FT4222HQ-R - USB 2.0 to Quad SPI/I2C Bridge | FTDI | 32-VQFN
MPN: FT4222HQ-R ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.92 | $5.92 |
| 10 | $5.45 | $54.50 |
| 100 | $4.95 | $495.00 |
| 500 | $4.55 | $2,275.00 |
| 1,000 | $4.2 | $4,200.00 |
FT4222HQ-R Overview
A USB Bridge IC is a category of interface controller that translates USB transactions into serial protocols such as UART, SPI, I2C, or GPIO so that a host PC or embedded processor can communicate with downstream devices using only USB. The FT4222H family fits the USB-to-SPI/I2C sub-segment of this hierarchy, and within the FTDI portfolio sits alongside the FT232H (USB-to-UART/SPI/FIFO) and FT260 (USB-to-I2C) parts.
Key features include multi-voltage I/O support at 3.3 V, 2.5 V, or 1.8 V, four configurable GPIO pins with adjustable drive strength and slew rate, and 128 bytes of one-time-programmable (OTP) memory for storing vendor-specific configuration via the FT_PROG utility. The internal PLL derives all required clocks from an external 12 MHz crystal, so no external clock generator is needed.
The FT4222HQ-R uses FTDI's established USB protocol stack, freeing the host from writing low-level USB firmware: the on-chip hardware handles enumeration, descriptors, and bulk/isochronous transfers automatically. The device presents as a vendor-specific USB class, and FTDI provides royalty-free D2XX and LibFT4222 host drivers for Windows, macOS, and Linux. Compared with discrete USB microcontrollers, the FT4222H approach eliminates firmware development, regulatory USB compliance work, and the need for a HID or vendor-class driver on the host side.
Typical applications include USB-to-SPI bridges for touch-screen controllers and display panels, USB-to-I2C bridges for EEPROM programming and sensor hubs, USB-controlled GPIO expansion for industrial test fixtures, prototyping interfaces for FPGA configuration flash, and USB DAQ front-ends that stream SPI ADC samples to a host PC at high speed. Designers typically choose the FT4222HQ-R when they need a drop-in, driver-supported USB interface without writing embedded firmware.
When designing with the FT4222HQ-R, pay close attention to PCB layout: keep the 12 MHz crystal traces short and symmetric, place the bulk USB VBUS capacitor close to the VCC pin, and provide a solid ground plane beneath the exposed thermal pad to meet USB-IF radiated-emissions requirements. The VIO rail must be sequenced after the 3.3 V core supply to avoid latch-up on the multi-voltage I/O banks; FTDI's reference schematic shows a simple RC delay from VCC to VIO for this purpose.
This page synthesizes distributor pricing, pin-compatible alternatives, and practical design notes that are not aggregated on a single manufacturer or distributor page.
Drop-in alternatives for FT4222HQ-R — 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 FT4222HQ-R (same form factor and footprint) — differing in Function, OTP Memory, Package, USB Speed.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
FT4222HQ-D-R
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →FT4222HQ-T
✅ Drop-In📋 Reference alternative (not in catalog)
FT4222HQ-C-T
✅ Drop-In📋 Reference alternative (not in catalog)
FT4222H-32QFN
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
FT4222HQ
✅ Drop-In📋 Reference alternative (not in catalog)
FT4222HQ-R Specifications
| Function | USB 2.0 to Quad SPI / I2C Bridge |
| USB Speed | High-Speed (480 Mbps) / Full-Speed (12 Mbps) |
| SPI Modes | Single, Dual, Quad SPI |
| Maximum SPI Data Rate | 53.8 Mbps |
| I2C Support | Yes (master) |
| GPIO Pins | 4 (configurable drive strength and slew rate) |
| I/O Voltage | 3.3 V / 2.5 V / 1.8 V selectable |
| Core Supply Voltage | 3.3 V |
| External Crystal Frequency | 12 MHz |
| OTP Memory | 128 bytes |
| Package | VQFN-32 (5 x 5 mm, 0.5 mm pitch, exposed pad) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C |
| RoHS Status | Compliant |
FT4222HQ-R Pin Configuration
| Pin 1 | VCC — 3.3 V core supply |
| Pin 2 | GND — Ground |
| Pin 3 | VBUS — USB VBUS sense (5 V input) |
| Pin 4 | D- — USB D- differential data line |
| Pin 5 | D+ — USB D+ differential data line |
| Pin 6 | RESET — Active-low reset input |
| Pin 7 | XTIN — 12 MHz crystal input |
| Pin 8 | XTOUT — 12 MHz crystal output |
| Pin 9 | VIO — I/O supply voltage (1.8/2.5/3.3 V) |
| Pin 10 | GPIO0 — Configurable GPIO 0 |
| Pin 11 | GPIO1 — Configurable GPIO 1 |
| Pin 12 | GPIO2 — Configurable GPIO 2 |
| Pin 13 | GPIO3 — Configurable GPIO 3 |
| Pin 14 | SS0 — SPI slave select 0 (active low) |
| Pin 15 | SS1 — SPI slave select 1 (active low) |
| Pin 16 | SS2 — SPI slave select 2 (active low) |
| Pin 17 | SS3 — SPI slave select 3 (active low) |
| Pin 18 | SCLK — SPI serial clock output |
| Pin 19 | MISO — SPI master-in slave-out (IO1 in Quad mode) |
| Pin 20 | MOSI — SPI master-out slave-in (IO0 in Quad mode) |
| Pin 21 | IO2 — SPI Quad-mode IO2 / WP# |
| Pin 22 | IO3 — SPI Quad-mode IO3 / HOLD# |
| Pin 23 | SCL — I2C serial clock (open-drain) |
| Pin 24 | SDA — I2C serial data (open-drain) |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | NC — Not connected (per datasheet) |
| Pin 27 | TEST — Test pin - leave floating or ground per datasheet |
| Pin 28 | NC — Not connected (per datasheet) |
| Pin 29 | NC — Not connected (per datasheet) |
| Pin 30 | NC — Not connected (per datasheet) |
| Pin 31 | NC — Not connected (per datasheet) |
| Pin 32 | EP — Exposed thermal pad - connect to GND |
Typical Applications
FT4222HQ-R is suitable for 6 applications: USB-to-Quad-SPI Flash Programmer, USB-to-I2C Sensor Hub Bridge, Industrial Test & Measurement Fixture, FPGA Configuration & Debug Interface, USB Touch-Screen Controller Interface, USB Audio DAC / SPDIF Interface Bridge.
USB-to-Quad-SPI Flash Programmer
The FT4222HQ-R bridges a host PC's USB 2.0 High-Speed port to a Quad-SPI NOR flash for in-system programming at up to 53.8 Mbps. Its quad-mode IO2/IO3 pins and 4 chip-select lines (SS0-SS3) support multi-slave flash arrays, while the FTDI LibFT4222 host library eliminates the need for custom USB firmware. Compared with bit-banged USB-to-SPI MCUs, the FT4222HQ-R delivers 5-10x faster Quad-SPI write throughput.
Recommended
USB-to-I2C Sensor Hub Bridge
For multi-sensor I2C hubs (temperature, pressure, IMU) the FT4222HQ-R provides a transparent USB-to-I2C master path with FTDI's standard D2XX drivers across Windows, macOS, and Linux. The 3.3/2.5/1.8 V selectable VIO rail interfaces directly with modern low-voltage sensors without level shifters. Its 4 GPIOs can serve as interrupt or enable lines, reducing external logic in compact sensor pods and environmental monitoring modules.
Recommended
Industrial Test & Measurement Fixture
Test fixtures for production-line validation benefit from the FT4222HQ-R's combination of USB-to-SPI for ADC/DAC control, USB-to-I2C for EEPROM verification, and 4 configurable GPIOs for pass/fail signaling. The -40C to +85C industrial temperature rating supports factory-floor deployment, while FTDI's royalty-free host drivers integrate directly with National Instruments LabVIEW and Python testbench scripts. Throughput matches bench multimeters and LCR meters in production ATE racks.
Recommended
FPGA Configuration & Debug Interface
Engineers use the FT4222HQ-R to load FPGA bitstreams over USB-to-SPI for in-field firmware updates on Xilinx Spartan-7, Artix-7, and similar SPI-configured FPGAs. Quad-SPI mode reduces configuration time by up to 4x versus single-SPI, critical for boot-time-constrained applications. The same device then serves as a runtime SPI debug port for register access without adding a second USB bridge to the BOM.
Recommended
USB Touch-Screen Controller Interface
Touch-screen controllers using SPI or I2C (such as those in industrial HMIs and medical displays) connect directly to the FT4222HQ-R over USB. The bridge's 53.8 Mbps Quad-SPI bandwidth easily handles 1000 Hz touch-report streams with sub-millisecond latency. Multi-voltage I/O at 1.8/2.5/3.3 V matches common touch-IC supply rails, eliminating external level shifters on the HMI PCB.
Recommended
USB Audio DAC / SPDIF Interface Bridge
Audiophile USB-to-S/PDIF or USB-to-I2S bridges can use the FT4222HQ-R to feed a downstream DAC chipset at high speed, taking advantage of FTDI's asynchronous USB protocol stack for low-jitter isochronous transfers. The 128-byte OTP memory stores vendor-specific USB descriptors so the bridge enumerates with custom device names without external EEPROM. Engineers pair it with PCM51xx or ES90xx DACs in headphone amplifier and digital audio source designs.
Recommended
Recommended Products Summary
Engineering reference data for FT4222HQ-R — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | FT4222HQ-D-R | FT4222HQ-T | FT4222HQ-C-T | FT4222H-32QFN | FT4222HQ |
|---|---|---|---|---|---|---|
| Package | VQFN-32 (5 x 5 mm) | VQFN-32 (5 x 5 mm) - same | VQFN-32 (5 x 5 mm) - same | VQFN-32 (5 x 5 mm) - same | VQFN-32 (5 x 5 mm) - same | VQFN-32 (5 x 5 mm) - same |
| Brand | FTDI | FTDI | FTDI | FTDI | FTDI | FTDI |
| USB Speed | High-Speed 480 Mbps | High-Speed 480 Mbps | High-Speed 480 Mbps | High-Speed 480 Mbps | High-Speed 480 Mbps | High-Speed 480 Mbps |
| SPI Max Data Rate | 53.8 Mbps (Quad-SPI) | 53.8 Mbps (Quad-SPI) | 53.8 Mbps (Quad-SPI) | 53.8 Mbps (Quad-SPI) | 53.8 Mbps (Quad-SPI) | 53.8 Mbps (Quad-SPI) |
| I2C Support | Yes (master) | Yes (master) | Yes (master) | Yes (master) | Yes (master) | Yes (master) |
| GPIO Pins | 4 | 4 | 4 | 4 | 4 | 4 |
| I/O Voltage | 3.3/2.5/1.8 V | 3.3/2.5/1.8 V | 3.3/2.5/1.8 V | 3.3/2.5/1.8 V | 3.3/2.5/1.8 V | 3.3/2.5/1.8 V |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Packaging Suffix | -R (Tape & Reel) | -D-R (distributor reel) | -T (alt T&R) | -C-T (commercial T&R) | no suffix | no suffix (tray) |
Key Differentiators
- True Quad-SPI throughput at 53.8 Mbps in a QFN-32 (vs FT260Q)
- Multi-voltage I/O without external level shifters (vs CP2112 (Silicon Labs))
- Royalty-free D2XX and LibFT4222 host drivers (vs Generic USB microcontrollers (e.g., PIC18F4550))
- 128-byte OTP for vendor USB descriptors (vs FT232H)
Design Notes
Place the 12 MHz crystal within 5 mm of the FT4222HQ-R XTIN/XTOUT pins with symmetric trace lengths and a guard ring tied to ground. Use a crystal with 20 pF load capacitance and follow FTDI's reference layout for the VQFN-32 exposed pad - it must be soldered to a ground plane with at least 8 thermal vias (0.3 mm drill) for USB-IF radiated-emissions compliance. Keep the USB D+/D- differential pair matched to 90 ohm impedance and free of stubs.
Sequence VIO after VCC to avoid latch-up on the multi-voltage I/O banks. The FTDI reference schematic uses an RC delay (10 kohm + 1 uF) from VCC to VIO, providing a 10 ms power-on lag. Place 100 nF decoupling capacitors as close as possible to each VCC and VIO pin, plus a 4.7 uF bulk capacitor on VBUS. The internal PLL draws brief inrush current during USB enumeration; budget at least 100 mA headroom on the 3.3 V rail.
Do not omit the 12 MHz crystal or substitute a clock signal - the FT4222HQ-R's internal PLL requires a true crystal reference per the datasheet, and external clock injection is not supported. Always pull RESET high through a 10 kohm resistor; leaving it floating can cause intermittent enumeration failures. The TEST pin must be left floating or grounded per datasheet, not driven externally. For USB-IF compliance, add common-mode chokes on D+/D- and a ferrite bead on VBUS.
For Quad-SPI runs above 30 MHz, keep the SCLK, MOSI/MISO, and IO2/IO3 traces length-matched within 5 mm. Add 33 ohm series-termination resistors at the FT4222HQ-R output pins when the SPI bus length exceeds 50 mm or when driving multiple loads. The 4 SS (slave-select) lines are push-pull CMOS outputs and do not require pull-ups; however, I2C SCL/SDA must have external pull-ups (typically 2.2 kohm to VIO) since the FT4222HQ-R uses open-drain drivers on the I2C bus.
Compliance Information
RoHS and REACH compliant per FTDI product page. Industrial grade (-40C to +85C), not AEC-Q100 qualified for automotive applications.
