庐
ISL4238E, ISL4244E, ISL4245E
Data Sheet
April 2004
FN8038.3
QFN Packaged,
卤15kV
ESD Protected,
+2.7V to +5.5V, 10Nanoamp, 250kbps/
1Mbps, RS-232 Transceivers with
Enhanced Automatic Powerdown
The Intersil ISL4238E/44E/45E devices are 2.7V to 5.5V
powered RS-232 transmitters/receivers which meet
ElA/TIA-232 and V.28/V.24 specifications, even at
V
CC
= 3.0V. Additionally, they provide
卤
15kV ESD protection
(IEC6100-4-2 Air Gap and Human Body Model) on
transmitter outputs and receiver inputs (RS-232 pins).
Targeted applications are PDAs, Palmtops, and notebook
and laptop computers where the low operational, and even
lower standby, power consumption is critical. Efficient on-
chip charge pumps, coupled with manual and enhanced
automatic powerdown functions, reduce the standby supply
current to a
10nA
trickle. Tiny 5mm x 5mm
Quad Flat No-
Lead
(QFN) packaging and the use of small, low value
capacitors ensure board space savings as well. Data rates
greater than 250kbps (ISL4238E/44E)/1Mbps (ISL4245E)
are guaranteed at worst case load conditions.
The ISL424XE are 3 driver, 5 receiver (DTE) devices that,
coupled with the QFN package, provide the industry鈥檚
smallest, lowest power complete serial port suitable for
PDAs, and laptop or notebook computers. The 5x5 QFN
requires 60% less board area than a 28 lead TSSOP, and is
nearly 20% thinner. The devices also include a noninverting
always-active receiver for 鈥渨ake-up鈥?capability.
The ISL4238E is a 5 driver, 3 receiver device optimized for
DCE applications with full hardware handshaking. It also
includes a noninverting always-active receiver for RING
INDICATOR monitoring. Transmitter and logic inputs include
active feedback resistors that retain the input state once
driven to a valid logic level.
These devices feature an
enhanced automatic
powerdown
function which powers down the on-chip power-
supply and driver circuits. This occurs when all receiver and
transmitter inputs detect no signal transitions for a period of
30sec. These devices power back up, automatically,
whenever they sense a transition on any transmitter or
receiver input.
Table 1 summarizes the features of the ISL4238E/4XE, while
Application Note AN9863 summarizes the features of each
device comprising the 3V RS-232 family.
Features
鈥?Parameters Fully Specified for 10% Tolerance Supplies
and Full Industrial Temp Range
鈥?Available in Small QFN (5mm x 5mm) Package which is
60% Smaller than a 28 Lead TSSOP
鈥?ESD Protection for RS-232 I/O Pins to
卤
15kV (IEC6100)
鈥?DTE (ISL4244E/45E) and DCE (ISL4238E) Versions
鈥?Lowest Supply Current in Powerdown . . . . . . . . . . . .10nA
鈥?Active Feedback Resistors on T
X
and Logic Inputs
(ISL4238E)
鈥?Flow Through Pinouts
鈥?Manual and Enhanced Automatic Powerdown Features
鈥?Guaranteed Minimum Data Rate
250kbps (ISL4238E/44E) / 1Mbps (ISL4245E)
鈥?Latch-Up Free
鈥?On-Chip Charge Pumps Require Only Four External
0.1碌F Capacitors
鈥?Wide Power Supply Range. . . . . . . Single +2.7V to +5.5V
鈥?Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V
鈥?RS-232 Compatible with V
CC
= 2.7V
鈥?/div>
Pb-free Available as an Option
Applications
鈥?Any Space Constrained System Requiring RS-232 Ports
- Battery Powered, Hand-Held, and Portable Equipment
- Laptop Computers, Notebooks
- PDAs and Palmtops, Data Cables
- Cellular/Mobile Phones, Digital Cameras, GPS
Receivers
Related Literature
鈥?Technical Brief TB363 鈥淕uidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices鈥?/div>
鈥?Technical Brief TB379 鈥淭hermal Characterization of
Packages for ICs鈥?/div>
鈥?Technical Brief TB389 鈥淧CB Land Pattern Design and
Surface Mount Guidelines for QFN Packages鈥?/div>
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
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Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright 漏 Intersil Americas Inc. 2004. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
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