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CRYSTAL REQUIREMENTS

Frequency

Frequency Tolerances

Load Capacitance

Mechanical Characteristics

Reflow Conditions

MicroStar BGA™/

Junior™

Recommended Lead Free Reflow Profile

In the case of Sn/Ag/Cu solder paste

MicroStar

Reflow temperature is defined at package top.

Time

Peak temperature

260°C max

30 – 60 s

90 ± 30 s

1–5

sec

(°C)

260

235

225

200

150

TUSB6020

USB 2.0 HIGH-SPEED ON-THE-GO DUAL-ROLE CONTROLLER

SCPS170C – JANUARY 2007 – REVISED JULY 2007

The required frequency of oscillation for the crystal can be 19.200, 24.000, or 48.000 MHz.

Frequency tolerance is the maximum allowable deviation from the nominal crystal frequency at a specified

temperature, usually 25

°C. The recommended frequency tolerance of the crystal over the manufacturing process

is

±50 ppm. The maximum acceptable frequency tolerance of the crystal over the manufacturing process is

±100 ppm.

NOTE

The total system frequency tolerance from the crystal, the load capacitors, the

capacitive load of the board, the capacitive load of the device pins, the variation over

temperature, the variation with age, and the circuitry of the PHY must be less than

±500 ppm. Consequently, the individual tolerance for the crystal must be ≤ ±100 ppm.

The oscillator of the USB device may have difficulty driving a large load capacitance, so crystals that specify

large load capacitances should be avoided. For more information on crystal requirements, see the following

application report from TI: Selection and Specification of Crystals for Texas Instruments USB 2.0 Devices

(literature number SLLA122).

The TUSB6020 controller uses an 80-pin MicroStar BGA™ package. The lead-free solder ball composition is

Sn/Ag1.2Cu0.5 (proportions by weight). The substrate plating on the die side where the die bonds to is NiAu.

The substrate finish on the bottom side where the solder balls attach to is bare Cu.

Figure 2. Reflow Conditons

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