max5970 Maxim Integrated Products, Inc., max5970 Datasheet - Page 35

• Manufacturer Part Number: max5970
• Description: 0v To 16v, Dual Hot-swap Controller With 10-bit Current And Voltage Monitor And 4 Led Drivers
• Manufacturer: Maxim Integrated Products, Inc.

0V to 16V, Dual Hot-Swap Controller with 10-Bit
IFAULTSx indicates the overcurrent status from slow
comparator. IFAULTFx indicates overcurrent status from
fast comparator. The status of FAULT_ reflects the NOR
operation of IFAULTSx and IFAULTFx.
These fault register bits latch upon fault condition and
are reset by restarting the affected channel as described
in the Autoretry or Latched-Off Fault Management sec-
tion.
When an overcurrent event (fast-trip or slow-trip)
causes the MAX5970 to shut down the affected
channel(s), a corresponding open-drain FAULT_ out-
put is asserted low. Note that the FAULT_ outputs are
not asserted for shutdowns caused by critical under-
voltage or overvoltage.
The FAULT_ output is cleared when the channel is dis-
abled by pulling ON_ low or by clearing the bits in the
chxen register.
ALERT is an open-drain output that is asserted low any
time that a fault or other condition requiring attention has
occurred. The state of the ALERT output is also indi-
cated by status3[4].
Table 51. LED_Flash/GPIO Enable Register
Table 52. LED Phase/Weak Pullup Enable Register
Description:
Register Title:
Register Address:
Description:
Register Title:
Register Address:
LED4 Flash
Current and Voltage Monitor and 4 LED Drivers
Phase
LED4
bit 7
bit 7
R/W
R/W
LED3 Phase
LED3 Flash
______________________________________________________________________________________
bit 6
bit 6
R/W
R/W
LED_Flash/GPIO Enable register
LED_flash
0x43
LED Phase/Weak Pullup Enable register
LED_ph_pu
0x44
LED2 Phase
LED2 Flash
bit 5
bit 5
R/W
R/W
ALERT Output
FAULT_ Outputs
LED1 Phase
LED1 Flash
bit 4
bit 4
R/W
R/W
LED4 Weak
LED4 Set
R/W
bit 3
R/W
bit 3
PU
ALERT is the NOR of registers 0x31, 0x35, 0x36 and
0x37, so when the ALERT output goes low, the system
microcontroller should query these registers through
the I
assertion.
The MAX5970 has four open-drain LED drivers/user-
programmable GPIOs. When programmed as LED driv-
ers, each driver can sink up to 25mA of current. Table
51 shows the register that enables the drivers as either
LED drivers or GPIOs.
When any of the LED_Set bit in the register is set to 1, the
corresponding open-drain LED driver is turned OFF. The
LED_Flash bits enable each corresponding LED driver
to flash on and off at 1Hz frequency regardless of the
condition of the corresponding LED_Set bit.
Bits 7-4 in Table 52 show how to set the LED drivers to
be either in phase or out of phase with the internal 1Hz
clock. Bits 3-0 show how to enable the 4FA pullup cur-
rent to disable a corresponding LED driver.
2
C interface to determine the cause of the ALERT
LED3 Weak
LED3 Set
bit 2
bit 2
R/W
R/W
PU
LED2 Set
Weak PU
LED2
bit 1
bit 1
R/W
R/W
LED Set Registers
LED1 Set
Weak PU
LED1
bit 0
bit 0
R/W
R/W
VALUE
VALUE
RESET
RESET
0x0F
0x00
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