Rainbow Electronics MAX5961 - Manual (Page 14)

MAX5961
0 to 16V, Quad, Hot-Swap Controller
with 10-Bit Current and Voltage Monitor
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Detailed Description
The MAX5961 0 to 16V, quad, hot-swap controller pro-
vides complete protection for multisupply systems. The
device allows the safe insertion and removal of circuit
cards into live backplanes. The MAX5961 is an
advanced hot-swap controller that monitors voltage and
current with an internal 10-bit ADC. The device provides
two levels of overcurrent circuit-breaker protection; a
fast-trip threshold for a fast turn-off and a lower slow-trip
threshold for a delayed turn-off. The maximum overcur-
rent circuit-breaker threshold range is set independently
for each channel with a three-state input (ILIM_) or by
programming though an I
2 C interface.
The internal 10-bit ADC is multiplexed to monitor the
output voltage and current of each hot-swap channel.
The total time to cycle through all the eight measure-
ments is 100µs (typ). Each 10-bit value is stored in an
internal circular buffer so that 50 past samples of each
signal can be read back through the I
2 C interface at
any time or after a fault condition.
The MAX5961 can be configured as four independent
hot-swap controllers, hot-swap controllers operating in
pairs, or as a group of four hot-swap controllers.
The device also includes five digital comparators per
hot-swap channel to implement overcurrent warning,
two levels of overvoltage detection, and two levels of
undervoltage detection. The limits for overcurrent, over-
voltage, and undervoltage are user-programmable.
When any of the measured values violates the program-
mable limits, an external ALERT signal is asserted. In
addition to the ALERT signal, depending on the select-
ed operating mode, the MAX5961 can deassert a
power-good signal and/or turn-off the external MOSFET.
Table 1a. Register Address Map (Channel Specific)
ADDRESS (HEX CODE)
REGISTER DESCRIPTION
CHANNEL 1 CHANNEL 2 CHANNEL 3 CHANNEL 4
RESET
VALUE
TABLE
adc_chx_cs_h
High 8 bits ([9:2]) of latest
current-signal ADC result
0x00 0x04 0x08 0x0C 0x00 9
adc_chx_cs_l
Low 2 bits ([1:0]) of latest
current-signal ADC result
0x01 0x05 0x09 0x0D 0x00 10
adc_chx_mon_h
High 8 bits ([9:2]) of latest
voltage-signal ADC result
0x02 0x06 0x0A 0x0E 0x00 19
adc_chx_mon_l
Low 2 bits ([1:0]) of latest
voltage-signal ADC result
0x03 0x07 0x0B 0x0F 0x00 20
min_chx_cs_h
High 8 bits ([9:2]) of current-
signal minimum value
0x10 0x18 0x20 0x28 0xFF 13
min_chx_cs_l
Low 2 bits ([1:0]) of current-
signal minimum value
0x11 0x19 0x21 0x29 0x03 14
max_chx_cs_h
High 8 bits ([9:2]) of current-
signal maximum value
0x12 0x1A 0x22 0x2A 0x00 15
max_chx_cs_l
Low 2 bits ([1:0]) of current-
signal maximum value
0x13 0x1B 0x23 0x2B 0x00 16
min_chx_mon_h
High 8 bits ([9:2]) of voltage-
signal minimum value
0x14 0x1C 0x24 0x2C 0xFF 32
min_chx_mon_l
Low 2 bits ([1:0]) of voltage-
signal minimum value
0x15 0x1D 0x25 0x2D 0x03 33
max_chx_mon_h
High 8 bits ([9:2]) of voltage-
signal maximum value
0x16 0x1E 0x26 0x2E 0x00 34
max_chx_mon_l
Low 2 bits ([1:0]) of voltage-
signal maximum value
0x17 0x1F 0x27 0x2F 0x00 35