DS14C535 Datasheet, PDF (5/8 Pages) National Semiconductor (TI) – +5V Supply EIA/TIA-232 3 x 5 Driver/Receiver

Parameter Measurement Information (Continued)
DS011910-9
FIGURE 7. Receiver SHUTDOWN (SD) Delay Test Circuit
DS011910-10
FIGURE 8. Receiver SHUTDOWN (SD) Delay Timing
Pin Descriptions
V_CC (Pin 3). Power supply pin for the device, +5V (±0.5V).
V+ (Pin 1). Positive supply for EIA/TIA-232-E drivers. Rec-
ommended external capacitor — 0.1 µF (16V). This supply is
not intended to be loaded externally.
V− (Pin 25). Negative supply for EIA/TIA-232-E drivers. Rec-
ommended external capacitor — 0.1 µF (16V). This supply is
not intended to be loaded externally.
C1+, C1− (Pins 2, 4). External capacitor connection pins.
C2+, C2− (Pins 28, 26). External capacitor connection pins.
SHUTDOWN (SD) (Pin 23). A High on the SHUTDOWN pin
will lower the total I_CC current to less than 10 µA, providing a
low power state. In this mode receiver R5 remains active.
The SD pin should be driven or tied low (GND) to disable the
shutdown mode.
D_IN 1–3 (Pins 7, 8, 9). Driver input pins.
D_OUT 1–3 (Pins 22, 21, 20). Driver output pins conform to
EIA/TlA-232 -E levels.
R_IN 1–5 (Pins 19, 18, 17, 16, 15). Receiver input pins accept
EIA/TIA-232-E input voltages (±25V). Receivers guarantees
hysteresis of TBD mV. Unused receiver input pins may be
left open. Internal input resistor (5 kΩ) pulls input LOW, pro-
viding a failsafe HIGH output.
R_OUT 1–5 (Pins 10, 11, 12, 13, 14). Receiver output pins.
GND (Pins 5, 27). Ground Pins. Both pins must be con-
nected to external ground. These pins are not connected to-
gether on the chip.
Application Information
In a typical Data Terminal Equipment (DTE) to Data
Circuit-Terminating Equipment (DCE) 9-pin de-facto inter-
face implementation, 2 data lines and 6 control lines are re-
quired. The data lines are TXD and RXD and the control
lines are RTS, DTR, DSR, DCD, CTS and RI. The
DS14C535 is a 3 x 5 Driver/Receiver and offers a single chip
solution for the DTE interface as shown in Figure 9 .
Ring Indicator (RI) is used to inform the DTE that an incom-
ing call is coming from a remote DCE. When the DS14C535
is in SHUTDOWN (SD) mode, receiver five (R5) remains ac-
tive and monitors RI circuit. This active receiver (R5) alerts
the DTE to switch the DS14C535 from SHUTDOWN to ac-
tive mode.
To achieve minimum power consumption, the DS14C535
can be in SHUTDOWN mode and only activated when com-
munications are needed.
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