High Current H-Bridge

BTM7745G

General Product Characteristics

Data Sheet

8

Rev. 1.0, 2010-05-28

5.3

Thermal Resistance

Note: This thermal data was generated in accordance with JEDEC JESD51 standards. For more information, go

to www.jedec.org.

Pos.

Parameter

Symbol

Limit Values

Unit

Conditions

Min.

Typ.

Max.

Thermal Resistance

Junction to Soldering Point, Low Side Switch

R

–

29

K/W

1) Not subject to production test, specified by design.

Thermal Resistance

Junction to Soldering Point, High Side Switch

R

–

29

K/W

1)

Thermal Resistance

Junction to Soldering Point, both switches

(

P

R

thjSP

–

–

29

K/W

1)

Thermal Resistance

Junction-Ambient

R

thja

–

46

–

K/W

1)

2) Specified

R

(chip+package) was simulated on a 76.2 x 114.3 x 1.5 mm board with 2 inner copper layers (2 x 70µm Cu, 2 x 35µm Cu).

; 2)

1)

Transient thermal impedance

Z

thja

Figure 5 is showing the typical transient thermal impedance of high side or low side switch of BTM7745G mounted

according to JEDEC JESD51-7 at natural convection on FR4 2s2p board. The device (chip+package) was

simulated on a 76.2 x 114.3 x 1.5 mm board with 2 inner copper layers (2 x 70µm Cu, 2 x 35µm Cu). For the

simulation each chip was separately powered with 1W at an ambient temperature

T

0

5

10

15

20

25

30

35

40

45

50

0,001

0,01

0,1

1

10

100

1000

High side sw itch / Low side sw itch

Figure 5

Typical transient thermal impedance of BTM7745G on JESD51-7 2s2p board

(1W each chip (separately heated),

T

5.3.1

5.3.2

5.3.3

5.3.4