Rainbow Electronics MAX5970 User Manual
Page 18
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