MAX16047ETN+W Maxim Integrated, MAX16047ETN+W Datasheet - Page 54

• Manufacturer Part Number: MAX16047ETN+W
• Description: Supervisory Circuits 12-Channel EEPROM-Programmable System Manager with Nonvolatile Fault Registers
• Manufacturer: Maxim Integrated
• Series: MAX16047, MAX16049r

Specifications of MAX16047ETN+W

• Number Of Voltages Monitored: 12
• Undervoltage Threshold: Adjustable
• Overvoltage Threshold: Adjustable
• Manual Reset: Resettable
• Watchdog: Watchdog
• Supply Voltage - Max: 14 V
• Maximum Power Dissipation: 3810 mW
• Supply Current (typ): 3800 uA
• Supply Voltage - Min: 3 V

12-Channel/8-Channel EEPROM-Programmable
System Managers with Nonvolatile Fault Registers
Maintain power for shutdown during fault conditions in
applications where the always-on power supply cannot
be relied upon by placing a diode and a large capaci-
tor between the voltage source, V
15). The capacitor value depends on V
delay required, t
to calculate the capacitor size:
where the capacitance is in Farads and t
in seconds. I
drop across the diode, and V
ple, with a V
t
tance is 100µF.
The MAX16047/MAX16049 use external n-channel
MOSFET switches for voltage tracking applications. To
configure the part for closed-loop voltage tracking using
series-pass MOSFETs, configure up to four of the pro-
grammable outputs (EN_OUT1–EN_OUT4) of the
MAX16047/MAX16049 as closed-loop tracking outputs
and configure up to four of the GPIOs as sense-return
inputs (INS1–INS4). Connect the EN_OUT_ output to the
gate of an n-channel MOSFET, connect the source of the
MOSFET to the INS_ feedback input, and monitor the
drain side of the MOSFET with the corresponding MON_
input (see Figure 16). Both the input and the output must
be assigned to the same slot (see the Closed–Loop
Tracking section). Configure the power-up and power-
down slew rates in the configuration registers. To provide
Figure 15. Power Circuit for Shutdown During Fault Conditions
54
FAULT_SAVE
______________________________________________________________________________________
V
Driving High-Side MOSFET Switches
IN
of 0.204s, the minimum required capaci-
C
IN
CC(MAX)
=
of 14V, a diode drop of 0.7V, and a
FAULT_SAVE
C
t
V
FAULT_SAVE
IN
−
V
is 5mA, V
DIODE
V
CC
MAX16047
MAX16049
. Use the following formula
UVLO
×
−
GND
V
I
CC(MAX)
CC(MIN)
DIODE
IN
is 2.85V. For exam-
, and V
IN
is the voltage
FAULT_SAVE
and the time
CC
(Figure
is
additional control over power-down, enable the internal
100Ω pulldown resistors on the INS_ connections.
Up to six of the programmable outputs (EN_OUT1–
EN_OUT6) of the MAX16047/MAX16049 may be config-
ured as charge-pump outputs. In this case, they can
drive the gates of series-pass n-channel MOSFETs with-
out closed-loop tracking functionality. When configured
in this way, these outputs act as simple power switches
to turn on the voltage supply rails. Approximate the slew
rate, SR, using the following formula:
where I
rent, C
and C
to ground. Power-down is not well controlled due to the
absence of the 100Ω pulldowns.
If more than six series-pass MOSFETs are required for
an application, additional series-pass p-channel
MOSFETS may be connected to outputs configured as
active-low open drain (Figure 17). Connect a pullup
resistor from the gate to the source of the MOSFET, and
ensure the absolute maximum ratings of the
MAX16047/MAX16049 are not exceeded.
Figure 16. Closed-Loop Tracking
REFERENCE
EXT
ADC MUX
GATE
LOGIC
RAMP
CP
V
IN
is the capacitance connected from the gate
MON_
is the 6µA (typ) charge-pump source cur-
is the gate capacitance of the MOSFET,
SR
=
(
C
GATE
DRIVE
GATE
EN_OUT_
I
CP
+
C
EXT
INS_
)
V
100Ω
TH_PG
V
OUT