MAX34461EVKIT# Maxim Integrated, MAX34461EVKIT# Datasheet - Page 28

• Manufacturer Part Number: MAX34461EVKIT#
• Description: Power Management IC Development Tools MAX34461 Eval Kit
• Manufacturer: Maxim Integrated
• Type: Voltage Detectorsr

Specifications of MAX34461EVKIT#

• Rohs: yes
• Product: Evaluation Kits
• Tool Is For Evaluation Of: MAX34461
• Input Voltage: 3 V to 3.6 V
• Output Voltage: 3 V to 3.6 V
• Interface Type: USB
• Part # Aliases: 90-34461#EVK

The device uses an internal watchdog timer that is
internally reset every 5ms. In the event the device is
locked up and this watchdog reset does not occur after
210ms, the device automatically resets. After the reset
occurs, the device reloads all configuration values that
were stored to flash and begins normal operation. After
the reset, the device also does the following:
1) Sets the MFR bit in STATUS_WORD.
2) Sets the WATCHDOG_INT bit in STATUS_MFR_
3) Notifies the host through ALERT assertion (if enabled
Upon reset, the device runs an internal algorithm to
check the integrity of the key internal nonvolatile memory.
If the CRC check fails, the device does not power up and
remains in a null state with all pins high impedance, but
asserts the FAULT output.
FAULT is an open-drain, active-low input/output pin. The
primary purpose of the FAULT pin is to provide sequenc-
ing control across multiple devices in fault situations.
Within the device, any power supply tagged as a
power supply (with the MFR_FAULT_RESPONSE com-
mand) asserts the FAULT pin to indicate to other
power supplies in other devices that action should be
taken. FAULT is also an input that can be configured with
the FAULT_IGNORE bit in the MFR_MODE command
to cause all
to shut down and retry when FAULT is released. The
input status of FAULT is available in the STATUS_MFR_
SPECIFIC command when the PAGE is set to 255. FAULT
is pulled low when the device is reset until monitoring
begins.
The MONOFF control (which is shared with the A0 I
slave address-select function) is an active-low input with
an internal weak pullup. To allow the device to properly
set the I
Maxim Integrated
PMBus 16-Channel Voltage Monitor and Sequencer
MONOFF Disable Monitoring Control Input
SPECIFIC (for PAGE 255).
in MFR_MODE).
2
C address, this pin should be high impedance
GLOBAL
power supplies within the device
System Watchdog Timer
FAULT Input/Output Pin
CRC Memory Check
GLOBAL
GLOBAL
2
C
upon power-up or device reset (it is recommended that
a small-signal MOSFET be used to pull this pin low). See
the
up, when this pin is pulled low, the device stops monitor-
ing for overvoltage/undervoltage and temperature faults/
warnings and freezes the current state of the power-good
and fault signals. The MONOFF input is useful in systems
that do not use the external DS4424 current DACs to
margin the power supplies and instead use some other
technique such as a bed-of-nails tester. Asserting this
pin lets the system be margin tested without causing any
voltage faults or warnings. The MONOFF input is ignored
when faults are active and when the power-good signals
are not asserted. No sequencing should be performed
while MONOFF is active.
A summary of the PMBus commands supported by the
device are described in the following sections.
The device can monitor up to 16 voltages, sequence
up to 16 power supplies, and margin up to 16 power
supplies using four external current DACs (DS4424).
The device can monitor up to five temperature sensors,
one internal local temperature sensor, plus four external
remote temperature sensors (DS75LV). All the monitor-
ing and control is accomplished using one PMBus (I
address. Send the PAGE command with data 0–15 and
17–21 (decimal) to select which power supply or tem-
perature sensor is affected by all the following PMBus
commands. Not all commands are supported within each
page. If an unsupported command is received, the CML
status bit is set. Some commands are common, which
means that any selected page has the same effect on
and the same response from the device. See
PAGE commands.
Set the PAGE command to 255 when the following
PMBus commands should apply to all pages at the same
time. There are only a few commands (OPERATION,
CLEAR_FAULTS) where this function has a real
application.
Typical Operating Circuit
PMBus Commands
for an example. After power-
MAX34461
PAGE (00h)
Table 6
2
for
C)
28