3A, 52kHz, Step-Down Switching Regulator
LM2576
PIN CONFIGURATION
VIN
VOUT
1
2
3
4
8
7
6
5
N.C
Exposed
PAD
N.C
FEEDBACK
ON/OFF
GND
N.C.
SOP8-PP
TO220-5L
TO263-5L
PIN DESCRIPTION
Package
Symbol
VIN
Description
TO-220 5L
SOP8-PP
TO-263 5L
1
This pin is the positive input supply for the LM2576 step–down
switching 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).
1
This is the emitter of the internal switch. The saturation voltage
VSAT of this output switch is typically 1.5V. 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.
Circuit ground pin. See the information about the printed circuit
board layout.
2
3
2
6
VOUT
GND
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 LM2576 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.
4
3
FEEDBACK
It allows the switching regulator circuit to be shutdown using logic
level signals, thus dropping the total input supply current to
approximately 80uA.
5
-
4
ON/OFF
N.C.
The threshold voltage is typically 1.4V. 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
5, 7, 8
No Connect.
* Exposed Pad of SOP8-PP package should be externally connected to GND.
Dec 2011 – Rev. 1.3
- 3 -
HTC
HTC [ HTC KOREA TAEJIN TECHNOLOGY CO. ]
