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1
For any questions, contact
foil@vpgsensors.com
Document No.: 63187
Revision: 01-Nov-2016
Z Series (Z Foil)
Ultra High Precision Z Foil Though-Hole Resistor
Ultra High Precision Z Foil Though-Hole Resistor
with TCR of ±0.2ppm/°C, Tolerance of ±0.005% (50ppm),
Load Life Stability of ±0.005%
FEATURES
• Temperature coefficient of resistance (TCR):
±0.2 ppm/°C typical (–55°C to +125°C, +25°C ref.)
(see table 1)
• Rated power: to 1W at +125°C (see table 2)
• Resistance tolerance: to ±0.005% (50 ppm)
• Load life stability: ±0.005% at 70°C, 2000 h or
±0.015% at 70°C, 10000 h (see table 4)
• Resistance range: 5 Ω to 600 kΩ
• Bulk Metal
®
Foil resistors are not restricted to standard
values; specific “as required” values can be supplied
at no extra cost or delivery (e.g. 1K2345 vs. 1K)
• Total accumulated change in resistance value over life
or Total Error Budget <0.1% (or tighter with PMO)**
• Electrostatic Discharge (ESD): at least to 25 kV
• Non-inductive, non-capacitive design
• Rise time: 1 ns effectively no ringing
• Current noise: ≤0.010 μV
RMS
/V of applied voltage
(<–40 dB)
• Thermal EMF: 0.05 μV/°C typical
• Voltage coefficient: <3 ppm/V
• Low inductance: <0.08 μH typical
• Thermal stabilization time <1 s (to reach within 10 ppm
of steady state value)
• Pattern design minimizing hot spots
• Terminal finish: lead (Pb)-free or tin/lead alloy
• Matched sets are available per request
(TCR tracking: to 0.5 ppm/°C)
• Military established reliability “R” level resistor available
(see resistor model RNC90Z)
• Screen/test flow as modified from S-311-P813
proposed by NASA available
(see datasheet for resistor model 303143)
• Prototype quantities available please contact
foil@vpgsensors.com
INTRODUCTION
The Bulk Metal
®
Foil resistor is based on a special
thermo-metalic stress concept wherein a proprietary bulk
metal cold rolled foil is cemented to a ceramic substrate.
It is then photoetched into a resistive pattern. Then it
is laser adjusted to any desired value and tolerance.
Because the metals used are not drawn, wound or
mistreated in any way during manufacturing process,
the Bulk Metal Foil resistor maintains all its design,
physical and electrical characteristics while winding
of wire or sputtering does not. Z Foil resistors achieve
maximum stability and near-zero TCR. These performance
characteristics are built-in for every unit, and do not
rely on screening or other artificial means for uniform
performance.
The stability of a resistor depends primarily on its history
of exposures to temperature. Stability is affected by:
1. Reversible changes in the ambient temperature
and heat from adjacent components (defined by the
Temperature Coefficient of Resistance, or TCR)
2. Short-term steady-state self-heating (defined by
Power TCR or PCR)
3. Irreversible destabilizing shock of suddenly-applied
power
4. Long-term exposure to applied power (load-life
stability)
In very high-precision resistors, these effects must be
taken into account to achieve high stability with changes
in load (Joule Effect) and ambient temperature.
Vishay Foil Resistors’ Z Foil technology provides an order
of magnitude reduction in the Bulk Metal Foil element’s
sensitivity to temperature changes – both external and
internal. This technology provides TCR of ±0.2 ppm/°C
typical (military range: –55°C to +125°C, +25°C ref), and a
PCR of 5 ppm at rated power.
In order to take full advantage of this TCR improvement,
it is necessary to take into account the differences in
the resistor’s response to each of the above-mentioned
effects. The Z series has been developed to successfully
deal with these factors.
* This datasheet provides information about parts that are
RoHS-compliant and/or parts that are non-RoHS-compliant.
For example, parts with lead (Pb) terminations are not
RoHS compliant. Please see the information/tables in this
datasheet for details.
** See PMO page 5
Document No.: 63187
Revision: 01-Nov-2016
Z Series (Z Foil)
TABLE 1 – TYPICAL TCR AND MAX. SPREAD
(–55°C to +125°C, +25°C ref.)
VALUE
STANDARD
TOLERANCE
TYPICAL TCR AND
MAX. SPREAD (ppm/°C)
100 Ω to 600 kΩ ±0.005% ±0.2 ±0.6
80 Ω to <100 Ω ±0.005% ±0.2 ±0.8
50 Ω to <80 Ω ±0.01% ±0.2 ±1.0
25 Ω to <50 Ω ±0.01% ±0.2 ±1.3
10 Ω to <25 Ω ±0.02% ±0.2 ±1.6
5 Ω to <10 Ω ±0.05% ±0.2 ±2.3
