PCA9306DP-T NXP Semiconductors, PCA9306DP-T Datasheet - Page 12

• Manufacturer Part Number: PCA9306DP-T
• Manufacturer: NXP Semiconductors

Specifications of PCA9306DP-T

• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Package Type: TSSOP
• Pin Count: 8
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Compliant

NXP Semiconductors
PCA9306
Product data sheet
11.2.1.1 Example maximum frequency
Question — We need to make the PLL area of a new line card backwards compatible and
need to need to convert one GTL signal to LVTTL, invert it, and convert it back to GTL.
The signal we want to convert is random in nature but will mostly be around 19 MHz with
very long periods of inactivity where either a HIGH or LOW state will be maintained. The
traces are 1 or 2 inches long with trace capacitance of about 2 pF per inch.
Answer — The frequency of the PCA9306 is limited by the capacitance of the part, the
capacitance of the traces and the pull-up resistors used. The limiting case is probably the
LOW-to-HIGH transition in the GTL to LVTTL direction, and there the use of the lowest
acceptable resistor values will minimize the rise time delay. Assuming 50 pF capacitance
and 220 Ω resistance, the RC time constant is 11 ns (50 pF × 220 Ω). With 19 MHz
corresponding to 50 ns period the PCA9306 will support this application.
All information provided in this document is subject to legal disclaimers.
Rev. 6 — 25 November 2010
Dual bidirectional I
2
C-bus and SMBus voltage-level translator
PCA9306
© NXP B.V. 2010. All rights reserved.
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