RHC Series Stackpole Electronics, Inc. High Power Thick Film Chip Resistor Features: * * * * * * Type / Code Resistive Product Solutions Handles 2W of power Resistances from 0.1 to 1M RoHS compliant / lead-free TCR of 100 ppm/C 1% and 5% tolerances Runs significantly cooler than standard thick film 2512 chip Electrical Specifications Electrical Specifications Package Type Power Rating (Watts) @ 70C Maximum Working Voltage (1) Maximum Overload Voltage Resistance Temperature Coefficient 2512 2W 200V 400V 100 ppm/C RHC2512 Ohmic Range () and Tolerance 1% 5% 0.1 - 1M 0.1 - 1M (1) Lesser of PR or maximum working voltage Please refer to the High Power Resistor Application Note (page 4) for more information on designing and implementing high power resistor types. Mechanical Specifications Type / Code RHC2512 L Body Length 0.248 0.008 6.30 0.20 W Body Width 0.126 0.008 3.20 0.20 H Body Height 0.024 0.004 0.60 0.10 a Top Termination 0.028 0.008 0.70 0.20 b Bottom Termination 0.087 0.008 2.20 0.20 Unit inches mm Solder Pad Dimensions L Total Length 0.315 8.00 Type / Code RHC2512 W Total Width 0.138 3.50 D Pad Depth 0.118 3.00 Unit inches mm Performance Characteristics Test Typical Moisture Resistance 1% Load Life 1% Resistance to Soldering 1% Temperature Cycling 1% Thermal Shock 1% Short Time Overload 1% Insulation Resistance 1M Operating Temperature Range: -55C to +155C Rev Date: 06/19/2012 This specification may be changed at any time without prior notice Please confirm technical specifications before you order and/or use. 1 www.seielect.com marketing@seielect.com RHC Series Stackpole Electronics, Inc. High Power Thick Film Chip Resistor Power Derating Curve: Resistive Product Solutions Percent Rated Power (%) 100 -55C 70C 80 60 40 20 155C 0 -60 -40 -20 0 20 40 60 80 100 Ambient Temperature (C) Temperature Rise: 120 140 160 180 Temperature Rise C 140 1 2 120 100 80 60 40 Hot Spot Solder Joint 20 1 2 0 Load (w) 0 1 2 Repeated Overload: Test condition: Voltage (Power): 2.0, 2.25, 2.5, 2.75, 3.0, 3,25 times of rated voltage. (8W, 10.1W, 12.5W, 15.1W, 18W, 21.1W) Applied time: Each voltage 5 seconds. As a reference test, the RMC was tested with the same rated voltage and testing substrate. Rev Date: 06/19/2012 This specification may be changed at any time without prior notice Please confirm technical specifications before you order and/or use. 2 www.seielect.com marketing@seielect.com RHC Series Stackpole Electronics, Inc. High Power Thick Film Chip Resistor Resistive Product Solutions How to Order 1 2 3 4 5 6 7 8 9 10 11 12 13 R H C 2 5 1 2 F T 1 0 K 0 Product Series High Power RHC Size Power Rating 2W 2512 Code F J Tolerance Tol Value 1% E96, E24 5% E24 Code T Packaging Description Size 7" Reel 2512 Plastic Tape Quantity 4,000 Legacy Part Number (before January 3, 2011): Resistance Value Four characters with the multiplier used as the decimal holder. 0.1 ohm = R100 4.75 ohm = 4R75 10.2 Kohm = 10K2 1 Mohm = 1M00 SEI Type Code Nominal Resistance Tolerance Packaging RHC 2512 10K 1% R Type RHC Description High Power Code Wattage Size 2512 2W 2512 Rev Date: 06/19/2012 This specification may be changed at any time without prior notice Please confirm technical specifications before you order and/or use. Tolerance 1% 5% 3 Values E24, E96 E24 SEI Types Pkg Qty 2512 4,000 Description 7" reel plastic tape Code R www.seielect.com marketing@seielect.com RHC Series Stackpole Electronics, Inc. High Power Thick Film Chip Resistor Resistive Product Solutions 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 1/2 100 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 m. This should be taken into account when designing. Rev Date: 06/19/2012 This specification may be changed at any time without prior notice Please confirm technical specifications before you order and/or use. 4 www.seielect.com marketing@seielect.com