LM2574, NCV2574
http://onsemi.com
4
SYSTEM PARAMETERS ([Note 3] Test Circuit Figure 16)
ELECTRICAL CHARACTERISTICS (continued) (Unless otherwise specified, V
in
= 12 V for the 3.3 V, 5.0 V, and
Adjustable version, V
in
= 25 V for the 12 V version, V
in
= 30 V for the 15 V version. I
Load
= 100 mA. For typical values T
J
= 25°C, for
min/max values T
J
is the operating junction temperature range that applies [Note 4], unless otherwise noted).
Characteristic
Symbol Min Typ Max Unit
ALL OUTPUT VOLTAGE VERSIONS
Feedback Bias Current V
out
= 5.0 V (Adjustable Version Only) I
b
nA
T
J
= 25°C − 25 100
T
J
= −40 to +125°C − − 200
Oscillator Frequency (Note 5) f
O
kHz
T
J
= 25°C − 52 −
T
J
= 0 to +125°C 47 52 58
T
J
= −40 to +125°C 42 − 63
Saturation Voltage (I
out
= 0.5 A, [Note 6]) V
sat
V
T
J
= 25°C − 1.0 1.2
T
J
= −40 to +125°C − − 1.4
Max Duty Cycle (“on”) (Note 7) DC 93 98 − %
Current Limit Peak Current (Notes 5 and 6) I
CL
A
T
J
= 25°C 0.7 1.0 1.6
T
J
= −40 to +125°C 0.65 − 1.8
Output Leakage Current (Notes 8 and 9), T
J
= 25°C I
L
mA
Output = 0 V − 0.6 2.0
Output = − 1.0 V − 10 30
Quiescent Current (Note 8) I
Q
mA
T
J
= 25°C − 5.0 9.0
T
J
= −40 to +125°C − − 11
Standby Quiescent Current (ON/OFF Pin = 5.0 V (“off”)) I
stby
mA
T
J
= 25°C − 60 200
T
J
= −40 to +125°C − − 400
ON/OFF Pin Logic Input Level V
V
out
= 0 V V
IH
T
J
= 25°C 2.2 1.4 −
T
J
= −40 to +125°C 2.4 − −
Nominal Output Voltage V
IL
T
J
= 25°C − 1.2 1.0
T
J
= −40 to +125°C − − 0.8
ON/OFF P
in
Input Current
mA
ON/OFF P
in
= 5.0 V (“off”), T
J
= 25°C I
IH
− 15 30
ON/OFF P
in
= 0 V (“on”), T
J
= 25°C I
IL
− 0 5.0
3. External components such as the catch diode, inductor, input and output capacitors can affect the switching regulator system performance.
When the LM2574 is used as shown in the Figure 16 test circuit, the system performance will be as shown in the system parameters section
of the Electrical Characteristics.
4. Tested junction temperature range for the LM2574, NCV2574: T
low
= −40°C T
high
= +125°C.
5. 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%.
6. Output (Pin 2) sourcing current. No diode, inductor or capacitor connected to the output pin.
7. Feedback (Pin 4) removed from output and connected to 0 V.
8. Feedback (Pin 4) removed from output and connected to 12 V for the Adjustable, 3.3 V, and 5.0 V versions, and 25 V for the 12 V and 15 V
versions, to force the output transistor OFF.
9. V
in
= 40 V.
