Mlv Design Guide Page 13 MLV Selection Steps

Table 13. Step 1 Illustration Table 14. Step 3 Illustration EXAMPLE 1 (GENERAL SURGE PROTECTION) Circuit conditions and requirements: 20VDC Current waveform for surge is 8x20s One-time peak current 100A Repetitive peak current at 3A Other components (Most vulnerable device to be protected, such as a IC rated at 300V Approach to Finding Solution Compare Requirement to V26MLA1206N Step 1: To find the voltage rating of the MLV, allow for 20% head room take into account voltage variations (20VDC x 1.2 + 24VDC; So look at 26VDC rated MLVs) (Refer to the summary in Table 13) Voltage rating of 26VDC Step 2: Determine which MLV size to use (Identify those that minimally meet the 100A surge requirement) (Refer to the summary in Table 14) Device size of 1206 (3.2 x 1.6mm) Step 3: Check datasheet or contact factory for pulse withstanding curve (Refer to the summary in Figure 13) Can meet 10000 time surge pulses Step 4: Use V-I Curve of selected MLV to varify that the peak voltage will be below 300V ceiling (Refer to the summary in Figure 14) Peak voltage of 150V Step 1 - Determine the voltage rating of the MLV device Step 2 - Determine the size of the MLV device Part Number Maximum Ratings (125 C ) Specifications (25 C ) Maximum Continuous Working Voltage Maximum Non- repetitive Surge Current (8/20 s) Maximum Non- repetitive Surge Energy (10/1000 s) Maximum Clamping Voltage at 1A (or as Noted) (8/20 s) Nominal Voltage at 1mA DC Test Current Typical Capacitance at f = 1MHz V M(DC) V M(AC) I TM W TM V C V N(DC) Min V N(DC) Max C (V) (A) (J) (V) (pF) V18MLA0805N 18.0 14.0 120 0.300 44.0 22.0 28.0 520 V18MLA0805LN 18.0 14.0 40 0.100 44.0 22.0 28.0 290 V18MLA1206N 18.0 14.0 150 0.400 44.0 22.0 28.0 1270 V18MLA1210N 18.0 14.0 500 2.500 44.0 at 2.5 22.0 28.0 2930 V26MLA0603N 26.0 20.0 30 0.100 60.0 31.0 38.0 110 V26MLA0805N 26.0 20.0 100 0.300 60.0 29.5 38.5 220 V26MLA0805LN 26.0 20.0 40 0.100 60.0 29.5 38.5 190 V26MLA1206N 26.0 20.0 150 0.600 60.0 29.5 38.5 720 V26MLA1210N 26.0 20.0 300 1.200 60.0 at 2.5 29.5 38.5 1480 Part Number Maximum Ratings (125 C ) Specifications (25 C ) Maximum Continuous Working Voltage Maximum Non- repetitive Surge Current (8/20 s) Maximum Non- repetitive Surge Energy (10/1000 s) Maximum Clamping Voltage at 1A (or as Noted) (8/20 s) Nominal Voltage at 1mA DC Test Current Typical Capacitance at f = 1MHz V M(DC) V M(AC) I TM W TM V C V N(DC) Min V N(DC) Max C (V) (A) (J) (V) (pF) V18MLA0805N 18.0 14.0 120 0.300 44.0 22.0 28.0 520 V18MLA0805LN 18.0 14.0 40 0.100 44.0 22.0 28.0 290 V18MLA1206N 18.0 14.0 150 0.400 44.0 22.0 28.0 1270 V18MLA1210N 18.0 14.0 500 2.500 44.0 at 2.5 22.0 28.0 2930 V26MLA0603N 26.0 20.0 30 0.100 60.0 31.0 38.0 110 V26MLA0805N 26.0 20.0 100 0.300 60.0 29.5 38.5 220 V26MLA0805LN 26.0 20.0 40 0.100 60.0 29.5 38.5 190 V26MLA1206N 26.0 20.0 150 0.600 60.0 29.5 38.5 720 V26MLA1210N 26.0 20.0 300 1.200 60.0 at 2.5 29.5 38.5 1480 2016 Littelfuse Multilayer Varistors (MLVs) Design Guide www.littelfuse.com Surface Mount Multilayer Varistors (MLVs) Design Guide MLV Selection - Examples (continued) 13

Previous Page
Next Page