XR21B1424IV64-F - 4-Ch FS USB UART Bridge, 64-LQFP | MaxLinear
Référence : XR21B1424IV64-F ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $13.6877 | $13,69 |
| 10 | $12.32 | $123,20 |
| 100 | $10.95 | $1 095,00 |
| 500 | $9.78 | $4 890,00 |
| 1 000 | $8.65 | $8 650,00 |
XR21B1424IV64-F Présentation
A USB-to-UART bridge is a mixed-signal interface IC that converts USB packet traffic from a host controller into asynchronous serial (start/stop/data bit) streams that legacy MCUs and peripherals understand. Within the system hierarchy, the XR21B1424 belongs to the class of USB interface bridges > peripheral controllers > interface ICs > integrated circuits. It eliminates the need for a dedicated USB-capable MCU on the peripheral side, allowing any MCU with a UART to gain a USB interface by simply connecting its serial lines to the bridge.
Key features include a 512-byte TX and 512-byte RX FIFO per channel (deep enough to sustain Full-Speed throughput without host-side flow-control stalls), hardware flow control (RTS/CTS and DTR/DSR), programmable baud rates, on-chip clock generator, power-on reset, low-power suspend mode, and wake-up signaling. Supply voltage is 3.0 V to 3.6 V or 4.4 V to 5.25 V (wide-range VBAT-tolerant I/O design for industrial and POS terminals). The 64-pin LQFP provides ample GPIO and is suitable for hand-solderable prototypes as well as volume SMT lines.
The XR21B1424 architecture pairs a USB 2.0 Full-Speed PHY + SIE with four enhanced 16550-compatible UART cores. Each UART supports data rates from 50 baud to 12 Mbaud (with asynchronous clock domain), 5/6/7/8-bit characters, and odd/even/mark/space/1/0 parity, and the FIFOs can be triggered at 1 to 128 bytes to minimize host interrupt overhead. The internal oscillator and PLL are trimmed for low jitter, allowing reliable communication over RS-232/RS-485 external transceivers without an external crystal.
Typical applications include industrial USB-to-RS-422/RS-485 adapters, point-of-sale (POS) terminals, multi-port serial expansion cards, factory-floor PLC debug ports, USB-to-serial fan-out hubs, and embedded systems that need multiple COM ports from a single USB connection. The 4-channel density is particularly attractive when a host needs to talk to several MCUs or sensors that only expose UART.
When designing with this device, ensure the USB DP/DM pair is routed as a 90-ohm differential pair and that the upstream UART lines are short and referenced to a clean ground. The internal EEPROM should be locked before firmware release if the Vendor/Product IDs are sensitive, and the suspend current budget must be respected for USB-IF compliance.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical layout notes that supplement the manufacturer datasheet with engineering-decision context.
Alternatives de remplacement direct pour XR21B1424IV64-F — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
XR21B1424IV64TR-F
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
XR21B1424IV64-F Spécifications
| Fonction | USB to UART Bridge |
| Number of UART Channels | 4 |
| USB Compliance | USB 2.0 Full-Speed (12 Mbps) |
| Supply Voltage (VCC) | 3.0 V to 3.6 V |
| I/O Tolerance (VBUS/VBAT) | 4.4 V to 5.25 V |
| TX FIFO per Channel | 512 bytes |
| RX FIFO per Channel | 512 bytes |
| Flow Control | Hardware (RTS/CTS, DTR/DSR) and Software (XON/XOFF) |
| USB Suspend / Wakeup | Supported (suspend, resume, remote wakeup) |
| On-chip Clock | Internal oscillator + PLL (no external crystal required) |
| Programmable USB IDs | Vendor ID, Product ID, power mode stored in internal EEPROM |
| Boîtier | 64-pin LQFP (10x10 mm) |
| Type de montage | Surface Mount |
| Température de fonctionnement | -40C to +85C (industrial) |
| Statut RoHS | Compliant |
| Niveau MSL | 3 (168 hours) |
Configuration des broches de XR21B1424IV64-F
| Broche 1 | VBUS — USB VBUS sense input (4.4 V to 5.25 V tolerant) |
| Broche 2 | DP — USB D+ differential data line |
| Broche 3 | DM — USB D- differential data line |
| Broche 4 | GND — Ground reference for USB PHY |
| Broche 5 | VCC — 3.3 V core supply |
| Broche 6 | RESET — Active-low device reset |
| Broche 7 | TEST — Factory test pin (tie to GND in normal operation) |
| Broche 8 | GPIO0 — General-purpose I/O 0 |
| Broche 9 | GPIO1 — General-purpose I/O 1 |
| Broche 10 | CH1_DTR — Channel 1 UART DTR output |
| Broche 11 | CH1_DSR — Channel 1 UART DSR input |
| Broche 12 | CH1_RTS — Channel 1 UART RTS output |
| Broche 13 | CH1_CTS — Channel 1 UART CTS input |
| Broche 14 | CH1_TX — Channel 1 UART transmit output |
| Broche 15 | CH1_RX — Channel 1 UART receive input |
| Broche 16 | GND — Ground |
| Broche 17 | VCC — 3.3 V supply |
| Broche 18 | CH2_DTR — Channel 2 UART DTR output |
| Broche 19 | CH2_DSR — Channel 2 UART DSR input |
| Broche 20 | CH2_RTS — Channel 2 UART RTS output |
| Broche 21 | CH2_CTS — Channel 2 UART CTS input |
| Broche 22 | CH2_TX — Channel 2 UART transmit output |
| Broche 23 | CH2_RX — Channel 2 UART receive input |
| Broche 24 | GND — Ground |
| Broche 25 | CH3_DTR — Channel 3 UART DTR output |
| Broche 26 | CH3_DSR — Channel 3 UART DSR input |
| Broche 27 | CH3_RTS — Channel 3 UART RTS output |
| Broche 28 | CH3_CTS — Channel 3 UART CTS input |
| Broche 29 | CH3_TX — Channel 3 UART transmit output |
| Broche 30 | CH3_RX — Channel 3 UART receive input |
| Broche 31 | VCC — 3.3 V supply |
| Broche 32 | GND — Ground |
| Broche 33 | CH4_DTR — Channel 4 UART DTR output |
| Broche 34 | CH4_DSR — Channel 4 UART DSR input |
| Broche 35 | CH4_RTS — Channel 4 UART RTS output |
| Broche 36 | CH4_CTS — Channel 4 UART CTS input |
| Broche 37 | CH4_TX — Channel 4 UART transmit output |
| Broche 38 | CH4_RX — Channel 4 UART receive input |
| Broche 39 | GND — Ground |
| Broche 40 | NC — Not connected (per datasheet) |
| Broche 41 | NC — Not connected (per datasheet) |
| Broche 42 | NC — Not connected (per datasheet) |
| Broche 43 | GPIO2 — General-purpose I/O 2 |
| Broche 44 | GPIO3 — General-purpose I/O 3 |
| Broche 45 | GPIO4 — General-purpose I/O 4 |
| Broche 46 | GPIO5 — General-purpose I/O 5 |
| Broche 47 | GPIO6 — General-purpose I/O 6 |
| Broche 48 | GPIO7 — General-purpose I/O 7 |
| Broche 49 | SUSPEND — USB suspend indicator output |
| Broche 50 | WAKE — USB remote wakeup input |
| Broche 51 | EE_CS — Internal EEPROM chip-select (internal use) |
| Broche 52 | EE_SK — Internal EEPROM serial clock (internal use) |
| Broche 53 | EE_DI — Internal EEPROM data in (internal use) |
| Broche 54 | EE_DO — Internal EEPROM data out (internal use) |
| Broche 55 | VCC — 3.3 V supply |
| Broche 56 | GND — Ground |
| Broche 57 | NC — Not connected (per datasheet) |
| Broche 58 | NC — Not connected (per datasheet) |
| Broche 59 | NC — Not connected (per datasheet) |
| Broche 60 | NC — Not connected (per datasheet) |
| Broche 61 | NC — Not connected (per datasheet) |
| Broche 62 | NC — Not connected (per datasheet) |
| Broche 63 | NC — Not connected (per datasheet) |
| Broche 64 | NC — Not connected (per datasheet) |
Applications typiques
XR21B1424IV64-F convient pour 6 applications: Industrial USB-to-RS-485 Multi-Drop Adapter, Point-of-Sale (POS) Terminal Multi-Port Hub, Multi-Port Serial Expansion Card (PCIe/USB Host Side), PLC and Factory Automation Debug Port, USB-to-Serial Fan-Out for Embedded Sensor Hubs, USB Dongle with Multiple COM Ports for Service Engineers.
Industrial USB-to-RS-485 Multi-Drop Adapter
The XR21B1424IV64-F fits industrial USB-to-RS-485 fan-out adapters because it exposes 4 independent UART channels from a single USB port, each with a 512-byte TX/RX FIFO that sustains sustained 12 Mbps Full-Speed USB traffic without host-side flow-control stalls. The 4.4 V to 5.25 V VBAT-tolerant I/O lets each UART pair drive an external 5 V transceiver (such as MAX485 or ISL3179) directly without level shifters. Hardware RTS/CTS flow control is essential for half-duplex RS-485 bus direction switching at high baud rates, and the on-chip clock generator eliminates the external crystal that competitors typically require, reducing BOM cost. Operating temperature of -40C to +85C supports factory-floor deployments.
Recommandé
Point-of-Sale (POS) Terminal Multi-Port Hub
In POS terminals, the XR21B1424IV64-F exposes 4 UART channels that can simultaneously drive a magnetic-stripe reader, a receipt printer, a barcode scanner, and a customer-display panel from one USB upstream port. The USB suspend and remote-wakeup features keep the terminal compliant with USB-IF standby-power budgets when the POS is idle, and the programmable Vendor/Product IDs in internal EEPROM let OEM brands re-label the device without external EEPROM chips. Hardware flow control (RTS/CTS) handles bursty scanner/printer traffic without character loss. The 64-LQFP package is hand-solderable for low-volume terminal prototypes.
Recommandé
Multi-Port Serial Expansion Card (PCIe/USB Host Side)
Adding 4 COM ports to an embedded SBC or mini-PC is straightforward with the XR21B1424IV64-F: a single USB upstream delivers 4 UART channels to the host OS, and each channel enumerates as a distinct /dev/ttyACMx device on Linux. The 512-byte FIFOs absorb burst traffic from modems or sensors, and the 4-channel density keeps the per-port cost low compared to stacking single-channel bridges. The internal oscillator + PLL saves board space versus FTDI-class parts that need a 12 MHz crystal. The part is pin-compatible in footprint with the XR21B1424IV64TR-F for volume migration.
Recommandé
PLC and Factory Automation Debug Port
The XR21B1424IV64-F serves as a multi-channel debug bridge for PLCs and factory automation controllers, giving engineers simultaneous visibility over multiple UART-based subsystems (motor drivers, sensor hubs, HMI panels) from a single USB connection to a service laptop. The -40C to +85C industrial temperature rating matches cabinet environments, and the wide 4.4 V to 5.25 V VBAT tolerance lets the bridge be powered from the PLC's 5 V rail. USB suspend and remote wakeup are useful for unattended cabinets that power down between service visits. The internal EEPROM allows OEM-specific VID/PID for plug-and-play driver binding on Windows and Linux.
Recommandé
USB-to-Serial Fan-Out for Embedded Sensor Hubs
Sensor hubs that aggregate data from multiple UART-only sensor modules (GPS, IMU, environmental sensors) benefit from the XR21B1424IV64-F's 4-channel density. Each UART channel can be clocked independently at up to several Mbaud, supporting GPS modules at 115200 baud while a higher-speed IMU streams at 921600 baud concurrently. Hardware flow control prevents FIFO overflow on the RX side, and the 512-byte FIFOs per channel give headroom for OS latency. The 3.0 V to 3.6 V VCC range matches typical 3.3 V sensor rails, simplifying power architecture. The internal clock avoids routing an extra crystal trace near sensitive analog sensors.
Recommandé
USB Dongle with Multiple COM Ports for Service Engineers
Field-service engineers often need to talk to several pieces of equipment simultaneously (a controller, a sensor, and a modem), and a USB dongle based on the XR21B1424IV64-F provides exactly that - one USB plug, four COM ports. The compact 10x10 mm 64-LQFP footprint fits in a small dongle enclosure, and the on-chip oscillator eliminates the crystal that would otherwise constrain enclosure height. Programmable VID/PID via internal EEPROM lets the OEM brand the dongle and bind drivers without external EEPROM. The industrial temperature rating ensures the dongle works in cold outdoor cabinets and hot machinery rooms.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour XR21B1424IV64-F — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | XR21B1424IV64TR-F | XR21B1422IL40-F |
|---|---|---|---|
| Package | LQFP-64 (10x10 mm) | LQFP-64 (10x10 mm) - same | QFN-40 (6x6 mm) - smaller, requires re-layout |
| Brand | MaxLinear | MaxLinear (same) | MaxLinear (same) |
| Number of UART Channels | 4 | 4 | 2 |
| USB Compliance | USB 2.0 Full-Speed (12 Mbps) | USB 2.0 Full-Speed (12 Mbps) | USB 2.0 Full-Speed (12 Mbps) |
| Supply Voltage (VCC) | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V |
| VBAT/VBUS I/O Tolerance | 4.4 V to 5.25 V | 4.4 V to 5.25 V | 4.4 V to 5.25 V |
| FIFO per Channel (TX/RX) | 512 / 512 bytes | 512 / 512 bytes | 512 / 512 bytes |
| External Crystal Required | No (internal oscillator + PLL) | No | No |
| Programmable USB VID/PID | Yes (internal EEPROM) | Yes (internal EEPROM) | Yes (internal EEPROM) |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C |
| Packaging Format | Tray | Tape & Reel | Tray |
Principaux différenciateurs
- 4 UART channels in a single 64-LQFP, with on-chip oscillator (vs FTDI FT4232H (cross-brand Hi-Speed alternative))
- Same-die drop-in availability via tape-and-reel (vs XR21B1424IV64TR-F)
- Wide VBAT/VBUS tolerance (4.4 V to 5.25 V) on UART pins (vs XR21B1422IL40-F)
Notes de conception
Route the USB DP/DM pair as a 90-ohm differential pair with controlled impedance, keeping the pair length-matched within 150 mil. Place the ESD protection array (such as USBLC6-2SC6) within 3 mm of the USB connector pins. Decouple VCC with a 0.1 uF ceramic close to each VCC pin and a bulk 4.7 uF tantalum near the regulator. The internal clock eliminates the crystal but the PCB still benefits from a grounded guard ring around the DP/DM traces to minimize EMI.
Each UART channel has 6 signals (TX/RX/RTS/CTS/DTR/DSR); route these as short traces (under 50 mm) and keep them away from switching DC-DC nodes to preserve signal integrity at high baud rates. If routing to an external RS-485 transceiver on a different board, add series termination resistors (22-33 ohm) close to the UART pins to damp reflections. The GPIO pins can be used for flow-control or activity LEDs - if used as LEDs, place a 470 ohm resistor in series to limit current.
Do not skip the RESET pull-up or leave the TEST pin floating - tie TEST to GND per the datasheet. The internal EEPROM stores VID/PID and must be locked via the vendor utility before firmware release if brand identity matters. Suspend current budget must be measured under the actual OS (Windows/Linux/macOS enumerate differently); the part is rated for low-power suspend but PCB leakage through ESD diodes can invalidate the budget. When migrating between IV64-F and IV64TR-F, ensure the pick-and-place footprint handles the tray vs tape-and-reel packaging difference.
Estimated: at 921600 baud with 8-N-1, each bit is about 1.085 us. With 512-byte FIFOs, the bridge can absorb ~5.5 ms of host latency before back-pressuring. For RS-485 half-duplex, ensure RTS-to-data turn-around time is configured to at least 1 bit time so the transceiver fully releases the bus before the reply begins. Add 100 ohm termination at each end of long RS-485 cable runs to suppress reflection.
Informations de conformité
RoHS and lead-free compliance per MaxLinear product page. Not AEC-Q100 qualified (industrial temperature grade only). Halogen-free status not explicitly stated in retrieved data.
