±15kV ESD Protected, +3V to +5.5V, 1µA, 250kbps, RS-232 Transmitters/Receivers

Product Status: Mass Production


The ICL3221E, ICL3222E, ICL3223E, ICL3232E, ICL3241E, and ICL3243E are 3.0V to 5.5V powered RS-232 transmitters/receivers that meet ElA/TIA-232 and V.28/V.24 specifications, even at VCC = 3.0V. Additionally, 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 notebook and laptop computers in which the low operational power consumption and even lower standby power consumption is critical. Efficient on-chip charge pumps, coupled with manual and automatic power-down functions (except for the ICL3232E), reduce the standby supply current to a 1µA trickle. Small footprint 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. This family is fully compatible with 3.3V-only systems, mixed 3.3V and 5.0V systems, and 5.0V-only systems.

The ICL324XE are 3-driver, 5-receiver devices that provide a complete serial port suitable for laptop or notebook computers. Both devices also include noninverting always-active receivers for “wake-up” capability.

The ICL3221E, ICL3223E, and ICL3243E feature an automatic power-down function that powers down the on-chip power supply and driver circuits. Power-down occurs when an attached peripheral device is shut off or the RS-232 cable is removed, which conserves system power automatically without changes to the hardware or operating system. These devices power up again when a valid RS-232 voltage is applied to any receiver input.


    ESD protection for RS-232 I/O pins to ±15kV (IEC61000)

    Drop-in replacements for the MAX3221E, MAX3222E, MAX3223E, MAX3232E, MAX3241E, MAX3243E, and SP3243E

    The ICL3221E is a low-power, pin-compatible upgrade for the 5V MAX221E

    The ICL3222E is a low-power, pin-compatible upgrade for the 5V MAX242E and SP312E

    The ICL3232E is a low-power upgrade for the HIN232E, ICL232, and pin-compatible competitor devices

    RS-232 compatible with VCC = 2.7V

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

    Latch-up free

    On-chip voltage converters require only four external 0.1µF capacitors at VCC = 3.3V

    Manual and automatic power-down features

    Ensured mouse driveability (ICL324xE only)

    Receiver hysteresis for improved noise immunity

    Ensured minimum data rate : 250kbps

    Wide power supply range : single +3V to +5.5V

    Low supply current in power-down state : 1µA

    Pb-free (RoHS compliant)


 Block Diagram


Basic Information
Production Status
Mass Production
# of Rx
# of Tx
High ESD Protection
Data Rate
0.5 Mbps
Supply Voltage Vcc (Min) (V)
Supply Voltage Vcc (Max) (V)
Manual Shutdown
Auto Shutdown
Rx Disable
Capacitance Value
0.1 µF
IS Enabled (mA)
IS Disabled
1 µA
Qualification Level
Supply Voltage Vcc Range (V)
3 to 5.5
Can Sample
Temperature Range
-40 to +85

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