Copyright © 2010 Future Technology Devices International Limited

21

Document No.: FT_000052

FT245R USB FIFO IC Datasheet Version 2.10

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.