For customers designing Freescale Semiconductor

We are pleased to introduce you to our crystal unit

Crystal Recommendations for Freescale Semiconductor "Kinetis K Families".

Items to Confirm (designing of oscillation circuit)

Please note: to design oscillation circuit, you need to confirm the electronic characteristics as follows:

Oscillation allowance and Negative resistance (-R):
You need to confirm oscillation capability.
We recommend the condition: (-R) / ESR > 5
* -R: Negative resistance, ESR: Equivalent Series Resistance
Please refer to our web site:
http://www5.epsondevice.com/cn/information/precaution/design.html
Support information > Precautions in Designing oscillation circuits > 2. Allowance for oscillation

Drive Level:
You need to confirm if oscillation is stable, and if the drive level is within the specification.
Please refer to our web site:
http://www5.epsondevice.com/cn/information/precaution/design.html
Support information > Precautions in Designing oscillation circuits > 1. Drive level

Load Capacitance:
Load capacitance affects frequency stability, oscillation allowance, negative resistance, and start-up time of oscillation.
In addition the load capacitance is determinative factor of crystal unit's load capacitance (CL value) directly.
Please refer to our web site:
http://www5.epsondevice.com/cn/information/precaution/design.html
Support information > Precautions in Designing oscillation circuits > 3. Load capacitance

* frequency stability: frequency deviation out of circuit conditions.

Selection Guidance for crystal unit

When Customer selects crystal unit, lload capacitance (CL value) is an important factor of the selection.
For instance, crystal with small CL(7.0 pF) makes larger oscillation allowance, smaller current consumption and worse frequency stability, like below table.
Oppositely, crystal with large CL(12.5 pF) makes smaller oscillation allowance, larger current consumption and better frequency stability.
Please select it in consideration of these characteristics.

Selection Guidance for crystal unit

Epson Crystal Product Lineups

Product Size [mm] Applications Images
FC-135
3.2×1.5×0.8t
PMP, DSC, Portable equipment FC135
FA-238
FA-238V
3.2×2.5×0.7t -Mobile phone,Bluetooth,W-LAN
-ISM band,Clock for MPU
FA238

Oscillation Circuit and Selection Guidance of Crystal Unit for Kinetis K Application processor

1) 32kHz

32kHz


Internal programmable capacitors : 0 (RTC control register=0, default)

IC
name
Epson Product External
parts *3
Product
name
Freq.
[kHz]
CL
*1
[pF]
Product
Code*2
Package
size[mm]
WxDxH
Cg
[pF]
Cd
[pF]
MK60DN512ZVLQ10 FC-135 32.768 12.5 Q13FC13500002** 3.2x1.5x0.8 10 10

2) MHz24MHz


Internal programmable capacitors : 0 (RTC control register=0, default)

IC
name
Product
name
Freq.
[MHz]
CL
*1
[pF]
Product
Code*2
Package
size[mm]
WxDxH
External
parts *3
Cg
[pF]
Cd
[pF]
Rf
[Ω]
MK10FX512VLQ12 FA-238V 12 10.0 Q22FA23V00019xx 3.2x2.5x0.8 10 10 1000
MK50DX256ZCLL10 FA-238 16 10.0 Q22FA23800421xx 3.2x2.5x0.8 10 10 1000
MK60DN512ZVLQ10 FA-238 20 10.0 Q22FA23800264xx 3.2x2.5x0.8 5 5 -

Notes:*

  1. Load capacitance.
  2. Two digits of the product code is packing specification, please refer here for the detail.
  3. Above recommendations are based on actual evaluation results and intended to support users in picking the right components. As the actual board layout and choice of external components. As the actual board layout and choice of external components influences the best suitable crystal load capacitance, We does not assume any responsibility and grant warranty for above recommendations. Users design must be verified and decided by own and individual evaluation.

Precautions for designing of PCB Board

<Layout of pins, Crystal unit, Capacitor and Resistor>
-Please lay out crystal unit, capacitor and resistor near Kinetis K family as far as possible.
-The length of signal patterns in oscillatiton circuit should be as short as possible, and do not cross other signal lines.

TOP View
For 32kHZ Crystal Unit

<GND Line Pattern and Interconnection of PCB>

-Please lay out GND line pattern under crystal unit.
-In case of multi-layered PCB board, do not lay out other signal lines under crystal unit.

Cross-seection View(Multi-layered PCB Board)

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