Bulk Metal
®
Foil Ultra High Technology Precision Trimming Potentiometers,
3
/
8
" Square, RJ24 Style, Designed to Meet or Exceed the Requirements of
MIL-PRF-39035, Char. H with a Smooth and Unidirectional Output
Accutrim™ 1260 (RJ24 Style)
Vishay Foil Resistors
Document Number: 63054 For any questions, contact: foil@vishaypg.com www.vishayfoilresistors.com
Revision: 8-Nov-12 1
INTRODUCTION
Vishay Foil Resistors (VFR) precision trimmers have the
Bulk Metal
®
Foil resistive element which possesses a unique
inherent temperature and load life stability. Plus, their
advanced virtually back lash-free adjustment mechanism
makes them easy to set quickly and accurately and keeps
the setting exactly on target.
FEATURES
Temperature coefficient of resistance (TCR):
± 10 ppm/°C (- 55 °C to + 150 °C ref. at + 25 °C);
through the wiper
(2)
; ± 25 ppm/°C (see table 2 for
low values)
A
smooth and unidirectional resistance with
leadscrew adjustment
Load life stability: 0.1 % typical R, 1.0 % maximum R
under full rated power at + 85 °C for 10 000 h
Se
ttability: 0.05 % typical; 0.1 % maximum
Se
tting stability: 0.1 % typical; 0.5 % maximum
Power rating: 0.25 W at + 85 °C
R
esistance range: 5 to 10 k
R
esistance tolerance: ± 5 %, ± 10 %
“O”-ring prevents ingress of fluids during any board
cleaning operation
El
ectrostatic discharge (ESD) up to 25 000 V
T
erminal finish: tin/lead or lead free
CERMET
Wiper Travel
Resistance
Wiper Travel
Resistance
BULK METAL
FOIL
WIREWOUND
Wiper Travel
Resistance
TABLE 1 - MODEL SELECTION
MODEL TERMINATION STYLE AVERAGE WEIGHT (g) POWER RATING at + 85 °C AMBIENT NO. OF TURNS
1260
W-edge mount, top adjust
0.4 0.25 W 21 ± 2
X-edge mount, side adjust
Note
• See figure 1
TABLE 2 - 1260 (RJ24 STYLE) SERIES
ELECTRICAL SPECIFICATIONS
Temperature Coefficient of
Resistance (TCR) 50 to
10 k
End-to-end
(1)
± 10 ppm/°C maximum
(- 55 °C to + 150 °C,
+ 25 °C ref.)
Temperature Coefficient of
Resistance (TCR) 5 , 10
and 20
Through the wiper
(2)
± 20 ppm/°C
± 25 ppm/°C
Stability
Load life at 10 000 h
0.1 % typical R
1.0 % maximum R
(under full rated power
of 0.25 W at + 85 °C)
Power Rating
(3)
0.25 W at + 85 °C
Settability
0.05 % typical;
0.1 % maximum
Setting Stability 0.1 % typical;
0.5 % maximum
Contact Resistance
Variation - CRV (noise)
3
typical;
10
maximum
Hop-off
0.25 % typical;
1.0 % maximum
High-Frequency Operation
Rise/decay time
Inductance
Capacitance
1 ns without ringing
0.08 µH typical
0.5 pF typical
Operating Temperature Range - 55 °C to + 150 °C
TABLE 3 - VALUES VS. TOLERANCES
STANDARD RESISTANCE VALUES
(in )
STANDARD
TOLERANCE
5, 10 ± 10 %
20, 50, 100, 200, 500, 1K, 2K, 5K, 10K ± 5 %
TABLE 4 - MECHANICAL SPECIFICATIONS
Adjustment Turns
21 ±
2
Mechanical Stops
Wiper idles - no discontinuity
Internal Terminations
All welded - no flux
Case Material
Diallyl-phthalate: black (DAP)
Shaft Torque
3 oz. in. maximum
Backlash
0.005 % typical
