MAX3229EEBV MAXIM [Maxim Integrated Products], MAX3229EEBV Datasheet - Page 11

• Manufacturer Part Number: MAX3229EEBV
• Manufacturer: MAXIM [Maxim Integrated Products]

Figure 7 shows a transmitter output when exiting shut-
down mode. The transmitter is loaded with 3kΩ in par-
allel with 1000pF. The transmitter output displays no
ringing or undesirable transients as it comes out of
shutdown, and is enabled only when the magnitude of
V- exceeds approximately -3V.
The MAX3228E/MAX3229E maintain the RS-232 ±5.0V
minimum transmitter output voltage even at high data
rates. Figure 8 shows a transmitter loopback test cir-
cuit. Figure 9 shows a loopback test result at 120kbps,
and Figure 10 shows the same test at 250kbps. For
Figure 7. Transmitter Outputs Exiting Shutdown or Powering Up
Figure 8. Transmitter Loopback Test Circuit
FORCEON =
FORCEOFF
0.1µF
TOUT
C2
C1
C1+
C1-
C2+
C2-
T1IN
R1OUT
FORCEON
______________________________________________________________________________________
Transmitter Outputs when
V
V
CC
CC
MAX3229E
GND
4µs/div
V
V
L
L
±15kV ESD-Protected +2.5V to +5.5V
V
V
L
L
FORCEOFF
INVALID
T1OUT
5kΩ
Exiting Shutdown
R1IN
High Data Rates
V+
V-
TO POWER-
MANAGEMENT UNIT
V
L
0
2V/div
5V/div
0
0.1µF
C3
C4
1000pF
RS-232 Transceivers in UCSP
Figure 9, the transmitter was driven at 120kbps into an
RS-232 load in parallel with 1000pF. For Figure 10, a
single transmitter was driven at 250kbps, and loaded
with an RS-232 receiver in parallel with 1000pF.
Figure 9. Loopback Test Result at 120kbps
Figure 10. Loopback Test Result at 250kbps
T_OUT
R_OUT
T_OUT
R_OUT
T_IN
T_IN
4µs/div
4µs/div
5V
0
5V
0
-5V
5V
0
5V
0
5V
0
-5V
5V
0
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