USB-to-serial UART interface IC in an SSOP-28 package, with integrated clock generation, EEPROM, USB termination, and configurable CBUS I/O, so it needs no external crystal or EEPROM. It bridges a host USB 2.0 full-speed port to a TTL UART at 300 baud to 3 Mbaud, with 128-byte RX and 256-byte TX FIFOs and bus- or self-powered operation. An on-chip 3.3 V level converter drives the UART I/O at 1.8-5 V. The classic no-fuss programmer/console adapter.

Pinout

Pin	Name	Type	Function
1	TXD	output	Transmit Asynchronous Data Output (UART TXD).
2	DTR#	output	Data Terminal Ready control output / handshake signal (active low).
3	RTS#	output	Request To Send control output / handshake signal (active low).
4	VCCIO	power_in	+1.8V to +5.25V supply for the UART interface and CBUS group pins. Connect to 3V3OUT for +3.3V CMOS drive, to VCC for +5V CMOS drive, or to an external +1.8V–+2.8V rail for lower-level drive.
5	RXD	input	Receiving Asynchronous Data Input (UART RXD).
6	RI#	input	Ring Indicator control input (active low). When remote wake-up is enabled in the EEPROM, a 20 ms active-low pulse can resume the PC USB host from suspend.
7	GND	power_in	Device digital ground supply pin.
8	NC	unconnected	No internal connection. Leave unconnected.
9	DSR#	input	Data Set Ready control input / handshake signal (active low).
10	DCD#	input	Data Carrier Detect control input (active low).
11	CTS#	input	Clear To Send control input / handshake signal (active low).
12	CBUS4	bidirectional	Configurable CBUS output-only pin. Function is set in the internal EEPROM. Factory default is SLEEP#. See CBUS Signal Options (Table 3.9).
13	CBUS2	bidirectional	Configurable CBUS I/O pin. Function set in internal EEPROM. Factory default is TXDEN. See CBUS Signal Options (Table 3.9).
14	CBUS3	bidirectional	Configurable CBUS I/O pin. Function set in internal EEPROM. Factory default is PWREN# (use with a 10kΩ pull-up resistor). See CBUS Signal Options (Table 3.9).
15	USBDP	bidirectional	USB Data Signal Plus (D+). Incorporates internal series resistor and 1.5kΩ pull-up resistor to +3.3V (from 3V3OUT).
16	USBDM	bidirectional	USB Data Signal Minus (D-). Incorporates internal series resistor.
17	3V3OUT	power_out	+3.3V output from the integrated LDO regulator. Decouple with a 100 nF capacitor to ground. Supplies the internal USB transceiver and 1.5kΩ pull-up on USBDP. Up to 50 mA available to power external logic or supply VCCIO.
18	GND	power_in	Device digital ground supply pin.
19	RESET#	input	Active-low reset input. Can be driven by an external device to reset the FT232R. If not required, leave unconnected or pull up to VCC.
20	VCC	power_in	+3.3V to +5.25V supply to the device core. Minimum +4.0V (or VBUS=+5V) when using the internal clock; operation at +3.3V requires an external crystal oscillator.
21	GND	power_in	Device digital ground supply pin.
22	CBUS1	bidirectional	Configurable CBUS I/O pin. Function set in internal EEPROM. Factory default is RXLED#. See CBUS Signal Options (Table 3.9).
23	CBUS0	bidirectional	Configurable CBUS I/O pin. Function set in internal EEPROM. Factory default is TXLED#. See CBUS Signal Options (Table 3.9).
24	NC	unconnected	No internal connection. Leave unconnected.
25	AGND	power_in	Analog ground supply for the internal clock multiplier.
26	TEST	input	Puts the device into IC test mode. Must be tied to GND for normal operation, otherwise the device will appear to fail.
27	OSCI	input	Input for the 12 MHz oscillator cell. Optional — can be left unconnected when using the internal oscillator.
28	OSCO	output	Output from the 12 MHz oscillator cell. Optional — can be left unconnected when using the internal oscillator.

Key specifications

Parameter	Value
Type	USB 2.0 full-speed to UART bridge
Data rate	300 baud to 3 Mbaud
Integrated	Clock generation, EEPROM, USB termination
CBUS I/O	5 configurable pins
FIFO	128 B RX / 256 B TX
I/O drive	1.8-5 V CMOS (on-chip 3.3 V converter)
Power	Bus- or self-powered
Package	SSOP-28
Body (L×W×H)	10.2 × 5.3 × 1.75 mm

Ordering variants

Same part, different packaging or reel option.

FT232RL-REEL (SSOP-28, tape & reel)

CAD (KiCad official)

Symbol: Interface_USB:FT232RL
Footprint: Package_SO:SSOP-28_5.3x10.2mm_P0.65mm
3D model: SSOP-28 (KiCad packages3D)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: FTDI datasheet (43 pp, sha256 0f4e94f51a392d25, retrieved 2026-08-17, tier: cse)
Extractor: ds2sf (Claude) — every pin and dimension is cited to a datasheet page; refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF