Datasheet

MAX3384E
5kΩ
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
V
CC
C4
C3
C1
C2
0.1µF
V
CC
SHDN
T_ OUT
T_ IN
GND
V
CC
1000pF
Figure 6. Loopback Test Circuit
2µs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
V
CC
= 3.3V
C1–C4 = 0.1µF
Figure 7. MAX3384E Loopback Test Result at 120kbps
2µs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
V
CC
= 3.3V
C1–C4 = 0.1µF
Figure 8. MAX3384E Loopback Test Result at 250kbps
MAX3384E
±15kV ESD-Protected, 3.0V to 5.5V, Low-Power,
up to 250kbps, True RS-232 Transceiver
8 _______________________________________________________________________________________
Transmitter Outputs when
Exiting Shutdown
Figure 2 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two trans-
mitter outputs are shown going to opposite RS-232 lev-
els (one transmitter input is high, the other is low). Each
transmitter is loaded with 3kΩ in parallel with 2500pF.
The transmitter outputs display no ringing or undesir-
able transients as they come out of shutdown. Note that
the transmitters are enabled only when the magnitude
of V- exceeds approximately -3V.
High Data Rates
The MAX3384E maintains the RS-232 ±5.0V minimum
transmitter output voltage even at high data rates.
Figure 6 shows a transmitter loopback test circuit.
Figure 7 shows a loopback test result at 120kbps, and
Figure 8 shows the same test at 250kbps. For Figure 7,
all transmitters were driven simultaneously at 120kbps
into RS-232 loads in parallel with 1000pF. For Figure 8,
a single transmitter was driven at 250kbps, and all
transmitters were loaded with an RS-232 receiver in
parallel with 1000pF.