© 2013 Littelfuse, Inc.

Specifications are subject to change without notice.

Revised: 04/24/13

General Purpose ESD Protection - SP721 Series

ESD Capability

ESD capability is dependent on the application and defined

test standard.The evaluation results for various test

standards and methods based on Figure 1 are shown in

Table 1.

For the “Modified”MIL-STD-3015.7 condition that is defined

as an “in-circuit” method of ESD testing, the V+ and V- pins

have a return path to ground and the SP721 ESD capability

is typically greater than 15kV from 100pF through 1.5kΩ.By

strict definition of MIL-STD-3015.7 using “pin-to-pin”device

testing, the ESD voltage capability is greater than 6kV.The

MIL-STD-3015.7 results were determined from AT&T ESD

Test Lab measurements.

The HBM capability to the IEC 61000-4-2 standard is

greater than 15kV for air discharge (Level 4) and greater

than 4kV for direct discharge (Level 2).Dual pin capability (2

adjacent pins in parallel) is well in excess of 8kV (Level 4).

For ESD testing of the SP721 to EIAJ IC121 Machine

Model (MM) standard, the results are typically better than

1kV from 200pF with no series resistance.

Standard

Type/Mode

R

D

C

D

±V

D

MIL STD 3015.7

Modified HBM

1.5kΩ 100pF 15kV

Standard HBM

1.5kΩ 100pF

6kV

IEC 61000-4-2

HBM, Air Discharge

330Ω 150pF 15kV

HBM, Direct Discharge

330Ω 150pF

4kV

HBM, Direct Discharge,

Two Parallel Input Pins

330Ω 150pF

8kV

EIAJ IC121

Machine Model

0kΩ

200pF

1kV

H.V.

SUPPLY

IN

DUT

CHARGE

SWITCH

DISCHARGE

SWITCH

100

80

60

40

20

0

T

SINGLE PULSE

2.5

2

1.5

1

0.5

0

V FWD

IFWD

EQUIV. SAT. ON

THRESHOLD ~ 1.1V

600

800

1000

1200

FORWARD SCR VOLTAGE DROP (mV)

0

1

2

3

FORWARD SCT VOLTAGE DROP (V)

T

SINGLE PULSE

100

80

60

40

20

0

T

SINGLE PULSE

2.5

2

1.5

1

0.5

0

V FWD

IFWD

EQUIV. SAT. ON

THRESHOLD ~ 1.1V

600

800

1000

1200

FORWARD SCR VOLTAGE DROP (mV)

0

1

2

3

FORWARD SCT VOLTAGE DROP (V)

T

SINGLE PULSE

Figure 1: Electrostatic Discharge Test

Table 1: ESD Test Conditions

Figure 3: High Current SCR ForwardVoltage Drop Curve

Figure 2: Low Current SCR Forward Voltage Drop Curve