TRS3221EIRGTR - 3-5.5V RS-232 Transceiver, 250kbps, ±15kV ESD | Texas Instruments
MPN: TRS3221EIRGTR ✓ Hoạt độngTRS3221EIRGTR Tóm tắt
An RS-232 transceiver is a charge-pump-based interface IC that translates between TTL/CMOS logic levels (0-3.3 V or 0-5 V) and the ±5 V to ±15 V swing required by the legacy TIA/EIA-232-F serial communication standard. RS-232 transceivers belong to the broader interface IC family, which sits hierarchically between discrete level-shifters and protocol controllers (UARTs) in wired communication systems. RS-232 remains widely deployed in industrial equipment, point-of-sale terminals, medical instruments, and embedded debug ports where simplicity, point-to-point connectivity, and proven robustness outweigh the bandwidth advantages of USB or Ethernet.
Key features include ±15 kV Human-Body Model (HBM) ESD protection on RS-232 pins, ±8 kV IEC 61000-4-2 contact discharge, ±15 kV IEC 61000-4-2 air-gap discharge, and an automatic powerdown feature that disables drivers when no valid RS-232 cable is detected. The on-chip dual charge pump requires only four external 0.1 µF capacitors, enabling true 5 V operation from a single 3.3 V supply without a separate ±12 V rail. The 250 kbps data rate is adequate for all standard RS-232 baud rates up to and beyond 115200 with margin to spare.
The architecture combines a regulated switched-capacitor voltage doubler/inverter with a proprietary low-dropout RS-232 driver stage and a precision hysteresis receiver. ESD protection is implemented at the cable-side pins using TI's integrated silicon-controlled-rectifier (SCR) clamps. The 16-pin VQFN package's exposed pad provides a low thermal resistance path, which is useful when the part operates near the upper end of its 1 mA quiescent current budget in warm enclosures.
Typical applications include industrial PLC programming ports, point-of-sale (POS) terminals, medical device serial consoles, battery-powered handhelds, and embedded debug UARTs that need robust ESD performance in the field. The TRS3221EIRGTR's small 3x3 mm footprint suits space-constrained designs such as USB-to-serial dongles, IoT gateways, and barcode scanners.
When designing with this part, place the four charge-pump capacitors as close as possible to the C1+ / C1- / C2+ / C2- pins and keep the RS-232 trace lengths short to maximize ESD margin. Note that the TRSF3221E is the higher-speed (1 Mbit/s) pin-compatible alternative if 250 kbps is insufficient. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho TRS3221EIRGTR — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
TRS3221EIRGTR
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →SN75C3221EIRGTR
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
TRSF3221EIRGTR
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX3221EIRGTR
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
TRS3221EIRGTR Thông số kỹ thuật
| Chức năng | RS-232 line driver/receiver (transceiver) |
| Number of Drivers | 1 |
| Number of Receivers | 1 |
| Tốc độ dữ liệu | 250 kbps |
| Supply Voltage (VCC) | 3.0 V to 5.5 V |
| Logic Supply Voltage | Same as VCC (no separate VL pin) |
| RS-232 Driver Output Swing | ±5.4 V minimum into 5 kΩ load |
| Receiver Input Voltage Range | ±25 V |
| Receiver Hysteresis | 0.5 V typical |
| ESD Protection (HBM, RS-232 pins) | ±15 kV |
| ESD Protection (IEC 61000-4-2 contact) | ±8 kV |
| ESD Protection (IEC 61000-4-2 air-gap) | ±15 kV |
| Quiescent Current (powered, no load) | 1 mA typical |
| Auto Powerdown Feature | Yes (drivers disable when no valid RS-232 signal detected) |
| External Capacitors Required | 4 × 0.1 µF ceramic |
| Nhiệt độ hoạt động | -40 °C to +85 °C |
| Hộp | VQFN-16 (RGT) 3 × 3 mm with exposed pad |
| Kiểu lắp đặt | Surface Mount |
| Cấp MSL | 2 (1 year floor life at ≤30 °C / 60 % RH) |
| Trạng thái RoHS | Compliant |
| Lead Finish | NiPdAu lead-free |
| Standards Compliance | TIA/EIA-232-F, ITU v.28 |
Cấu hình chân TRS3221EIRGTR
| Chân 1 | DOUT — Driver input (TTL/CMOS, from UART TX) |
| Chân 2 | DIN — Receiver output (TTL/CMOS, to UART RX) |
| Chân 3 | GND — Ground |
| Chân 4 | C1+ — Charge-pump flying capacitor positive terminal |
| Chân 5 | V+ — Charge-pump +5.4 V generated rail |
| Chân 6 | C1- — Charge-pump flying capacitor negative terminal |
| Chân 7 | C2+ — Charge-pump flying capacitor positive terminal |
| Chân 8 | C2- — Charge-pump flying capacitor negative terminal |
| Chân 9 | V- — Charge-pump -5.4 V generated rail |
| Chân 10 | GND — Ground |
| Chân 11 | VCC — Supply voltage, 3.0 V to 5.5 V |
| Chân 12 | RIN — Receiver input (RS-232, ±25 V tolerant) |
| Chân 13 | ROUT — Receiver output (TTL/CMOS, to UART RX) |
| Chân 14 | NC — Not connected (per datasheet) |
| Chân 15 | NC — Not connected (per datasheet) |
| Chân 16 | EPAD — Exposed thermal pad - tie to GND for thermal dissipation |
Ứng dụng tiêu biểu
TRS3221EIRGTR phù hợp cho 6 Áp dụngs: Industrial PLC Programming Port, Point-of-Sale (POS) Terminal Serial Console, Medical Device Service/Diagnostic Port, USB-to-Serial Dongle, Battery-Powered Handheld Scanner, Embedded Firmware Debug UART.
Industrial PLC Programming Port
The TRS3221EIRGTR is well suited to industrial PLC programming ports because its ±15 kV HBM and ±15 kV IEC 61000-4-2 air-gap ESD ratings protect the cable-side pins from charged-cable discharge when technicians hot-plug a programming terminal. The 250 kbps data rate covers all common PLC vendor baud rates (9600, 19200, 38400, 57600, 115200) with margin, while the 3.0-5.5 V VCC range lets the same part interface with both legacy 5 V PLC logic and newer 3.3 V microcontrollers. Place four 0.1 µF X7R capacitors near the charge-pump pins to ensure stable ±5.4 V rail generation even on long factory cables. The exposed thermal pad helps dissipate heat in sealed IP65 enclosures without airflow.
Được đề xuất
Point-of-Sale (POS) Terminal Serial Console
POS terminals require a robust debug and service console port that survives accidental cable mis-wiring and static discharge from cashiers. The TRS3221EIRGTR's ±25 V receiver input range tolerates the ±12-15 V transients seen on poorly shielded RJ45-to-DB9 cables in retail environments, and the auto-powerdown feature disables drivers when no cable is attached, cutting idle current for energy-star compliance. The 16-pin VQFN (RGT) 3×3 mm package fits inside the tight enclosures of modern POS card readers, and the 1 mA quiescent current keeps total standby power below 5 mW at 5 V. The exposed pad provides a low thermal resistance path when the part sits adjacent to a warm printer stepper driver.
Được đề xuất
Medical Device Service/Diagnostic Port
Medical equipment such as infusion pumps and patient monitors require IEC 60601-1-compliant RS-232 service ports for biomed technicians to download event logs and run calibration routines. The TRS3221EIRGTR meets the ±15 kV IEC 61000-4-2 air-gap ESD requirement that simplifies the overall IEC 60601-1-2 EMC certification, reducing retest cycles when the connector is touched by a charged operator. The 3.0-5.5 V supply integrates cleanly with the 3.3 V rails used by modern ARM Cortex-M host MCUs such as the STM32L4 family. Reliable 250 kbps data rate ensures that 1 MB log dumps complete in under one minute, minimizing downtime in clinical settings.
Được đề xuất
USB-to-Serial Dongle
Compact USB-to-serial bridge dongles benefit from the TRS3221EIRGTR's 3×3 mm VQFN footprint, which fits inside the DB-9 hood alongside a USB-C connector and a CP2102N bridge IC. The 250 kbps data rate supports legacy equipment at any standard baud rate, while the ±15 kV ESD on the DB-9 pins protects the dongle from charged cable discharge when users hot-plug into industrial equipment. The integrated charge pump eliminates the need for a bulky ±12 V switching regulator, allowing the entire dongle to draw less than 10 mA from the USB 5 V rail. Operating temperature range of -40 to +85 °C accommodates outdoor field-engineering laptops.
Được đề xuất
Battery-Powered Handheld Scanner
Battery-powered barcode scanners and rugged handhelds use the TRS3221EIRGTR as a charging-crate communication port, where its 1 mA quiescent current preserves battery life between docking events. The auto-powerdown feature automatically disables the RS-232 drivers when no cable is connected, dropping standby consumption below 1 µA when the device is in its cradle. The 3.0-5.5 V supply lets the part share a single Li-ion battery rail directly without a boost converter. The VQFN-16 3×3 mm package occupies minimal PCB area in compact handheld enclosures, freeing space for the lithium battery and barcode imager.
Được đề xuất
Embedded Firmware Debug UART
Embedded development boards expose a TTL-level UART header for firmware debugging, but many legacy firmware tools and lab bench equipment still expect a full RS-232 port with ±5 V swing. The TRS3221EIRGTR bridges this gap on a 16-pin VQFN footprint with the ±5.4 V swing required to drive RS-232 inputs on test equipment such as spectrum analyzers and protocol analyzers. The wide 3.0-5.5 V VCC range means the same board can use a 3.3 V STM32 or a 5 V Arduino without modification. ±15 kV ESD protects the lab environment from charged fixture discharge during repeated connection cycles.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho TRS3221EIRGTR — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | SN75C3221EIRGTR | TRSF3221EIRGTR | MAX3221EIRGTR |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices (Maxim) |
| Package | VQFN-16 (RGT) 3×3 mm | VQFN-16 (RGT) - same | VQFN-16 (RGT) - same | VQFN-16 (RGT) - same |
| Supply Voltage | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
| Data Rate | 250 kbps | 250 kbps | 1000 kbps (1 Mbit/s) | 250 kbps |
| ESD (HBM, RS-232 pins) | ±15 kV | ±15 kV | ±15 kV | ±15 kV |
| ESD (IEC 61000-4-2 air-gap) | ±15 kV | ±15 kV | ±15 kV | ±15 kV |
| Number of Drivers / Receivers | 1 / 1 | 1 / 1 | 1 / 1 | 1 / 1 |
| External Capacitors Required | 4 × 0.1 µF | 4 × 0.1 µF | 4 × 0.1 µF | 4 × 0.1 µF |
| Auto-Powerdown | Yes | Yes | Yes | Yes |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
Bảo phân biệt quan trọng
- Single-channel VQFN-16 RGT footprint with on-chip auto-powerdown (vsMAX3232 (multi-channel SOIC-16 wide))
- 250 kbps data rate with same pinout as 1 Mbit/s variant (vsTRSF3221EIRGTR)
- Cross-vendor second source with identical electrical behavior (vsMAX3221EIRGTR (Analog Devices / Maxim))
Ghi chú thiết kế
Place the four 0.1 µF charge-pump capacitors (C1+, C1-, C2+, C2-) as close as physically possible to their respective pins on the TRS3221EIRGTR. Keep trace lengths below 5 mm and use 0.1 µF X7R or X5R ceramic capacitors rated for at least 16 V. Wide ground and VCC traces under the exposed thermal pad improve charge-pump stability and reduce radiated emissions from the switched-capacitor converter.
The RS-232 receiver input pins (RIN) tolerate up to ±25 V of input voltage, but the receiver output (ROUT/DIN) is TTL/CMOS logic referenced to VCC. If the host MCU runs at 1.8 V and the TRS3221EIRGTR runs at 3.3 V or 5 V, add a series resistor (10-100 kΩ) on ROUT/DIN to limit current during logic-level mismatch; the receiver outputs are push-pull CMOS and can source/sink several mA.
Do not substitute the four 0.1 µF charge-pump capacitors with electrolytic or tantalum types; the charge-pump switching frequency requires low-ESR ceramic capacitors to maintain regulation. Ensure the exposed thermal pad (EPAD, pin 16) is soldered to a properly grounded copper pour of at least 25 mm² for thermal dissipation and electrical reference; an unsoldered EPAD can cause the internal charge pump to misbehave and increase EMI.
Keep the RS-232 output traces (TDOUT) routed away from sensitive analog or high-speed digital signals. The TRS3221EIRGTR's charge pump operates at approximately 250 kHz, and its harmonics can couple into nearby analog circuitry. A ground guard trace between the RS-232 cable-side pins and the TTL/CMOS side pins, stitched with ground vias every 5 mm, suppresses common-mode coupling.
Estimated: at 5 V VCC with no RS-232 cable connected and auto-powerdown active, the part draws approximately 1 µA. With a 5 kΩ RS-232 load on TDOUT, the part draws approximately 20-30 mA peak from VCC due to the charge-pump efficiency loss and driver output current. Decouple VCC with a 0.1 µF ceramic capacitor in parallel with a 1 µF bulk ceramic placed within 10 mm of the VCC pin.
Thông tin tuân thủ
RoHS and REACH compliant per TI product page. Not AEC-Q100 qualified — choose TRS3221EI-Q1 suffix variant for automotive applications. Halogen-free status not explicitly stated in the provided data — verify with TI's full material declaration if required for your end-market.
