivers
The receivers convert RS-232 signals to CMOS-logic output levels.
±15kV ESD Protection
ESD-protection structures are incorporated to protect against electrostatic discharges encountered during handling and
assembly. The driver outputs and receiver inputs of the STC3232E have extra protection against static electricity. The
ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an ESD event,
Circuits keep working without latch up. ESD protection can be tested in various ways; the transmitter outputs and
receiver inputs for the STC3232E are characterized for protection to the following limits:
±15kV using the Human Body Model
±8kV using the Contact Discharge method specified in IEC 1000-4-2
±15kV using the Air-Gap Discharge method specified in IEC 1000-4-2.
STC3232E Datasheet Rev.0.1, Dec.2005
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