MAX11080 Datasheet, PDF (16/27 Pages) Maxim Integrated Products – 12-Channel, High-Voltage Battery-Pack Fault Monitor

12-Channel, High-Voltage Battery-Pack
Fault Monitor
Table 2. Undervoltage Threshold Selection
THRESHOLD (V)
Disabled
1.6
1.8
2.0
2.2
2.4
2.6
2.8
UVSEL2
0
0
0
0
1
1
1
1
UNDERVOLTAGE SELECTION
UVSEL1
0
0
1
1
0
0
1
1
UVSEL0
0
1
0
1
0
1
0
1
Internal Linear Regulator
The MAX11080 has an internal linear regulator for gen-
erating the internal supply from DCIN (Figure 11). The
regulator can accept a supply voltage on the DCIN pin
from +6.0V to +72V, which it regulates to 3.3V to run
the voltage-detection system, control logic, and low-
side alarm-pulse interface. When the SHDN pin is not
active and a sufficient voltage is applied to DCIN, the
output of the regulator becomes active. The regulator is
paired with a power-on-reset (POR) circuit that senses
its output voltage and holds the MAX11080 in a reset
state until the internal supply has reached a sustainable
threshold of +3.0V (±5%). The internal comparators
have built-in hysteresis that can reject noise on the sup-
ply line. Because secondary metal batteries are never
fully discharged to 0V, the MAX11080 is designed for a
hot-swap insertion of the battery cells. Once the POR
threshold is reached, approximately 1ms later the inter-
nal reset signal disables, the internal oscillator starts,
and the charge pump begins operating. The charge
DCIN
SHDN
+6.0V TO +72V
LINEAR
REGULATOR
REGULATOR
ENABLE
DIE OVERTEMPERATURE
DETECT
BANDGAP
REFERENCE
INTERNAL +3.3V
CHARGE
PUMP
CHARGE-PUMP
ENABLE
V_AA
GND_U
VDD_U
POR THRESHOLD +3.0V ±5%
Figure 11. Internal Linear Regulator Block Diagram
POR
COMPARATOR
35mV
HYSTERESIS
+3.3V TO GND_U
INTERNAL POR
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