G5J2596M

Page: 3/6

ISSUED DATE :2006/03/09

REVISED DATE :2006/05/17B

All Output Voltage Version Electrical Characteristics

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Feedback bias current

-

-10

-50/-100

nA

Oscillator frequency

127/110

150

173/173

kHz

Oscillator frequency of

short circuit protect

5

15

25

kHz

Saturation voltage

LOAD

=3A No outside circuit

-

1.4

1.6/1.7

V

Max. duty cycle (ON)

-

100

-

Max. duty cycle (OFF)

DC

-

0

-

%

Current limit

Peak current No outside circuit

3.6

4.5

5.5/6.5

A

-

-

-200

uA

Output leakage current

-

-5

-

mA

Quiescent current

-

5

10

mA

Low (Regulator ON)

-

-

-

0.6

ON/OFF pin logic input

Threshold Voltage

High (Regulator OFF)

2.0

-

-

V

ON/OFF pin Logic input

current

-

-

-0.01

ON/OFF pin input

current

-

-0.1

-1

uA

Standby quiescent

current

-

150

200

uA

JC

Junction to Case

-

10

-

Thermal Resistance

JA

Junction to Ambient with copper

-

50

-

: /W

Function Description

The TO-252-5L surface mount package tab is designed to be soldering to the copper on a printed circuit board. The copper and the board

are the heat sink for this package and the other heat producing components, such as the catch diode and inductor. The PC board copper

dissipation are realized. If further thermal improvements are needed, double sided, multi-layer PC board with large copper areas and/or

airflow will be recommended. The G5J2596M junction temperature rises above ambient temperature with a 3A load and different input and

output voltages. The data was taken with the circuit operating as a buck-switching regulator with all components mounted on a PC board

to simulate the junction temperature under actual operating conditions. This curve can be used for a quick check for the approximate

junction temperature for various conditions, but be aware that there are many factors that can affect the junction temperature. When load

current higher than 3A are used, double sided or multi-layer PC boards with large copper areas and/or airflow might be needed, especially

for high ambient temperatures and high output voltages.

For the best thermal performance, wide copper traces and generous amounts of printed circuit board copper should be used in the board

layout. (One exception to this is the output (switch) pin, which should not have large areas of copper.) Large areas of copper provide the

best transfer of heat (lower thermal resistance) to the surrounding air, and moving air lowers the thermal resistance even further.

Package thermal resistance and junction temperature rise numbers are all approximate, and there are many factors will affect these

numbers. Some of these factors include board size, shape, thickness, position, location and even board temperature. Other factors are,

trace width, total printed circuit copper area, copper thickness, single or double-sided, multi-layer board and the amount of solder on the

board. The effectiveness of the PC board to dissipate heat also depends on the size, quantity and spacing of other components on the

board, as well as the surrounding air is still or moving. Furthermore, some of these components such as the catch diode will add heat to

the PC board and the heat can vary as the input voltage changes. For the inductor, depending on the physical size, type of core material

and the DC resistance, it could either act as a heat sink taking heat away from the board, or it could add heat to the board.