USB2512 datasheet(36/37 Pages) SMSC

36 / 37 page

USB 2.0 High-Speed 2-Port Hub Controller

Datasheet

SMSC USB2512

Revision 1.92 (11-28-07)

DATASHEET

Chapter 6 AC Specifications

6.1

Oscillator/Clock

Crystal: Parallel Resonant, Fundamental Mode, 24 MHz

±350ppm.

External Clock: 50% Duty cycle

± 10%, 24 MHz ± 350ppm, Jitter < 100ps rms.

Figure 6.1 Typical Crystal Circuit

Note: CB equals total board/trace capacitance.

Figure 6.2 Formula to find value of C1 and C2

6.1.1

SMBus Interface:

The SMSC Hub conforms to all voltage, power, and timing characteristics and specifications as set

forth in the SMBus 1.0 Specification for Slave-Only devices (except as noted in Section 4.3).

6.1.2

I2C EEPROM:

Frequency is fixed at 58.6KHz

± 20%.

6.1.3

USB 2.0

The SMSC Hub conforms to all voltage, power, and timing characteristics and specifications as set

forth in the USB 2.0 Specification. Please refer to the USB 2.0 Specification for more information.

XTAL1

(CS1 =

CB + CXTAL )

XTAL2

(CS2 =

CB + CXTAL )

1Meg

Crystal

(C1 + CS1) x (C2 + CS2)

(C1 + CS1 + C2 + CS2)

USB2512 Datasheet(PDF) 36 Page - SMSC Corporation