SC461 데이터 시트보기 (PDF) - Semtech Corporation

부품명

상세내역

제조사

SC461

EcoSpeed® DC-DC Buck Controller with Integrated LDO

Semtech Corporation 

SC461

Pin Descriptions

Pin #

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

PAD

Pin Name Pin Function

FB

Feedback input for switching regulator — connect to an external resistor divider from output — used to pro-

gram the output voltage.

VOUT

Switcher output voltage sense pin. The voltage at this pin must not exceed the VDDA pin. For output voltages

up to VDDA connect this pin directly to the switcher output. For output voltages exceeding 5V connect this

pin to the switcher output through a resistor divider.

VDDA

Supply input for internal analog circuits — connect to an external 3.3V or 5V supply or connect to VLDO

— also the sense input for VDDA Under Voltage Lockout (VDDA UVLO).

VLDO

Output of the 5V LDO — The voltage at this pin must not exceed the voltage at the VDDA pin.

VIN

Input supply voltage — connect to the same supply used for the high-side MOSFET. Connect a 100nF capaci-

tor from this pin to AGND to filter high frequency noise.

SS

Soft-Start — connect an external capacitor to AGND to program the soft-start and automatic recovery time.

NC

No Connection

BST

Bootstrap pin — connect a 100nF minimum capacitor from BST to LX to develop the floating voltage for the

high-side gate drive.

DH

High-side gate drive output

LX

Switching (phase) node

PGND

Power ground for the DL and DH drivers and the low-side external MOSFET.

DL

Low-side gate drive output

VDDP

Supply input for the DH and DL gate drives — connect to the same 3.3V or 5V supply used for VDDA.

PSV

PGOOD

ILIM

EN

AGND

Power-save programming input — float pin to select power-save with no minimum frequency — pull up to

VDDA to disable power-save and select forced continuous mode.

Open-drain Power Good indicator — high impedance indicates the switching regulator output is good. An

external pull-up resistor is required.

Current limit sense pin — used to program the current limit by connecting a resistor from ILIM to LX.

Enable input for switching regulator — logic low disables the switching regulator — logic high enables the

switching regulator.

Analog ground

TON

ON time programming input — set the on-time by connecting through a resistor to AGND.

ENL

AGND

Enable input for the LDO and VIN UVLO input for the switching regulator — connect ENL to AGND to disable

the LDO — drive to logic high (>1.7V) to enable the LDO and inhibit VIN UVLO — connect to resistor divider

from VIN to AGND to program the VIN UVLO threshold.

Analog ground

11

Share Link: