Instruction Manual

0V to 16V, Dual Hot-Swap Controller with 10-Bit
Current and Voltage Monitor and 4 LED Drivers
MAX5970
18 _____________________________________________________________________________________
The MAX5970 provides a great deal of system flexibil-
ity because the current-sense range, DAC setting, and
threshold ratio can be changed on the fly for systems
that must protect a wide range of interchangeable
load devices, or for systems that control the allocation
of power to smart loads. Table 6 shows the specified
ranges for the fast-trip and slow-trip thresholds for all
combinations of current-sense range and threshold ratio.
When an overcurrent event causes the MAX5970 to shut
down a channel, a corresponding open-drain FAULT_
output alerts the system. Figure 2 shows the operation
and fault-management flowchart for one channel of the
MAX5970.
Table 6. Specified Current-Sense and Circuit-Breaker Threshold Ranges
Table 7a. IRNG Inputs Status Register Format
Table 7b. Setting Current-Sense Range
IRNG_ INPUT
FAST-TRIP DAC
OUTPUT RANGE (mV)
GAIN (2-BIT) (V
FAST
/V
SLOW
)
ifast2slow
(DEFAULT = 11)
SLOW-TRIP THRESHOLD RANGE
(mV)
Low 10 to 25
00 (125%) 8.00 to 20.00
01 (150%) 6.67 to 16.67
10 (175%) 5.71 to 14.29
11 (200%) 5.00 to 12.50
High 20 to 50
00 (125%) 16.00 to 40.00
01 (150%) 13.33 to 33.33
10 (175%) 11.48 to 28.57
11 (200%) 10.00 to 25.00
Unconnected 40 to 100
00 (125%) 32.00 to 80.00
01 (150%) 26.67 to 66.67
10 (175%) 22.86 to 57.14
11 (200%) 20.00 to 50.00
Description: Fast-trip threshold maximum range setting bits, from IRNG_ three-state inputs
Register Title: Status 2
Register Address: 0x33
R/W R/W R/W R/W
RESET
VALUE
— — — —
CH1_
IRNG1
CH1_
IRNG0
CH0_
IRNG1
CH0_
IRNG0
—
bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
IRNG_ PIN STATE Chx_IRNG1 Chx_IRNG0
MAXIMUM CURRENT-SENSE
SIGNAL (mV)
Low 1 0 25
High 0 1 50
Open 0 0 100