RS-232 transceivers eliminate level shifters

October 23, 2015 // By Graham Prophet
Exar’s RS-232 (EIA/TIA-232) transceivers are designed to operate from 3V to 5.5V supplies. The XR32220, XR32430 and XR32431 include an adjustable low voltage logic interface, via a VL pin, hat simplifies their use in low voltage and multi-voltage systems.

In many applications, RS-232 transceivers interface with UARTs, MCUs and other logic devices operating from supplies less than 3.3V. The XR32220 and XR32431 feature a low voltage logic pin (VL) that can be used to adjust the transceiver’s logic output levels and input thresholds for compatibility with lower supply voltage logic. The VL range is 1.65V to 5.5V. The adjustable low voltage interface eliminates the need for a level shifter/translator between the transceiver and UART or MCU.

The devices offer;

• 3.0V to 5.5V supply operation

• 1.65V to 5.5V logic interface VL pin (XR32220, XR32431)

• Auto on-line circuitry automatically wakes up from a 1 µA shutdown

• Regulated charge pump yields stable RS-232 outputs regardless of VCC variations

• XR32220: 250 kbps min transmission rate

• XR32430, XR32431: 250 kbps/460 kbps/1 Mbps min transmission rate

The XR32220, XR32430 and XR32431 occupy 4 x 4mm QFN (XR32220) and 5 x 5mm QFN (XR32430/31) packages, for $0.74 to $0.94 (1000).