LM2575D2T-12 ON Semiconductor, LM2575D2T-12 Datasheet - Page 7

• Manufacturer Part Number: LM2575D2T-12
• Description: EASY SWITCHERE 1.0 A STEP-DOWN VOLTAGE REGULATOR
• Manufacturer: ON Semiconductor

circuit board is very important. Rapidly switching currents
associated with wiring inductance, stray capacitance and
parasitic inductance of the printed circuit board traces can
generate voltage transients which can generate
electromagnetic interferences (EMI) and affect the desired
operation. As indicated in the Figure 14, to minimize
inductance and ground loops, the length of the leads
indicated by heavy lines should be kept as short as possible.
For best results, single–point grounding (as indicated) or
ground plane construction should be used.
MOTOROLA ANALOG IC DEVICE DATA
As in any switching regulator, the layout of the printed
Unregulated
8.0 V – 40 V
DC Input
8.0 V – 40 V
Unregulated
DC Input
V in
+
–
+
–
C in
100 F/50 V
V in
C in
100 F/50 V
1
V in
3
1
Adjustable
Adjustable Output Voltage Versions
Gnd
LM2575
3
Figure 14. Typical Test Circuit
PCB LAYOUT GUIDELINES
5.0 Output Voltage Versions
LM2575–5
Gnd
5
V out
R2
Where V ref = 1.23 V, R1
between 1.0 k and 5.0 k
ON/OFF
+
5
+
LM2575
2
R1
4
Output
Feedback
V
ON/OFF
ref
V out
V
2
ref
4
Output
Feedback
1
)
(emitter of the internal switch) of the LM2575 should be kept
to a minimum in order to minimize coupling to sensitive
circuitry.
important to keep the sensitive feedback wiring short. To
assure this, physically locate the programming resistors near
to the regulator, when using the adjustable version of the
LM2575 regulator.
– 1
R2
R1
330 H
D1
1N5819
On the other hand, the PCB area connected to the Pin 2
Another sensitive part of the circuit is the feedback. It is
L1
330 H
D1
1N5819
L1
C out
330 F
/16 V
C out
330 F
/16 V
Regulated
R2
R1
Output
Load
V out
Regulated
Output
Load
V out
7