MODEL PTF
Metal Film Resistors
Industrial, Precision
Low TC - Tight Tolerance
FEATURES
•
Extremely low temperature coefficients of resistance
•
Very low noise and voltage coefficient
•
Wide precision resistance range in small package
•
100% laser spiralled
•
Very good high frequency characteristics
•
Acceptance testing available
•
Can replace wirewound bobbins
•
Proprietary epoxy coating provides superior moisture
protection
STANDARD ELECTRICAL SPECIFICATIONS
+ 85
°
C
RATING
1/20 W
1/8 W
1/4 W
MAXIMUM
WEIGHT
(Grams)
MATERIAL SPECIFICATIONS
RESISTANCE
RANGE
(Ohms)
MODEL
PTF-51
PTF-56
PTF-65
MAXIMUM
WORKING
VOLTAGE
200
300
500
AVAILABLE
TOLERANCE
RANGE
±
1% to
±
0.02%
±
1% to
±
0.01%
±
1% to
±
0.05%
Element:
Precision deposited nickel-
chrome alloy with controlled annealing.
Core:
Fire-cleaned high purity ceramic.
Encapsulant:
Specially formulated epoxy
compounds. Coated construction.
Termination:
Standard lead material is
solder-coated copper. Solderable and
weldable per MIL-STD-1276, Type C.
.11
.35
.75
15 - 100k
15 - 500k
15 - 1M
DIMENSIONAL CONFIGURATIONS
[Numbers in brackets indicate millimeters]
C
MODEL
1.50
±
.125
[38.1
±
3.18]
A
A
.150
±
.020
[3.81
±
.508]
.250 + .031 - .046
[6.35 + .787 - 1.17]
.375
±
.062
[9.53
±
1.57]
B
.070
±
.010
[1.78
±
.254]
.091
±
.009
[2.31
±
.229]
.145
±
.016
[3.68
±
.406]
(Max.)
D
.016
[.406]
.025
[.635]
.025
[.635]
PTF-51
.200
[5.08]
.300
[7.62]
.475
[12.07]
C
Max.
D
B
PTF-56
PTF-65
ENVIRONMENTAL PERFORMANCE
TEST DESCRIPTION
Thermal Shock
(- 55°C to + 85°C)
Short Time Overload
Low Temperature Operation
Moisture
Resistance to Soldering Heat
Damp Heat
Life
(1000 hours rated power @ + 85°C)
Dielectric Withstanding Voltage
TEST SPECIFICATION
MIL-STD-202, Method 107
MIL-R-10509, Para. 4.6.6
MIL-STD-55182, Methods 4.7.9
MIL-R-202, Method 106
MIL-STD-202, Methods 210
IEC Publication #68-2-3 (56 days)
MIL-R-55182, Para. 4.7.17
MIL-STD-202, Methods 301 & 105
MAXIMUM
∆
R (Typical Test Lots)
±
.02%
±
.01%
±
.02%
±
.08%
±
.02%
±
.08%
±
.04%
±
.01%
Vishay Dale
2300 Riverside Blvd., Norfolk, NE 68701-2242 •
Phone
(402) 371-0080 •
Fax
402-644-4206 •
Internet
www.vishay.com
Major Vishay Brands
Dale • Draloric • Foil Resistors • Measurements Group • Roederstein • Sfernice • Sprague • Thin Film • Vitramon
MODEL PTF
TEMPERATURE COEFFICIENT OF RESISTANCE
Temperature coefficient (TC) of resistance is normally stated as the maximum
amount of resistance change from the original + 25°C value as the ambient
temperature increases or decreases. This is most commonly expressed in
parts per million per degree centigrade (PPM/°C).
The resistance curve over the operating temperature range is usually a
non-linear curve within predictable maximum limits. PTF resistors have a very
uniform resistance temperature characteristic when measured over the
operating range of - 20°C to + 85°C. The standard temperature coefficients
available are T-10 =
±
15PPM/°C, T-13 =
±
10PPM/°C and T-16 =
±
5PPM/°C.
Some applications of the PTF require operation beyond the specifications of
- 20°C to + 85°C. The change in temperature coefficient of resistance is very
small (less than
±
0.05PPM/°C) over the expanded temperature range of
- 55°C to + 150°C. Therefore, when operating outside the range of - 20°C to
+ 85°C, the designer can plan for a worst case addition of
±
0.05PPM/°C for
each degree centigrade beyond either - 20°C or + 85°C as indicated in the
graph. This applies to all three temperature coefficient codes.
MATCHED SETS - NETWORKS
Dale’s
®
many years of experience in matching resistors
for sets and networks, combined with the superb
performance of the PTF product, provide the best and
most economical solution to your precision resistor
requirements. Why? Because most applications for
precision resistors depend on two or more discretes
having an initial tolerance ratio and a resistance
tracking capability over temperature rather than each
discrete resistor meeting the absolute requirements of
the application.
Cost savings approaching 50% can be realized when
relatively tight matching requirements are specified
while permitting the absolute parameters of the
discrete resistors to have more relaxed specifications.
Dale
®
application engineers are available to assist you
in specifying your requirements in the most
economical way possible.
DERATING
PPM/
°
C
ADDITION TO BASE TC IN THE
EXPANDED PORTION OF THE
TEMPERATURE RANGE
4
3
2
PTF resistors have an operating temperature range of
- 55°C to + 150°C. They must be derated according to
the curve below.
% OF RATED POWER
120
100
80
60
40
20
0
30
50
70
90
110
130
150
AMBIENT TEMP. DEG. CENTIGRADE
+ 85
°
C
1
0
- 50
- 40
- 30 - 20
- 20°C TO + 85°C
BASE TC LIMIT
90
T-10, T-13
or T-16
100
110 120
130 140 150
EXPANDED
OPERATING RANGE
- 55°C TO - 20°C
EXPANDED
OPERATING RANGE
+ 85°C TO + 150°C
Example:
Assume the operating characteristics demand a temperature
range from - 55°C to + 125°C. This requires a
±
35°C
∆
below - 20°C and a
±
40°C
∆
above + 85°C. The extreme
∆
being
±
40°C means that the worst
case addition to the specified TC limit of
±
0.05PPM/°C times
±
40°C or
±
2PPM/°C. Therefore, a T-16 which is characterized by a base TC limit of
±
5PPM/°C over the temperature range of - 20°C to + 85°C will exhibit a
maximum temperature coefficient of
±
7PPM/°C over the expanded portion
of the temperature range of - 55°C to + 125°C.
PART MARKING
— Model
— Value
— Tolerance
— TC
— Date code
HOW TO ORDER
PTF
MODEL
56
SIZE
20K01
VALUE
B
TOLERANCE
F =
±
1.0%
D =
±
0.5%
C =
±
0.25%
B =
±
0.1%
A =
±
0.05%
BC =
±
0.02%
BB =
±
0.01%
T-13
TEMPERATURE
COEFFICIENT
T-10 = 0
±
15PPM/°C
T-13 = 0
±
10PPM/°C
T-16 = 0
±
5PPM/°C
DECIMAL LOCATOR/MULTIPLIER
Code
R
K
M
Resistance
= x1
= x 1000
= x 1,000,000
=
=
=
=
=
=
=
50Ω
62.2Ω
100.1Ω
1001Ω
10,100Ω
100,100Ω
1,000,000Ω
Examples:
50R
62R2
100R1
1K001
10K1
100K1
1M0
Example:
PTF-56, 20K01, B, T-13 = A precision thin film resistor, 1/8 watt with resistance of 20,010 ohms, tolerance of
±
0.1% and 0
±
10PPM/°C TCR.
Vishay Dale
2300 Riverside Blvd., Norfolk, NE 68701-2242 •
Phone
(402) 371-0080 •
Fax
402-644-4206 •
Internet
www.vishay.com
Major Vishay Brands
Dale • Draloric • Foil Resistors • Measurements Group • Roederstein • Sfernice • Sprague • Thin Film • Vitramon
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