1µA, +3V to +5.5V, 250kbps, RS-232 Transceivers with Enhanced Automatic Powerdown


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 enhanced automatic powerdown functions, 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 ICL3244 is a 3 driver, 5 receiver device that provides a complete serial port suitable for laptop or notebook computers. The ICL3244/38 also include a noninverting always-active receiver for RING INDICATOR monitoring.

These devices feature an enhanced automatic powerdown function which powers down the on-chip powersupply 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.


  • Pb-Free Plus Anneal Available (RoHS Compliant)
  • ±15kV ESD Protected (Human Body Model)
  • Manual and Enhanced Automatic Powerdown Features
  • Drop in Replacements for MAX3224, MAX3226, MAX3238, MAX3244
  • Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V
  • Latch-Up Free
  • RS-232 Compatible with VCC = 2.7V
  • On-Chip Voltage Converters Require Only Four External 0.1µF Capacitors
  • Flow-Through Pinout (ICL3238)
  • Guaranteed Mouse Driveability (ICL3244)
  • "Ready to Transmit" Indicator Output (ICL3224/26)
  • 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
Temperature Range
-40 to +85

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