MODEL PTF
Metal Film Resistors
Industrial, Precision
Low TC - Tight Tolerance
MODEL
PTF-51
PTF-56
PTF-65
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 MATERIAL SPECIFICATIONS
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.
DIMENSIONAL CONFIGURATIONS [Numbers in brackets indicate millimeters]
D
.016
[.406]
.025
[.635]
.025
[.635]
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
ENVIRONMENTAL PERFORMANCE
MODEL
PTF-51
PTF-56
PTF-65
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]
C
(Max.)
.200
[5.08]
.300
[7.62]
.475
[12.07]
+ 85°C
RATING
1/20 W
1/8 W
1/4 W
MAXIMUM
WEIGHT
(Grams)
.11
.35
.75
MAXIMUM
WORKING
VOLTAGE
200
300
500
RESISTANCE
RANGE
(Ohms)
15 - 100k
15 - 500k
15 - 1M
AVAILABLE
TOLERANCE
RANGE
± 1% to ± 0.02%
± 1% to ± 0.01%
± 1% to ± 0.05%
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%
C
Max. BD
A
1.50 ± .125
[38.1 ± 3.18]
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 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
PART MARKING
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.
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.
PTF resistors have an operating temperature range of
- 55°C to + 150°C. They must be derated according to
the curve below.
— Model
— Value
— Tolerance
— TC
— Date code
T-10 = 0 ± 15PPM/°C
T-13 = 0 ± 10PPM/°C
T-16 = 0 ± 5PPM/°C
T-13
TEMPERATURE
COEFFICIENT
AMBIENT TEMP. DEG. CENTIGRADE
30 50 70 90 110 130 150
120
100
80
60
40
20
0
% OF RATED POWER
+ 85°C
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.
- 20°C TO + 85°C
BASE TC LIMIT
EXPANDED
OPERATING RANGE
+ 85°C TO + 150°C
T-10, T-13
or T-16
EXPANDED
OPERATING RANGE
- 55°C TO - 20°C
4
3
2
1
0
PPM/°C
ADDITION TO BASE TC IN THE
EXPANDED PORTION OF THE
TEMPERATURE RANGE
- 50 - 40 - 30 - 20 90 100 110 120 130 140 150
HOW TO ORDER
PTF
MODEL B
TOLERANCE
F=± 1.0%
D=± 0.5%
C=± 0.25%
B=± 0.1%
A=± 0.05%
BC= ± 0.02%
BB = ± 0.01%
20K01
VALUE
DECIMAL LOCATOR/MULTIPLIER
56
SIZE
Code Resistance
R = x 1
K = x 1000
M = x 1,000,000
Examples:
50R = 50Ω
62R2 = 62.2Ω
100R1 = 100.1Ω
1K001 = 1001Ω
10K1 = 10,100Ω
100K1 = 100,100Ω
1M0 = 1,000,000Ω
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
