1µA Supply-Current, +3V to +5.5V, 250kbps, RS-232 Transmitters/Receivers


The Intersil ICL32XX devices are 3.0V to 5.5V powered RS-232 transmitters/receivers which meet ElA/TIA-232 and V.28/V.24 specifications, even at VCC = 3.0V. 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 automatic powerdown 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 guaranteed 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 alwaysactive receivers for "wake-up" capability.

The ICL3221, ICL3223 and ICL3243, feature an automatic powerdown function which 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. These devices power up again when a valid RS-232 voltage is applied to any receiver input.

Table 1 summarizes the features of the devices represented by this data sheet, while Application Note AN9863 summarizes the features of each device comprising the ICL32XX 3V family.


  • Pb-Free Plus Anneal Available as an Option (RoHS Compliant) (See Ordering Info)
  • 15kV ESD Protected (Human Body Model)
  • Drop in Replacements for MAX3221, MAX3222, MAX3223, MAX3232, MAX3241, MAX3243, SP3243
  • ICL3221 is Low Power, Pin Compatible Upgrade for 5V MAX221
  • ICL3222 is Low Power, Pin Compatible Upgrade for 5V MAX242, and SP312A
  • ICL3232 is 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)
  • Guaranteed Mouse Driveability (ICL324X Only)
  • Receiver Hysteresis For Improved Noise Immunity
  • Guaranteed Minimum Data Rate 250kbps
  • Guaranteed Minimum Slew Rate 6V/µs
  • Wide Power Supply Range Single +3V to +5.5V
  • Low Supply Current in Powerdown State 1µA


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
0 to +70

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