ISL4243E

Features:

* Pb-free Available as an Option
* Parameters Fully Specified for 10% Tolerance Supplies and Full Industrial Temp Range
* Available in Small QFN (5mm x 5mm) Package which 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
* RS-232 Compatible with V_CC = 2.7V
* On-Chip Voltage Converters Require Only Four External 0.1F Capacitors
* Manual and Automatic Powerdown Features
* Receiver Hysteresis For Improved Noise Immunity
* Guaranteed Minimum Data Rate . . . . . . . . . . . . . 250kbps
* Wide Power Supply Range. . . . . . . Single +2.7V to +5.5V
* Low Supply Current in Powerdown State. . . . . . . . . .10nA




Application

* Any Space Constrained System Requiring RS-232 Ports
- Battery Powered, Hand-Held, and Portable Equipment
- Laptop Computers, Notebooks
- PDAs and Palmtops, Data Cables
- Cellular/Mobile Phones, Digital Cameras, GPS Receivers




Pinout






Specifications

V_CC to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V
V+ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V
V- to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3V to -7V
V+ to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14V
Input Voltages
T_IN , FORCEOFF, FORCEON, EN, SHDN . . . . . . . . . -0.3V to 6V
R_IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±25V
Output Voltages
T_OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±13.2V
R_OUT , INVALID. . . . . . . . . . . . . . . . . . . . . . . . -0.3V to V_CC +0.3V
Short Circuit Duration
T_OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table




Description

The Intersil ISL424XE devices are 2.7V to 5.5V powered RS-232 transmitters/receivers which meet ElA/TIA-232 and V.28/V.24 specifications, even at V_CC = 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 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, reduce the standby supply current to a 10nA trickle. Tiny 5mm x 5mm 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.

The ISL424XE are 3 driver, 5 receiver devices that, coupled with the 5x5 QFN package, provide the industry's smallest, lowest power complete serial port suitable for PDAs, and laptop or notebook computers. The 5x5 QFN requires 60% less board area than a 28 lead TSSOP, and is nearly 20% thinner. The devices also include a noninverting always-active receiver for "wake-up" capability.

The ISL4243E 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.

Table 1 summarizes the features of the ISL424XE, while Application Note AN9863 summarizes the features of each device comprising the 3V RS-232 family.