Datasheet

Copyright © 2010 Future Technology Devices International Limited 21
Document No.: FT_000052
FT245R USB FIFO IC Datasheet Version 2.12
Clearance No.: FTDI# 39
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
UDrvZ
Driver Output
Impedance
26
29
44
Ohms
See Note 1
Table 5.12 USB I/O Pin (USBDP, USBDM) Characteristics
Note 1: Driver output impedance includes the internal USB series termination resistors on USBDP and
USBDM pins
6.1 EEPROM Reliability Characteristics
The internal 1024 Bit EEPROM has the following reliability characteristics:
Parameter
Value
Unit
Data Retention
10
Years
Read / Write Cycle
10,000
Cycles
Table 5.13 EEPROM Characteristics
6.2 Internal Clock Characteristics
The internal Clock Oscillator has the following characteristics:
Parameter
Value
Unit
Minimum
Typical
Maximum
Frequency of Operation
(see Note 1)
11.98
12.00
12.02
MHz
Clock Period
83.19
83.33
83.47
ns
Duty Cycle
45
50
55
%
Table 5.14 Internal Clock Characteristics
Note 1: Equivalent to +/-1667ppm
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
Voh
Output Voltage High
2.1
2.8
3.2
V
I source =
3mA
Vol
Output Voltage Low
0.3
0.4
0.6
V
I sink = 8mA
Vin
Input Switching Threshold
1.0
1.2
1.5
V
Table 5.15 OSCI, OSCO Pin Characteristics – see Note 1
Note1: When supplied, the FT245R is configured to use its internal clock oscillator. These characteristics
only apply when an external oscillator or crystal is used.