General Semiconductor SM8A27 Datasheet

SM8A27 TRANSIENT SUPPRESSOR

SURFACE MOUNT AUTOMOTIVE TRANSIENT VOLTAGE SUPPRESSOR

Zener Voltage - 27.0 Volts Peak Pulse Current - 130.0 Amps

FEATURES

¨ Ideally suited for load dump protection
¨ Plastic package has Underwriters Laboratory

Flammability Classification 94V-0

¨ High temperature stability due to unique oxide passivation
¨ Exclusive patented PARª oxide passivated

chip construction

¨ Integrally molded heatsink provides

a very low thermal resistance
for maximum heat dissipation

¨ Low leakage current at TJ=175¡C
¨ Low forward voltage drop
¨ High temperature soldering guaranteed:

260¡C for 10 seconds at terminals

MECHANICAL DATA

Case: Molded plastic body, surface mount with heatsink

integrally mounted in the encapsulation
Terminals: Plated, solderable per MIL-STD-750,
Method 2026

Polarity: Heatsink is anode
Mounting Position: Any
Weight: 0.091 ounce, 2.58 grams

MAXIMUM RATINGS AND ELECTRICAL CHARACTERISTICS

Ratings at 25¡C ambient temperature unless otherwise specified.

SYMBOLS SM8A27 UNITS

Steady state power dissipation P

D

8.0 Watts

Non-repetitive peak reverse surge current for 10ms/10ms
exponentially decaying waveform

I

RSM

130.0 Amps

Maximum working peak stand-off voltage V

WM

22.0 Volts

Minimum reverse zener voltage at 10mA V

Z

24.0 Volts

Maximum reverse zener voltage at 10mA V

Z

30.0 Volts

Maximum zener voltage temperature coefficient at I

Z

=10mA Vztc 36.0 m V/¡C

Peak forward surge current, 8.3ms single half sine-wave I

FSM

700.0 Amps

Maximum clamping voltage for 10ms/10ms exponentially
decaying waveform at I

PP

=75A

V

C

40.0 Volts

Maximum instantaneous forward voltage at 6.0A

(NOTE 1)

V

F

0.98 Volts

Maximum reverse leakage current at rated V

WM

TJ=25¡C 1.0
T

J

=175¡C

I

R

50.0

mA

Maximum thermal resistance junction to case R

QJC

0.90 ¡C/W

Operating junction and storage temperature range T

J

, T

STG

-55 to +175 ¡C

NOTE:

(1) Measured on a 300ms square pulse width

NOTICE: Advanced product information is subject to change without notice

2/23/99

Dimensions in inches

and

(millimeters)

NEW PRODUCT NEW PRODUCT NEW PRODUCT

*Patent #Õs, 4,980,315,

5,166,769,
5,278,095

0.093(2.4)

0.116(3.0)

0.059(1.5)

0.098(2.5)

0.098(2.5)

0.138(3.5)

0.366(9.3)

0.343(8.7)

0.406(10.3)

0.382(9.7)

0.342(8.7)

0.327(8.3)

0.413(10.5)

0.374(9.5)

0.539(13.7)

0.524(13.3)

LEAD 2/METAL HEATSINK

0.020(0.5)

0.028(0.7)

0.028(0.7)

0.012(0.3)

0.197(5.0)

0.185(4.7)

LEAD 1

0.628(16.0)

0.592(15.0)

DO-218

PATENTED

*

RATINGS AND CHARACTERISTIC CURVES SM8A27

FIG. 1 - POWER DERATING CURVE

FIG. 3 - PULSE WAVEFORM

POWER DISSIPATION, WATTS

CASE TEMPERATURE, ¡C

FIG. 2 - TYPICAL INSTANTANEOUS FORWARD

CHARACTERISTICS

INSTANTANEOUS FORWARD CURRENT,

AMPS

FORWARD VOLTAGE, VOLTS

175¡C

INPUT PEAK PULSE CURRENT %

t, TIME, ms

tr=10ms

PEAK VALUE I

PP

10/1000ms

TA=25¡C
PULSE WIDTH (t

d

) is
DEFINED as the POINT
WHERE the PEAK CURRENT
DECAYS to 50% of I

PP

FIG. 4 - REVERSE POWER CAPABILITY

REVERSE SURGE POWER, WATTS

PULSE WIDTH (ms) - 1/2 IPPEXPONENTIAL WAVEFORM

FIG. 6 - TYPICAL REVERSE CHARACTERISTICS

FIG. 7 - TYPICAL TRANSIENT THERMAL IMPEDANCE

PERCENTAGE OF V

(BR)

, %

PULSE WIDTH, sec.

175¡C

FIG. 5 - LOAD DUMP POWER CHARACTERISTICS

(10ms EXPONENTIAL WAVEFORM)

LOAD DUMP POWER, WATTS

TRANSIENT THERMAL IMPEDANCE, ¡C/W

CASE TEMPERATURE, ¡C

R

QJC

R

QJA

25¡C

25¡C

t

d

HALF VALUE -

I

PP

2

INSTANTANEOUS REVERS CUR-

RENT, MICRO AMPERES

8.0

7.0

6.0

5.0

4.0

3.0

2.0

1.0

0

0 25 50 75 100 125 150 175 200

150

100

50

0

0 5 10 15 20 25 30 35 40

6,000

5,000

4,000

3,000

2,000

1,000

0

75

50

25

100

125

100

100

10

1

0.1

0.01

0.35

0.45

0.55

10,000

1,000

10

100

10

1

0.1

0.01

0.001

150

175

0.0001
20

5

0.65

0.75



50

35

0.85

0.95

100

95

80

65

10

1

0.1

0.01

0.01

0.1

1

10

100