Rainbow-electronics MAX5098A User Manual download pdf

General Description

The MAX5098A is a dual-output, high-switching-frequen-

cy DC-DC converter with integrated n-channel switches

that can be used either in high-side or low-side configura-

tion. Each output can be configured either as a buck con-

verter or a boost converter. In the buck configuration, this

device delivers up to 2A from converter 1 and 1A from

converter 2. The MAX5098A also integrates a load-dump

protection circuitry that is capable of handling load-dump

transients up to 80V for automotive applications. The

load-dump protection circuit utilizes an internal charge-

pump to drive the gate of an external n-channel MOSFET.

When an overvoltage or load-dump condition occurs, the

series protection MOSFET absorbs the high voltage tran-

sient to prevent damage to lower voltage components.

The DC-DC converters operate over a wide operating

voltage range from 4.5V to 19V. The MAX5098A oper-

ates 180° out-of-phase with an adjustable switching fre-

quency to minimize external components while allowing

the ability to make trade-offs between the size, efficiency,

and cost. The high switching frequency (up to 2.2MHz)

also allows this device to operate outside the AM band

for automotive applications.

This device utilizes voltage-mode control for stable oper-

ation and external compensation, thus the loop gain is

tailored to optimize component selection and transient

response. This device can be synchronized to an exter-

nal clock fed at the SYNC input. Also, a clock output

(CKO) allows a master-slave connection of two devices

with a four-phase synchronized switching sequence.

Additional features include internal digital soft-start, indi-

vidual enable for each DC-DC regulator (EN1 and EN2),

open-drain power-good outputs (PGOOD1 and

PGOOD2), and a shutdown input (ON/OFF).

Other features of the MAX5098A include overvoltage pro-

tection, short-circuit (hiccup current limit) and thermal

protection. The MAX5098A is available in a thermally

enhanced, exposed pad, 5mm x 5mm, 32-pin TQFN

package and is fully specified over the automotive

-40°C to +125°C temperature range.

Applications

Automotive AM/FM Radio Power Supply

Automotive Instrument Cluster Display

Features

o Wide 4.5V to 5.5V or 5.2V to 19V Input Voltage

Range (with Up to 80V Load-Dump Protection)

o Dual-Output DC-DC Converter with Integrated

Power MOSFETs

o Each Output Configurable in Buck or Boost Mode

o Adjustable Outputs from 0.8V to 0.85V

Buck

Configuration) and from V

to 28V (Boost

Configuration)

o I

OUT1

and I

OUT2

of 2A and 1A (Respectively) in

Buck Configuration

o Switching Frequency Programmable from 200kHz

to 2.2MHz

o Synchronization Input (SYNC)

o Clock Output (CKO) for Four-Phase Master-Slave

Operation

o Individual Converter Enable Input and Power-

Good Output

o Low-I

(7µA) Standby Current (ON/OFF)

o Internal Digital Soft-Start and Soft-Stop

o Short-Circuit Protection on Outputs and

Maximum Duty-Cycle Limit

o Overvoltage Protection on Outputs with Auto

Restart

o Thermal Shutdown

o Thermally Enhanced 32-Pin TQFN Package

Dissipates up to 2.7W at +70°C

MAX5098A

Dual, 2.2MHz, Automotive Buck or Boost

Converter with 80V Load-Dump Protection

________________________________________________________________

Maxim Integrated Products

Ordering Information

19-4111; Rev 0; 5/08

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

Pin Configuration appears at end of data sheet

EVALUATION KIT

AVAILABLE

Denotes a lead-free package.

EP = Exposed pad.

PART TEMP RANGE PIN-PACKAGE

MAX5098AATJ+

-40°C to +125°C 32 TQFN-EP*

1 2 3 4 5 6 ... 27 28

MAX5098A 1

Summary of Contents

Page 1 - MAX5098A

General DescriptionThe MAX5098A is a dual-output, high-switching-frequen-cy DC-DC converter with integrated n-channel switchesthat can be used either

Page 2

MAX5098ADual, 2.2MHz, Automotive Buck or BoostConverter with 80V Load-Dump Protection10 ______________________________________________________________

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