ft232hq Future Technology Devices International Ltd., ft232hq Datasheet - Page 57

• Manufacturer Part Number: ft232hq
• Description: Ft232h Single Channel Hi- Speed Usb To Multipurpose Uart/fifo Ic
• Manufacturer: Future Technology Devices International Ltd.

6.3 Oscillator Configuration
Figure 6.4 Recommended FT232H Oscillator Configuration
Figure 6.4 illustrates how to connect the FT232H with a 12MHz ± 0.003% crystal. In this case loading
capacitors should to be added between OSCI, OSCO and GND as shown. A value of 27pF is shown as the
capacitor in the example – this will be good for many crystals but it is recommended to select the loading
capacitor value based on the manufacturer‟s recommendations wherever possible. It is recommended to
use a fundamental mode, parallel cut type crystal.
It is also possible to use a 12 MHz Oscillator with the FT232H. In this case the output of the oscillator
would drive OSCI, and OSCO should be left unconnected. The oscillator must have a CMOS output drive
capability.
Table 6.1 OSCI Input characteristics
Parameter
OSCI Vin
FIn
Ji
Cycle to cycle jitter
Input Frequency
Input Voltage
Copyright © 2011 Future Technology Devices International Limited
Description
FT232H SINGLE CHANNEL HI-SPEED USB TO MULTIPURPOSE UART/FIFO IC
Minimum
2.97
Typical
12MHz
<150
3.3V
Maximum
3.63
Document No.: FT_000288
Units
MHz
Clearance No.: FTDI #199
pS
V
Datasheet Version 1.0
Conditions
± 30ppm
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