Resistors
High Power MELF Resistors
WRM-HP Series
AEC-Q200 qualified
High power up to 1W
Tolerance down to ±0.1%
TCR down to ±15ppm/°C
High pulse handling capability
All parts are Pb-free and comply with EU Directive 2011/65/EU (RoHS2)
Electrical Data
WRM0204HP
Power rating at 70°C
Resistance range
Limiting element voltage
Maximum overload voltage
TCR
Resistance tolerance
Standard values
Thermal impedance
Ambient temperature range
Insulation resistance
Voltage proof
watts
ohms
volts
volts
ppm/°C
%
°C /W
°C
ohms
volts
0.4
R10 – 1M0
200
400
15, 25, 50, 100
0.1, 0.25, 0.5, 1, 5
E24 & E96
200
-55 to +155
>10
10
284
497
140
350
700
15, 25, 50, 100
WRM0207HP
1
Physical Data
Dimensions (mm) and weight (g)
Type
WRM 0204HP
WRM 0207HP
L
max
3.7
6.1
D
max
1.55
2.4
D1
max
1.55
2.4
K
min
0.7
1.2
L
1
min
1.5
2.9
Weight
0.02
0.08
Construction
A metal film is deposited onto a high dissipation ceramic former to which
tin plated terminating caps are fitted.
The resistor is adjusted to value by a helical cut in the film and the body is
protected by a lacquer coating.
Terminations
Material
Plated steel cap.
Solderability
The pure tin finish produces ageing free contacts on which
low melting solders can be used. Dipped area shall be
covered with a smooth and bright solder coating after
3 seconds immersion at 215°C.
Marking
Resistance values are colour coded with three or four bands, indicating
value and multiplier.
Solvent Resistance
The body protection and marking are resistant to all normal industrial
cleaning solvents suitable for printed circuit boards.
General Note
TT Electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
BI Technologies IRC Welwyn
www.ttelectronics.com/resistors
© TT Electronics plc
10.17
High Power
MELF Resistors
WRM-HP Series
TCR and Tolerance Range
Type
TCR (±ppm/°C)
±100
±50
±25
±15
±100
±50
±25
±15
Tolerance (±%)
5
0R1 – 1M0
0R2 – 1M0
–
–
0R1 – 1M0
0R2 – 1M0
–
–
–
1R0 – 1M0
10R – 1M0
10R – 300K
1
0.5
–
1R0 – 1M0
10R – 1M0
10R – 300K
–
0.25
–
0.1
–
10R – 1M0
WRM0204HP
WRM0207HP
–
10R – 1M0
Performance Data
Maximum
Short time overload: 5s at lesser of 6.25 x rated power or 2 x LEV
Biased humidity: 1000hrs 85°C/85%RH 10% of rated power
Surge test: IEC 60115-1, 10/700µs at lesser of √(P
70
.R) & 2 x LEV
High temperature exposure: 1000hrs at 155°C
Bending test: 2mm deflection for 60s
Resistance to soldering heat: 260±5°C for 10s
Temperature rapid change: 1000cycles -55/125°C
Endurance: 1000hrs rated power at 70°C
(For endurance at 8000hrs multiply stability by 2,
for endurance at 225,000hrs multiply stability by 6)
Mechanical shock: half-sine waveform, peak 100g, duration 6ms
Vibration: 5g for 20min, 12 cycles each of 3 orientations, 10-2000Hz
ESD: 2kV human body model
Solderability: 245±5°C for 3s
Voltage proof: 1.42 x LEV
±ΔR%
±ΔR%
±ΔR%
±ΔR%
±ΔR%
±ΔR%
±ΔR%
±ΔR%
±ΔR%
±ΔR%
±ΔR%
0.15
0.15
0.15
0.3
0.05
0.15
0.2
0.25
0.1
0.15
0.5
>95% coverage
No breakdown or flashover
Pulse & Thermal Performance
Single Pulse: 50 rectangular pulses applied at 60s intervals such that mean power is <10% of rated power. Maximum permitted change ±1%. The peak
power for high values is also subject to the restrictions of the pulse voltage graph.
Continuous Pulses: Continuous rectangular pulses applied at intervals such that mean power is equal to the rated power. Maximum permitted change ±1%
The peak power for high values is also subject to the restrictions of the pulse voltage graph.
Single Pulse
1000
1000
Continuous Pulses
Peak Power (W)
Peak Power (W)
100
100
0207
10
0207
10
0204
1
0.0001
0.001
0.01
0.1
1
1
0.0001
0.001
0204
0.01
0.1
1
Pulse Duration (s)
Pulse Duration (s)
General Note
TT Electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
BI Technologies IRC Welwyn
www.ttelectronics.com/resistors
© TT Electronics plc
10.17
High Power
MELF Resistors
WRM-HP Series
Pulse Voltage
1000
0207
Peak Voltage (V)
100
0204
10
1
0.0001
0.001
0.01
0.1
1
Pulse Duration (s)
Lightning Surge Performance
Resistors are tested in accordance with IEC 60115-1 using both 1.2/50µs and 10/700µs pulse shapes. 10 pulses are applied. The limit of acceptance is a
shift in resistance of less than 0.5% from the initial value.
1.2/50µs Lightning Surge
10,000
10,000
10/700µs Lightning Surge
0207
Peak Voltage (V)
Peak Voltage (V)
1,000
1,000
0207
100
0204
100
0204
10
10
10
100
1,000
10,000
100,000
1,000,000
10
100
1,000
10,000
100,000
1,000,000
Value (ohms)
Value (ohms)
Ordering Procedure
Example: WRM0204HPC-2K49FT3 (WRM0204HP, 50ppm/°C, 2.49 kilohms ±1%, Pb-free)
General Note
TT Electronics reserves the right to make changes in product specification without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
BI Technologies IRC Welwyn
www.ttelectronics.com/resistors
© TT Electronics plc
10.17
