JN5148 NXP Semiconductors, JN5148 Datasheet - Page 93

• Manufacturer Part Number: JN5148
• Description: The JN5148 is an ultra low power, high performance MCU combined with an IEEE802
• Manufacturer: NXP Semiconductors

Three examples of typical crystals are given, each with the value of external capacitors to use, plus the likely supply
current and start-up time that can be expected. Also given is the maximum recommended ESR based on the start-up
criteria given in Appendix B.1.3. The values of the external capacitors can be calculated using the equation in
Appendix B.1.2 .
Below is measurement data showing the variation of the crystal oscillator supply current with voltage and with crystal
ESR, for two load capacitances.
© NXP Laboratories UK 2011
9pF
6pF
12.5pF
Load Capacitance
1.6
1.4
1.2
0.8
0.6
1.6
1.4
1.2
0.8
0.6
1
1
2.2
10
2.4
20
32KHz Crystal Oscillator Current
32KHz Crystal Oscillator Current
2.6
30
Ext Capacitors
Crystal ESR (K ohm)
15pF
22pF
Supply Voltage (VDD)
9pF
2.8
40
JN-DS-JN5148-001 1v7
50
Current
3
1.6uA
1.4uA
2.4uA
60
3.2
Start-up Time
0.8Sec
0.6sec
1.1sec
70
3.4
70KΩ
80KΩ
35KΩ
80
3.6
Max ESR
9pF
12.5pF
93