Rainbow Electronics MAX8723 User Manual

General Description

The MAX8723 is a high-efficiency, switch-mode, step­down regulator with a 14V internal power switch. With only
a few external passive components, this low-cost regulator
can generate a fixed 3.3V or adjustable DC output voltage
of 2.0V to 3.6V (dual mode) from a 6V to 13.2V DC source.
The 13.2V input voltage range makes this part ideal for
LCD displays, point-of-load regulators, and other 8/12V­powered industrial equipment applications.

The MAX8723 can deliver up to 2A. It features an inter­nal power MOSFET, a built-in bootstrap diode for its
MOSFET driver, and an interface for an external syn­chronous rectifier MOSFET drive to replace the
Schottky diode and improve efficiency. Its fixed-fre­quency PWM/skip-mode operation and current-mode
control architecture provide fast load-transient
response without compensation. The switching fre­quency is a pin-selectable 500kHz, 1MHz, or 1.5MHz,
minimizing the size of external components.

The MAX8723 has built-in soft-start, current-limit, ther­mal-shutdown, and timer-delayed output-fault shutdown
functions. The soft-start function limits inrush current
during startup, avoiding transients that can trigger the
front-end protection circuits and lock up the system.
The current limit, thermal-shutdown, and timer-delayed
output-fault shutdown functions protect the power sup­ply against fault conditions.

The MAX8723 also includes a linear regulator (VL) which
provides a fixed 5V output (25mA) to support small exter­nal loads. The reference output is high-precision (2V
± 1%) and can also supply small external load currents.

The MAX8723 is available in the 16-pin 4mm x 4mm
TQFN package.

Applications

LCD TVs

LCD Monitors

Digital System Power Supplies

Point-of-Load Regulators

8/12V Industrial Equipment

Features

♦ 6V to 13.2V Input Supply Range

♦ Integrated 14V 2A N-Channel MOSFET Switch

♦ Preset 1.5% Accurate 3.3V fixed Output Voltage or

2.0V to 3.6V Adjustable Output (Dual Mode)

♦ Current-Mode PWM Operation

♦ Frequency-Selectable 500kHz/1MHz/1.5MHz

♦ Internal 5V Linear Regulator Supports Up to 25mA

External Load

♦ 2V Precision Reference (1%)

♦ Integrated Bootstrap Diode for High-Side

MOSFET Drive

♦ External Synchronous Rectifier Driver

♦ Built-In Soft-Start

♦ 200µA Standby Mode

♦ Timer-Delayed Output Fault Protection

♦ Thermal Shutdown Protection

♦ Small 16-Pin 4mm x 4mm Thin QFN Package

MAX8723

Low-Cost, Internal-Switch, Step-Down

Regulator for LCD Displays

________________________________________________________________ Maxim Integrated Products 1

PART

TEMP RANGE

PIN-PACKAGE

PKG

CODE

MAX8723ETE+

16-pin Thin QFN
4mm x 4mm

T1644-4

Simplified Operating Circuit

Ordering Information

REF BST

V

CC

SHDN
SKIP
VL

GND

FSEL

C

REF

C

VL

EXT

I.C.

EP

C

BST

PGND

OUT

FB

IN

LX

C

OUT

OUT

IN

C

INL

INL

C

IN

D

L

MAX8723

XX-XXXX; Rev 0; 3/06

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Pin Configuration appears at end of data sheet.

-40°C to +85°C