ISL33357E: 5V, ±15kV ESD Protected, Two Port, Dual Protocol (RS-232/RS-485) Transeiver in a QFN Package

The ISL33354E, ISL33357E are two port interface ICs where port 1 is configured as a dual (2 Tx, 2 Rx) RS-232 transceiver, and port 2 is a single RS-485/422 transceiver.

An on-board charge pump generates RS-232 compliant ±5V Tx output levels from a single VCC supply as low as 4.5V. The transceivers are RS-232 compliant, with the Rx inputs handling up to ±25V.

The port 2 transceiver supports both the RS-485 and RS-422 differential communication standards. The receiver features "full fail-safe" operation, so the Rx output remains in a high state if the inputs are open or shorted together. The transmitter supports two data rates, one of which is slew rate limited for problem free communication at low data rates. The active low Rx enable pin (RE485) allows Tx/Rx direction control, via a single signal, simply by connecting the corresponding DE485 and RE485 pins together.

The ISL33354E and ISL33357E also include a shutdown function, which disables the Tx and Rx outputs, disables the charge pumps and places the IC in a low current (55µA) mode.

The ISL33357E is a QFN packaged device for space constrained applications.

Key Differences in Family
Part NumberVCC (V)PKGChannelsRS485 (bps) Data RateRS232 (bps) Data RateProgrammableDatasheet
ISL33354E528Ld SSOP220M, 115k650kNoisl33354e-57e.pdf
ISL33357E540Ld QFN220M, 115k650kNoisl33354e-57e.pdf
ISL33334E3.328Ld SSOP220M, 115k400kNoisl33334e-37e.pdf
ISL33337E3.340Ld QFN220M, 115k400kNoisl33334e-37e.pdf
Key Features
  • ±15kV (HBM) ESD protected bus pins (RS-232 or RS-485)
  • Operates from a single 5V supply
  • Two independent ports: port 1 set for RS-232 (2 transceivers) and port 2 for RS-485/RS-422 (1 transceiver)
  • True flow-through pinouts (Rx inputs and Tx outputs all on the same side) simplify board layouts
  • Pb-free (RoHS compliant)
  • Full fail-safe (open/short) RS-485/422 port 2 Rx
  • User selectable RS-485 data rates
    • Fast speed: up to 20Mbps
    • Slew rate limited: up to 115kbps
  • Fast RS-232 data rate: 460kbps (Minimum)
  • Small charge pump capacitors: 4 x 0.1µF
  • Low current shutdown mode: 55µA
  • QFN package saves board space (ISL33357E only)
Applications
  • Gaming applications (e.g., slot machines)
  • Single board computers
  • Factory automation
  • Security networks
  • Industrial/process control networks
  • Level translators (e.g., RS-232 to RS-422)
  • Point-of-sale equipment
Typical Diagram
Datasheets
TitleTypeUpdatedSizeOther Languages
ISL33354E, ISL33357E DatasheetPDF08 Nov 2016769 KB
White Papers
TitleTypeUpdatedSizeOther Languages
Dual Protocol Transceivers Ease the Design of Industrial InterfacesPDF16 Nov 2016505 KB
Order Information
Part NumberPackage TypeWeight(g)PinsMSL RatingPeak Temp (°C)RoHS Status
ISL33357EIRZ40 Ld QFN0.102403260RoHS
ISL33357EIRZ-T40 Ld QFN T+R0.102403260RoHS
ISL33357EIRZ-T7A40 Ld QFN T+R0.102403260RoHS
ISL33354E, ISL33357E Datasheet 08 Nov 2016
Dual Protocol Transceivers Ease the Design of Industrial Interfaces 16 Nov 2016