LM5166DRCT datasheet(32/57 Pages) TI2

32 / 57 page

PGOOD

ILIM

VIN

GND

HYS

COUT

47 PF

47 PH

RESR

0.2 :

RFB1

169 k:

RFB2

100 k:

VIN = 4.5 V...65 V

VOUT = 3.3V

RRT

100 k:

CIN

2.2 PF

IOUT = 0.5 A

CSS

47 nF

LM5166

SNVSA67B – DECEMBER 2016 – REVISED JUNE 2017

www.ti.com

Product Folder Links: LM5166

Submit Documentation Feedback

8.2.2 Design 2: Wide VIN, Low IQ COT Converter Rated at 3.3 V, 500 mA

Figure 63. Schematic for Design 2 With VIN(nom) = 12 V, VOUT = 3.3 V, IOUT(max) = 500 mA, FSW(nom) = 200 kHz

8.2.2.1 Design Requirements

The target efficiency is 85% for loads above 10 mA based on a nominal input voltage of 12 V and an output

voltage of 3.3 V. The required input voltage range is 4.5 V to 65 V. The LM5166 is chosen to deliver a 3.3-V

output voltage. The switching frequency is set at 200 kHz. The output voltage soft-start time is 4 ms. The

required components are listed in Table 5.

(1)

See Third-Party Products Disclaimer.

Table 5. List of Components for Design 2(1)

COUN

REF DES

DESCRIPTION

PART NUMBER

MFR

CIN

Capacitor, Ceramic, 2.2 μF, 100 V, X7R, 10%, 1210

GRM32ER72A225KA35L

Murata

COUT

Capacitor, Ceramic, 47 μF, 10 V, X7R, 10%, 1210

GRM32ER71A476KE15L

Murata

CSS

Capacitor, Ceramic, 47 nF, 16 V, X7R, 10%, 0402

Std

Inductor, 47 µH, 0.245 Ω max, 1.2 A Isat, 3.5 mm max

LPS6235-473MR

Coilcraft

Inductor, 47 µH, 0.315 Ω typ, 1.3 A Isat, 2.8 mm max

74404063470

Würth

RRT

Resistor, Chip, 100 kΩ, 1/16W, 1%, 0402

Std

RFB1

Resistor, Chip, 169 kΩ, 1/16W, 1%, 0402

Std

RESR

Resistor, Chip, 0.2 Ω, 1/16W, 1%, 0402

Std

RFB2

Resistor, Chip, 100 kΩ, 1/16W, 1%, 0402

Std

LM5166, Synchronous Buck Converter, VSON-10, ADJ

LM5166DRCR

8.2.2.2 Detailed Design Procedure

8.2.2.2.1

Feedback Resistors – RFB1, RFB2

The output voltage of the LM5166 is externally adjustable using a resistor divider network. The divider network

comprises the upper feedback resistor RFB1 and lower feedback resistor RFB2. Select RFB1 of 169 kΩ to minimize

quiescent current and improve light-load efficiency in this application. With the desired output voltage setpoint of

3.3 V and VFB = 1.223 V, calculate the resistance of RFB2 using Equation 15 as 100.1 kΩ. Choose the closest

available standard value of 100 kΩ for RFB2. See Adjustable Output Voltage (FB) for more detail.

LM5166DRCT Datasheet(PDF) 32 Page - Texas Instruments

LM5166DRCT Datasheet(HTML) 32 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57

Datasheet Download

Link URL