The DLPC34xx controller requires an external reference clock to feed the internal PLL. Use either a crystal or oscillator to supply this reference. The DLPC34xx reference clock must not exceed a frequency variation of ±200 ppm (including aging, temperature, and trim component variation).

Figure 10-2 shows the required discrete components when using a crystal.

C_L = Crystal load capacitance (farads)

C_L1 = 2 × (C_L – Cstray_pll_refclk_i)

C_L2 = 2 × (C_L – Cstray_pll_refclk_o)

where:

• Cstray_pll_refclk_i = Sum of package and PCB stray capacitance at the crystal pin associated with the controller pin pll_refclk_i.
• Cstray_pll_refclk_o = Sum of package and PCB stray capacitance at the crystal pin associated with the controller pin pll_refclk_o.

Figure 10-2 Required Discrete Components