TC1304 datasheet(20/38 Pages) MICROCHIP

20 / 38 page

TC1303A/TC1303B/TC1303C/TC1304

DS21949C-page 20

3.8

Buck Regulator Shutdown Input

Pin (SHDN1)

SHDN1 is a logic-level input used to turn the buck

regulator on and off. A logic-high (> 45% of VIN), will

enable the regulator output. A logic-low (< 15% of VIN)

will ensure that the output is turned off.

3.9

Buck Regulator Input Voltage Pin

(VIN1)

VIN1 is the buck regulator power input supply pin.

Connect a variable input voltage source to VIN1.

Connect VIN1 and VIN2 together with board traces as

short as possible.

3.10

Buck Inductor Output Pin (LX)

Connect LX directly to the buck inductor. This pin

carries large signal-level current; all connections

should be made as short as possible.

3.11

Power Ground Pin (PGND)

Connect all large-signal level ground returns to PGND.

These large-signal, level ground traces should have a

small loop area and length to prevent coupling of

switching noise to sensitive traces. Please see the

physical layout information supplied in Section 5.0

“Application

Circuits/Issues”

for

grounding

recommendations.

3.12

Exposed Pad (EP)

For the DFN package, connect the EP to AGND, with

vias into the AGND plane.

TC1304 Datasheet(PDF) 20 Page - Microchip Technology