Riedon Inc. 300 Cypress Avenue Alhambra CA 91801 (626) 284-9901 (626) 284-1704
www.riedon.com Page 80
07/13
NPR NPS 2-T220
NHR NHS 2-T220 T221
Power Resistors
Type NPR / NPS NHR / NHS
Resistance Range 0.02 Ohms to 100kOhms 0.02 Ohms to 15kOhms
Power rating
free air 70°C
with heatsink
1.5 W
30 W
1.5 W
50 W
Thermal Resistance Rthj-c 3.5 K/W 2.1 K/W
Tolerances
from 0.02 Ohms
from 1.0 Ohms
2% / 5%
1% / 2% / 5%
Stability 0.5%
Temperature Coefcient
0.02 to 0.049 Ohms
0.05 to 0.099 Ohms
0.1 Ohms to 100 kOhms
±600 ppm/°C
±300 ppm/°C
±100 ppm/°C
upon request ±50 ppm/°C
Voltage Proof 2.0 kVDC 1.5 kVDC
Max. Voltage
depending on resistance value
1
10
100
1000
10000
2 Ohm 10 Ohm 100 Ohm 1 kOhm 5 kOhm 10 kOhm 100 kOhm
max. working voltage (VDC)
Operating Temperature Range -40 to 155°C
Resistor Material Thick Film
Substrate Al2O3
Housing Epoxy or PPS
Connector Material Cu tinned
Terminals 2
Max. Torque T220: 1 Nm
T221: 0.8 Nm
SPECIFICATIONS
Part Description: Part Type - Resistance - Contact - Tolerance
NHR 2-T221 C 1.1 kOhms 1%
Ordering Information
• Resistances from 0.02Ohm to 100kOhms
• Power Rating to 50Watt
• Resistance Tolerances to ±1%
• TCR to ±50ppm/°C
• Load Stability to 0.5%
• TO-220 Housing
• Convenient SMD D2Pak Available
Power Resistors
Riedon Inc. 300 Cypress Avenue Alhambra CA 91801 (626) 284-9901 (626) 284-1704
www.riedon.com Page 81
07/13
0
20
40
60
80
100
120
25 50 85 100 115 130 145 155
Temperature of the backplate (°C)
Power ( % from
nominal power)
Temperature Coefcient
SPECIFICATIONS (continued)
NPR NPS 2-T220 T221
NHR NHS 2-T220 T221
Derating
Power Resistors
-8000
-3000
2000
7000
-50 -25 025 50 75 100 125
50ppm/°C
100ppm/°C
∆R/R (ppm)
Temperature (°C)
Dimension mm
tol.
(±mm) inches
tol.
(±inches)
A 12.70 0.2 0.50 0.008
B 10.16 0.2 0.40 0.008
C 0.76 0.1 0.03 0.004
D 5.08 0.1 0.20 0.004
E 4.00 0.1 0.16 0.004
F 1.20 0.1 0.05 0.004
G 14.60 0.2 0.57 0.008
H 15.00 0.2 0.59 0.008
I 17.33 0.2 0.68 0.008
J 0.40 0.1 0.02 0.004
K 1.85 0.1 0.07 0.004
Dimension mm inches
A 12.10 0.476
B 11.16 0.439
C 18.33 0.722
D 5.08 0.200
E 1.76 0.069
F 3.20 0.126
NPS / NHS 2-T220
Dimensions
Power Rating Notes -
The NPR / NHR Series Resistors must be attached to a suitable
heatsink. The maximum internal resistor temperature is 155°C.
To specify an appropriate heatsink use the following formula :
RqH = TMAX - ( P x RqR ) - TA
P
Where: RqH = Thermal Resistance of Heatsink ( K/W )
RqR = Thermal Resistance of Resistor ( K/W )
TMAX = Maximum Temperature of Resistor
TA = Ambient Temperature of Heatsink ( °C )
P = Power Through Resistor ( W )
Riedon Inc. 300 Cypress Avenue Alhambra CA 91801 (626) 284-9901 (626) 284-1704
www.riedon.com Page 82
07/13
SPECIFICATIONS (continued)
NPR NPS 2-T220 T221
NHR NHS 2-T220 T221
Power Resistors
NPR / NHR 2-T220
NPR / NHR 2-T221
Dimension mm
tol.
(±mm) inches
tol.
(±inches)
A 17.30 0.2 0.68 0.008
B 10.16 0.2 0.40 0.008
C 6.00 0.1 0.24 0.004
D Ø3.7 0.1 Ø0.146 0.004
E 16.40 0.2 0.65 0.008
F 5.08 0.1 0.20 0.004
G 0.76 0.1 0.03 0.004
H 1.30 0.1 0.05 0.004
I 13.80 0.2 0.54 0.008
J 2.00 0.1 0.08 0.004
K 1.20 0.1 0.05 0.004
L 4.00 0.1 0.16 0.004
M 2.90 0.1 0.11 0.004
N 0.40 0.1 0.02 0.004
O 1.85 0.1 0.07 0.004
Dimension mm
tol.
(±mm) inches
tol.
(±inches)
A 18.30 0.2 0.72 0.008
B 10.16 0.2 0.40 0.008
C 3.70 0.1 0.15 0.004
D Ø3.2 0.1 Ø0.126 0.004
E 16.40 0.2 0.65 0.008
F 5.08 0.1 0.20 0.004
G 0.76 0.1 0.03 0.004
H 1.30 0.1 0.05 0.004
I 13.80 0.2 0.54 0.008
J 2.00 0.1 0.08 0.004
K 1.20 0.1 0.05 0.004
L 4.00 0.1 0.16 0.004
M 3.90 0.1 0.15 0.004
N 0.40 0.1 0.02 0.004
O 1.85 0.1 0.07 0.004