CAR (Charcroft Audio Resistor)
Charcroft Foil Resistors
Ultra High Precision, High Resolution Z-Foil Audio Resistor,
with TCR of
± 0.2 ppm/°C,Tolerance
to
± 0.01 %
and Noise
< - 40 dB
F E AT U R E S
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Temperature coefficient of resistance (TCR):
- 55°C to + 125°C, 25°C ref.
± 0.2 ppm/°C typical (see table 1)
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Any value at any tolerance available within resistance range
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®
Rated power: to 0.4 W at + 70°C
Tolerance: to ± 0.01 %
Load life stability: to ± 0.01 % at 70°C, 2000 h at rated power
Resistance range: 10Ω to 100 kΩ (higher or lower values of
resistance are available)
Electrostatic discharge (ESD) above 25 000 V
Non inductive, non capacitive design
Rise time: 1 ns without ringing
Current noise: < - 40 dB
Thermal EMF: 0.05 µV/°C typical
Voltage coefficient: < 0.1 ppm/V
Low inductance: < 0.08 µH typical
Non hot spot design
Terminal Finishes Available:
RoHS Compliant
Tin/Lead Alloy
INTRODUCTION
The CAR, composed of Vishay’s Bulk Metal Z-foil technology,
with improved sound quality, provides a combination of low
noise and low inductance/capacitance, making it unrivalled for
applications requiring low noise and distortion-free properties.
While the regular foil resistors are already widely acknowledged
as the leading resistors for audio applications, the special “naked
Z-foil resistor” design without case or encapsulation, adds an
additional dimension for reducing signal distortion and increasing
clarity in signal processing.
For non standard requirements such as higher values (using
multiple chips) and tighter tolerances, please contact our
application engineering department.
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A P P L I C AT I O N S
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High precision amplifiers
High-end speaker system
High-end audio circuit
Transducer
High fidelity audio amplifier
TABLE 1 - RESISTANCE VERSUS TCR (- 55 °C to + 125 °C, + 25 °C Ref.)
RESISTOR
RESISTANCE VALUE
(Ω)
100 to < 100K
CAR
50 to < 100
10 to < 50
TYPICAL TCR AND MAXIMUM SPREAD
(ppm/°C)
± 0.2 ± 1.8
± 0.2 ± 2.8
± 0.2 ± 3.8
TIGHTEST TOLERANCE
(%)
0.01
0.01
0.02
FIGURE 1 - TYPICAL TCR CURVE Z-FOIL
FIGURE 2 - STANDARD DIMENSIONS
www.charcroft.com
Document No:
ACC100
Issue:
5
Page:
1
Date:
07/09
CAR (Charcroft Audio Resistor)
Charcroft Foil Resistors
Ultra High Precision, High Resolution Z-Foil Audio Resistor, with TCR of
± 0.2 ppm/°C,
Tolerance to
± 0.01 %
and Noise
< - 40 dB
TABLE 2 - SPECIFICATIONS
RESISTANCE RANGE
(Ω)
MAXIMUM
WORKING
VOLTAGE
AMBIENT
POWER RATING
at
at
+ 70°C
+ 125°C
DIMENSIONS
mm
10 to 100K
200V
0.4 W
0.2 W
W: 2.50 max.
L: 7.50 max.
H: 8.00 max.
LL: 25 min
LS: 5.08 ± 0.13
FIGURE 3 - POWER DERATING CURVE
FIGURE 4 -TRIMMING TO VALUES
(
CONCEPTUAL ILLUSTRATION)
NOTE:
Foil shown in BLACK, etched spaces in white.
Interloop Capacitance
Reduction in Series
Current Path
Before Trimming
Mutual Inductance
Reduction due
to Opposing
Current in
Adjacent Lines
Current Path
After Trimming
Trimming Process
Removes this Material
from Shorting Strip
Area Changing
Current Path and
Increasing
Resistance
TA B L E 3 - O R D E R I N G I N F O R M AT I O N
Specify CAR (Charcroft audio resistors) as follows:
Example:
CAR
MODEL NO.
T = RoHS compliant
None = Tin/Lead alloy
TERMINATION
250R00
RESISTANCE VALUE
T = ± 0.01%
Q = ± 0.02%
A = ± 0.05%
B = ± 0.1%
C = ± 0.25%
D = ± 0.5%
F = ± 1.0%
TOLERANCE
Resistance Value, in ohms, is expressed by a series of 6 characters, 5 of which represent significant digits while the 6th is
a dual purpose letter that designates both the multiplier and the location of the comma or decimal.
RESISTANCE
RANGE
10Ω to <1KΩ
1KΩ to 100KΩ
LETTER
DESIGNATOR
R
K
MULTIPLIER
FACTOR
x1
x 10
3
EXAMPLE
100R01 = 100.01Ω
5K2310 = 5,231Ω
TR = Tape & Reel
None = Bulk (loose)
PACKAGING
For example: CAR T 250R00Q -
Model:
CAR Version,
Termination:
RoHS compliant;
Value:
250
Ω,
Tolerance:
0.02 %
Packaging:
Bulk
www.charcroft.com
Document No:
ACC100
Issue:
5
Page:
2
Date:
07/09
