ADM3202/ADM3222/ADM1385
Transmitter (Driver) Section
The drivers convert 3.3 V logic input levels into RS-232 output
levels. With V
CC
= 3.3 V and driving an RS-232 load, the output
voltage swing is typically ±6 V.
HIGH BAUD RATE
The ADM3202/ADM3222 feature high slew rates permitting
data transmission at rates well in excess of the EIA/RS-232E
specifications. RS-232 voltage levels are maintained at data rates
up to 460 kbps even under worst-case loading conditions. This
allows high speed data links between two terminals and is
suitable for the new generation ISDN modem standards that
require data rates of 230 kbps. The slew rate is internally
controlled to less than 30 V/μs to minimize EMI interference.
Receiver Section
The receivers are inverting level-shifters that accept RS-232
input levels and translate them into 3 V logic output levels. The
inputs have internal 5 kΩ, pull-down resistors to ground and are
protected against overvoltages up to ±30 V. Unconnected inputs
are pulled to 0 V by the internal 5 kΩ, pull-down resistor. This
results in a Logic 1 output level for unconnected inputs or for
inputs connected to GND.
The receivers have Schmitt-trigger inputs with a hysteresis level
of 0.4 V. This ensures error-free reception for both noisy inputs
and for inputs with slow transition times.
Rev. E | Page 9 of 16
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