www.vishay.com For technical questions contact: copalsupport@vishay.com Document Number: 58010
5Revision: 06-Mar-06
ST-4
Vishay Surface Mount Cermet Trimmers (single turn)
MECHANICAL SPECIFICATIONS
Mechanical angle 240° (1 turn)
Operating torque 10 mN m {102 gf cm} maximum
Stop strength 30 mN m {306 gf cm} minimum
Rotational life 100 cycles [ΔR/R ≤ ± (2 Ω + 3 %]
Thrust to rotor 5 N {0.51 kgf} minimum
Solderability
Sn-Pb: 235 °C, 2 s
Sn-Cu (Lead (Pb)-free): 245 ± 3 °C, 2 ∼
3 s
Shear (Adhesion) 5 N {0.51 kgf} 10 s
Substrate bending Width 90 mm, bend 3 mm, 5 s, 1 time
Pull-off strength 5 N {0.51 kgf} 10 s
ELECTRICAL SPECIFICATIONS
Nominal resistance
range 10 Ω ∼ 2 MΩ
Resistance tolerance ± 20 %
Power ratings 0.25 W (70 °C) 0 W (125 °C)
Resistance law Linear law (B)
Maximum input
voltage
DC200 V or power rating, whichever is
smaller
Maximum wiper
current
100 mA or power rating, whichever is
smaller
Effective electrical turn 210° (1 turn)
End resistance 1 % or 2 Ω, whichever is greater
C.R.V. 1 % or 3 Ω, whichever is greater
Operating temp. range - 55 ∼ 125 °C
Temp. coefficient 10 Ω ∼ 50 Ω: ± 250 10-6 /°C maximum
100 Ω ∼ 2MΩ: ± 100 10-6 /°C maximum
Insulation resistance 1000 MΩ minimum (DC500 V)
Dielectric strength AC500 V, 60 s
Net weight
Approx. 0.12 g (ST-4A, B, C, D, F, EA,
EB, EC, ED, EF)
Approx. 0.22 g (ST-4G, H, EG, EH)
ENVIRONMENTAL SPECIFICATIONS
Test item Test conditions Specifications
Thermal shock - 65 ∼ 125 °C (0.5 h),
5 cycles
[ΔR/R ≤ 2 %]
[S.S. ≤ 1 %]
Humidity
- 10 ∼ 65 °C (Relative
humidity 80 ∼ 98 %),
10 cycles, 240 h [ΔR/R ≤ 2 %]
Shock
981 m/s2, 6 ms
6 directions for 3 times
each
[ΔR/R ≤ 1%]
[S.S. ≤ 1 %]
Vibration
Amplitude 1.52 mm or
Acceleration 196 m/s2,
10 ∼ 2000 Hz, 3
directions, 12 times
each
Load Life 70 °C, 0.25 W, 1000 h [ΔR/R ≤ 3 %]
[S.S. ≤ 1 %]
Low
temperature
operation
- 55 °C, 2 h [ΔR/R ≤ 2 %]
[S.S. ≤ 2 %]
High
temperature
exposure
125 °C, 250 h [ΔR/R ≤ 3 %]
[S.S. ≤ 2 %]
Immersion seal 85 °C, 60 s No leaks (No
continuous bubbles)
Soldering heat
Sn-Pb
260 °C, 10 s or 215 °C,
35 s
[ΔR/R ≤ 1 %]
Sn-Cu
Flow: 260 °C ± 3 °C as
the temperature in a pot
of molten solder,
immersion from head of
terminal to backside of
board, 5 ∼ 6 s, two times
maximum
Reflow: Peak
temperature 255 °C
(Please refer to the
profile below.)
Manual soldering:
350 ± 10 °C, 3 ∼ 4 s
Reflow : two times maximum
Peak : 250
Over 230 °C
Pre Heating Zone
180°C
(°C)
250
200
150
100
50
150°C
90 ± 30 s
30 ± 10 s
Soldering Zone
Heating time
Te
rut
a
r
epm
e
°C
+5
0
Reflow profile for soldering heat evolution