LM2574, LM2574HV

SNVS104C – JUNE 1999 – REVISED APRIL 2013

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All Output Voltage Versions Electrical Characteristics

Symbol

Parameter

Conditions

LM2574-XX

Units

LM2574HV-XX

(Limits)

Typ

DEVICE PARAMETERS

Feedback Bias

50

100/500

nA

Current

Oscillator Frequency

52

kHz

47/42

kHz(Min)

58/63

kHz(Max)

Saturation Voltage

(3)

0.9

V

1.2/1.4

V(max)

DC

Max Duty Cycle (ON)

98

%

93

%(Min)

Current Limit

1.0

A

0.7/0.65

A(Min)

1.6/1.8

A(Max)

Current

Output = 0V

2

mA(Max)

Output Leakage

Output =

−1V

7.5

mA

Output =

30

mA(Max)

Quiescent Current

5

mA

10

mA(Max)

Standby Quiescent

ON /OFF Pin= 5V (OFF)

50

μA

Current

200

μA(Max)

Thermal Resistance

92

72

°C/W

10

2 78

ON /OFF CONTROL Test Circuit Figure 24

ON /OFF Pin Logic

1.4

2.2/2.4

V(Min)

Input Level

1.2

1.0/0.8

V(Max)

ON /OFF Pin Input

ON /OFF Pin = 5V (OFF)

12

μA

Current

30

μA(Max)

ON /OFF Pin = 0V (ON)

0

μA

10

μA(Max)

(1)

All limits specified at room temperature (Standard type face) and at temperature extremes (bold type face). All room temperature limits

are 100% production tested. All limits at temperature extremes are specified via correlation using standard Statistical Quality Control

(SQC) methods. All limits are used to calculate Average Outgoing Quality Level.

(2)

The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated

output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average power

dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%.Figure 9

(3)

Output pin sourcing current. No diode, inductor or capacitor connected to output pin.

(4)

Feedback pin removed from output and connected to 0V.

(5)

Feedback pin removed from output and connected to +12V for the Adjustable, 3.3V, and 5V versions, and +25V for the 12V and 15V

versions, to force the output transistor OFF.

(6)

(7)

Junction to ambient thermal resistance with approximately 1 square inch of printed circuit board copper surrounding the leads. Additional

copper area will lower thermal resistance further. See Application Hints in this data sheet and the thermal model in Switchers Made

Simple software.

(8)

Junction to ambient thermal resistance with approximately 4 square inches of 1 oz. (0.0014 in. thick) printed circuit board copper

surrounding the leads. Additional copper area will lower thermal resistance further (See Note 7)

6

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