SNLS090C – MARCH 2000 – REVISED APRIL 2013
APPLICATION INFORMATION
9-PIN SERIAL PORT APPLICATION
In a typical Data Terminal Equipment (DTE) to Data Circuit-Terminating Equipment (DCE) 9-pin de-facto
interface implementation, 2 data lines and 6 control lines are required. The data lines are TXD and RXD and the
control lines are RTS, DTR, DSR, DCD, CTS and RI. The DS14C335 is a 3 x 5 Driver/Receiver and offers a
single chip solution for the DTE interface as shown in
Ring Indicator (RI) is used to inform the DTE that an incoming call is coming from a remote DCE. When the
DS14C335 is in SHUTDOWN (SD) mode, receiver five (R5) remains active and monitors RI circuit. This active
receiver (R5) alerts the DTE to switch the DS14C335 from SHUTDOWN to active mode.
Figure 10. Typical DTE Application
MOUSE DRIVING
The DS14C335 was tested for drive current under the following mouse driving conditions:
• Two driver outputs set at V
OH
and their outputs were tied together (paralleled), sourcing current to supply the
V+ terminal of the mouse electronics
• One driver output set at V
OL
to sink the current from the V− terminal of the mouse electronics
• One receiver was used to accept data from the mouse
• Power Supply Voltage (V
CC
): 3.0V to 3.6V
Completion of the testing (performed by TI's Data Transmission Applications Group and a major PC
manufacturer) concluded that the DS14C335 and it's DC-DC Convertor supplied adequate drive capability to
power a typical PC mouse. The mouse tested was specified with the following conditions:
10 mA at +6V
5.0 mA at
−6V
Since driver current is limited, it is recommended that newer lower power mice be specified for battery powered
applications. Using older high power mice is wasteful of precious battery charge.
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