MAX5978 Datasheet, PDF (20/38 Pages) Maxim Integrated Products – 0 to 16V, Hot-Swap Controller with 10-Bit Current, Voltage Monitor, and 4 LED Drivers

0 to 16V, Hot-Swap Controller with 10-Bit
Current, Voltage Monitor, and 4 LED Drivers
Digital Current Monitoring
The current-sense signal is sampled by the internal
10-bit, 10ksps ADC, and the most recent results are
stored in registers for retrieval through the I²C interface.
The current conversion values are 10 bits wide, with the
8 high-order bits written to one 8-bit register and the 2
low-order bits written to the next-higher 8-bit register
address (Tables 8 and 9). This allows use of just the
high-order byte in applications where 10-bit precision is
not required. This split 8-bit/2-bit storage scheme is used
throughout the device for ADC conversion results and
digital comparator thresholds.
Once the PG output is asserted, the current-sense sam-
ples are continuously compared to the programmable
overcurrent warning register value. If the measured cur-
rent value exceeds the warning level, the ALERT output
is asserted. The device response to this digital com-
parator is not altered by the setting of the PROT input
(Tables 10 and 11).
Table 8. ADC Current-Conversion Results Register Format (High-Order Bits)
Description:
Register Title:
Register Addresses:
Most recent current-conversion result, high-order bits [9:2]
adc_cs_msb
0x00
R
inew_9
Bit 7
R
inew_8
Bit 6
R
inew_7
Bit 5
R
inew_6
Bit 4
R
inew_5
Bit 3
R
inew_4
Bit 2
R
inew_3
Bit 1
R
inew_2
Bit 0
RESET
VALUE
0x00
—
Table 9. ADC Current-Conversion Results Register Format (Low-Order Bits)
Description:
Register Title:
Register Addresses:
Most recent current-conversion result, low-order bits [0:1]
adc_cs_ lsb
0x01
R
—
Bit 7
R
—
Bit 6
R
—
Bit 5
R
—
Bit 4
R
—
Bit 3
R
—
Bit 2
R
inew_1
Bit 1
R
inew_0
Bit 0
RESET
VALUE
0x00
—
Table 10. Overcurrent Warning Threshold Register Format (High-Order Bits)
Description:
Register Title:
Register Addresses:
Overcurrent warning threshold high-order bits [9:2]
oithr_msb
0x22
R/W
oi_9
Bit 7
R/W
oi_8
Bit 6
R/W
oi_7
Bit 5
R/W
oi_6
Bit 4
R/W
oi_5
Bit 3
R/W
oi_4
Bit 2
R/W
oi_3
Bit 1
R/W
oi_2
Bit 0
RESET
VALUE
0xFF
—
Table 11. Overcurrent Warning Threshold Register Format (Low-Order Bits)
Description:
Register Title:
Register Addresses:
Overcurrent warning threshold low-order bits [1:0]
oithr_lsb
0x23
R/W
—
Bit 7
R/W
—
Bit 6
R/W
—
Bit 5
R/W
—
Bit 4
R/W
—
Bit 3
R/W
—
Bit 2
R/W
oi_1
Bit 1
R/W
oi_0
Bit 0
RESET
VALUE
0x03
—
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