SWRS245B December 2021 – December 2023 AM2732 , AM2732-Q1
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
An external crystal is connected to the device pins. Figure 6-2 shows the crystal implementation.
The load capacitors, Cf1 and Cf2 in Figure 6-2, should be chosen such that Equation 1 is satisfied. CL in the equation is the load specified by the crystal manufacturer. All discrete components used to implement the oscillator circuit should be placed as close as possible to the associated oscillator CLKP and CLKM pins. Note that Cf1 and Cf2 include the parasitic capacitances due to PCB routing.
Table 6-10 lists the electrical characteristics of the clock crystal.
NAME | DESCRIPTION | MIN | TYP | MAX | UNIT |
---|---|---|---|---|---|
fP | Parallel resonance crystal frequency | 40 | MHz | ||
CL | Crystal load capacitance | 5 | 8 | 12 | pF |
ESR | Crystal ESR | 50 | Ω | ||
Temperature range | Expected temperature range of operation | –40 | 150 | °C | |
Frequency tolerance | Crystal frequency tolerance(1)(2)(3) | –200 | 200 | ppm | |
Drive level | 50 | 200 | µW |
A non-crystal oscillator can also be used as the clock reference source. In this case the signal is fed to the CLKP pin only and CLKM is grounded. Table 6-11 lists the electrical, AC timing, and phase noise requirements of the external oscillator input signal.
PARAMETER | SPECIFICATION | UNIT | |||
---|---|---|---|---|---|
MIN | TYP | MAX | |||
Input Clock: External AC-coupled sine wave or DC-coupled square wave Phase Noise referrenced to 40 MHz |
Frequency | 40 | MHz | ||
AC-Amplitude | 700 | 1200 | mV (pp) | ||
DC-VIL | 0.00 | 0.02 | V | ||
DC-VIH | 1.40 | 1.95 | V | ||
DC-trise/fall | 10 | ns | |||
Phase Noise at 1 kHz | –132 | dBc/Hz | |||
Phase Noise at 10 kHz | –143 | dBc/Hz | |||
Phase Noise at 100 kHz | –152 | dBc/Hz | |||
Phase Noise at 1 MHz | –153 | dBc/Hz | |||
Duty Cycle | 35 | 65 | % | ||
Freq Tolerance | –50 | 50 | ppm |