Ultra High Precision Z-Bulk Metal
®
Foil Technology Low Profile Conformally Coated
Voltage Divider Resistor with TCR Tracking to 0.1 ppm/°C, Power Coefficient
Tracking of 5 ppm at Rated Power, and Tolerance Match to 0.01 % (100 ppm)
VSH144Z (Z-Foil)
Vishay Foil Resistors
Document Number: 63173 For any questions, contact: foil@vishaypg.com www.foilresistors.com
Revision: 29-Mar-10 1
APPLICATIONS
Instrumentation amplifiers
Bridge networks
Differential amplifiers
Military
Space
Medical
Automatic test equipment
Down-hole (high temperature)
FEATURES
Temperature coefficient of resistance (TCR):
absolute: ± 0.05 ppm/°C typical (0 °C to + 60 °C)
± 0.2 ppm/°C typical (- 55 °C to + 125 °C,
+ 25 °C ref.)
tracking: 0.1 ppm/°C typical
Tolerance: absolute and matching to 0.01 % (100 ppm)
Power coefficient tracking “R due to self heating”: 5 ppm
at rated power
Power rating: 0.2 W at 70 °C, for the entire resistive
element R1 and R2, divided proportionally between the two
values
Load life ratio stability: < 0.01 % (100 ppm) 0.2 W at 70 °C
for 2000 h
Maximum working voltage: 200 V
Resistance range: 100R to 20K per resistive element
Vishay Foil resistors are not restricted to standard
values/ratios; specific “as requested” values/ratios can be
supplied at no extra cost or delivery (e.g. 1K2345 vs. 1K)
Electrostatic discharge (ESD) up to 25 000 V
Non-inductive, non-capacitive design
Rise time: 1 ns effectively no ringing
Current noise: 0.010 µVRMS/V of applied voltage (< - 40 dB)
Thermal EMF: 0.05 µV/°C typical
Voltage coefficient: < 0.1 ppm/V
Non-inductive: < 0.08 µH
Non hot spot design
Thermal stabilization time < 1 s (nominal value achieved
within 10 ppm of steady state value)
Terminal finish: lead (Pb)-free or tin/lead alloy
Compliant to RoHS directive 2002/95/EC
Prototype quantities available in just 5 working days
or sooner. For more information, please contact
foil@vishaypg.com
For better performances please contact us
* Pb containing terminations are not RoHS compliant, exemptions may apply
TABLE 1A - MODEL VSH144Z
SPECIFICATIONS
RESISTANCE
VALUES
ABSOLUTE
TOLERANCE
ABSOLUTE TCR
(- 55 °C to + 125 °C, + 25 °C ref.)
TYPICAL AND MAX. SPREAD
500
to 20 k
± 0.01 % ± 0.2 ppm/°C ± 2.5 ppm/°C
100
to < 500
± 0.02 %
TABLE 1B - MODEL VSH144Z
SPECIFICATIONS
RESISTANCE
RATIO
TOLERANCE
MATCH TCR TRACKING MAX.
1:1 0.01 % 0.5 ppm/°C
> 1:1 to 4:1 0.75 ppm/°C
> 4:1 to 10:1 0.02 % 1.5 ppm/°C
> 10:1 2.0 ppm/°C
VSH144Z
-
+
Vout
Vin
R1
R2
VSH144Z (Z-Foil)
Vishay Foil Resistors
www.foilresistors.com For any questions, contact: foil@vishaypg.com Document Number: 63173
2Revision: 29-Mar-10
INTRODUCTION
The VSH144Z voltage divider is based on the latest
generation of Bulk Metal® Z-Foil technology which is the
most recommended solution for ultra high precision, stability
and reliable voltage division or anywhere else that requires
two resistors to maintain a stable ratio under power and
throughout all application variables.
Why are extremely low TCR resistors required?
This is a proper question when evaluating system cost. The
answers are as numerous as the system in which they are
installed but a few examples may provide insight:
1) Commercial broadcast equipment heats up through the
day and requires constant manual adjustment through the
day for proper signal adjustment.
2) Satellites in synchronous orbit rotate through temperature
extremes.
3) A fighter jet resting on the 115° desert floor takes off and
reaches altitude at - 60° in less than two minutes.
4) A system that requires fast response time in order to
produce the required signal with minimum stabilization
time.
Resistors may be selected for TCR tracking but that is
only useful when the resistors are operating at the same
temperature. If the resistors are operating at different
temperatures because of differential self-heating, or due
to locally-different thermal influence from different
adjacent components, or because they are operating in
different regions of the equipment, the ratios change
proportional to the differences in operating temperature
times and the absolute TCR in addition to differences in
TCR tracking ratios. Additionally, when resistors within a
set have different absolute TCR’s (individual TCR’s - not
relative or tracking TCR), the ratios change even more
due to the differential self-heating as well as to differential
ambient temperatures:
ratio = (TCR track x
temp 1) + (absolute TCR x
temp 2)
where temp 1 is the change of ambient temperature
and temp 2 is the temperature difference between two
resistors due to differential self-heating.
Differential self-heating can occur, for example, when the
same current flows through resistors of different
resistance values. The construction of the VSH144Z
keeps both resistors at the same temperature regardless
of resistance value or differential power.
For best performance in such applications, low absolute
TCRs are required.
What is TCR tracking and why it is important?
TCR tracking is a measure of the uniformity of the
thermally-induced resistance changes in two or more
resistors. Resistors “track” closely when their individual
TCRs are close, and this is a measure of how closely these
resistors will maintain their initial ratios over various
temperature changes. Some resistors may increase in value
with an increase in temperature (positive TCR) while others
will decrease in value with an increase in temperature
(negative TCR), or, they may not change in value at the
same rate (differential TCR). Other temperature effects, such
as self heating due to the application of power can add to the
ambient temperature effects. An example of these effects
can be seen where two resistors with different TCR
characteristics are used around an operation amplifier. The
amplification ratio will be affected by the differential TCR of
the resistors and will be compounded by the differential self
heating effects of the I2R differences of the feedback VS the
input resistor.
Good design practice requires fundamentally low TCR
networks in this application since this would minimize both
varying temperature and self heating effects.
This could not be accomplished with high TCR resistors,
even with good tracking.
What is the reason for such excellent stability?
The secret of Bulk Metal Z-Foil technology’s benchmark
stability lies in the fact that it retains the inherent metallurgical
stability of the alloy from which it is made: the alloy is not
melted and drawn as it is in the manufacture of wirewound
resistors, nor is it evaporated and re-deposited or sputtered
as it is in thin-film resistors. This underlying metallurgical
stability is preserved throughout the manufacturing
processes by preventing the introduction of additional
stresses into the final component.
Our application engineering department is available to
advise and make recommendations. For non-standard
technical requirements and special applications. Please
contact foil@vishaypg.com.
VSH144Z (Z-Foil)
Vishay Foil Resistors
Document Number: 63173 For any questions, contact: foil@vishaypg.com www.foilresistors.com
Revision: 29-Mar-10 3
Note:
• Power is divided proportionally between the 2 values
FIGURE 1 - TRIMMING TO VALUES (conceptual illustration)
Note: Foil shown in black, etched spaces in white
Mutual
Inductance
Reduction due
to Opposing
Current in
Adjacent Lines
Current Path
Before Trimming
Interloop
Capacitance
Reduction
in Series
Trimming Process
Removes this Material
from Shorting Strip Area
Changing Current Path
and Increasing Resistance
Current Path
After Trimming
FIGURE 2 - STANDARD PRINTING AND DIMENSIONS in inches (millimeters)
Dimensional Tolerance: ± 0.010" (0.25)
(1) Lead wires: #22 AWG solder coated copper,
0.75" minimum length
(2) Each divider pair consists of two resistors on one
single chip
(3) For lead (Pb)-free: print “T” after 144Z and “-” after (D.C.)
Model VSH144Z and Schematic
(2)
0.263 ± 0.02
(6.7 ± 0.5)
VSH
144Z T
0.100
(2.54)
0.200
(5.08)
0.098 + 0.008/- 0.01
(2.5 + 0.2/- 0.3)
1.0 (25.4)
Min.
(D.C.) -
1K/1K 0.283 ± 0.04
(7.2 ± 1.0)
R2
R1
13
2
(3)
(3)
FIGURE 3 - POWER DERATING CURVE
100 %
75 %
50 %
25 %
0
- 75 - 50 - 25 0 + 25 + 50 + 75 + 100 + 125 + 150 + 175
Ambient Temperature (°C)
Percent of Rated Power at + 70 °C
- 55 °C + 70 °C
Recommended
operation for
< 150 ppm ΔR
after 2000 h
load life
Rated Power
FIGURE 4 - TYPICAL RESISTANCE/
TEMPERATURE CURVE
(for more details see table 1A)
+ 500
+ 200
+ 100
0
- 100
- 200
- 300
- 500
- 55 - 25 + 25 + 60 + 75 + 100 + 125
Ambient Temperature (°C)
ΔR
R
(ppm)
0
0.05 ppm/°C
- 0.1 ppm/°C 0.1 ppm/°C
0.14 ppm/°C
0.2 ppm/°C
- 0.16 ppm/°C
- 400
+ 300
+ 400
TCR Chord Slopes for Different Temperature Ranges
VSH144Z (Z-Foil)
Vishay Foil Resistors
www.foilresistors.com For any questions, contact: foil@vishaypg.com Document Number: 63173
4Revision: 29-Mar-10
Note
• A combination of these values are available in reverse order and in values up to 5 digits
TABLE 2 - EXAMPLES OF VCODES FOR POPULAR VALUES (other values available on request)
VSH144Z RATIOS
VCODES R1R2VCODES R1R2
V0009 20K 20K V0058 2K 20K
V0010 20K 10K V0030 2K 18K
V0100 20K 2K V0029 2K 4K
V0055 19K4 9K7 V0059 2K 2K
V0223 17K5 20K V0103 2K 3K
V0097 15K 15K V0154 1K5 3K
V0001 10K 10K V0032 1K 16K
V0042 10K 8K323 V0121 1K 2K
V0006 10K 2K V0004 1K 1K
V0166 10K 15K V0379 1K 7K
V0226 9K 10K V0374 800R 800R
V0003 9K 1K V0022 511R 16K2
V0013 8K 16K V0091 500R 500R
V0107 6K 20K V0162 500R 15K
V0014 6K 7K V0378 500R 4K5
V0160 6K 6K V0061 300R 300R
V0159 5K5 7K7 V0088 100R 100R
V0005 5K 10K V0380 100R 15K
V0002 5K 5K V0375 100R 12K3
V0373 4K 12K V0381 100R 50R
V0026 3K 19K2 V0377 50R 28K
V0156 3K 6K V0376 35R 20K
V0158 2K7 10K - - -
VSH144Z (Z-Foil)
Vishay Foil Resistors
Document Number: 63173 For any questions, contact: foil@vishaypg.com www.foilresistors.com
Revision: 29-Mar-10 5
Note
(1) For non-standard requests, please contact application engineering
TABLE 3 - GLOBAL PART NUMBER INFORMATION (1)
NEW GLOBAL PART NUMBER: Y1680V0058QT9L (preferred part number format)
DENOTES PRECISION VCODE TOLERANCE MATCH PACKAGING
YRESISTANCE
VALUE CODE
V= 0.005 %
T= 0.01 %
Q= 0.02 %
A= 0.05 %
B= 0.1 %
D= 0.5 %
F= 1.0 %
L = bulk pack
PRODUCT CODE RESISTANCE TOLERANCE CHARACTERISTICS
1680 = VSH144Z V= ± 0.005 %
T= ± 0.01 %
Q= ± 0.02 %
A= ± 0.05 %
B= ± 0.1 %
D= ± 0.5 %
F= ± 1.0 %
0 = standard
9 = lead (Pb)-free
1 to 999 = custom
FOR EXAMPLE: ABOVE GLOBAL ORDER Y1680 V0058 Q T 9 L:
TYPE: VSH144Z
VALUES: 2K/20K
ABSOLUTE TOLERANCE: ± 0.02 %
TOLERANCE MATCH: 0.01 %
TERMINATION: lead (Pb)-free
PACKAGING: bulk pack
HISTORICAL PART NUMBER: VSH144ZT 2K/20K TCR0.2 Q T B (will continue to be used)
VSH144Z T 2K/20K TCR0.2 Q T B
MODEL TERMINATION OHMIC VALUE
TCR
CHARACTERISTIC
ABSOLUTE
TOLERANCE
TOLERANCE
MATCH PA CK A G I N G
VSH144Z T = lead (Pb)-free
None = tin/lead alloy
R1= 2 k
R2= 20 k
V= ± 0.005 %
T= ± 0.01 %
Q= ± 0.02 %
A= ± 0.05 %
B= ± 0.1 %
D= ± 0.5 %
F= ± 1.0 %
V= 0.005 %
T= 0.01 %
Q= 0.02 %
A= 0.05 %
B= 0.1 %
D= 0.5 %
F= 1.0 %
B = bulk pack
680V 0580Y1 T9Q L
Vishay Precision Group
Document No.: 63999
Revision: 27-Apr-11
www.vishaypg.com
1
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Document No.: 63999
Revision: 27-Apr-11