The ICL3221, ICL3222, ICL3223, ICL3232, ICL3241, ICL3243 (ISL32xx) devices 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. Targeted applications are PDAs, notebook, and laptop computers where the low operational power consumption and even lower standby power consumption are critical. Efficient on-chip charge pumps, coupled with manual and automatic power-down functions (except for the ICL3232), reduce the standby supply current to a 1µA trickle. Small footprint packaging, and the use of small, low value capacitors ensure board space savings as well. 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 ICL324x 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 ICL3221, ICL3223 and ICL3243 feature an automatic powerdown 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, conserving 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.


  • RoHS Compliant
  • 15kV ESD protected (Human Body Model)
  • Drop-in replacements for MAX3221, MAX3222, MAX3223, MAX3232, MAX3241, MAX3243, SP3243
  • ICL3221 is a low-power, pin compatible upgrade for 5V MAX221
  • ICL3222 is a low-power, pin compatible upgrade for 5V MAX242, and SP312A
  • ICL3232 is a low-power upgrade for HIN232/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
  • Manual and automatic powerdown features (except ICL3232)
  • Assured mouse driveability (ICL324x only)
  • Receiver hysteresis for improved noise immunity
  • Assured minimum data rate : 250kbps
  • Assured minimum slew rate : 6V/ms
  • Wide power supply range : single +3V to +5.5V
  • Low supply current in powerdown state :1µA




  • Any System Requiring RS-232 Communication Ports Battery Powered, Hand-Held, and Portable Equipment Laptop Computers, Notebooks, Palmtops Modems, Printers and other Peripherals Digital Cameras Cellular/Mobile Phones


Design & Development