General Description

The MAX6880–MAX6883 dual-/triple-voltage monitors

are designed to sequence power supplies during

power-up condition. When all of the voltages exceed

their respective thresholds, these devices turn on volt-

ages to the system sequentially, enhancing n-channel

MOSFETs used as switches. The time between each

sequenced voltage is determined by an external

capacitor, thus allowing flexibility in delay timing. The

MAX6880/MAX6881 sequence three voltages and the

MAX6882/MAX6883 sequence two voltages.

These devices initially monitor all of the voltages and

when all of them are within their tolerances, the inter-

nal charge pumps enhance external n-channel

MOSFETs in a sequential manner to apply the volt-

ages to the system. Internal charge pumps drive the

gate voltages 5V above the respective input voltage

thereby ensuring the MOSFETs are fully enhanced to

reduce the on-resistance.

The MAX6880–MAX6883 feature capacitor-adjustable

slew-rate control to provide controlled turn-on charac-

teristics. After all of the voltages reach 92.5% of their

final value, a power-good output (MAX6880/MAX6882)

signal is active. The power-good output (PG/RST) can

be delayed with an external capacitor to create a

power-on reset delay. After the initial power-up phase,

the MAX6880–MAX6883 continue to monitor the volt-

ages. If any of the voltages falls below its threshold, the

MOSFETs are quickly turned off and the voltages are

tracked down together. An internal 100Ω pulldown

resistor ensures that the capacitance at the MOSFET’s

source is discharged quickly. The power-good output

goes low to provide a system reset.

The MAX6880–MAX6883 are available in small 4mm x

4mm 24-pin and 16-pin thin QFN packages and speci-

fied over the -40°C to +85°C extended operating tem-

perature range.

Applications

Multivoltage Systems

Networking Systems

Telecom

Storage Equipment

Servers/Workstations

Features

♦ Capacitor-Adjustable Power-Up Sequencing

Delay

♦ Internal Charge Pumps to Enhance External

n-Channel FETs

♦ Capacitor-Adjustable Timeout Period Power-Good

Output (MAX6880/MAX6882)

♦ Adjustable Undervoltage Lockout or

Logic-Enable Input

♦ Internal 100Ω Pulldown for Each Output to

Discharge Capacitive Load Quickly

♦ 0.5V to 5.5V Nominal IN_/OUT_ Range

♦ 2.7V to 5.5V Operating Voltage Range

♦ Immune to Short Voltage Transients

♦ Small 4mm x 4mm 24-Pin or 16-Pin Thin QFN

Packages

Dual-/Triple-Voltage, Power-Supply

Sequencers/Supervisors

________________________________________________________________ Maxim Integrated Products

1

23

24

22

21

8

7

9

10

12

IN3

45

6

17

18

16

14

13

IN2

IN1

TIMEOUT

*EXPOSED PADDLE CONNECTED TO GND.

SLEW

DELAY

GND

EP*

+

MAX6880

3

15

GATE1

20

11

N.C.

OUT1

19

12

N.C.

GATE2

4mm x 4mm THIN QFN

TOP VIEW

Pin Configurations

Ordering Information

19-3772; Rev 1; 10/05

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.

+Denotes lead-free package.

Selector Guide appears at end of data sheet.

PART

TEMP RANGE

PIN-

PACKAGE

PKG

CODE

MAX6880ETG+

-40°C to +85°C

24 Thin QFN

T2444-4

MAX6881ETE+

-40°C to +85°C

16 Thin QFN

T1644-4

MAX6882ETE+

-40°C to +85°C

16 Thin QFN

T1644-4

MAX6883ETE+

-40°C to +85°C

16 Thin QFN

T1644-4

Pin Configurations continued at end of data sheet.