ISL4270EIRZ Intersil, ISL4270EIRZ Datasheet - Page 10

• Manufacturer Part Number: ISL4270EIRZ
• Description: IC 3DRVR/3RCVR RS232 3V 32-QFN
• Manufacturer: Intersil
• Type: Transceiverr

Specifications of ISL4270EIRZ

• Number Of Drivers/receivers: 3/3
• Protocol: RS232
• Voltage - Supply: 3 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

High Data Rates
The ISL4270E maintains the RS-232
transmitter output voltages even at high data rates. Figure 9
details a transmitter loopback test circuit, and Figure 10
illustrates the loopback test result at 120kbps. For this test,
all transmitters were simultaneously driving RS-232 loads in
parallel with 1000pF, at 120kbps. Figure 11 shows the
loopback results for a single transmitter driving 1000pF and
an RS-232 load at 250kbps. The static transmitters were
also loaded with an RS-232 receiver.
5V/DIV
2V/DIV
FIGURE 8. TRANSMITTER OUTPUTS WHEN EXITING
FIGURE 9. TRANSMITTER LOOPBACK TEST CIRCUIT
V
V
C
C
CC
CC
1
2
V
C1 - C4 = 0.1μF
+
+
CC
= +3.3V
POWERDOWN
FORCEOFF
0.1μF
C1+
C1-
C2+
C2-
T
R
FORCEON
FORCEOFF
IN
OUT
+
TIME (20μs/DIV.)
ISL4270E
V
10
CC
T
V
OUT
L
±
R
5K
V+
5V minimum
V-
IN
T2
T1
+
+
C
C
1000pF
3
4
ISL4270E
Interconnection with 3V and 5V Logic
Standard 3.3V powered RS-232 devices interface well with
3V and 5V powered TTL compatible logic families (e.g., ACT
and HCT), but the logic outputs (e.g., R
the V
CD4000. The ISL4270E V
By connecting V
the logic device, the ISL4270E logic outputs will swing from
GND to the logic V
5V/DIV.
5V/DIV.
R1
R1
T1
T1
T1
T1
OUT
OUT
OUT
OUT
IH
IN
IN
level of 5V powered CMOS families like HC, AC, and
V
C1 - C4 = 0.1μF
V
C1 - C4 = 0.1μF
FIGURE 10. LOOPBACK TEST AT 120kbps
FIGURE 11. LOOPBACK TEST AT 250kbps
CC
CC
= +3.3V
= +3.3V
L
to the same supply (1.8V to 5V) powering
CC
.
L
supply pin solves this problem.
2μs/DIV.
5μs/DIV.
OUTS
) fail to reach
June 16, 2010
FN6041.2