LDO

C5

U2

D2

L2

R1

R2

EN

FB

SW

VINA

VIND

GND

VO = 3.3V @ 1.0A

VO = 5V @ 150mA

C4

C6

C2

C3

D1

L1

U1

C1

LM2830

VIN = 5V

LM2830, LM2830-Q1

www.ti.com

SNVS454E – AUGUST 2006 – REVISED DECEMBER 2014

8.2.7 LM2830X Buck Converter and Voltage Double Circuit With LDO Follower

Figure 28 shows an example where the LM2830 device is used to provide regulated output voltage (3.3 V) as

well as input voltage for an LDO, effectively providing solution with two output voltages.

Figure 28. LM2830X (1.6 MHz): Vin = 5 V, Vo = 3.3 V at 1.0 A and LP2986-5.0 at 150-mA Schematic

Table 8. Bill of Materials

PART ID

PART VALUE

MANUFACTURER

PART NUMBER

U1

1.0-A Buck Regulator

TI

LM2830X

U2

200-mA LDO

TI

LP2986-5.0

C1, Input Cap

22 µF, 6.3 V, X5R

TDK

C3216X5ROJ226M

C2, Output Cap

22 µF, 6.3 V, X5R

TDK

C3216X5ROJ226M

C3 – C6

2.2 µF, 6.3 V, X5R

TDK

C1608X5R0J225M

D1, Catch Diode

0.3 Vf Schottky 1.5 A, 30 VR

TOSHIBA

CRS08

D2

0.4 Vf Schottky 20 VR, 500 mA

ON Semi

MBR0520

L2

10 µH, 800 mA

CoilCraft

ME3220-103

L1

3.3 µH, 2.2 A

TDK

VLCF5020T-3R3N2R0-1

R2

45.3 k

Ω, 1%

Vishay

CRCW08054532F

R1

10.0 k

Ω, 1%

Vishay

CRCW08051002F

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