Rainbow-electronics MAX5097 User Manual download pdf

General Description

The MAX5096/MAX5097 easy-to-use, Dual Mode™,

DC-DC converters operate as LDO (low dropout) or

switch-mode buck converters. At a high output load,

the converters operate as high-efficiency pulse-width-

modulated (PWM) switch-mode converters and reduce

the power dissipation. The devices switch to a low-qui-

escent-current (I

) LDO mode of operation at light load.

During the key-off condition, the system’s microcon-

troller drives the LDO/BUCK input on the fly and forces

the MAX5096/MAX5097 into LDO Mode, thereby reduc-

ing the quiescent current significantly.

In Buck Mode, the MAX5096/MAX5097 operate from a 5V

to 40V input voltage range and deliver up to 600mA of

load current with excellent load and line regulation. The

fixed-switching frequency versions of 135kHz and

330kHz are available. The MAX5096/MAX5097 DC-DC

internal oscillator can be synchronized to an external

clock. External compensation and a current-mode control

scheme make it easy to design with.

In LDO Mode, the MAX5096/MAX5097 operate from a

4V to 40V input voltage. The LDO Mode operation is

intended for a lower output load current of up to

100mA. The quiescent current at 100µA load in LDO

Mode is only 41µA (typ).

The MAX5096/MAX5097 feature an enable input that

shuts down the device, reducing the current consump-

tion to 6µA (typ). Additional features include a power-on

reset output with a capacitor-adjustable timeout period,

programmable soft-start, output tracking, output over-

load, short-circuit and thermal shutdown protections.

The MAX5096/MAX5097 operate over the -40°C to

+125°C automotive temperature range and are avail-

able in thermally enhanced 20-pin TSSOP or 16-pin

TQFN packages.

Applications

Automotive

Industrial

Features

♦ High-Efficiency Switcher Mode (Buck Mode) or

Low-Quiescent-Current Linear Regulator

(LDO Mode) Operation

♦ Wide Operating Input Voltage Range

+5V to +40V Buck Mode

+4V to +40V LDO Mode

♦ Fixed 3.3V or 5V and Adjustable (1.24V to 11V)

Output Voltage Versions

♦ 6µA (typ) Shutdown Current

♦ Fixed 135kHz or 330kHz Switching Frequency

♦ External Frequency Synchronization

♦ Programmable Soft-Start

♦ Integrated Microprocessor Reset (RESET) Circuit

with Programmable Timeout Period

♦ Thermal and Short-Circuit Protection

♦ -40°C to +125°C Automotive Temperature Range

♦ Thermally-Enhanced Package Dissipates

2.6W at T

= +70°C (16-Pin TQFN)

1.7W at T

= +70°C (20-Pin TSSOP)

MAX5096/MAX5097

40V, 600mA Buck Converters with Low-

Quiescent-Current Linear Regulator Mode

________________________________________________________________ Maxim Integrated Products 1

19-0603; Rev 0; 7/06

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.

Ordering Information

PART

TEMP RANGE

PIN-PACKAGE

PKG

CODE

MAX5096AATE+*

-40°C to +125°C 16 TQFN-EP**

T1655-2

MAX5096BATE+

-40°C to +125°C 16 TQFN-EP**

T1655-2

MAX5096AAUP+*

-40°C to +125°C 20 TSSOP-EP**

U20E-4

MAX5096BAUP+*

-40°C to +125°C 20 TSSOP-EP**

U20E-4

MAX5097AATE+

-40°C to +125°C 16 TQFN-EP**

T1655-2

MAX5097BATE+*

-40°C to +125°C 16 TQFN-EP**

T1655-2

MAX5097AAUP+*

-40°C to +125°C 20 TSSOP-EP**

U20E-4

MAX5097BAUP+*

-40°C to +125°C 20 TSSOP-EP**

U20E-4

TQFN

15 14 13

5678

OUT

ADJ

LDO/BUCK

SGND

RESET

SYNC

COMP

PGND

MAX5096

MAX5097

TOP VIEW

N.C.

ENPGND

TOP VIEW

MAX5096

MAX5097

OUT

ADJ

N.C.BP

138N.C.

129 COMPSYNC

1110 CTSS

SGND

TSSOP

LDO/BUCK

RESET

Pin Configurations

*Future product—contact factory for availability.

+Denotes lead-free package.

**EP = Exposed pad.

Dual Mode is a trademark of Maxim Integrated Products, Inc.

1 2 3 4 5 6 ... 19 20

MAX5096/MAX5097 1

Summary of Contents

Page 1 - MAX5096/MAX5097

General DescriptionThe MAX5096/MAX5097 easy-to-use, Dual Mode™,DC-DC converters operate as LDO (low dropout) orswitch-mode buck converters. At a high

Page 2

MAX5096/MAX509740V, 600mA Buck Converters with Low-Quiescent-Current Linear Regulator Mode10 _________________________________________________________

Page 3

Detailed DescriptionThe MAX5096/MAX5097 are easy-to-use, high-efficien-cy, PWM current-mode, step-down switching convert-ers in normal operation. The

Page 4

MAX5096/MAX5097Output Voltage Tracking/Sequencing The output voltages of multiple MAX5096/MAX5097converters can be made to track by using the SS pindu

Page 5

lower end of the AM band. The MAX5096 is suitable fornoise-sensitive applications like AM radio power sup-ply. For an application where size is more i

Page 6

MAX5096/MAX5097use typical values of VINand fSWso that efficiency is opti-mum for typical conditions. The switching frequency (fSW)is fixed at 135kHz

Page 7

ripple is mainly composed of ∆VQ(caused by thecapacitor discharge) and ∆VESR(caused by the volt-age drop across the ESR of the output capacitor).Norma

Page 8

MAX5096/MAX5097Compensation NetworkThe MAX5096/MAX5097 in LDO Mode are compensat-ed internally with a compensation network around theLDO error amplifi

Page 9