These specifications apply for 2V

≤ V

IN

≤ 40V (2.2V ≤ V

IN

≤ 40V for T

J

≤ −25˚C), timing capacitor C

≤

duty cycle

≤ 75%, unless otherwise specified. Values in standard typeface are for T

operation over the specified operating junction temperature range.

LM2578A/

Symbol

Parameter

Conditions

Typical

LM3578A

Units

(Note 5)

Limit (Note 6)

CURRENT LIMIT

∆V

∆T

Sense Voltage Temperature Drift

0.3

%/˚C

I

CL

Sense Bias Current

Referred to V

IN

4.0

µA

Referred to ground

0.4

µA

DEVICE POWER CONSUMPTION

I

S

Supply Current

Output OFF, V

2.0

mA

3.5/4.0

mA (max)

Output ON, I

14

mA

V

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating

the device beyond its rated operating conditions.

Note 3: At elevated temperatures, devices must be derated based on package thermal resistance. The device in the 8-pin DIP must be derated at 95˚C/W, junction

to ambient. The device in the surface-mount package must be derated at 150˚C/W, junction-to-ambient.

Note 4: Human body model, 1.5 k

Ω in series with 100 pF.

Note 6: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). Room temperature limits are 100% production

tested. Limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used to calculate

AOQL.

Note 7: Input terminals are protected from accidental shorts to ground but if external voltages higher than the reference voltage are applied, excessive current will

flow and should be limited to less than 5 mA.

Note 9: Connection of a 10 k

Ω resistor from pin 1 to pin 4 will drive the duty cycle to its maximum, typically 90%. Applying the minimum Current Limit Sense Voltage

to pin 7 will not reduce the duty cycle to less than 50%. Applying the maximum Current Limit Sense Voltage to pin 7 is certain to reduce the duty cycle below 50%.

Increasing this voltage by 15 mV may be required to reduce the duty cycle to 0%, when the Collector output swing is 40V or greater (see Ground-Referred Current

Limit Sense Voltage typical curve).

Typical Performance Characteristics

Oscillator Frequency Change

with Temperature

Oscillator Voltage Swing

00871132

00871133

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