Mlv Design Guide Page 12 Application Examples

MLV Key Parameters Although the AUML and MLA Series varistors are used in automotive electrical systems, the MLA, MHS, MLE, and MLN Series can be used in general applications. Refer to the summary in Table 11. MLV Series AUML Series MLA AUTO Series MHS Series MLA Series MLE Series MLN Series Features Auto- motive Grade Auto- motive Grade Low Capa- citance Standard Chip Sizes ESD 1206 4X Array Voltage 18VDC 3.5-48 VDC 2.5-40 VRMS 42VDC (3pF) 18VDC (12pF) 9VDC (22pF) 3.5V-30 VDC 30V-120 VDC 18VDC 5.5-18 VDC Size 1206 -2220 0603 -1210 0402 -0603 0201 -1210 0402 -1206 1206 Table 11. Voltages and Sizes of Littelfuse MLVs These are the most critical parameters used for MLV selection: 1. Continuous Voltage Rating, RMS or DC, should be >110% of the maximum expected voltage. 2. Device size depends on the transient energy or current expected or on the required clamping voltage. 3. Energy and Peak Current ratings are a measure of capability. 4. Max Clamping voltage is a reference point on the V-I curve and is a measure of the protection level. 5. Varistor voltage can be used for incoming inspection and internal manufacturing test purposes. The essence of MLV selection is finding the best match for the application in terms of electrical parameters, such as voltage and peak pulsing current, as well as the device size that best fits within the available board space. Selection Steps Protection Notes Continuous Voltage Rating Continuous Working Voltage Rating DC condition; the operating voltage of the protected equipment or device plus the tolerance of the operating voltage. Tolerance and maximum allowable voltage of normal operating voltage. Device size Physical size of the MLV to best fit the available board space Energy and Peak Current Maximum expected surge current and number of hits Clamping Voltage Maximum voltage level that may be harmful to protected IC Verify the Leakage Current Leakage current of the selected varistor is appropriate for the circuit Capacitance Requirement Maximum allowable varistor capacitance Table 12. MLV Selection Table (Worksheet) Figure 14. MLV Electrical Specifications 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) V26MLA0603N 26.0 20.0 30 0.100 60.0 31.0 38.0 110 Part Number Continuous Voltage Rating One Pulse Current Rating One Pulse Energy Clamping Voltage at Specific Current Varistor Voltage Typical Capacitance Surface Mount Multilayer Varistors (MLVs) Design Guide 2016 Littelfuse Multilayer Varistors (MLVs) Design Guide www.littelfuse.com MLV Selection - Examples 12

Previous Page
Next Page