TC1303A_08 Datasheet, PDF (20/38 Pages) Microchip Technology – 500 mA Synchronous Buck Regulator, + 300 mA LDO with Power-Good Output

TC1303A/TC1303B/TC1303C/TC1304
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 V_IN), will
enable the regulator output. A logic-low (< 15% of V_IN)
will ensure that the output is turned off.
3.9 Buck Regulator Input Voltage Pin
(V_IN1)
V_IN1 is the buck regulator power input supply pin.
Connect a variable input voltage source to V_IN1.
Connect V_IN1 and V_IN2 together with board traces as
short as possible.
3.10 Buck Inductor Output Pin (L_X)
Connect L_X 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 (P_GND)
Connect all large-signal level ground returns to P_GND.
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 A_GND, with
vias into the A_GND plane.
DS21949C-page 20
© 2008 Microchip Technology Inc.