Datasheet
ISL3232E, ISL4221E, ISL4223E
QFN Packaged, ±15kV ESD Protected, +2.7V to +5.5V, 150nA, 250kbps,
RS-232 Transmitters/Receivers
The ISL3232E, ISL4221E, and ISL4223E devices are
2.7V to 5.5V powered RS-232 transmitters/receivers
Features
• Available in near chip scale QFN (5mmx5mm)
package, which is 40% smaller than a 20 Ld
TSSOP
that meet ElA/TIA-232 and V.28/V.24 specifications,
even at V = 3.0V. They provide ±15kV ESD
CC
protection (IEC61000-4-2 Air Gap and Human Body
Model) on transmitter outputs and receiver inputs
(RS-232 pins). Targeted applications are PDAs,
Palmtops, and hand-held products where the low
operational power consumption and even lower
standby power consumption are critical. Efficient
on-chip charge pumps, coupled with manual and
automatic powerdown functions, reduce the standby
supply current to a 150nA trickle. The 5mmx5mm
Quad Flat No-Lead (QFN) packaging and the use of
small, low value capacitors ensure board space
savings. Data rates greater than 250kbps are ensured
at worst case load conditions.
• ESD protection for RS-232 I/O pins to ±15kV
(IEC61000)
• Meets EIA/TIA-232 and V.28/V.24 specifications at
3V
• RS-232 compatible with V = 2.7V
CC
• On-chip voltage converters require only four
external 0.1µF capacitors
• Manual and automatic powerdown features (except
ISL3232E)
• Receiver hysteresis for improved noise immunity
• Assured minimum data rate: 250kbps
The ISL4221E is a 1 driver, 1 receiver device and the
ISL3232E and ISL4223E are 2 driver, 2 receiver
devices that, coupled with the 5mmx5mm QFN
package, provide the industry’s smallest, lowest
power serial port suitable for PDAs, and hand-held
applications. The 5mmx5mm QFN requires 40% less
board area than a 20 Ld TSSOP, and is nearly 20%
thinner.
• Wide power supply range: single +2.7V to +5.5V
• Low supply current in powerdown state: 150nA
• Pb-free (RoHS compliant)
Applications
• Any space-constrained system requiring RS-232
ports
The ISL4221E and ISL4223E versions feature an
automatic powerdown function that powers down the
on-chip power supply and driver circuits. Automatic
powerdown occurs when an attached peripheral
device is shut off or the RS-232 cable is removed, and
conserves system power automatically without
changes to the hardware or operating system. The
ISL4221E and ISL4223E power back up automatically
when a valid RS-232 voltage is applied to any
receiver input.
○ Battery powered and portable equipment
○ Hand-held products (GPS receivers, bar code
scanners, etc.)
○ PDAs and Palmtops, data cables
○ Cellular/mobile phones, digital cameras
Related Literature
For a full list of related documents, visit our website:
• ISL3232E, ISL4221E, and ISL4223E device pages
Table 1 summarizes the features of the IC’s and
AN9863 summarizes the features of each device
comprising the 3V RS-232 family.
Table 1.
Summary of Features
Number Number
QFN Pkg.
Available?
Rx. Enable
Data Rate (kbps) Function?
Manual
Powerdown?
Automatic Powerdown
Function?
Part Number
ISL4221E
of Tx.
of Rx.
1
2
2
1
2
2
Yes
250
250
250
Yes
No
Yes
No
Yes
No
ISL3232E
Yes
ISL4223E
Yes
Yes
Yes
Yes
FN6045 Rev.7.00
May.2.19
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