19-7054; Rev 1; 7/16

General Description

The MAX17543 high-efficiency, high-voltage, synchronous

step-down DC-DC converter with integrated MOSFETs

operates over a 4.5V to 42V input. The converter can

deliver up to 2.5A and generates output voltages from

accurate to within ±1.1% over -40°C to +125°C.

The MAX17543 uses peak current-mode control. The

device can be operated in the pulse-width modulation

(PWM), pulse-frequency modulation (PFM), or

discontinuous conduction mode (DCM) control schemes.

The device is available in a 20-pin (4mm x 4mm) TQFN

package. Simulation models are available.

Applications

● Industrial Power Supplies

● Distributed Supply Regulation

● High-Voltage Single-Board Systems

● Base Station Power Supply

● General-Purpose Point-of-Load

Benefits and Features

● Reduces External Components and Total Cost

• No Schottky—Synchronous Operation

• Internal Compensation for Any Output Voltage

• Built-In Soft-Start

• All-Ceramic Capacitors, Compact Layout

● Reduces Number of DC-DC Regulators to Stock

• Wide 4.5V to 42V Input

• 100kHz to 2.2MHz Adjustable Switching Frequency

with External Synchronization

● Reduces Power Dissipation

• Peak Efficiency >90%

• PFM/DCM Enables Enhanced Light-Load

Efficiency

• 2.8µA Shutdown Current

● Operates Reliably in Adverse Industrial Environments

• Peak Current-Limit Protection

• Built-In Output Voltage Monitoring with RESET

• Programmable EN/UVLO Threshold

• Monotonic Startup into Prebiased Load

• Overtemperature Protection

• High Industrial -40°C to +125°C Ambient Operating

Temperature Range/-40°C to +150°C Junction

Temperature Range

Ordering Information appears at end of data sheet.

Typical Application Circuit—5V, 500kHz Switching Frequency

RESET

BST

RT

SYNC

MODE

SGND

CF

SS

FB

PGND

PGND

PGND

LX

LX

LX

EN/UVLO

MAX17543

L1

10µH

C5

0.1µF

C4

22µF

R3

178kΩ

R4

39kΩ

5V, 2.5A

(6.5V TO 42V)

C1

2.2µF

C3

5.6nF

C2

2.2µF

MAX17543

4.5V–42V, 2.5A, High-Efficiency,

Synchronous Step-Down DC-DC Converter

with Internal Compensation

EVALUATION KIT AVAILABLE