RNS Series
Ultra Miniature Metal Film Resistor
Stackpole Electronics, Inc.
Resistive Product Solutions
Rev Date: 02/11/2011 1 www.seielect.com
This specification may be changed at any time without prior notice. marketing@seielect.com
Please confirm technical specifications before you order and/or use.
ABCD
Body Le ngth Body Dia m eter Lead Length (Bul k) Lead Diameter
0.13 ± 0.01 0.07 ± 0.01 1.10 ± 0.08 0.017 ± 0.002 inches
3.40 ± 0.40 1.80 ± 0.30 28.0 ± 2.0 0.43 ± 0.05 mm
0.26 ± 0.02 0.09 ± 0.006 1.10 ± 0.08 0.022 ± 0.002 inches
6.50 ± 0.50 2.30 ± 0.20 28.0 ± 2.0 0.56 ± 0.05 mm
0.35 ± 0.02 0.14 ± 0.02 1.10 ± 0.08 0.31 ± 0.004 inches
9.00 ± 0.50 3.50 ± 0.50 28.0 ± 2.0 0.80 ± 0.10 mm
Operating Temperature Range: -55ºC to +155ºC
RNS 2
Type / Code Units
RNS 1/2
RNS 1
Maximum Maximum
T
y
pe / Code Workin
g
Pulse
Voltage1Voltage 0.5% 1%
±50 ppm/ºC
±100 ppm/ºC
±25 ppm/ºC
±50 ppm/ºC
±100 ppm/ºC
±25 ppm/ºC
±50 ppm/ºC
±100 ppm/ºC
1Lesser of√PR or maximum working voltage
2.0WRNS 2 100 - 511K 10 - 1M700V350V
100 - 511K 10 - 1M600V
RNS 1/2
350V1.0WRNS 1
Power Rating
(Watts) @ 70ºC Resistance Temperature Coefficient Ohmic Range (Ω) and Tolerance
10 - 1M 4.99 - 1M400V200V0.5W
Test Standard / Method Requirement
Biased Humidity MIL-STD 202, Method 103 ± 1.5%
Resistance to Solder Heat MIL-STD 202, Method 210 ± 0.5%
Insulation Resistance JIS C 5202 5.6 ± 0.5%
Load Life MIL-STD 202, Method 208 ± 1.0%
Terminal Strength MIL-STD 202, Method 211 ± 0.2%
Temperature Cycling JESD22 Method JA-104 ± 1.0%
Moisture Resistance MIL-STD 202, Method 106 ± 0.5%
Features:
Electrical Specifications
Please refer to the High Power Resistor Application Note (page 3) for more information on designing and implementing
high power resistor types.
Mechanical Specifications
Performance Characteristics
• Miniature metal film for tight size constraints
• Superior electrical, TCR performances
• Flame-retardant coatings are standard
• 1/2-watt in standard 1/8-watt package, 1-watt part in
1/4-watt package, 2-watt part in 1/2-watt package
• RoHS compliant
RNS Series
Ultra Miniature Metal Film Resistor
Stackpole Electronics, Inc.
Resistive Product Solutions
Rev Date: 02/11/2011 2 www.seielect.com
This specification may be changed at any time without prior notice. marketing@seielect.com
Please confirm technical specifications before you order and/or use.
1234567891011
RNS1FTD4K75
RNS Ultra Mini Code Quantity Code ppm
5,000 E25
2,500 C50
A5,000
D100
B1,000
Description Size
TCR Resistance ValuePackagingProduct Series Size Power Tolerance
12 0.5W Code Tol
RNS12, RNS1 Four characters with
the multiplier used as
the decimal holder.
RNS2
RNS12, RNS1, RNS2
D0.5%
22W
11W
10.2 Kohm = 10K2
1 Mohm = 1M00
F1%
4.99 ohms = 4R99RNS12, RNS1, RNS2
T tape and reel
ammo
bulk
Nominal
Resistance
4.75K
T
y
pe Description Code Watta
g
e Tolerance
V
alues T
y
pes Qt
y
Description Code
RNS Ultra Mini 1/2 0.5W T1 100ppm 0.5% E96 RNS 1/2, RNS 1 5,000
1 1W T2 50ppm 1% E96, E24 RNS 2 2,500
2 2W T9 25ppm RNS 1/2, RNS 1, RNS 2 5,000 Ammo T
RNS 1/2, RNS 1, RNS 2 1,000 Bulk A
TCR
Tape and Reel R
PackagingTCR
R
T1
RNS 1 1%
SEI Type Code Tolerance
How to Order
New part number format starting January 3rd, 2011:
How to Order
RNS Series
Ultra Miniature Metal Film Resistor
Stackpole Electronics, Inc.
Resistive Product Solutions
Rev Date: 02/11/2011 3 www.seielect.com
This specification may be changed at any time without prior notice. marketing@seielect.com
Please confirm technical specifications before you order and/or use.
CSR 1/2 100m Surface Temp Rise
72
50
41
36
35
102
0
20
40
60
80
100
120
0.10 0.13 0.17 0.25 0.50 0.75
Power Rating
℃
Test equipment:
Chroma Programmable DC Power supply
YF-162 TYPE--K thermometer
High Power Chip Resistors and Thermal Management
Stackpole has developed several surface mount resistor series in addition to our current sense resistors,
which have had higher power ratings than standard resistor chips. This has caused some uncertainty and
even confusion by users as to how to reliably use these resistors at the higher power ratings in their designs.
The data sheets for the RHC, RMCP, RNCP, CSR, CSRN, CSRF, CSS, and CSSH state that the rated
power assumes an ambient temperature of no more than 100 degrees C for the CSS / CSSH series and 70
degrees C for all other high power resistor series. In addition, IPC and UL best practices dictate that the
combined temperature on any resistor due to power dissipated and ambient air shall be no more than 105C.
At first glance this wouldn’t seem too difficult, however the graph below shows typical heat rise for the CSR
½ 100 milliohm at full rated power. The heat rise for the RMCP and RNCP would be similar. The RHC with
its unique materials, design, and processes would have less heat rise and therefore would be easier to
implement for any given customer.
The 102 degrees C heat rise shown here would indicate there will be additional thermal reduction techniques
needed to keep this part under 105C total hot spot temperature if this part is to be used at 0.75 watts of
power. However, this same part at the usual power rating for this size would have a heat rise of around 72
degrees C. This additional heat rise may be dealt with using wider conductor traces, larger solder pads and
land patterns under the solder mask, heavier copper in the conductors, vias through PCB, air movement, and
heat sinks, among many other techniques. Because of the variety of methods customers can use to lower
the effective heat rise of the circuit, resistor manufacturers simply specify power ratings with the limitations
on ambient air temperature and total hot spot temperatures and leave the details of how to best accomplish
this to the design engineers. Design guidelines for products in various market segments can vary widely so it
would be unnecessarily constraining for a resistor manufacturer to recommend the use of any of these
methods over another.
Note: The final resistance value can be affected by the board layout and assembly process, especially the size of the
mounting pads and the amount of solder used. This is especially notable for resistance values ≤ 50 mΩ.
This should be taken into account when designing.
