Product SPEC Product: PL-2303 Data Sheet for PL2303 USB-to-RS232 Bridge Features ¤ Full compliance with the USB Specification v1.1 ¤ Support the RS232 Serial interface ¤ Support automatic handshake mode ¤ Over 1Mbps transfer rate ¤ Support remote wake-up and power management ¤ Dual data buffers for upstream and downstream data flow ¤ Support default ROM or external EEPROM for device configuration ¤ On chip USB transceiver ¤ On chip crystal oscillator running at 12M Hz ¤ 28 Pins SSOP package SSOP 28 PACKAGE (TOP VIEW) TXD DTR_N RTS_N VDD_232 RXD RI_N GND VDD DSR_N DCD_N CTS_N SHTD_N EE_CLK EE_DATA 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 OSC2 27 OSC1 26 25 24 23 22 21 20 19 PLL_TEST GND_PLL VDD_PLL LD_MODE TRI_MODE GND VDD RESET 18 GND_3V3 17 VDD_3V3 16 DM 15 DP 00/03/27 Company Confidential 1/5; Rev 1.1 

Product SPEC Product: PL-2303 1. Introduction The PL-2303 operates as a bridge between one USB port and one standard RS232 Serial port. Figure 1 in the following page shows its interface and internal block diagram. The two large on-chip buffers accommodate the data flow from two different buses. The USB bulk-type data is adopted for maximum data transfer. Automatic handshake is supported at the Serial port. With these, a much higher baud rate can be achieved compared to the legacy UART controller. This device is also compliant with USB power management and remote wakeup scheme. Only minimum power is consumed from the host during suspend. By integrating all the functions into the SSOP-28 package, this chip is suitable for cable embedding. Users just simply hook the cable into PC or hub’s USB port, then they can connect to any RS-232 devices. 00/03/27 Company Confidential 2/5; Rev 1.1 

Product SPEC Product: PL-2303 USB Transceiver Control Unit USB SIE DOWN STREAM BUFFER CLOCK SYNTHESIZER OSCILLATOR REGISTER/ CONFIG/ STATUS/ CONTROL UP STREAM BUFFER RS-232 SERIAL INTERFACE EEPROM INTERFACE Serial Port I2C Bus USB Port 00/03/27 Company Confidential 3/5; Rev 1.1 

Product SPEC Product: PL-2303 Figure 1. USB-Serial Block Diagram 2. Pin Description I – Input signal O – Output signal I/O – Bi-directional signal I* – 5V TTL Schmitt Input signal O* – 3.3V tri-state output P – Power/Ground TXD Name Pin No. 1 2 DTR_N 3 RTS_N 4 VDD_232 RXD 5 RI_N 6 7 GND 8 VDD 9 DSR_N 10 DCD_N 11 CTS_N 12 SHTD_N 13 EE_CLK 14 EE_DATA 15 DP 16 DM 17 VDD_3V3 18 GND_3V3 19 RESET 20 VDD 21 GND 22 TRI_MODE 23 LD_MODE Table 1. Pins Description Type Description O* Data output to Serial port O* Data Terminal Ready,active low O* Request To Send, active low P RS-232 VDD. The RS-232 output signals(Pin 1 ~ Pin 3) are designed for 5V, 3.3V or 3V operation. VDD_232 should be connected to the same power level of the RS-232 interface. (The RS-232 input signals are always 5V~3V tolerant.) I* Data input from Serial Bus I* Ring Indicator, active low P Ground P Power I* Data Set Ready, active low I* Data Carrier Detect, active low I* Clear To Send, active low O Shut Down RS232 Transceiver I/O During Reset, this pin is input for simulation purpose. During normal operation, this pin is Serial ROM clock I/O Serial ROM data signal I/O USB DPLUS signal I/O USB DMINUS signal O 3.3V power output from internal voltage regulator 3.3V ground P System Reset I P Power P Ground I I RS232 tri-state output control during Suspend Load Mode. At reset, LD_MODE is used to decide if this is a heavy load or light load device. High: indicates this is a 500 mA device. Low: indicates this is a 100 mA device. 00/03/27 Company Confidential 4/5; Rev 1.1 

Product SPEC Product: PL-2303 24 VDD_PLL 25 GND_PLL 26 PLL_TEST 27 OSC1 28 OSC2 5V power for PLL P P Ground for PLL I PLL test mode control I Crystal oscillator input O Crystal oscillator output 00/03/27 Company Confidential 5/5; Rev 1.1