SUPERSIP26 11/99 REV C

Page 3

Thermal Design Guide

Locate your operating current, read the junction temp

rise from the graph and add to your maximum ambient.

135°C is the maximum allowable operating junction tem-

perature. Test conditions: Device soldered into 4” x 4”

PCB, 2 sided with power and ground planes for heat con-

duction. Due to the difficulty in predicting the thermal

effects of airflow velocity and direction, and thermal con-

duction through ground planes it is important that the SS26

For high ambient temperature/high current application

please request our Application Note 35-118-01, “Accurate

ture”, for further assistance.

Programming

sistor is connected across pins 8 and 4 (Gnd).

(Junction Temp Rise vs. Output Current)

OUTPUT CURRENT AMPS

Efficiency

100

95

90

85

80

75

0.5

1.5

2.5

3.5

4.5

5.5

OUTPUT CURRENT - AMPS

70

60

50

40

30

20

10

0

STILL

AIR

100LFM

300LFM

3.3V 25C

2.1V 25C

Table 2

Resistor Value

ResistorValue

1.8

576

Ω

2.8

18.2k

1.9

1.21k

2.9

24.3k

2.0

1.96k

3.0

34.8k

2.1

2.8k

3.1

54.9k

2.2

3.83k

3.2

110.0k

2.3

4.99k

3.3

OPEN

2.4

6.49k

3.4

66.5k

2.5

8.25k

3.5

29.4k

2.6

10.7k

3.6

18.2k

2.7

13.7k

Transient Response

Operating conditions are as follows: Vin=5V, Vo=3.3V, Load

change from Io=0% to Io=100%, TA=25°C, Cin=0F, Co=

µF.

Operating conditions are as follows: Vin=5V, Vo=3.3V, Load

change from Io=100% to Io=0%, TA=25°C, Cin=0F, Co=

µF.