ISL4270E

±15kV ESD Protected, +3V to +5.5V, 300nA, 250kbps, RS-232 Transceivers

Product Status: Mass Production

OVERVIEW

The ISL4270E is a 3.0V to 5.5V powered RS-232 transceiver that meets ElA/TIA-232 and V.28/V.24 specifications, even at VCC = 3.0V. 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 notebook and laptop computers where the low operational power consumption 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 300nA trickle. The 5mmx5mm Quad Flat No-Lead (QFN) packaging and the use of small, low value capacitors ensure board space savings. Data rates greater than 250kbps are ensured at worst case load conditions.

The ISL4270E features a VL pin that adjusts the logic pin output levels and input thresholds to values compatible with the VCC powering the external logic (for example, a UART).

This device includes an enhanced automatic powerdown function that powers down the on-chip power-supply and driver circuits. Automatic powerdown occurs when all receiver and transmitter inputs detect no signal transitions for a period of 30 seconds. The ISL4270E automatically powers back up whenever it senses a transition on any transmitter or receiver input.

Application Note AN9863 summarizes the features of each device comprising the 3V RS-232 family.

KEY FEATURES

    • Available in near chip scale QFN (5mmx5mm) package
    • VL 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 0.1µF capacitors
    • Receivers stay active in powerdown
    • Very low supply current: 300µA
    • Guaranteed minimum data rate: 50kbps
    • Wide power supply range: single +3V to +5.5V
    • Low supply current in powerdown state: 300nA
    • Pb-free (RoHS compliant)

BLOCK DIAGRAM

 Block Diagram

PARAMETRICS

Parameters
ISL4270E
Basic Information
Production Status
Mass Production
# of Rx
3
# of Tx
3
High ESD Protection
Yes
Data Rate
0.5 Mbps
Supply Voltage Vcc (Min) (V)
3
Supply Voltage Vcc (Max) (V)
5.5
Manual Shutdown
Yes
Auto Shutdown
Enhanced
Rx Disable
No
Capacitance Value
0.1 µF
IS Enabled (mA)
0.3
IS Disabled
0.3 µA
Qualification Level
Standard
Supply Voltage Vcc Range (V)
3 to 5.5
Temperature Range
-40 to +85

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