The recommended layout and routing for the crystal oscillator circuit involves keeping the crystal and capacitors as close to the DS1388Z-33+ as possible, and using a ground plane to minimize noise and radiation. The crystal should be placed near the X1 and X2 pins, and the capacitors should be placed near the X1 and X2 pins as well. The traces should be as short as possible and should not be routed near noisy signals or high-current paths.
To ensure the DS1388Z-33+ is properly powered and bypassed, connect a 0.1uF to 1uF ceramic capacitor between the VCC pin and the GND pin, and place it as close to the VCC pin as possible. Additionally, use a low-ESR capacitor (e.g. 10uF) connected between the VCC pin and the GND pin, and place it near the power supply input. This will help to filter out noise and ensure stable operation.
The maximum frequency deviation of the DS1388Z-33+ oscillator is ±100 ppm over the operating temperature range of -40°C to +85°C. This means that the oscillator frequency can deviate by up to ±100 parts per million from the nominal frequency of 32.768 kHz.
To adjust the oscillator frequency to compensate for crystal variations, use the trim-in and trim-out pins (TRIMIN and TRIMOUT) to adjust the oscillator frequency. The trim-in pin can be connected to a voltage source or a potentiometer to adjust the oscillator frequency. The trim-out pin can be used to monitor the oscillator frequency and adjust it accordingly.
The recommended operating temperature range for the DS1388Z-33+ is -40°C to +85°C. Operating the device outside of this range may affect its performance and reliability.
DS1388Z-33+ datasheet
by Maxim Integrated Products
