max5931aeep Maxim Integrated Products, Inc., max5931aeep Datasheet - Page 9

• Manufacturer Part Number: max5931aeep
• Description: Low-voltage, Triple, Hot-swap Controllers/ Power Sequencers/voltage Trackers
• Manufacturer: Maxim Integrated Products, Inc.

The MAX5930A/MAX5931A/MAX5931B are circuit-
breaker ICs for hot-swap applications where a line card
is inserted into a live backplane. The MAX5931A/
MAX5931B operate down to 1V provided one of the
inputs is above 2.7V. Normally, when a line card is
plugged into a live backplane, the card’s discharged
filter capacitors provide low impedance that can
momentarily cause the main power supply to collapse.
The MAX5930A/MAX5931A/MAX5931B reside either on
the backplane or on the removable card to provide
inrush current limiting and short-circuit protection. This
is achieved by using external n-channel MOSFETs,
external current-sense resistors, and on-chip compara-
tors. The startup period and current-limit threshold of
the MAX5930A/MAX5931A/MAX5931B can be adjusted
with external resistors. Figure 1 shows the MAX5930A/
MAX5931A/MAX5931B functional diagram.
The MAX5930A offers three programmable current lim-
its, selectable fault-management mode, and selectable
STAT_ output polarity. The MAX5930A features fixed
current limits, selectable fault-management mode, and
fixed STAT_ output polarity.
The MAX5930A/MAX5931A/MAX5931B support three
modes of operation: voltage-tracking, power-sequenc-
ing, and independent mode. Select the appropriate
mode according to Table 1.
Connect MODE high to enter voltage-tracking mode.
While in voltage-tracking mode, all channels turn on
and off together. To turn all channels on:
• At least one V
• All V
• All V
• No faults may be present on any channel.
MAX5930A
UVLO to startup delay (37.5ms).
23
24
IN_
ON_
PIN
must exceed V
must exceed V
MAX5931A/
MAX5931B
Low-Voltage, Triple, Hot-Swap Controllers/
IN_
19
20
_______________________________________________________________________________________
must exceed V
Detailed Description
PWRRDY
NAME
MODE
ON,TH
ON3
Power Sequencers/Voltage Trackers
Voltage-Tracking Mode
(0.875V).
(0.95V).
On/Off Channel 3 Control Input. See the Mode section.
Mode Configuration Input. Mode is configured according to Table 1 as soon as one of the
IN_ voltages exceeds UVLO and before turning on OUT_ (see the Mode section).
UVLO
(2.45V) for the
Mode
The MAX5930A/MAX5931A/MAX5931B turn off all
channels if any of the above conditions are not met.
After a fault-latched shutdown, cycle any of the ON_
pins to unlatch and restart all channels.
Leave MODE unconnected to enter power-sequencing
mode. While in power-sequencing mode, the
MAX5930A/MAX5931A/MAX5931B turn on and off each
channel depending on the state of the corresponding
V
• At least one V
• All V
• The corresponding V
• No faults may be present on any channel.
The MAX5930A/MAX5931A/MAX5931B turn off all chan-
nels if any of the above conditions are not met. After a
fault-latched shutdown, cycle any of the ON_ inputs to
unlatch and restart all channels, dependent on the corre-
sponding V
Connect MODE to GND to enter independent mode.
While in independent mode the MAX5930A/
MAX5931A/MAX5931B provide complete independent
control for each channel. To turn on a given channel:
• At least one V
• The corresponding V
• The corresponding V
Table 1. Operational Mode Selection
ON_
UVLO to startup delay (37.5ms).
(0.875V).
UVLO to startup delay (37.5ms).
(0.95V).
(0.875V).
High (Connect to BIAS)
. To turn on a given channel:
IN_
Unconnected
FUNCTION
MODE
must exceed V
ON_
GND
Pin Description (continued)
state.
IN_
IN_
must exceed V
must exceed V
Power-Sequencing Mode
PWRRDY
IN_
ON_
ON_
Voltage Tracking
Voltage Sequencing
Independent
must exceed V
Independent Mode
must exceed V
must exceed V
(0.95V).
UVLO
UVLO
OPERATION
(2.45V) for the
(2.45V) for the
PWRRDY
ON,TH
ON,TH
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