LM2576BM
APPLICATION CIRCUIT
Typical
LM2576BM
Low Noise
LM2576BM
APPLICATION INFORMATION
Careful layout is important with any switching regulator. Rapidly switching currents
associated with wiring inductance generate voltage transients which can cause problems. To
minimize inductance and ground loops, the lengths of the leads indicated by heavy lines in
Figure 1 below should be kept as short as possible. Single point grounding or ground plane
construction should be used for best results. When using the Adjustable version, place the
programming resistors as close as possible to LM2576BM, to keep the sensitive feedback
wiring short.
INPUT CAPACITOR CIN
A low ESR aluminum or tantalum bypass capacitor is needed between the input pin and
ground pin. It must be located near the regulator using short leads. This capacitor prevents
large voltage transients from appearing at the input, and provides the instantaneous current
needed each time the switch turns on. Selecting an input capacitor requires consulting the
manufacturers data sheet for maximum allowable RMS ripple current. For a maximum
ambient temperature of 40°C, a general guideline would be to select a capacitor with a
ripple current rating of approximately 50% of the DC load current. For ambient
6/9
TGS [ Tiger Electronic Co.,Ltd ]
