Littelfuse SP724 Lead-Free_Green Series - Manual (Page 4)

© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 11/25/13
TVS Diode Arrays
(SPA ® Diodes)
General Purpose ESD Protection - SP724 Series
Peak Transient Current Capability for Long Duration Surges
The peak transient current capability is inversely
proportional to the width of the current pulse. Testing was
done to fully evaluate the SP724’s ability to withstand long
duration current pulses using the circuit of Figure 4. Figure
5 shows the point of overstress as defined by increased
leakage in excess of the data sheet published limits.
The safe operating range of the transient peak current
should be limited to no more than 75% of the measured
overstress level for any given pulse width as shown in the
curve of Figure 5.
The test circuit of Figure 4 is shown with a positive pulse
input. For a negative pulse input, the (-) current pulse input
goes to an SP724 ‘IN’ input pin and the (+) current pulse
input goes to the SP724 V- pin. The V+ to V- supply of the
SP724 must be allowed to float. (i.e., It is not tied to the
ground reference of the current pulse generator.)
Note that two input pins of the SP724 may be paralleled to
improve current (and ESD) capability. The sustained peak
current capability is increased to nearly twice that of a
single pin.
FIGURE 5. TYPICAL SP724 PEAK CURRENT TEST CIRCUIT
WITH A VARIABLE PULSE WIDTH INPUT
+
- CURRENT
SENSE
VOLTAGE
PROBE
+
-
R 1 ~ 10 TYPICAL
SP724
V X
V X ADJ. 10V/A TYPICAL
R 1
(-)
(+)
C1 ~ 100 µF
C 1
VARIABLE TIME DURATION
CURRENT PULSE GENERATOR
123 654
0.001 0.01 0.1 1 10
7
6
5
4
3
2
1
0
100 1000
8
SQUARE WAVE PULSE WIDTH (ms)
PEAK CURRENT (A)
NOTE: TO ENSURE SAFE OPERATION LIMIT
THE MAXIMUM PEAK CURRENT FOR A GIVEN
PULSE WIDTH TO BE NO GREATER THAN 75%
OF THE VALUES SHOWN.
T
A
= 25ºC
V+ TO V-SUPPLY = 15V
Showing the Measured Point of Overstress in Amperes vs
pulse width time in milliseconds
Figure 5: SP724 Typical Nonrepetitive Peak Current
Pulse Capability
Figure 4: Typical SP724 Peak Current Test Circuit
with a Variable Pulse Width Input