LM2578A, LM3578A

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SNVS767E – AUGUST 2000 – REVISED APRIL 2013

Electrical Characteristics

These specifications apply for 2V

duty cycle

for operation over the specified operating junction temperature range.

LM2578A/

Symbol

Parameter

Conditions

LM3578A

Units

OSCILLATOR

Frequency

20

kHz

24

kHz (max)

16

kHz (min)

Frequency Drift with Temperature

−0.13

%/°C

Amplitude

550

Input Reference

1.0

V

Voltage

(4)

1.050/1.070

V (max)

0.950/0.930

V (min)

Input Reference Voltage Line

0.003

%/V

Regulation

(4)

0.01/0.02

%/V (max)

Inverting Input Current

0.5

μA

Level Shift Accuracy

Level Shift Current = 1 mA

1.0

%

10/13

% (max)

Input Reference Voltage Long Term

100

ppm/1000h

Stability

OUTPUT

Collector Saturation Voltage

0.7

V

grounded

0.90/1.2

V (max)

Emitter Saturation Voltage

1.4

V

1.7/2.0

V (max)

Collector Leakage Current

0.1

μA

Output OFF

200/250

μA (max)

Collector-Emitter Sustaining Voltage

60

V

50

V (min)

CURRENT LIMIT

Sense Voltage Shutdown Level

110

mV

80

mV (min)

160

mV (max)

Sense Voltage Temperature Drift

0.3

%/°C

Sense Bias Current

4.0

μA

Referred to ground

0.4

μA

(1)

(2)

All limits specified 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 specified via correlation using standard Statistical Quality Control (SQC)

methods. All limits are used to calculate AOQL.

(3)

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.

(4)

(5)

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).

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