Datasheet
  Copyright © 2011 Future Technology Devices International Limited  18 
Document Reference No.: FT_000204 
DB9-USB Datasheet 
Version 2.1 
Clearance No.: FTDI# 130 
5  Electrical details 
5.1  USB 
Parameter 
Description 
Minimum 
Typical 
Maximum 
Units 
Conditions 
USB_VCC 
Input Power Voltage* 
4.25 
5.0* 
5.25 
V 
*Present when USB 
cable is attached and 
USB Host or Hub 
powered. 
Icc 
USB current 
30 
50 
mA 
Table 5.1 – USB Electrical Details 
5.2  RS232 Level UART 
Parameter 
Description 
Minimum 
Typical 
Maximum 
Units 
Conditions 
Vtrans 
Transmitter output 
voltage swing 
± 5 
V 
RL = 3KΩ 
Vrec 
Receiver input voltage 
range 
±2.4 
±25 
V 
Input resistance = 3KΩ 
to 7KΩ 
ESD HBM 
±15 
KV 
RS-232 Inputs and 
Outputs 
Table 5.2 – RS232 Electrical Details 
5.3  3.3V Level UART 
Parameter 
Description 
Minimum 
Typical 
Maximum 
Units 
Conditions 
Voh 
Output Voltage High 
2.2 
2.7 
3.2 
V 
I source = 1mA 
Vol 
Output Voltage Low 
0.3 
0.4 
0.5 
V 
I sink = 2mA 
Vin 
Input Switching 
Threshold 
1.0 
1.2 
1.5 
V 
** 
Table 5.3 – 3.3V Level UART Electrical Details 
5.4  5V Level UART 
Parameter 
Description 
Minimum 
Typical 
Maximum 
Units 
Conditions 
Voh 
Output Voltage High 
3.2 
4.1 
4.9 
V 
I source = 2mA 
Vol 
Output Voltage Low 
0.3 
0.4 
0.6 
V 
I sink = 2mA 
Vin 
Input Switching 
Threshold 
1.0 
1.2 
1.5 
V 
** 
Table 5.4 – 5V Level UART Electrical Details 










