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MAX6877, MAX6878, MAX6879
Dual-/Triple-Voltage, Power-Supply Trackers/Sequencers/Supervisors
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Status
Active: In Production.
Description
The MAX6877/MAX6878/MAX6879 multivoltage power
trackers/sequencers/supervisors monitor up to three
system voltages and provide proper power-up and
power-down control for systems requiring voltage tracking
or sequencing. These devices ensure controlled
voltage tracking within a specified range or sequencing
in the proper order as system power supplies are
enabled. The MAX6877/MAX6878/MAX6879 generate
all required voltages and timing to control up to three
external n-channel pass FETs for the OUT1/OUT2/OUT3 supply voltages (see the Selector Guide for different features of each device).
The MAX6877/MAX6878/MAX6879 feature adjustable
undervoltage thresholds for each input supply. When all
the voltages are above these adjustable thresholds, the
devices turn on the external n-channel MOSFETs to
either sequence or track the voltages to the system.
During voltage-tracking mode, the voltage at the GATE
of each MOSFET is increased to slowly bring up all
supplies at a controlled slew rate. The MAX6877/MAX6878/MAX6879 feature an autoretry or latch-off mode with capacitor-adjusted timing.
These devices also provide a controlled power-down
(tracking mode) when the system shuts off in an orderly
manner. When an unexpected fault occurs, the outputs
are all pulled down simultaneously with an internal
100Ω pulldown to help discharge capactive loads at the MOSFET's source. The MAX6877/MAX6878/MAX6879 feature independent internal charge pumps to fully enhance the external FETs for low-voltage drop at highpass current. The MAX6877 and MAX6878 also
feature a power-good output with a selectable timeout period that can be used for system reset.
The MAX6877/MAX6878/MAX6879 are available in
small 4mm x 4mm 24-pin and 16-pin thin QFN packages
and are fully specified over the -40°C to +85°C
extended operating temperature range.
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Data Sheet
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An evaluation kit is available: MAX6877EVKIT
Key Features
- Pin-Selectable Tracking or Sequencing Control for Up to Three Supply Voltages
- Capacitor-Adjustable Power-Up/Down Tracking Slew Rate
- Capacitor-Adjustable Power-Up Sequencing Delay
- Internal Charge Pumps to Enhance External n-Channel FETs
- Capacitor-Adjustable Timeout Period Power-Good Output (MAX6877/MAX6878)
- 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
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Applications/Uses
- Multivoltage Systems
- Networking Systems
- Servers/Workstations
- Storage Equipment
- Telecom
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Key Specifications:
| Power-Supply Sequencers and Voltage Trackers |
| Part Number |
Option |
Interface |
Input Chan. |
VIN
(V) |
Features |
Oper. Temp.
(°C) |
Package/Pins |
Smallest Available Pckg.
(mm2) |
Budgetary Price |
| max |
max w/pins |
See Notes |
| MAX6877 |
| Sequence | | Sequence and Track | | Track |
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| Factory Fixed | | R/C Adjustable |
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3 |
<6 |
| Charge Pump Output | | Enable Input | | Reset Output | | Slew Rate Control |
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-40 to +85 |
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16.8 |
$3.67 @1k |
| MAX6878 |
2 |
| Charge Pump Output | | Enable Input | | Reset Output | | Slew Rate Control |
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$3.35 @1k |
| MAX6879 |
2 |
| Charge Pump Output | | Enable Input | | Slew Rate Control |
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$3.18 @1k |
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See All Power-Supply Sequencers and Voltage Trackers (55)
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Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
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Diagram
 Typical Application Circuit
More Information
Didn't Find What You Need?
Information Index
Document Ref.: 19-3771
Rev 1;
2005-11-04
This page last modified: 2007-04-18
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