4

Typical Performance Characteristics

0A

20mA

40mA

60mA

80mA

100mA

3.5mA

4.0mA

4.5mA

-30mA

-40mA

0A

0.5A

-20mA

-10mA

0A

1.0A

1.5A

2.0A

ISW

0A

0.5A

1.0A

1.5A

2.0A

0.4V

0.0V

0.6V

0.8V

1.2V

1.0V

0.2V

1.4V

Package Lead Description

PACKAGE LEAD #

LEAD SYMBOL

FUNCTION

40

0

0

80

120

160

1000

20

60

100

140

2000

3000

500

1500

2500

180

Figure 1a. 5V Regulator Bias Current vs. Load Current.

Figure 1b. Supply Current vs. Switch Current.

Figure 1c. Switch Saturation Voltage.

64.9kΩ.

24 Lead SO Wide

Supply Voltage.

2, 3

NC

No connection.

Collector of NPN power switch for switching regulator section.

5,6,7,8,17,18,19,20

Gnd

Connected to the heat removing leads.

Feedback input voltage 1 (referenced to 1.25V)

10

Feedback input voltage 2 (referenced to 1.25V)

11

SELECT

12

COMP

Output of the transconductance error amplifier.

13

A capacitor connected to Gnd sets the switching frequency.

Refer to Figure 1d.

14

WDI

Watchdog input. Active on falling edge.

15

A capacitor connected to Gnd sets the Power On Reset and

Watchdog time.

16

If watchdog timeout is reached, a reset pulse train is issued.

21

A resistor connected to Gnd sets internal bias currents as well as

22

Regulated 5V output from the linear regulator section.

23

Input voltage to the linear regulator and the internal supply cir-

cuitry.

24

Logic level input to shut down the switching regulator.

ENABLE

RESET

RESET