TIP120 TIP121 TIP122 TIP125 TIP126 TIP127

3

Motorola Bipolar Power Transistor Device Data

Figure 4. Thermal Response

t, TIME (ms)

1.0

0.01

0.01

0.5

0.2

0.1

0.05

0.02

0.05

0.1

0.2

0.5

1.0

2.0

5.0

10

20

50

100

200

1.0 k

500

Z

θJC(t) = r(t) RθJC

R

θJC = 1.92°C/W MAX

D CURVES APPLY FOR POWER

PULSE TRAIN SHOWN

READ TIME AT t1

TJ(pk) – TC = P(pk) Z

θJC(t)

P(pk)

t1

t2

DUTY CYCLE, D = t1/t2

D = 0.5

0.2

0.05

0.02

0.01

SINGLE PULSE

0.1

0.7

0.3

0.07

0.03

0.02

20

1.0

Figure 5. Active–Region Safe Operating Area

VCE, COLLECTOR–EMITTER VOLTAGE (VOLTS)

10

5.0

2.0

1.0

0.02

2.0

5.0

20

50

100

BONDING WIRE LIMITED

THERMALLY LIMITED

@ TC = 25°C (SINGLE PULSE)

0.5

TJ = 150°C

dc

1 ms

100

µs

0.2

0.1

10

0.05

SECOND BREAKDOWN LIMITED

CURVES APPLY BELOW

RATED VCEO

5 ms

3.0

7.0

30

70

TIP120, TIP125

TIP121, TIP126

TIP122, TIP127

500

µs

There are two limitations on the power handling ability of a

transistor: average junction temperature and second break-

down. Safe operating area curves indicate IC – VCE limits of

the transistor that must be observed for reliable operation,

i.e., the transistor must not be subjected to greater dissipa-

tion than the curves indicate.

The data of Figure 5 is based on TJ(pk) = 150_C; TC is

variable depending on conditions. Second breakdown pulse

limits are valid for duty cycles to 10% provided TJ(pk)

< 150

_C. TJ(pk) may be calculated from the data in Figure 4.

At high case temperatures, thermal limitations will reduce the

power that can be handled to values less than the limitations

imposed by second breakdown

300

0.1

VR, REVERSE VOLTAGE (VOLTS)

30

2.0

5.0

10

20

100

50

0.2

0.5

1.0

100

50

TJ = 25°C

Cib

70

Cob

PNP

NPN

Figure 6. Small–Signal Current Gain

10,000

1.0

f, FREQUENCY (kHz)

10

20

50

100

200

1000

2.0

5.0

10

3000

500

100

TC = 25°C

VCE = 4.0 Vdc

IC = 3.0 Adc

1000

PNP

NPN

Figure 7. Capacitance

50

500

5000

2000

300

200

30

20

200