PL2303

The PL-2303 operates as a bridge between one USB port and one standard RS232 Serial port.The two large on-chip buffers accommodate 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.

Features of the PL-2303 are:(1)full compliance with the USB Specification v1.1 and USB CDC v1.1 support the RS232 serial interface; (2)support automatic handshake mode; (3)support remote wake-up and power management; (4)256 bytes buffer each for upstream and downstream data flow; (5)support default ROM or external EEPROM for device configuration on chip USB transceiver; (6)on chip crystal oscillator running at 12M Hz; (7)supports windows 98/SE, ME, 2000, XP, windows CE3.0, CE .NET, Linux, and Mac OS; (8)28 pins SOIC package.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 function in a SOIC-28 package, this chip is suitable for cable embedding. Users just simply hook the cable into PC or hub's USB port, and then they can connect to any RS-232 devices.

The absolute maximum ratings of the PL-2303 can be summarized as:(1)power supply voltage:-0.3 to 6.0V;(2)storage temperature range:-55 to 150;(3)output voltage:-0.3 to Vdd+0.3V;(4)input voltage:-0.3 to Vdd+0.3V.PL-2303 allows storing the configuration data in an external EEPROM. After reset, the first two bytes of EEPROM are checked. If the value is 067Bh, the EEPROM is valid and the contents of the EEPROM are loaded as the chip's default parameters. Otherwise, the chip's default setting is used. The content of EEPROM is shown in Table 4 below.When the EEPROM is programmed, these two bytes is configured as 067B.After reset, they will be checked for the value. If matched, the following information of PL-2303  will be loaded as the default parameters.