Littelfuse SP720 Lead-Free_Green Series - Manual (Page 4)

© 2013 Littelfuse, Inc.
Specifications are subject to change without notice.
Revised: 04/24/13
TVS Diode Arrays
(SPA ® Diodes)
General Purpose ESD Protection - SP720 Series
Peak Transient Current Capability for Long Duration Surges
The peak transient current capability rises sharply as the
width of the current pulse narrows. Destructive testing
was done to fully evaluate the SP720’s ability to withstand
a wide range of transient current pulses. The circuit used to
generate current pulses is shown in Figure 4.
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 SP720 ‘IN’ input pin and the (+) current pulse
input goes to the SP720 V- pin. The V+ to V- supply of the
SP720 must be allowed to float. (i.e., It is not tied to the
ground reference of the current pulse generator.) Figure
5 shows the point of overstress as defined by increased
leakage in excess of the data sheet published limits.
The maximum peak input current capability is dependent
on the V+ to V- voltage supply level, improving as the
supply voltage is reduced. Values of 0, 5, 15 and 30
voltages are shown. 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 Figure 5.
When adjacent input pins are paralleled, the sustained
peak current capability is increased to nearly twice that
of a single pin. For comparison, tests were run using dual
pin combinations 1+2, 3+4, 5+6, 7+9, 10+11, 12+13 and
14+15.
The overstress curve is shown in Figure 5 for a 15V supply
condition. The dual pins are capable of 10A peak current
for a 10µs pulse and 4A peak current for a 1ms pulse. The
complete for single pulse peak current vs. pulse width time
ranging up to 1 second are shown in Figure 5.
+
-
CURRENT
SENSE
VOLTAGE
PROBE
14
15
16
9
13
12
11
10
1
2
3
4
5
7
6
8
IN
IN
IN
IN
IN
IN
V-
IN
V+
IN
IN
IN
IN
IN
IN
IN
+
-
R 1
~ 10 TYPICAL
SP720
V G
V G ADJ. 10V/A TYPICAL
R 1
(-)
(+)
C1 ~ 100 µF
C1
VARIABLE TIME DURATION
CURRENT PULSE GENERA TOR
FIGURE 5. TYPICAL SP720 PEAK CURRENT TEST CIRCUIT
WITH A VARIABLE PULSE WIDTH INPUT
0.001 0.01 0.1 1
PEAK CURRENT (A)
10
7
6
5
4
3
2
1
0
0V
5V
15V
100 1000
10
9
30V
15V
8
CAUTION: SAFE OPERATING CONDITIONS LIMIT
THE MAXIMUM PEAK CURRENT FOR A GIVEN
PULSE WIDTH TO BE NO GREATER THAN 75%
OF THE VALUES SHOWN ON EACH CURVE.
SINGLE PIN STRESS CURVES
DUAL PIN STRESS CURVE
V+ TOV-SUPPLY
PULSE WIDTH TIME (ms)
Showing the Measured Point of Overstress in Amperes vs
pulse width time in milliseconds (T
A
= 25 o C)
Figure 5: SP720 Typical Nonrepetitive Peak Current
Pulse Capability
Figure 4: Typical SP720 Peak Current Test Circuit
with a Variable Pulse Width Input