MAX6880 Datasheet, PDF (1/19 Pages) Maxim Integrated Products – Dual-/Triple-Voltage, Power-Supply Sequencers/Supervisors

19-3772; Rev 1; 10/05
Dual-/Triple-Voltage, Power-Supply
Sequencers/Supervisors
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
Ordering Information
PART
TEMP RANGE
MAX6880ETG+ -40°C to +85°C
MAX6881ETE+ -40°C to +85°C
MAX6882ETE+ -40°C to +85°C
MAX6883ETE+ -40°C to +85°C
+Denotes lead-free package.
PIN-
PACKAGE
24 Thin QFN
16 Thin QFN
16 Thin QFN
16 Thin QFN
PKG
CODE
T2444-4
T1644-4
T1644-4
T1644-4
Pin Configurations
TOP VIEW
18 17 16 15 14 13
GATE2 19
12 N.C.
OUT1 20
11 N.C.
GATE1 21
IN3 22
MAX6880
IN2 23
EP*
+
IN1 24
12 3 4 5
10 TIMEOUT
9 SLEW
8 DELAY
7 GND
6
Selector Guide appears at end of data sheet.
4mm x 4mm THIN QFN
*EXPOSED PADDLE CONNECTED TO GND.
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
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