Rainbow Electronics MAX6871 - Manual (Page 11)

MAX6870/MAX6871
EEPROM-Programmable Hex/Quad
Power-Supply Sequencers/Supervisors with ADC
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COMPARATORS
ADC
MUX
ADC ADC REGISTERS
REGISTER BANK
CONTROLLER
EEPROM
(USER AND
CONFIG)
OUTPUT
STAGES
LOGIC NETWORK
FOR PO_
WATCHDOG
TIMERS
GPI_
GPI_, MR,
MARGIN
PO_ IN_
SDA,
SCL
ANALOG
BLOCK
DIGITAL
BLOCK
SERIAL
INTERFACE
AUXIN_
Figure 1. Top Level Block Diagram
watchdog timer to clear on a combination of one GPI_
input and one programmable output, one of the GPI_
inputs only, or one of the programmable outputs only.
The initial and normal watchdog timeout periods are
independently programmable from 6.25ms to 102.4s.
A virtual diode-ORing scheme selects the input that pow-
ers the MAX6870/MAX6871. The MAX6870/MAX6871
derive power from IN1 if V IN1 > +6.5V or from the highest
voltage on IN3–IN6 if V IN1 < +2.7V. The power source
cannot be determined if +4V < V IN1 < +6.5V and one
of V IN3 through V IN6 > +2.7V. The programmable out-
puts maintain the correct programmed logic state for
V
ABP > V UVLO . One of IN3 through IN6 must be
greater than +2.7V or IN1 must be greater than +4V for
device operation.