High Power MELF Resistors
WRM-HP Series
AEC-Q200qualied
Highpowerupto1W
Tolerancedownto±0.1%
TCRdownto±15ppm/°C
Highpulsehandlingcapability
Resistors
BI Technologies IRC Welwyn
07.18
General Note
TT Electronics reserves the right to make changes in product specication without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
© TT Electronics plc
www.ttelectronics.com/resistors
WRM0204HP WRM0207HP
Power rang at 70°C was 0.4 1
Resistance range ohms R10 – 1M0
Liming element voltage volts 200 350
Maximum overload voltage volts 400 700
TCR ppm/°C 15, 25, 50, 100 15, 25, 50, 100
Resistance tolerance % 0.1, 0.25, 0.5, 1, 5
Standard values E24 & E96
Thermal impedance °C /W 200 140
Ambient temperature range °C -55 to +155
Insulaon resistance ohms >1010
Voltage proof volts 284 497
Dimensions (mm) and weight (g)
Type L
max
D
max
D1
max
K
min
L1
min Weight
WRM 0204HP 3.7 1.55 1.55 0.7 1.5 0.02
WRM 0207HP 6.1 2.4 2.4 1.2 2.9 0.08
ElectricalData
PhysicalData
Construcon
A metal lm is deposited onto a high dissipaon ceramic former to which
n plated terminang caps are ed.
The resistor is adjusted to value by a helical cut in the lm and the body is
protected by a lacquer coang.
Terminaons
Material Plated steel cap.
Solderability The pure n nish produces ageing free contacts on which
low melng solders can be used. Dipped area shall be
covered with a smooth and bright solder coang aer
3 seconds immersion at 215°C.
Marking
Resistance values are colour coded with three or four bands, indicang
value and mulplier.
SolventResistance
The body protecon and marking are resistant to all normal industrial
cleaning solvents suitable for printed circuit boards.
AllpartsarePb-freeandcomplywithEUDirecve2011/65/EUamendedby(EU)2015/863(RoHS3)AllpartsarePb-freeandcomplywithEUDirecve2011/65/EUamendedby(EU)2015/863(RoHS3)
High Power
MELF Resistors
WRM-HP Series
BI Technologies IRC Welwyn
07.18
General Note
TT Electronics reserves the right to make changes in product specication without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
© TT Electronics plc
www.ttelectronics.com/resistors
Type TCR (±ppm/°C) Tolerance (±%)
5 1 0.5 0.25 0.1
WRM0204HP
±100 0R1 – 1M0 – – –
±50 0R2 – 1M0 1R0 – 1M0 10R – 1M0
±25 – 10R – 1M0
±15 – 10R – 300K
WRM0207HP
±100 0R1 – 1M0 – – –
±50 0R2 – 1M0 1R0 – 1M0 10R – 1M0
±25 – 10R – 1M0
±15 – 10R – 300K
Maximum
Short me overload: 5s at lesser of 6.25 x rated power or 2 x LEV ±ΔR% 0.15
Biased humidity: 1000hrs 85°C/85%RH 10% of rated power ±ΔR% 0.15
Surge test: IEC 60115-1, 10/700µs at lesser of √(P70.R) & 2 x LEV ±ΔR% 0.15
High temperature exposure: 1000hrs at 155°C ±ΔR% 0.3
Bending test: 2mm deecon for 60s ±ΔR% 0.05
Resistance to soldering heat: 260±5°C for 10s ±ΔR% 0.15
Temperature rapid change: 1000cycles -55/125°C ±ΔR% 0.2
Endurance: 1000hrs rated power at 70°C
(For endurance at 8000hrs mulply stability by 2,
for endurance at 225,000hrs mulply stability by 6)
±ΔR% 0.25
Mechanical shock: half-sine waveform, peak 100g, duraon 6ms ±ΔR% 0.1
Vibraon: 5g for 20min, 12 cycles each of 3 orientaons, 10-2000Hz ±ΔR% 0.15
ESD: 2kV human body model ±ΔR% 0.5
Solderability: 245±5°C for 3s >95% coverage
Voltage proof: 1.42 x LEV No breakdown or ashover
TCRandToleranceRange
PerformanceData
Pulse&ThermalPerformance
Single Pulse: 50 rectangular pulses applied at 60s intervals such that mean power is <10% of rated power. Maximum permied change ±1%.
Connuous Pulses: Connuous rectangular pulses applied at intervals such that mean power is equal to the rated power. Maximum permied change ±1%.
1
10
100
1000
0.0001 0.001 0.01 0.1 1
Peak Power (W)
Pulse Duration (s)
Single Pulse
1
10
100
1000
0.0001 0.001 0.01 0.1 1
Peak Power (W)
Pulse Duration (s)
Continuous Pulses
0204 0204
0207 0207
10
100
1,000
10,000
10 100 1,000 10,000 100,000 1,000,000
Peak Voltage (V)
Value (ohms)
1.2/50µs Lightning Surge
10
100
1,000
10,000
10 100 1,000 10,000 100,000 1,000,000
Peak Voltage (V)
Value (ohms)
10/700µs Lightning Surge
High Power
MELF Resistors
WRM-HP Series
BI Technologies IRC Welwyn
07.18
General Note
TT Electronics reserves the right to make changes in product specication without notice or liability.
All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.
© TT Electronics plc
www.ttelectronics.com/resistors
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
shiinresistanceoflessthan0.5%fromtheinialvalue.
OrderingProcedure
Example: WRM0204HPC-2K49FT3(WRM0204HP,50ppm/°C,2.49kilohms±1%,Pb-free)
0204 0204
0207 0207
0207
0204
0
20
40
60
80
100
120
140
0% 20% 40% 60% 80% 100%
Temperature Rise (°C)
Proportion of Rated Power
Temperature Rise