V131NA34 Datasheet, PDF (3/5 Pages) Littelfuse – Varistor Products - High Energy Industrial Square Disc

Varistor Products
High Energy Industrial Square Disc
NA Varistor Series
Power Dissipation Ratings
Should transients 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. The operating values must be derated as
shown in Figure 1.
100
90
80
70
60
50
40
30
20
10
0
-55
50 60 70 80 90 100 110 120 130 140 150
AMBIENT TEMPERATURE ( ^oC)
FIGURE 1. CURRENT, ENERGY AND POWER DERATING
100
CURVE
90
O₁ = Virtual Origin of Wave
T = Time From 10% to 90% of Peak
T₁ = Virtual Front time = 1.25 • t
T₂ = Virtual Time to Half Value (Impulse Duration)
50
Example: For an 8/20µs Current Waveform:
8µs = T₁ = Virtual Front Time
20µs = T₂ = Virtual Time to Half Value
10
O₁
T
T₁
T₂
TIME
FIGURE 2. PEAK PULSE CURRENT TEST WAVEFORM
Transient V-I Characteristics Curves
10000
MAXIMUM CLAMPING VOLTAGE
VARISTOR SIZE 34mm
130 TO 750 V_M(AC) RATING
T_A = -55^oC TO 85^oC
V511NA34
V481NA34
V421NA34
V751NA34
V661NA34
V571NA34
1000
100
-5
124
V131NA34
-4
1E-3
0.01
V321NA34
V271NA34
V251NA34
V151NA34
0.1
1
10
100
CURRENT (A)
1,000
10,000
100,000
FIGURE 3. CLAMPING VOLTAGE FOR V131NA34 - V751NA34
www.littelfuse.com