MAX16065 Datasheet, PDF (51/61 Pages) Maxim Integrated Products – 12-Channel/8-Channel, Flash-Configurable System Managers with Nonvolatile Fault Registers

12-Channel/8-Channel, Flash-Configurable System
Managers with Nonvolatile Fault Registers
Table 33. Maximum Write Time
R6Dh[1:0]
VALUE
00
01
10
11
DESCRIPTION
Save flags and ADC
readings
Save flags
Save ADC readings
Do not save anything
MAXIMUM
WRITE TIME
(ms)
244
77
153
—
V_IN
R
V_OUT
MON_
EN_OUT_
MAX16065
MAX16066
V_IN
V_CC
C
MAX16065
MAX16066
GND
Figure 17. Power Circuit for Shutdown During Fault Conditions
required, tFAULT_SAVE. Use the following formula to cal-
culate the capacitor size:
C = (tFAULT_SAVE x ICC(MAX))/(VIN - VDIODE - VUVLO)
where the capacitance is in Farads and tFAULT_SAVE is in
seconds, ICC(MAX) is 14mA, VDIODE is the voltage drop
across the diode, and VUVLO is 2.7V. For example, with
a VIN of 14V, a diode drop of 0.7V, and a tFAULT_SAVE
of 153ms, the minimum required capacitance is 202FF.
Driving High-Side MOSFET Switches
Up to eight of the programmable outputs (EN_OUT1–
EN_OUT8) of the MAX16065/MAX16066 can be config-
ured as charge-pump outputs to drive the gates of series-
pass n-channel MOSFETS. When driving MOSFETs,
these outputs act as simple power switches to turn on
the voltage supply rails. Approximate the slew rate, SR,
using the following formula:
SR = ICP/(CGATE + CEXT)
where ICP is the 4FA (typ) charge-pump source current,
CGATE is the gate capacitance of the MOSFET, and CEXT
is the capacitance connected from the gate to ground.
If more than eight series-pass MOSFETs are required
for an application, additional series-pass p-channel
MOSFETS can be connected to outputs configured as
Figure 18. Connection for a p-Channel Series-Pass MOSFET
active-low open drain (Figure 18). Connect a pullup
resistor from the gate to the source of the MOSFET, and
ensure the absolute maximum ratings of the MAX16065/
MAX16066 are not exceeded.
Configuring the Device
An evaluation kit and a graphical user interface (GUI) is
available to create a custom configuration for the device.
Refer to the MAX16065/MAX16066 Evaluation Kit for
configuration.
Cascading Multiple MAX16065/MAX16066s
Multiple MAX16065/MAX16066s can be cascaded to
increase the number of rails controlled for sequencing
and monitoring. There are many ways to cascade the
devices depending on the desired behavior. In general,
there are several techniques:
U Configure a GPIO_ on each device to be EXTFAULT
(open drain). Externally wire them together with a
single pullup resistor. Set register bits r72h[5] and
r6Dh[2] to ‘1’ so that all faults will propagate between
devices. If a critical fault occurs on one device,
EXTFAULT will assert, triggering the nonvolatile fault
logger in all cascaded devices and recording a snap-
shot of all system voltages.
U Connect open-drain RESET outputs together to obtain
a master system reset signal.
U Connect all EN inputs together for a master enable sig-
nal. Since the internal timings of each cascaded device
are not synchronized, EN_OUT_s placed in the same
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