UMA 0204, UMB 0207
www.vishay.com
Vishay Beyschlag
Ultra Precision Thin Film MELF Resistors
FEATURES
• Most advanced thin film technology
• Long term stability down to 0.02 %
• TCR down to ± 5 ppm/K
• High precision tolerance down to ± 0.02 %
• Operating voltage 350 V for UMB 0207
• Material categorization: for definitions of
compliance please see
www.vishay.com/doc?99912
UMA 0204 and UMB 0207 ultra precision thin film MELF
resistors combine the proven reliability of precision MELF
products with the most advanced level of precision and
stability first achieved with axial thin film precision resistors.
This unique combination makes the product perfectly suited
for all applications with outstanding requirements towards
reliable precision and stability.
APPLICATIONS
• Measuring and calibration equipment
• Industrial process control systems
• Space and aircraft electronics
• Medical equipment
TECHNICAL SPECIFICATIONS
DESCRIPTION
DIN size
Metric size code
Resistance range
Resistance tolerance
Temperature coefficient
Rated dissipation,
P
70 (1)
Operating voltage,
U
max.
AC
RMS
/DC
Permissible film temperature,
ϑ
max. (1)
Operating temperature range
(1)
Permissible voltage against ambient (insulation):
1 min;
U
ins
Failure rate: FIT
observed
Note
(1)
Please refer to APPLICATION INFORMATION below
300 V
≤
0.05 x 10
−9
/h
500 V
0.25 W
200 V
125 °C
-55 °C to 125 °C
UMA 0204
0204
RC3715M
22
Ω
to 332 kΩ
UMB 0207
0207
RC6123M
100
Ω
to 390 kΩ
± 0.25 %; ± 0.1 %; ± 0.05 %; ± 0.02 %
± 15 ppm/K; ± 10 ppm/K; ± 5 ppm/K
0.4 W
350 V
APPLICATION INFORMATION
When the resistor dissipates power, a temperature rise above the ambient temperature occurs, dependent on the thermal
resistance of the assembled resistor together with the printed circuit board. The rated dissipation applies only if the permitted
film temperature is not exceeded.
These resistors do not feature a limited lifetime when operated within the permissible limits. However, resistance value drift
increasing over operating time may result in exceeding a limit acceptable to the specific application, thereby establishing a
functional lifetime.
Revision: 30-Sep-2021
Document Number: 28715
1
For technical questions, contact:
melf@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT
www.vishay.com/doc?91000
UMA 0204, UMB 0207
www.vishay.com
DESCRIPTION
Production is strictly controlled and follows an extensive set
of instructions established for reproducibility. A
homogeneous film of special metal alloy is deposited on a
high grade ceramic body (Al
2
O
3
) and conditioned to achieve
the desired temperature coefficient. Nickel plated steel
termination caps are firmly pressed on the metallized rods.
A special laser is used to achieve the target value by
smoothly cutting a helical groove in the resistive layer
without damaging the ceramics. The resistor elements are
covered by a unique protective coating designed for
electrical, mechanical, and climatic protection. The
terminations receive a final pure matte tin on nickel plating.
Five color code rings designate the resistance value and
tolerance in accordance with
IEC 60062
(1)
.
The result of the determined production is verified by an
extensive testing procedure and optical inspection
performed on 100 % of the individual resistors. This includes
full screening for the elimination of products with a potential
risk of early field failures. Only accepted products are laid
directly into the blister tape in accordance with
IEC 60286-3, Type 2a
(1)
.
Vishay Beyschlag
MATERIALS
Vishay acknowledges the following systems for the
regulation of hazardous substances:
• IEC 62474, Material Declaration for Products of and for the
Electrotechnical Industry, with the list of declarable
substances given therein
(2)
• The Global Automotive Declarable Substance List
(GADSL)
(3)
• The REACH regulation (1907/2006/EC) and the related list
of substances with very high concern (SVHC)
(4)
for its
supply chain
The products do not contain any of the banned substances
as per IEC 62474, GADSL, or the SVHC list, see
www.vishay.com/how/leadfree.
Hence the products fully comply with the following
directives:
• 2000/53/EC End-of-Life Vehicle Directive (ELV) and
Annex II (ELV II)
• 2011/65/EU Restriction of the Use of Hazardous
Substances
Directive
(RoHS)
with
amendment
2015/863/EU
• 2012/19/EU Waste Electrical and Electronic Equipment
Directive (WEEE)
Vishay pursues the elimination of conflict minerals from its
supply chain, see the Conflict Minerals Policy at
www.vishay.com/doc?49037.
ASSEMBLY
The resistors are suitable for processing on automatic SMD
assembly systems. They are suitable for automatic
soldering using wave, reflow or vapor phase as shown in
IEC 61760-1
(1)
. The encapsulation is resistant to all
cleaning solvents commonly used in the electronics
industry, including alcohols, esters and aqueous solutions.
The suitability of conformal coatings, potting compounds
and their processes, if applied, shall be qualified by
appropriate means to ensure the long term stability of the
whole system.
The resistors are completely lead (Pb)-free, the pure matte
tin plating provides compatibility with lead (Pb)-free and
lead containing soldering processes. Solderability is
specified for 2 years after production or requalification,
however, excellent solderability is proven after extended
storage in excess of 10 years. The permitted storage time is
20 years. The immunity of the plating against tin whisker
growth has been proven under extensive testing.
APPROVALS
Where applicable the resistors are approved within the
IECQ-CECC Quality Assessment System for Electronic
Components to the detail specification
EN 140401-803
which refers to
EN 60115-1, EN 60115-8
and the variety of
environmental test procedures of the
IEC 60068
(1)
series.
Conformity is attested by the use of the
CECC
logo (
as the mark of conformity on the package label.
)
Vishay
Beyschlag
has
achieved
“Approval
of
Manufacturer”
in accordance with
IECQ 03-1.
The release
certificate for “Technology
Approval Schedule”
in
accordance with
CECC 240001
based on
IECQ 03-3-1
is
granted for the Vishay Beyschlag manufacturing process.
RELATED PRODUCTS
For products with a wider range of TCR, tolerance and
resistance, see the datasheets:
• “Professional Thin Film MELF Resistors”
(www.vishay.com/doc?28713)
• “Precision Thin Film MELF Resistors”
(www.vishay.com/doc?28714)
Notes
(1)
The quoted IEC standards are also released as EN standards with the same number and identical contents
(2)
The IEC 62474 list of declarable substances is maintained in a dedicated database, which is available at
http://std.iec.ch/iec62474.
(3)
The Global Automotive Declarable Substance List (GADSL) is maintained by the American Chemistry Council and available at
www.gadsl.org
(4)
The SVHC list is maintained by the European Chemical Agency (ECHA) and available at
http://echa.europa.eu/candidate-list-table
Revision: 30-Sep-2021
Document Number: 28715
4
For technical questions, contact:
melf@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT
www.vishay.com/doc?91000
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