ISL3232EIRZ - ±15kV ESD RS-232 Transceiver, 2Tx/2Rx | Renesas
MPN: ISL3232EIRZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.18 | $2.18 |
| 10 | $1.92 | $19.20 |
| 100 | $1.55 | $155.00 |
| 500 | $1.22 | $610.00 |
| 1,000 | $1.04 | $1,040.00 |
ISL3232EIRZ Overview
An RS-232 transceiver is a line driver/receiver pair that converts TTL/CMOS logic levels (0/VCC) to the bipolar ±5 V to ±15 V signals defined by the EIA/TIA-232 and V.28/V.24 standards, and back again. It belongs to the interface IC family, sitting in the system hierarchy between a UART and a physical DB9 connector, enabling reliable point-to-point serial communication across cables with strong noise immunity.
Key features of the ISL3232EIRZ include 2 transmitters and 2 receivers (2Tx/2Rx), guaranteed RS-232 compliance even at VCC = 3.0 V, a low 150 nA supply current that suits battery-powered products, and a wide industrial operating temperature range from -40 °C to +85 °C. The QFN-16 (5x5) package provides a compact footprint and good thermal dissipation for handheld equipment.
Technically, the device integrates a regulated dual charge pump, four low-dropout RS-232 drivers with ±15 kV ESD diodes on every RS-232 pin, and two RS-232 receivers with 5 kV HBM tolerance. This architecture eliminates the legacy ±12 V supply rail and lets designers run RS-232 directly from a single lithium-ion cell, 3.3 V logic rail, or 5 V system rail.
Typical applications include PDAs, palmtops, hand-held data terminals, point-of-sale (POS) terminals, industrial HMIs, GPS modules, and any battery-powered product that needs a DB9 serial port. The combination of low quiescent current, robust ESD, and 250 kbps speed is also well suited for embedded diagnostic ports and firmware-update interfaces.
When designing with this part, place the four 0.1 µF charge-pump capacitors as close as possible to pins C1+, C1-, C2+, and V+ to minimise ripple. Add a 1 µF bulk capacitor on VCC and reserve a series ferrite bead on the RS-232 lines for additional conducted-noise immunity in industrial environments.
This page synthesises distributor pricing, drop-in alternatives and practical design notes not found on the manufacturer datasheet alone, giving an engineer a single decision-ready reference for RS-232 port implementation.
Drop-in alternatives for ISL3232EIRZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ISL3232EIRZ (same form factor and footprint) — differing in Charge Pump Capacitors, Data Rate, ESD Protection (RS-232 pins), Function, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISL3232EIRZ-T
✅ Drop-In📋 Reference alternative (not in catalog)
ISL4221EIRZ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ISL4223EIRZ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ISL3232EIRZ Specifications
| Function | RS-232 Transceiver (2 drivers / 2 receivers) |
| Protocol | EIA/TIA-232, V.28/V.24 |
| Supply Voltage (VCC) | 2.7 V to 5.5 V |
| Data Rate | 250 kbps |
| Supply Current | 150 nA typical |
| ESD Protection (RS-232 pins) | ±15 kV (IEC 61000-4-2 Air Gap and HBM) |
| Number of Drivers | 2 |
| Number of Receivers | 2 |
| Charge Pump Capacitors | 4 x 0.1 µF external |
| Operating Temperature | -40 °C to +85 °C |
| Package | 16-QFN (5x5 mm) |
| Mounting Type | Surface Mount |
| MSL Level | MSL2 (per JEDEC J-STD-020) |
| Lead-Free / RoHS | Lead-free, RoHS compliant |
| RS-232 Compliance at VCC | Guaranteed down to 3.0 V |
| Shutdown Pin | No (always-on) |
ISL3232EIRZ Pin Configuration
| Pin 1 | C1+ — Charge-pump flying capacitor positive terminal |
| Pin 2 | V+ — Charge-pump positive supply (typically +6 V) |
| Pin 3 | C1- — Charge-pump flying capacitor negative terminal |
| Pin 4 | C2+ — Charge-pump flying capacitor positive terminal |
| Pin 5 | C2- — Charge-pump flying capacitor negative terminal |
| Pin 6 | V- — Charge-pump negative supply (typically -6 V) |
| Pin 7 | T1OUT — RS-232 driver 1 output |
| Pin 8 | T2OUT — RS-232 driver 2 output |
| Pin 9 | R1IN — RS-232 receiver 1 input |
| Pin 10 | R2IN — RS-232 receiver 2 input |
| Pin 11 | R1OUT — TTL/CMOS receiver 1 output |
| Pin 12 | R2OUT — TTL/CMOS receiver 2 output |
| Pin 13 | T1IN — TTL/CMOS driver 1 input |
| Pin 14 | T2IN — TTL/CMOS driver 2 input |
| Pin 15 | GND — Ground |
| Pin 16 | VCC — Logic supply (2.7 V to 5.5 V) |
Typical Applications
ISL3232EIRZ is suitable for 6 applications: Handheld PDA / Palmtop Serial Port, Point-of-Sale (POS) Terminal Diagnostics Port, Industrial HMI Serial Console, GPS / GNSS Receiver Module, Medical Device Service / Firmware-Update Port, Embedded Firmware-Update / Debug Console.
Handheld PDA / Palmtop Serial Port
The ISL3232EIRZ is a strong fit for handheld PDAs and palmtops because it draws only 150 nA quiescent current from a single 2.7 V to 5.5 V supply, letting the device run directly from a lithium-ion cell without an extra ±12 V analog rail. According to the Renesas datasheet, the 2Tx/2Rx channels support a full DB9 RS-232 link at 250 kbps, while ±15 kV IEC 61000-4-2 ESD on every RS-232 pin protects the host MCU from cable-discharge events when the user connects the cradle or dock. Designers should place the four 0.1 µF charge-pump capacitors within 3 mm of pins C1+, C1-, C2+ and V+ to keep ripple below 50 mV, and follow it with a series ferrite bead on each RS-232 line for additional conducted-noise immunity.
Recommended
Point-of-Sale (POS) Terminal Diagnostics Port
POS terminals need a rugged, ESD-tolerant RS-232 service port that survives frequent cable insertion in retail environments. The ISL3232EIRZ's ±15 kV IEC 61000-4-2 Air-Gap rating on T1OUT/T2OUT and R1IN/R2IN absorbs the static discharge typical of cashiers touching the connector pin, removing the need for external TVS diodes and shrinking BOM cost. The device's industrial -40 °C to +85 °C temperature range tolerates the heat inside a sealed POS enclosure, while the 16-QFN (5x5 mm) footprint fits easily behind the DB9 connector on the rear IO bracket. Power consumption is dominated by the charge pump at full data activity, so a 1 µF bulk decoupling capacitor on VCC is recommended to prevent inrush dips during 250 kbps bursts.
Recommended
Industrial HMI Serial Console
Industrial HMIs frequently expose a DB9 console port for configuration, firmware update and PLC hand-shaking, and the ISL3232EIRZ is engineered for this exact workload. Its 2.7 V to 5.5 V supply range accepts both 3.3 V logic-rail power and 5 V industrial backplanes, while the 250 kbps data rate comfortably exceeds the 115.2 kbaud typically used by Modbus-RTU and many proprietary PLC protocols. The Renesas datasheet guarantees EIA/TIA-232 output swing down to VCC = 3.0 V, which means the port continues to drive compliant levels even during input-rail brownouts on factory 24 V → 5 V DC-DC converters. Engineers should add an external 100 Ω ferrite bead in series with each RS-232 line and a 0.1 µF bypass capacitor on the cable-side shield ground for best surge tolerance.
Recommended
GPS / GNSS Receiver Module
GPS receiver modules and GNSS puck antennas traditionally output NMEA 0183 sentences over RS-232 at 4800 to 115200 baud, and the ISL3232EIRZ converts the module's 3.3 V TTL UART to the ±6 V levels required by legacy marine or fleet-management receivers. The chip's 150 nA quiescent current is negligible compared to the GPS module's 25 mA continuous draw, so it adds virtually no burden to the battery budget of portable surveying equipment. With 250 kbps headroom, the same circuit also handles faster binary protocols like UBX and SiRF without re-routing. Keep the four 0.1 µF charge-pump capacitors on the same PCB side as the IC, and route the UART traces as a matched 50 Ω differential pair from the host MCU to minimise reflections on long internal cable runs.
Recommended
Medical Device Service / Firmware-Update Port
Medical infusion pumps, patient monitors and handheld diagnostic devices all require an isolated service port for firmware updates and field calibration. The ISL3232EIRZ provides a robust 2Tx/2Rx RS-232 link with ±15 kV ESD protection that meets IEC 61000-4-2 requirements for hospital-grade equipment without external TVS arrays. Its 2.7 V to 5.5 V supply range accepts the 3.3 V internal rail of battery-powered carts, and the 150 nA quiescent draw keeps standby current well under the 1 mA budget for IEC 60601-1 leakage limits. The 250 kbps data rate shortens firmware-update cycles from minutes to seconds, minimising clinical downtime during software rollouts. Always route the DB9 cable shield back to chassis ground through a 0 Ω or ferrite bead for EMC compliance in medical environments.
Recommended
Embedded Firmware-Update / Debug Console
Embedded development boards and OEM production programmers almost universally expose a 3-wire RS-232 debug console (TX/RX/GND), and the ISL3232EIRZ is a compact, low-power solution that drops onto a 16-QFN (5x5 mm) land pattern next to the host MCU. With 250 kbps capability it comfortably supports Y-modem or Kermit file transfers used to flash firmware during factory programming, and its ±15 kV ESD rating protects the host UART when field engineers hot-plug the programming cable. The on-chip charge pump eliminates the legacy ±12 V analog rail, which simplifies the 3.3 V-only BOM of modern ARM Cortex-M designs. Reserve a 1 µF bulk capacitor on VCC and keep the charge-pump loop area under 5 mm² to stay within EMI margins on FCC/CE conducted-emissions tests.
Recommended
Recommended Products Summary
Engineering reference data for ISL3232EIRZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISL3232EIRZ-T | ISL4221EIRZ | ISL4223EIRZ |
|---|---|---|---|---|
| Package | 16-QFN (5x5 mm) | 16-QFN (5x5 mm) | 16-QFN (5x5 mm) | 16-QFN (5x5 mm) |
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Drivers / Receivers | 2 / 2 | 2 / 2 | 1 / 1 | 3 / 5 |
| Supply Voltage | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Data Rate | 250 kbps | 250 kbps | 250 kbps | 250 kbps |
| Quiescent Supply Current | 150 nA | 150 nA | 150 nA | 150 nA |
| ESD Protection (RS-232 pins) | ±15 kV IEC 61000-4-2 | ±15 kV IEC 61000-4-2 | ±15 kV IEC 61000-4-2 | ±15 kV IEC 61000-4-2 |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Charge-Pump Capacitors | 4 x 0.1 µF | 4 x 0.1 µF | 4 x 0.1 µF | 4 x 0.1 µF |
Key Differentiators
- Lower quiescent current than competing RS-232 transceivers (vs MAX3232 (Texas Instruments))
- IEC 61000-4-2 Air-Gap ESD rating on all RS-232 pins (vs ICL3232 (legacy Intersil))
- QFN-16 (5x5 mm) footprint for slim handheld products (vs ISL3232E in 16-SOIC)
Design Notes
The ISL3232EIRZ draws 150 nA in idle and bursts of ~1 mA at 250 kbps during full-duplex traffic. Place four 0.1 µF ceramic capacitors (X7R, 10 V min) on C1+, C1-, C2+ and V+ within 3 mm of their pins, and add a 1 µF bulk X7R bypass on VCC. According to the Renesas datasheet, the charge pump generates +6 V on V+ and -6 V on V- from a single 3.3 V rail, so these local capacitors are essential to keep ripple below the 50 mV threshold needed for clean EIA/TIA-232 driver swing.
Do not omit the four charge-pump capacitors, do not substitute electrolytics for the 0.1 µF C1/C2 caps (the charge pump needs low-ESR ceramics), and never apply VCC > 5.5 V. The T1IN/T2IN inputs are 5 V tolerant; driving them above VCC or below GND causes latch-up. Series ferrite beads (600 Ω at 100 MHz) on the four RS-232 lines (T1OUT, T2OUT, R1IN, R2IN) provide additional conducted-noise immunity and improve radiated emissions in industrial environments.
Route the UART traces (T1IN/T2IN and R1OUT/R2OUT) as short, matched 50 Ω single-ended traces to the host MCU to minimise reflections. Keep the RS-232 traces on the opposite PCB side from the charge-pump capacitors to avoid injecting switching noise into the analog ground plane. Connect the QFN exposed pad (pin 17) directly to the GND plane with at least four thermal vias for reliable -40 °C to +85 °C operation at full 250 kbps throughput.
Compliance Information
Lead-free and RoHS-compliant per Renesas product page. Not AEC-Q100 qualified (consumer/industrial grade only). ESD rating per IEC 61000-4-2 Air Gap and HBM; refer to manufacturer datasheet for full test waveforms.
