LM3578A MWC National Semiconductor, LM3578A MWC Datasheet - Page 3

• Manufacturer Part Number: LM3578A MWC
• Description: Switching Regulator
• Manufacturer: National Semiconductor

CURRENT LIMIT
I
DEVICE POWER CONSUMPTION
I
CL
S
These specifications apply for 2V
duty cycle
operation over the specified operating junction temperature range.
V
Symbol
Electrical Characteristics
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 2: For T
Note 3: At elevated temperatures, devices must be derated based on package thermal resistance. The device in the TO-99 package must be derated at 150˚C/W,
junction to ambient, or 45˚C/W, junction to case. 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
Note 5: Typical values are for T
Note 6: All limits guaranteed and 100% production tested at room temperature (standard type face) and at temperature extremes (bold type face). All limits are used
to calculate Average Outgoing Quality Level (AOQL).
Note 7: 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 8: 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: I
Note 10: Connection of a 10 k 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).
Note 11: A military RETS specification is available on request. At the time of printing, the LM1578A RETS spec complied with the boldface limits in this column. The
LM1578AH may also be procured as a Standard Military Drawing.
CL
V
/ T
CL
1
and I
J
75%, unless otherwise specified. Values in standard typeface are for T
Sense Voltage
Shutdown Level
Sense Voltage
Temperature Drift
Sense Bias Current
Supply Current
2
100˚C, the Emitter pin voltage should not be driven more than 0.6V below ground (see Application Information).
are the external sink currents at the inputs (refer to Test Circuit).
Parameter
J
= 25˚C and represent the most likely parametric norm.
in series with 100 pF.
V
IN
Referred to V
(Note 10)
Referred to V
Referred to ground
Output OFF, V
Output ON, I
V
E
= 0V
40V (2.2V
(Continued)
Conditions
C
IN
IN
E
= 750 mA pulsed,
or Ground
V
= 0V
IN
40V for T
3
J
−25˚C), timing capacitor C
(Note 5)
Typical
110
0.3
4.0
0.4
2.0
14
J
= 25˚C; values in boldface type apply for
LM1578A
(Note 11)
(Note 6)
3.0/3.3
Limit
140
95
T
= 3900 pF, and 25%
LM2578A/
LM3578A
(Note 7)
3.5/4.0
Limit
160
80
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mV
mV (min)
mV (max)
%/˚C
µA
µA
mA
mA (max)
mA
Units