Rainbow Electronics MAX8723 - Manual

General Description
The MAX8723 is a high-efficiency, switch-mode, step-
down 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 8/12V-
powered industrial equipment applications.
The MAX8723 can deliver up to 2A. It features an inter-
nal power MOSFET, a built-in bootstrap diode for its
MOSFET driver, and an interface for an external syn-
chronous rectifier MOSFET drive to replace the
Schottky diode and improve efficiency. Its fixed-fre-
quency PWM/skip-mode operation and current-mode
control architecture provide fast load-transient
response without compensation. The switching fre-
quency is a pin-selectable 500kHz, 1MHz, or 1.5MHz,
minimizing the size of external components.
The MAX8723 has built-in soft-start, current-limit, ther-
mal-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 sup-
ply against fault conditions.
The MAX8723 also includes a linear regulator (VL) which
provides a fixed 5V output (25mA) to support small exter-
nal 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+ -40°C to +85°C
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.