Datasheet ISL4270E QFN Packaged, 15kV ESD Protected, +3V to +5.5V, 300nA, 250kbps, RS-232 Transceivers with Enhanced Automatic Powerdown and a Separate Logic Supply The ISL4270E is a 3.0V to 5.5V powered RS-232 Features transceiver that meets ElA/TIA-232 and V.28/V.24 Available in near chip scale QFN (5mmx5mm) specifications, even at V = 3.0V. It provides 15kV CC package ESD protection (IEC61000-4-2 Air Gap and Human V supply pin for compatibility with mixed voltage Body Model) on transmitter outputs and receiver L systems inputs (RS-232 pins). Targeted applications are notebook and laptop computers where the low ESD protection for RS-232 I/O pins to 15kV operational power consumption and even lower (IEC61000) standby power consumption is critical. Efficient Manual and enhanced automatic powerdown on-chip charge-pumps coupled with manual and features enhanced automatic powerdown functions reduce the standby supply current to a 300nA trickle. The Meets EIA/TIA-232 and V.28/V.24 specifications 5mmx5mm Quad Flat No-Lead (QFN) packaging and at 3V the use of small, low value capacitors ensure board On-chip charge pumps require only four external space savings. Data rates greater than 250kbps are 0.1F capacitors ensured at worst case load conditions. Receivers stay active in powerdown The ISL4270E features a V pin that adjusts the logic L Very low supply current: 300A pin output levels and input thresholds to values compatible with the V powering the external logic CC Guaranteed minimum data rate: 50kbps (for example, a UART). Wide power supply range: single +3V to +5.5V This device includes an enhanced automatic Low supply current in powerdown state: 300nA powerdown function that powers down the on-chip Pb-free (RoHS compliant) power-supply and driver circuits. Automatic powerdown occurs when all receiver and transmitter Applications inputs detect no signal transitions for a period of 30 seconds. The ISL4270E automatically powers Any system requiring RS-232 communication ports back up whenever it senses a transition on any Battery powered, hand-held, and portable transmitter or receiver input. equipment Table 1 summarizes the features of the ISL4270E. Industrial laptops, Palmtops, and PDAs Application Note AN9863 summarizes the features of Digital cameras each device comprising the 3V RS-232 family. Related Literature For a full list of related documents, visit our website: ISL4270E device page Table 1. Summary of Features No. of No. of Data Rate Rx. Enable V Logic Manual Enhanced Automatic L Part Number Tx. Rx. (kbps) Function Supply Pin Powerdown Powerdown Function ISL4270E 3 3 250 No Yes Yes Yes FN6041 Rev.3.00 Page 1 of 23 Apr 26, 2019ISL4270E Contents 1. Overview . 3 1.1 Typical Operating Circuit 3 1.2 Ordering Information . 3 1.3 Pinout . 4 1.4 Pin Descriptions . 4 2. Specifications . 5 2.1 Absolute Maximum Ratings 5 2.2 Thermal Information 5 2.3 Recommended Operating Conditions 5 2.4 Electrical Specifications . 6 3. Typical Performance Curves . 8 4. Application Information 10 4.1 Charge Pump 10 4.1.1 Charge Pump Abs Max Ratings . 10 4.2 Transmitters . 11 4.3 Receivers . 11 4.4 Low Power Operation . 12 4.5 Powerdown Functionality . 12 4.6 Software Controlled (Manual) Powerdown . 12 4.7 Enhanced Automatic Powerdown 13 4.8 Emulating Standard Automatic Powerdown . 14 4.9 Hybrid Automatic Powerdown Options 15 4.10 VL Logic Supply Input . 15 4.11 INVALID Output 15 4.12 Capacitor Selection . 16 4.13 Power Supply Decoupling 16 4.14 Transmitter Outputs when Exiting Powerdown 16 4.15 High Data Rates . 17 4.16 Interconnection with 3V and 5V Logic . 18 5. 15kV ESD Protection . 19 5.1 Human Body Model (HBM) Testing . 19 5.2 IEC61000-4-2 Testing . 19 5.2.1 Air-Gap Discharge Test Method 19 5.2.2 Contact Discharge Test Method 19 6. Die Characteristics . 20 7. Revision History 21 8. Package Outline Drawing 22 FN6041 Rev.3.00 Page 2 of 23 Apr 26, 2019