LM2596
3.0A, 15V, Step-Down Switching Regulator
PIN FUNCTION DESCRIPTION
Symbol
Description
1
2
This pin is the positive input supply for the LM2596 step–down switching
Vin
regulator.In order to minimize voltage transients and to supply the switching
currents needed by the regulator, a suitable input bypass capacitor must be
present .(Cin in Figure 1).
Output This is the emitter of the internal switch. The saturation voltage Vsat of this
output switch is typically 1.5 V. It should be kept in mind that the PCB area
connected to this pin should be kept to a minimum in order to minimize
coupling to sensitive circuitry.
3
4
Gnd
Circuit ground pin. See the information about the printed circuit board layout.
Feedback This pin senses regulated output voltage to complete the feedback loop.
The signal is divided by the internal resistor divider network R2, R1 and
applied to the non–inverting input of the internal error amplifier. In the
Adjustable version of the LM2596 switching regulator this pin is the direct
input of the error amplifier and the resistor network R2, R1 is connected
externally to allow programming of the output voltage.
5
ON/OFF It allows the switching regulator circuit to be shut down using logic level
signals, thus dropping the total input supply current to approximately 80 mA.
The threshold voltage is typically 1.4 V. Applying a voltage above this value
(up to +Vin) shuts the regulator off. If the voltage applied to this pin is lower
than 1.4V or if this pin is left open, the regulator will be in the "on" condition
HTC
8
Oct 2004 - Rev 0
ETC [ ETC ]
