MAX6876 Datasheet, PDF (1/39 Pages) Maxim Integrated Products – EEPROM-Programmable, Quad, Power-Supply Tracker/Sequencer Circuit

19-3479; Rev 0; 10/04
EVAALVUAAILTAIOBNLEKIT
EEPROM-Programmable, Quad,
Power-Supply Tracker/Sequencer Circuit
General Description
The MAX6876 EEPROM-configurable, multivoltage
power tracker/supervisor monitors four system voltages
and ensures proper power-up and power-down condi-
tions for systems requiring voltage tracking and/or
sequencing. The MAX6876 provides a highly config-
urable solution as key thresholds and timing parame-
ters are programmed through an I²C interface and
these values are stored in internal EEPROM. The
MAX6876 also provides supervisory functions and an
overcurrent detection circuit.
The MAX6876 features programmable undervoltage and
overvoltage thresholds for each input supply. When all
voltages are within specifications, the device turns on the
external n-channel MOSFETs to either sequence or track
the voltages to the system. All of the voltages can be
sequenced or tracked or powered up with a combination
of the two options. During tracking, the voltage at the
GATE of each MOSFET is increased to slowly turn on
each supply. The voltages at the source of each MOSFET
are compared to each other to ensure that the voltage dif-
ferential between each monitored supply does not
exceed 250mV (typ). Tracking is dynamically adjusted to
force all outputs to track within a ±125mV window from a
reference ramp; if, for any reason, any supply fails to
track within ±250mV from the reference ramp, a FAULT
output is asserted, the power-up mode is terminated, and
all outputs are powered off. Power-up mode is also termi-
nated if the controlled voltages fail to complete the ramp-
up within a programmable FAULT timeout. The MAX6876
features latch-off and autoretry modes to power on again
after a fault condition has been detected.
Other features of the MAX6876 include a reset circuit, a
manual reset input (MR), and a margin disable input
(MARGIN). The device also features outputs for indicat-
ing a power-good condition (PG_) and an overcurrent
condition (OC), and a bus-removal (REM) output.
The MAX6876 is available in a small 6mm x 6mm, 36-
pin thin QFN package and is fully specified over the
extended -40°C to +85°C temperature range.
Applications
Multivoltage Systems
Storage Equipment
Networking Systems
Servers/Workstations
Telecom
Features
♦ Tracking/Sequencing for Up to Four Supply
Voltages (With One MAX6876 Device) and
Tracking for Up to 16 Supply Voltages (Using
Four MAX6876 Devices)
♦ EEPROM-Configurable Tracking/Sequencing
Control
♦ Bus Voltage Independent Operation (MAX6876 Is
Powered from the Tracked Supply Voltages or
Always-On Supply)
♦ EEPROM-Selectable Undervoltage/Overvoltage-
Lockout Thresholds for Each Input Supply
♦ EEPROM-Selectable Power-Up/Down Slew Rate
♦ Programmable Power-Good Output Thresholds
and Timing
♦ Global Adjustable Undervoltage Lockout or Logic
ENABLE Input
♦ Independent Internal Charge Pumps to Enhance
External n-Channel FETs (V_{GATE_SOURCE} = 5V)
♦ Post Power-Up Selectable Overcurrent Detection
♦ 0.5V to 5.5V IN_ Threshold Range
♦ ±1.5% Threshold Accuracy
♦ I²C/SMBus™-Compatible Serial Interface
♦ Small 6mm x 6mm, 36-Pin Thin QFN Package
Ordering Information
PART
MAX6876ETX
TEMP RANGE
-40°C to +85°C
PIN-
PACKAGE
36 Thin QFN
PKG
CODE
T3666-3
Pin Configuration
TOP VIEW
36 35 34 33 32 31 30 29 28
VCC 1
GND 2
ABP 3
TRKEN 4
SYNCH 5
HOLD 6
OC 7
REM 8
FAULT 9
MAX6876
EP*
27 IN4
26 GATE4
25 OUT4
24 REFIN
23 N.C.
22 PG4
21 PG3
20 PG2
19 PG1
10 11 12 13 14 15 16 17 18
SMBus is a trademark of Intel Corp.
*EXPOSED PADDLE
6mm x 6mm
THIN QFN
________________________________________________________________ Maxim Integrated Products 1
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