1

®

FN6768.1

ISL3241E, ISL3243E

QFN Packaged, ±15kV ESD Protected,

+2.7V to +3.6V, 250kbps, RS-232

Transmitters/Receivers with Separate

Logic Supply Pin

The Intersil ISL324xE devices are 2.7V to 3.6V powered

RS-232 transmitters/receivers which meet ElA/TIA-232 and

they provide ±15kV ESD protection (IEC61000-4-2 Air Gap

and Human Body Model) on transmitter outputs and receiver

inputs (RS-232 pins). Targeted applications are POS

systems, 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 automatic power-down functions, reduce the standby

supply current to a 0.5µA trickle. Tiny 5mmx5mm 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 are guaranteed at worst case load

conditions.

ISL324xE are 3 driver, 5 receiver devices that, coupled with

the 5x5 QFN package, provide the industry’s smallest,

lowest power complete serial port. The 5x5 QFN requires

60% less board area than a 28 Ld TSSOP, and is nearly

20% thinner. These devices also include a noninverting

always-active receiver for “wake-up” capability.

The ISL3243E features an automatic powerdown function

that powers down the on-chip power supply and driver

circuits. This occurs when an attached peripheral device is

shut off or the RS-232 cable is removed, conserving system

power automatically without changes to the hardware or

operating system. It powers up again when a valid RS-232

voltage is applied to any receiver input.

“Pin Descriptions” on page 2) output levels and input

external logic (e.g., a UART).

Table 1 summarizes the features of the ISL324xE.

Features

Adjusts Logic Output Levels and Input Thresholds for

Compatibility with Lower Supply Voltage Logic

• Parameters Specified for 10% Tolerance Supplies and Full

Industrial Temp Range

• Pb-free Small QFN (5mmx5mm) Package is 60% Smaller

than a 28 Lead TSSOP

• ESD Protection for RS-232 I/O Pins to ±15kV (IEC61000)

• Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V

• On-Chip Voltage Converters Require Only Four External

0.1µF Capacitors

• Manual and Automatic Power-down Features

• Receiver Hysteresis for Improved Noise Immunity

• Guaranteed Minimum Data Rate . . . . . . . . . . . . . 250kbps

• Low Supply Current in Power-down State . . . . . . . . 0.5µA

• Pb-Free (RoHS compliant)

Applications

• Any Space Constrained System Requiring RS-232 Ports

- Battery Powered, Hand-Held, and Portable Equipment

- POS Systems and Scanners

- Laptop Computers, Notebooks

- GPS Receivers

• Mixed Voltage Serial Ports

Related Literature

• Technical Brief TB363 “Guidelines for Handling and

Processing Moisture Sensitive Surface Mount Devices

• ”Technical Brief TB379 “Thermal Characterization of

Packages for ICs”

• Technical Brief TB389 “PCB Land Pattern Design and

Surface Mount Guidelines for QFN Packages”

TABLE 1. SUMMARY OF FEATURES

PART NUMBER

NO. OF

Tx.

NO. OF

Rx.

LOGIC

PIN?

NO. OF

MONITOR Rx.

DATA

RATE

(kbps)

Rx. ENABLE

FUNCTION?

Pb-FREE?

MANUAL

POWER-

DOWN?

AUTOMATIC

POWERDOWN

FUNCTION?

ISL3241E

3

5

YES

2

250

YES

YES

YES

NO

ISL3243E

3

5

YES

1

250

NO

YES

YES

YES

Data Sheet

May 13, 2010

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

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