Si52112-B3/B4

Rev 1.2

7

2. Crystal Recommendations

If using a crystal input, the device requires a parallel resonance crystal.

2.1. Crystal Loading

Crystal loading is critical in achieving low ppm performance. To realize low ppm performance, use the total

Figure 1 shows a typical crystal configuration using two trim capacitors. It is important that the trim capacitors are in

series with the crystal.

Figure 1. Crystal Capacitive Clarification

Table 6. Crystal Recommendations

Frequency

(Fund)

Cut

Loading Load Cap

ESR

Drive

Shunt

Cap (max)

Motional

(max)

Tolerance

(max)

Stability

(max)

Aging

(max)

25 MHz

AT

Parallel

12–15 pF <50

 >150 µW

5 pF

0.016 pF

35 ppm

30 ppm

5 ppm