SFSL4.5MDB YAMAR [Yamar Electronics Ltd.], SFSL4.5MDB Datasheet - Page 10

• Manufacturer Part Number: SFSL4.5MDB
• Description: Independent DC-LIN Slave For Asynchronous Communication Over Noisy Lines
• Manufacturer: YAMAR [Yamar Electronics Ltd.]

4.5 Ceramic Filter
*3.58
4.5
5.5
6.0
6.5
The ISL40 is designed to operate with one ceramic filter for transmission and reception. However, if
switching between two channels is desired, two ceramic filters are required. The minimum allowable
bandwidth of the ceramic filters is +/-70 kHz @ 3dB. Narrower bandwidth limits the maximal bit rate.
The ISL40 selectable frequencies are designed according to the market available ceramic filters.
•
The ISL40 is designed to operate with a low cost 32.768KHz crystal connected between OscIn and
OscOut pins. This type of crystal has the advantage of very low power consumption and low cost.
However there are also drawbacks. It is very sensitive to noise and has a temperature dependency that
should be carefully considered when selecting the crystal.
The following guidelines should be used when designing the PCB:
The exact values of C1, C2, R1 and R2 should be determined according to the crystal manufacturer.
The maximal cable length between extreme devices depends mainly on the AC impedance of loads
connected to that line and number of nodes. The DC cable length has less effect on communication.
The SIG40 needs at least 20mVpp for proper reception. Good communication should be achieved if an
oscilloscope at the SIG40 receiver can see the transmitted signal within the noise.
Nominal
© 2007 Yamar Electronics Ltd.
4.6
4.7
4.8
freq.
MHz
The 3.58MHz frequency can be operated with 9.6Kbps and 19.2Kbps only
1. Design the trace length as short as possible.
2. Avoid thin line on resonator traces (< 0.010"), keep them as wide as possible.
3. To avoid noise, protect these signals with Ground shields.
The overall frequency tolerance should not exceed 200ppm.
Oscillator
Recommended 32.768KHz Crystal Specifications
Communication performance
3 db BW 20db
+/-40
+/-70
+/-80
+/-80
+/-80
KHz
min.
Nominal Frequency:
Frequency tolerance @25ºC
Load capacitance
Serial resistance
Drive level
Quality factor
Turnover temperature
Parabolic constant
Aging
Operating temperature
Storage temperature
Proprietary and Confidential Information of YAMAR Electronics Ltd.
530
750
750
750
800
max.
KHz
BW
6.0
6.0
6.0
6.0
6.0
Insertion
Type
loss
max.
dB
25
30
30
30
30
attenuation
Stop band
min.
dB
10
32.768KHz
+/-20 ppm
12.5 pF
50K Ohm (max.)
1uW (max.)
50,000 (max.)
+25ºC +/- 5ºC
-0.04 ppm/ºC² (max.)
+/-3 ppm in first year (max.)
-40ºC to + 85ºC
-55ºC to + 125ºC
530
1000
600
470
470
imped.
In/Out
Ohm
Value
SFSH3.58MCB
SFSL4.5MDB
SFSL5.5MDB
SFSL6.0MDB
SFSL6.5MDB
Murata
part #
DS-ISL40 R1.6
773-0045
773-0055
773-0060
773-0065
Oscilent
part #