RA Varistor Series RoHS Description The RA Series transient surge suppressors are varistors (MOVs) supplied in a low-profile box that features a precise seating plane to increase mechanical stability for secure circuit-board mounting. This feature makes these devices suitable for industrial applications critical to vibration. Their construction permits operation up to ºC (ambient) without derating. Agency Approvals Agency Agency Approval Agency File Number The RA Series are available in voltage ratings up to 7V V M(AC)RMS, and energy levels up to 4J. These varistors are used in automotive, motor-control, telecommunication, and military applications. See RA Series Device Ratings and Specifications Table for part number and brand information. UL449 E36 Features Additional Information Datasheet Resources Samples Lead free/rohs compliant parts available (add suffix "x749") Low profile outline with precise seating plane No derating up to ºC ambient In-line leads Wide operating voltage range: V M(AC)RMS : 4 7V V M(DC):. 369V High energy absorption capability W TM up to 4J 3 model sizes available A8, RA6, and RA Absolute Maximum Ratings For ratings of individual members of a series, see Device Ratings and Specifications chart Continuous RA8 Series RA6 Series RA Series Units Steady State Applied Voltage: AC Voltage Range (V M(AC)RMS ) 4 to 7 to 7 4 to 7 V DC Voltage Range (V M(DC) ). to 369 4 to 369 8 to 369 V Transients: Peak Pulse Current (I TM ) For 8/µs Current Wave (See Figure ) to to 4 to 6 A Single Pulse Energy Range (Note ) For /µs Current Wave (W TM ).4 to 3 3. to 7 7 to 6 J Operating Ambient Temperature Range (T A ) - to + - to + - to + ºC Storage Temperature Range (T STG ) - to + - to + - to + ºC Temperature Coefficient (a V ) of Clamping Voltage (V C ) at Specified Test Current <. <. <. %/ºC Hi-Pot Encapsulation (COATING Isolation Voltage Capability) (Delectric must withstand indicated DC voltage for one minute per MIL-STD, Method 3) V COATING Insulation Resistance MΩ CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. 7 Littelfuse, Inc. Revised: 9/4/7
RA Series Ratings & Specifications Part Number Brand Maximum Rating ( C) Continuous Transient V RMS V DC Energy (/µs) Peak Current (8/µs) Varistor Voltage at ma DC Test Current Specifications ( C) Max Clamping Volt V C (8/µs) Typical Capacitance V M(AC) V M(DC) W TM I TM Min V N(DC) Max V C I p f = MHz (mm) (V) (V) (J) (A) (V) (V) (V) (V) (A) (pf) RA8 Series V8RA8 8R 4..4 6 8.6. VRA8 R 6 8.6 9. 6 34 V8RA8 8R 4.8 6. 8 9.8 4 VRA8 R 4 8 (Note 3) (Note ) 9.8 4. 47 V7RA8 7R 7. 4.3 7 9.7 7 V33RA8 33R 6. 9.7 33 36.3 68 V39RA8 39R 3. 3. 39 4.9 79 9 V47RA8 47R 3 38.8 4.3 47.7 9 V6RA8 6R 3 4.3.4 6 6.6 7 7 V68RA8 68R 4 6 3. 6. 68 74.8 7 V8RA8 8R 66 4. 73.8 8 9. 3 VRA8 R 6 8. 9 6 VRA8 R 7 6. 8 3 VRA8 R 9 7 8. 3 6 V8RA8 8R 3. 6 8 98 9 VRA8 R 3 7. 84.. 34 8 VRA8 R 4 8. 98 4 36 6 V4RA8 4R 3. 6 4 64 39 V7RA8 7R 7. 43 7 97 4 3 V36RA8 36R 3. 34 36 396 9 V39RA8 39R 33. 3 39 49 6 9 V43RA8 43R 7 369 3. 387 43 473 7 8 RA6 Series V8RA6 8R6 4 3. 6. 8 9.8 39 VRA6 R6 4 8 (Note 3) (Note ) 9.8 4. 43 9 V7RA6 7R6 7. 4.3 7 9.7 3 7 V33RA6 33R6 6 6. 9.7 33 36.3 64 V39RA6 39R6 3 7. 3. 39 4.9 76 V47RA6 47R6 3 38 8.8 4.3 47.7 89 4 V6RA6 6R6 3 4..4 6 6.6 3 39 V68RA6 68R6 4 6 3. 6. 68 74.8 3 3 V8RA6 8R6 66. 4 73.8 8 9. 4 VRA6 R6 6 8. 4 9 7 VRA6 R6 7. 4 8 3 7 VRA6 R6 9 7 3. 4 3 6 V8RA6 8R6 3 3. 4 6 8 98 VRA6 R6 3 7 38. 4 84.. 34 VRA6 R6 4 8 4. 4 98 4 36 9 V4RA6 4R6 4. 4 6 4 64 39 V7RA6 7R6 7. 4 43 7 97 4 7 V36RA6 36R6 3 7. 4 34 36 396 9 V39RA6 39R6 33 7. 4 3 39 49 6 V43RA6 43R6 7 369 7. 4 387 43 473 7 4 7 Littelfuse, Inc. Revised: 9/4/7
RA Series Ratings & Specifications Part Number RA Series Brand V4RA 4R 4 Maximum Rating ( C) Continuous Transient V RMS V DC Energy (/µs) Peak Current (8/µs) Varistor Voltage at ma DC Test Current Specifications ( C) Max Clamping Volt V C (8/µs) Typical Capacitance V M(AC) V M(DC) W TM I TM Min V N(DC) Max V C I p f = MHz (mm) (V) (V) (J) (A) (V) (V) (V) (V) (A) (pf) 8 (Note 3) V36RA 36R 3 3. (Note ) 6. (Note ).6 4 6.4 43 3.4 36 39.6 63 VRA R 3 7 7. 6 84.. 34 9 V4RA 4R 8. 6 6 4 64 39 V7RA 7R 7 9. 6 43 7 97 4 V39RA 39R 33 3. 6 3 39 49 6 V43RA 43R 7 369 4. 6 387 43 473 7 9 NOTES:. Average power dissipation of transients not to exceed.w for RA8 Series,.6W for RA6 Series, or.w for RA Series.. Energy ratings for impulse duration of 3ms minimum to one half of peak current value. 3. Also rated to withstand 4V for minutes. 4. ma DC Test Current. Under UL File No. E36 as a recognized component. CSA approved File No. 9788. Power Dissipation Ratings Peak Pulse Current Test Waveform PERCENT OF RATED VALUE 9 8 7 6 4 3-6 7 8 9 3 4 Figure AMBIENT TEMPERATURE ( o C) FIGURE. CURRENT, ENERGY AND POWER DERATING Should transients CURVE occur in rapid succession, the average power dissipation required is simply the energy (watt-seconds) per pulse times the number of pulses per second. The power so developed must be within the specifications shown on the Device Ratings and Specifications table for the specific device. Furthermore, the operating values need to be derated at high temperatures as shown above. Because varistors can only dissipate a relatively small amount of average power they are, therefore, not suitable for repetitive applications that involve substantial amounts of average power dissipation. PERCENT OF PEAK VALUE Figure 9 O TT T TIME O = Virtual Origin of W T = Time From % t T = Virtual Front time T = Virtual Time to Ha Example: For an 8/ s 8 s = T = Virtual Front s = T = Virtual Time FIGURE. PEAK PULSE CURRENT TEST WAVEFOR = Virtual Origin of Wave T = Time from % to 9% of Peak T = Rise Time =. x T T = Decay Time Example - For an 8/ µs Current Waveform: 8µs = T = Rise Time µs = T = Decay Time 7 Littelfuse, Inc. Revised: 9/4/7
Metal-Oxide Varistors (MOVs) 9 8 7 6 4 8 TO 68V N(DC) RATING T A = - o C TO o C V68RA6 V6RA6 V47RA6 V39RA6 V33RA6 V7RA6 3 VRA6 Maximum Clamping V8RA6 Voltage for 8mm Parts -3 - - 3 V8RA8 - V68RA8 8 TO 68V N(DC) RATING T A = - FIGURE o C TO. CLAMPING o C VOLTAGE FOR V8RA6 - V68RA6 8 TO 68V N(DC) RATING T A = - o C TO MAXIMUM o C CLAMPING VOLTAGE 4 TO 36V N(DC) RATING T A = - o C TO o C 9 8 V68RA8 7 V6RA8 6 9 V47RA8 8 V68RA8 9 7 V39RA8 V6RA8 8 46V33RA8 V47RA8 7 V7RA8 V39RA8 3 6 4VRA8 V33RA8 V36RA V8RA8 V7RA8 3 VRA8 VRA8 4 V8RA8 V4RA V8RA8 VRA8 3-3 V8RA8 - - 3-3 - -3 PEAK - - AMPERES - (A) Figure 3 3 3 4 PEAK AMPERES PEAK (A) AMPERES (A) FIGURE 3. CLAMPING VOLTAGE FOR V8RA8 - V68RA8 FIGURE 3. FIGURE CLAMPING 7. CLAMPING VOLTAGE FOR VOLTAGE V8RA8 - V68RA8 FOR V4RA - V36RA V8RA8 - V43RA8 Pulse Rating Curves MAXIMUM MAXIMUM PEAK VOLTS PEAK (V) VOLTS (V MAXIMUM SURGE PEAK CURRENT VOLTS (V) (A) 3, MODEL SIZE x 8mm 8 TO 43V N(DC) RATING T A = - o C TO o C,, 9 9 V4RA6 8 VRA8 7, 7 VRA8 V43RA6 9 6 V39RA6 V36RA 7 4 V36RA6 V4RA 3 V7RA6 V8RA6 VRA6-3 - - 3 4-3 VRA6 Repetitive VRA6 Surge Capability for 8mm V8RA6 Parts FIGURE 7. CLAMPING VOLTAGE FOR V4RA - V36RA FIGURE 8. -3 - - 3 V8RA8 Pulse - VRA8 Rating Curves 4 FIGURE 6. CLAMPING VOLTAGE FOR V8RA6 - V43RA6 4, V8RA8 - VRA8 MAXIMUM CLAMPING VOLTAGE 3, 4 TO 43V N(DC) RATING T A = - o C TO o C 6, 3 V43RA, V39RA 9 7 V7RA. V4RA. VRA. -3 - -, 3, IMPULSE DURATION(μs) 4 Figure FIGURE FIGURE 8. 9. CLAMPING SURGE CURRENT VOLTAGE RATING FOR VRA CURVES - V43RA FOR V8RA8 - VRA8 V8RA8 - V68RA8 MAXIMUM PEAK VOLTS (V. FIGURE 4, 4, MAXIMUM CLAMPING VOLTAGE 3, MODEL MAXIMUM SIZE CLAMPING x 8mm VOLTAGE 4 3, 8 MODEL TO 43V SIZE N(DC) x RATING 8mm 8 TO 43V T N(DC) RATING 6 A = - o T A = - o C TO o C TO o C, C, V4RA8 V4RA8 VRA8, 3 VRA8, V43RA8 V43RA8 VRA8 VRA8 9 9 V39RA8 V39RA8 7 7 V36RA8 V7RA8 V8RA8 - VRA8 V8RA8 VRA8 VRA8 VRA8. VRA8 VRA8 V8RA8 V8RA8-3. - - 3 4-3 - - PEAK AMPERES (A), 3 4, Figure 4 FIGURE 4. CLAMPING VOLTAGE FOR IMPULSE V8RA8 DURATION - V43RA8 (μs) FIGURE 4. CLAMPING VOLTAGE FOR V8RA8 - V43RA8 FIGURE 9. SURGE CURRENT RATING CURVES FOR V8RA8 - VRA8 Figure 6.. 3 4 6 V8RA8 - V68RA8,, FIGURE. SURGE CURRENT RATING CURVES FOR V8RA8 - V68RA8 V8RA8 - V43RA8,, V8RA8 - V43RA8 3 4 6,,, Figure 7 FIGURE. SURGE CURRENT RATING CURVES FOR V8RA8 - V43RA8 FIGUR 7 Littelfuse, Inc. Revised: 9/4/7 CURRENT (A), V8RA6 - V43RA6,, 3 4 6 CURRENT (A),, 3 4 V4R
Maximum Clamping Voltage for 6mm Parts V8RA6 - V68RA6 Repetitive Surge Capability for 6mm Parts V8RA6 - V68RA6 4,,, 8 TO 68V N(DC) RATING V8RA8 - V43RA8 3, MODEL SIZE x 8mm V8RA6 - V68RA6, 3 T A = - o C TO o 8 TO 43V C N(DC) RATING T 4, A = - o C TO o C, 3 4 6 V8RA8 - V43R V4RA6, VRA8 6, V43RA6 VRA8 9 3 V39RA6 4 7 6 9 8 V68RA6 V36RA6 7 V6RA6 6 V47RA6 V7RA6 V39RA6 4 V33RA6 V8RA6 V7RA6 VRA6 3 VRA6 VRA6 V8RA6 VRA6 V8RA6,,,, -3 - - IMPULSE DURATION (μs) 3-3 - - IMPULSE DURATION 3 (μs) 4 Figure 8 Figure, FIGURE. SURGE CURRENT RATING CURVES FOR FIGURE. SURGE CURRENT RATING CURVES FOR FIGURE. CLAMPING VOLTAGE V8RA8 - FOR V43RA8 V8RA6 - V68RA6 FIGURE 6. CLAMPING VOLTAGE V8RA6 FOR - V68RA6 V8RA6 - V43RA6 V8RA6 - V43RA6 4, V8RA6 - V43RA6 FIGURE. SURGE CURRENT RATING CURVES FOR,, V8RA8 - V43RA8 4 TO 36V V8RA6 N(DC) RATING 3, - V43RA6 TO 43V V4RA N(DC) RATING - V36RA, VRA - V43 4, T A = - o C TO o C, T A = - o C TO o C,, 3 4 6,, 3, MODEL SIZE x 8mm V8RA6 - V43RA6 3,, 4 8 TO 43V N(DC) RATING, T 6 3 A = - o C TO o C V43RA,, V39RA, 6 4 3 9 V4RA6 9 4 8 VRA8 7 6, 7 V43RA6 VRA8 3 6 9 V39RA6 V36RA 4 7 4 V36RA6 V4RA V7RA 3 V7RA6 V4RA VRA V8RA6 VRA6-3, - -, 3 4,, -3 - - 3 4 VRA6, IMPULSE DURATION VRA6 (μs) V8RA6 IMPULSE DURATION (μs),, RE 3. SURGE 3 FIGURE 7. CLAMPING VOLTAGE FOR V4RA - V36RA FIGURE 8. CLAMPING VOLTAGE FOR VRA - V43RA CURRENT RATING CURVES FOR FIGURE 4. SURGE CURRENT RATING CURVES FOR -3 - - 3 4 IMPULSE DURATION FIGURE. (μs) SURGE CURRENT RATING CURVES FOR VRA V8RA6 - V43RA6 V4RA - V36RA Figure Pulse 9 Rating Curves Figure 8RA6 FIGURE 6. CLAMPING VOLTAGE FOR V8RA6 - V43RA6 FIGURE 3. SURGE CURRENT RATING CURVES FOR FIGURE 4. SURGE V8RA6 - V43RA6 V4RA 4, V8RA8 - VRA8 V8RA8 - V68RA8 3, TO 43V N(DC) RATING 4 T A = - o C TO o 4 C 6 6, 3 V43RA 3, V39RA 9 7 V7RA. V4RA VRA. MAXIMUM MAXIMUM PEAK VOLTS PEAK (V) VOLTS (V) MAXIMUM SURGE PEAK CURRENT VOLTS (V) (A) 3 4 6RA. -3 - -, 3, 4 IMPULSE PEAK DURATION AMPERES (μs) (A) FIGURE 8. 9. CLAMPING SURGE CURRENT VOLTAGE RATING FOR VRA CURVES - V43RA FOR V8RA8 - VRA8.,, FIGURE. SURGE CURRENT RATING CURVES FOR V8RA8 - V68RA8 RA8 4 6 V8RA8 - V68RA8 3 7 Littelfuse, Inc. Revised: 9/4/7
Metal-Oxide Varistors (MOVs), T A = - o C TO o C, 9 7 8 TO 43V N(DC) RATING T A = - o C TO o C 3 4 6 V43RA6 V39RA6 V4RA6 VRA8 VRA8 9 8 V68RA6 V36RA6 7 V6RA6 6 V47RA6 V7RA6 V39RA6 4 V33RA6 V8RA6 V7RA6 VRA6 3 VRA6 VRA6 V8RA6 VRA6,, V8RA6, Maximum Clamping Voltage for mm Parts -3 - - 3 Repetitive Surge Capability for mm Parts IMPULSE -3 DURATION - (μs) - 3 4 FIGURE. SURGE CURRENT RATING CURVES PEAK FOR AMPERES (A) V4RA - V36RA V4RA - V36RA FIGURE. SURGE CURRENT RATING CUR FIGURE. CLAMPING VOLTAGE FOR V8RA6 - V68RA6 V8RA8 - FIGURE V43RA86. CLAMPING VOLTAGE FOR V8RA6 - V43RA6 V8RA6 - V68RA6 6 4, MAXIMUM,CLAMPING VOLTAGE MAXIMUM, CLAMPING VOLTAGE 4 TO 36V N(DC) RATING V8RA6 - V43RA6 3, TO 43V N(DC) RATING V4RA - V36RA T A = -, o C TO o C T A = -, o C TO o C,, 4,,, 3 3, MODEL SIZE x 8mm 4 6 V8RA8 - V43RA8 V8RA6 - V68RA6, 8 TO 43V N(DC) RATING 3 T A = - o C TO o V43RA C 4 3, V39RA, 9 3 9 4 8 4 6 V4RA6 7 7 VRA8 6, V43RA6 V36RA VRA8 9 V39RA6 7 4 V4RA V7RA 3 V36RA6 V4RA V7RA6 VRA V8RA6-3 - -, 3 4, -3 - -, 3 4, VRA6 PEAK AMPERES IMPULSE (A) DURATION (μs) PEAK AMPERES IMPULSE (A) DURATION (μs) Figure VRA6 Figure 4 FIGURE VRA6 7., CLAMPING FIGURE 3. VOLTAGE SURGE,CURRENT FOR V8RA6 V4RA RATING - V36RA CURVES FOR FIGURE 8. CLAMPING, FIGURE 4. VOLTAGE SURGE, FOR CURRENT VRA RATING - V43RA CURVES FOR 3 IMPULSE DURATION Pulse -3 (μs) V8RA6 - V43RA6 V4RA - V36RA Rating - Curves - 3 4 ) FIGURE. SURGE VRA CURRENT - V43RA RATING CURVES FOR FIGURE. SURGE CURRENT VRA RATING CURVES - V43RA FOR V8RA8 - V43RA8 V8RA6 - V68RA6 8RA6 - V68RA6 FIGURE 6. CLAMPING VOLTAGE FOR V8RA6 - V43RA6 V8RA8 - VRA8 V8RA8 - V68RA8 4, 4 3, 4,, TO 43V N(DC) RATING V8RA6 - V43RA6 V4RA - V36RA, 6 VRA - V43RA, T A = - o C TO o C, 3 4 3 6, 3 3, 4 V43RA 6 3 6, V39RA 9 7. V7RA V4RA. VRA..,,,,, 3 4, -3 - IMPULSE - DURATION, (μs) 3 4, IMPULSE DURATION (μs),, RATION (μs) ) FIGURE 9. SURGE CURRENT RATING CURVES FOR FIGURE Figure. SURGE CURRENT RATING CURVES FOR 4RA ATING CURVES - V36RA FOR Figure 3 FIGURE 8. FIGURE CLAMPING 4. SURGE V8RA8 - VRA8 VOLTAGE CURRENT FOR VRA RATING CURVES - V43RA FOR FIGURE V8RA8. SURGE - V68RA8 CURRENT RATING CURVES FOR VRA - V43RA V4RA - V36RA MAXIMUM PEAK MAXIMUM VOLTS PEAK (V) VOLTS (V) MAXIMUM SURGE PEAK VOLTS CURRENT (V) (A),,,, FIGURE. V8RA8 - VRA8, μs) URVES FOR NOTE: If pulse ratings are exceeded, a shift of V N(DC) (at specified current) of more than ±% could result. This type of shift, which normally results in a decrease of V N(DC), may result in the device not meeting the original published specifications, V8RA8 but - V68RA8 it does not prevent the device from continuing to function, and to provide 4 ample protection. 6.. 3,, FIGURE. SURGE CURRENT RATING CURVES FOR V8RA8 - V68RA8 7 Littelfuse, Inc. Revised: 9/4/7
Wave Solder Profile Reflow Condition Pb Free assembly Lead free Profile Pre Heat - Temperature Min (Ts(min)) C - Temperature Max (Ts(max)) C - Time (min to max) (ts) 6 8 secs Average ramp up rate (Liquidus Temp (TL) to peak C/second max TS(max) to TL - Ramp-up Rate C/second max - Temperature (TL) (Liquidus) 7 C Reflow - Temperature (tl) 6 seconds Peak Temperature (TP) +/- C Time within C of actual peak Temperature (tp) 4 seconds Ramp-down Rate C/second max Time C to peak Temperature (TP) 8 minutes Max. Do not exceed 6 C Maximum Wave 6C... 3 3. 4 Figure 6 TIME(MINUTES) TEMPERATURE (ºC) Non Lead free Profile Maximum Wave 4C TEMPERATURE (ºC)... 3 3. 4 Figure 7 TIME(MINUTES) Environmental Specifications Physical Specifications Operating/Storage Temperature Humidity Aging Thermal Shock - C to + C / - C to + C +8 C, 8% RH, hours +/-% Voltage +8 C to -4 C times +/-% Voltage Solvent Resistance MIL STD, Method Moisture Sensitivity Level, J-STD- Lead Material Soldering Characteristics Insulating Material Device Labeling Tin Coated Solderability per MIL STD, Method 8 Cured, flame retardant epoxy polymer meets UL94V requirements. Marked with LF, voltage, amperage rating, and date code. 7 Littelfuse, Inc. Revised: 9/4/7
Product Dimensions (mm) Y D MAX SYMBOL RA8 Series RA6 Series RA Series n MIN A MAX SEATING PLANE A (max.) D (max.) 8.8 (.348).4 (.4). (.94) 9.7 (.776) 9. (.7). (.4) Øb ±. (.) X. MIN (.97 MIN) e ± E (max.) n (max.) (.97). (.).7 (.7) 7. (.9) 6.3 (.48).7 (.7) 7. (.9) 6.3 (.48).7 (.7) E MAX e. (.39) Z MIN. MAX OFFSET (. MAX) Øb ±. Weight (typical) X.63 (.).8 (.3).8 (.3) Gram 3.4 Grams 4.4 Grams. (.87). (.87) 4.4 (.73) Y (Typ.) 3. -/+. (. -/+.) 6 -/+ (.36 -/+.4) 8.9 -/+ (.3 -/+.4) Z (min.).4 (.).8 (.3).8 (.3) NOTES: Dimensions are in mm, with dimensions in inches in parentheses. Inches for reference only. Part Numbering System The RA Series is supplied in bulk pack. Littelfuse Varistor Nominal Varistor Voltage V RA 6 X749 OPTIONAL SUFFIX: X749: Lead-Free and RoHS Compliant Option Device Size Series Designator Disclaimer Notice - Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and may not be used in, all applications. Read complete Disclaimer Notice at www.littelfuse.com/disclaimer-electronics. 7 Littelfuse, Inc. Revised: 9/4/7