SAW Filters for Automotive
Electronics
Series/Type:
B3712
The following products presented in this data sheet are being withdrawn.
Ordering Code
B39311B3712U410
Substitute Product
Date of Withdrawal
2014-08-29
Deadline Last
Orders
2014-11-30
Last Shipments
2015-02-28
For further information please contact your nearest EPCOS sales office, which will also support you in selecting a suitable substitute. The
addresses of our worldwide sales network are presented at www.epcos.com/sales.
SAW Components
SAW RF filter
Data sheet
Application
s
Low-loss RF filter for remote control application
s
No matching network required for operation at 50
Ω
B3712
312.20 MHz
Features
s
s
s
s
s
s
s
s
s
s
Package size 3.0 x 3.0 x 1.1 mm
3
Package code DCC6C
RoHS compatible
Approximate weight 0.037 g
Package for
Surface Mount Technology
(SMT)
Ni, gold-plated terminals
Lead free soldering compatible with J - STD20C
Passivation layer Elpas
AEC-Q200 qualified component family
Electrostatic Sensitive Device
(ESD)
Pin configuration
s
2
Input
s
5
Output
s
1,3,4,6 Ground (case)
Please read
cautions and warnings and
important notes
at the end of this document.
2
December 11, 2012
SAW Components
SAW RF filter
Data sheet
Characteristics
Temperature range for specification:
Terminating source impedance:
Terminating load impedance:
T = –40 ˚C to+110 ˚C
Z
S
=
50Ω
Z
L
=
50Ω
min.
Center frequency
f
C
—
typ.
@ 25 ˚C
312.20
max.
—
B3712
312.20 MHz
MHz
Maximum insertion attenuation
α
max
311.90 ... 312.50 MHz
Amplitude ripple (p-p)
311.90 ... 312.50 MHz
α
rel
Relative attenuation (relative to
α
min
)
270.00 ... 286.00 MHz
290.20 ... 291.10 MHz
301.20 ... 301.80 MHz
322.60 ... 323.20 MHz
333.30 ... 334.20 MHz
354.70 ... 355.90 MHz
Temperature coefficient of frequency
—
1.8
2.9
1)
dB
—
0.5
1.7
2)
dB
55
53
48
24
36
50
60
58
53
31
41
55
-30
—
—
—
—
—
—
—
dB
dB
dB
dB
dB
dB
ppm/K
TC
f
—
1)
2)
T = –40˚C to +85˚C : 2.5 dB
T = –40˚C to +85˚C : 1.3 dB
Maximum ratings
Operable temperature range
Storage temperature range
DC voltage
Source power
T
T
stg
V
DC
P
S
–45/+125
–45/+125
6
10
˚C
˚C
V
dBm
source impedance 50
Ω
Please read
cautions and warnings and
important notes
at the end of this document.
3
December 11, 2012
SAW Components
SAW RF filter
Data sheet
Transfer function
B3712
312.20 MHz
Transfer function
(wideband)
Please read
cautions and warnings and
important notes
at the end of this document.
4
December 11, 2012
SAW Components
SAW RF filter
Data sheet
ESD protection of SAW filters
B3712
312.20 MHz
SAW filters are
Electro Static Discharge
sensitive devices. To reduce the probability of damages
caused by ESD, special matching topologies have to be applied.
In general, “ESD matching” has to be ensured at that filter port, where electrostatic discharge is
expected.
Electrostatic discharges predominantly appear at the antenna input of RF receivers. Therefore
only the input matching of the SAW filter has to be designed to short circuit or to block the ESD
pulse.
Below three figures show recommended “ESD matching” topologies.
For wideband filters the high-pass ESD matching structure needs to be at least of 3
rd
order to
ensure a proper matching for any impedance value of antenna and SAW filter input. The required
component values have to be determined from case to case.
Cs1
Cs3
Cs1
Cs3
MLC1
Dp1
Lp2
to output
matching
Lp2
to output
matching
Fig. 1 MLC varistor plus ESD matching
Fig. 2 Suppressor diode plus ESD matching
In cases where minor ESD occur, following simplified “ESD matching” topologies can be used
alternatively.
Cs1
Cs3
Lp2
to output
matching
Fig. 3 3
rd
order high-pass structure for basic ESD protection
In all three figures the shunt inductor Lp2 could be replaced by a shorted microstrip with proper
length and width. If this configuration is possible depends on the operating frequency and
available pcb space.
Effectiveness of the applied ESD protection has to be checked according to relevant industry
standards or customer specific requirements
For further information, please refer to EPCOS Application report:
“ESD
protection for SAW filters”.
This report can be found under www.epcos.com/rke.Click on “Applications Notes”.
Please read
cautions and warnings and
important notes
at the end of this document.
5
December 11, 2012
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