For customers designing Freescale Semiconductor

We are pleased to introduce you to our crystal unit

Crystal Recommendations for Freescale Semiconductor "i.MX6 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/en/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/en/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/en/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, load 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
MC-146 7×1.5×1.4t DSC, Consumer equipment, Radio equipment, Blood pressure meter, Blood-sugar monitor, Security systems MC146
FC-135
3.2×1.5×0.8t
PMP, DSC, Portable equipment FC135
FC-13A
3.2×1.5×0.9t
Automotive accessories and ECU sub clock FC-13A
FA-238
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 i.MX Application processor

i.MX6Quad, 6Dual, 6DualLite, 6Solo


32kHz Crystal

32kHz

Pin number of RTC_XTALI/RTC_XTALO

21x21mm BGA

RTC_XTALI RTC_XTALO
All Families D9 C9

IC
name
Product
name
Freq.
[kHz]
CL
*1
[pF]
f_tol *2
[ppm]
Product
Code*3
External
parts *4
Package
size[mm]
WxDxH
Cg
[pF]
Cd
[pF]
Rf
[Ω]
MCIMX6U5DVM10x FC-135 32.768 7.0 20 Q13FC13500002** 10 10 - 3.2x1.5x0.8
MCIMX6D5EYM10x MC-146 12.5 20 Q13MC14620002** 22 22 10M 7.0x1.5x1.4
MCIMX6S6AVM08x FC-13A 9.0 20 X1A0000910005** 18 18 10M 3.2x1.5x0.9

24MHz Crystal

24MHz

Pin number of XTALI/XTALO

21x21mm BGA

XTALI XTALO
All Families A7 B7
IC
name
Product
name
Freq.
[MHz]
CL
*1
[pF]
f_tol *2
[ppm]
Product
Code*3
External
parts *4
Package
size[mm]
WxDxH
Cg
[pF]
Cd
[pF]
Rf
[Ω]
MCIMX6S6AVM08x FA-238 24 10.0 20 Q22FA23801201** 5 5 - 3.2x2.5x0.7
MCIMX6Q6AVT10x 30 Q22FA23800817** 7 7 -
MCIMX6D6AVT10x 7 7 -
MCIMX6S6AVM08x 7 7 1M

Notes:*

  1. Load capacitance.
  2. Frequency tolerance (standard)
  3. Two digits of the product code is packing specification, please refer here for the detail.
  4. 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 componentsinfluences 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.
  5. Please evaluate a crystal oscillator without an external feedback resistor Rf if you need. It is possible that a crystal oscillator works without it because i.MX6 series has an internal feedback resistor Rf in the MHz oscillator.

Precautions for designing of PCB Board

<Layout of pins, Crystal unit, Capacitor and Resistor>
-Please lay out crystal unit, capacitor and resistor near i.MX6 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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