LM2596
http://onsemi.com
4
SYSTEM PARAMETERS
ELECTRICAL CHARACTERISTICS Specifications with standard type face are for T
J
= 25°C, and those with boldface type apply
over full Operating Temperature Range −40°C to +125°C
Characteristics Symbol Min Typ Max Unit
LM2596 (Note 1, Test Circuit Figure 15)
Feedback Voltage (V
in
= 12 V, I
Load
= 0.5 A, V
out
= 5.0 V, ) V
FB_nom
1.23 V
Feedback Voltage (8.5 V ≤ V
in
≤ 40 V, 0.5 A ≤ I
Load
≤ 3.0 A, V
out
= 5.0 V) V
FB
1.193
1.18
1.267
1.28
V
Efficiency (V
in
= 12 V, I
Load
= 3.0 A, V
out
= 5.0 V) η − 73 − %
Characteristics Symbol Min Typ Max Unit
Feedback Bias Current (V
out
= 5.0 V) I
b
25 100
200
nA
Oscillator Frequency (Note 2) f
osc
135
120
150 165
180
kHz
Saturation Voltage (I
out
= 3.0 A, Notes 3 and 4) V
sat
1.5 1.8
2.0
V
Max Duty Cycle “ON” (Note 4) DC 95 %
Current Limit (Peak Current, Notes 2 and 3) I
CL
4.2
3.5
5.6 6.9
7.5
A
Output Leakage Current (Notes 5 and 6)
Output = 0 V
Output = −1.0 V
I
L
0.5
6.0
2.0
20
mA
Quiescent Current (Note 5) I
Q
5.0 10 mA
Standby Quiescent Current (ON/OFF Pin = 5.0 V (“OFF”))
(Note 6)
I
stby
80 200
250
mA
ON/OFF PIN LOGIC INPUT
Threshold Voltage
1.6 V
V
out
= 0 V (Regulator OFF) V
IH
2.2
2.4
V
V
out
= Nominal Output Voltage (Regulator ON) V
IL
1.0
0.8
V
ON/OFF Pin Input Current
ON
/OFF Pin = 5.0 V (Regulator OFF) I
IH
− 15 30
mA
ON/OFF Pin = 0 V (regulator ON) I
IL
− 0.01 5.0
mA
1. External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance.
When the LM2596 is used as shown in the Figure 15 test circuit, system performance will be as shown in system parameters section.
2. The oscillator frequency reduces to approximately 30 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 dissipation of the IC by
lowering the minimum duty cycle from 5% down to approximately 2%.
3. No diode, inductor or capacitor connected to output (Pin 2) sourcing the current.
4. Feedback (Pin 4) removed from output and connected to 0 V.
5. Feedback (Pin 4) removed from output and connected to +12 V to force the output transistor “off”.
6. V
in
= 40 V.
