ISL4270E

Features:

* Available in Near Chip Scale QFN (5mmx5mm) Package
*V_L Supply Pin for Compatibility with Mixed Voltage Systems
* ESD Protection for RS-232 I/O Pins to ±15kV (IEC61000)
* Manual and Enhanced Automatic Powerdown Features
* Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V
* On-Chip Charge Pumps Require Only Four External 0.1F Capacitors
* Receivers Stay Active in Powerdown
* Very Low Supply Current . . . . . . . . . . . . . . . . . . . . 300A
* Guaranteed Minimum Data Rate . . . . . . . . . . . . . 250kbps
* Wide Power Supply Range. . . . . . . . Single +3V to +5.5V
* Low Supply Current in Powerdown State. . . . . . . . 300nA
* Pb-Free Available (RoHS Compliant)




Application

* Any System Requiring RS-232 Communication Ports
- Battery Powered, Hand-Held, and Portable Equipment
- Laptop Computers, Notebooks, Palmtops
- Digital Cameras
- PDA's and PDA Cradles
- Cellular/Mobile Phones




Pinout






Specifications

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




Description

The Intersil ISL4270E is a 3.0V to 5.5V powered RS-232 transceiver which meets ElA/TIA-232 and V.28/V.24 specifications, even at V_CC = 3.0V. Additionally, it provides ±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 manua and enhanced automatic powerdown functions, reduce the standby supply current to a 300nA trickle. Tiny 5mm x 5mm Quad Flat No-Lead (QFN) packaging, and the use of smalllow value capacitors ensure board space savings as well. Data rates greater than 250kbps are guaranteed at worst case load conditions.

The ISL4270E features a V_L pin that adjusts the logic pin output levels and input thresholds to values compatible with the V_CC powering the external logic (e.g., a UART).

This device includes an enhanced automatic powerdown function which powers down the on-chip power-supply anddriver circuits. This occurs when all receiver and transmitte inputs detect no signal transitions for a period of 30 seconds It power back up, automatically, whenever it senses a transition on any transmitter or receiver input.

Table 1 summarizes the features of the ISL4270E, while Application Note AN9863 summarizes the features of each device comprising the 3V RS-232 family.