MAX11080GUU+ Maxim Integrated Products, MAX11080GUU+ Datasheet - Page 18

• Manufacturer Part Number: MAX11080GUU+
• Description: IC LI/BATTERY MANAGEMENT 38TSSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX11080GUU+

• Function: Battery Monitor
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 6 V ~ 72 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 38-TSSOP (0.173", 4.40mm Width)
• Product: Charge Management
• Operating Supply Voltage: 6 V to 72 V
• Supply Current: 0.05 uA
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Charge Safety Timers: No
• Mounting Style: SMD/SMT
• Temperature Monitoring: No
• Uvlo Start Threshold: 1.6 V
• Uvlo Stop Threshold: 2.8 V
• No. Of Batteries: 12
• Supply Voltage Range: 6V To 72V
• Battery Ic Case Style: TSSOP
• No. Of Pins: 38
• Operating Temperature Range: -40°C To +105°C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12-Channel, High-Voltage
Battery-Pack Fault Monitors
Figure 14. Battery Module Surge and Overvoltage Protection
Circuit
the SMCJ70 on the DCIN connection point. This protec-
tion circuit also helps to reduce power spikes that can
occur during the insertion of the battery cells. During
negative voltage excursions, the protection circuit stores
enough charge to power the regulator through the tran-
sient. Figure 14 shows the clamp configuration to protect
the DCIN supply input.
The DCIN input contains a comparator circuit to detect an
open circuit on this pin for fault-management purposes.
Whenever a nominal voltage of two silicon diode drops
appears between C12 and DCIN following the power-up
sequence, the ALRM
tion. This voltage drop must appear for at least the delay
time set by C
C12 to DCIN during normal operation should be kept at
no more than 0.5V to prevent erroneous tripping of the
DCIN open-circuit comparator under worst-case circum-
stances (lowest silicon diode forward bias voltage). The
diode D
demanded at startup by the decoupling circuit. In parallel
with this diode, R
normal operation. It is selected to be 5kΩ so that the max-
imum voltage drop between C12 and DCIN is about
0.25V with nominal supply currents.
High-power batteries are often used in noisy environ-
ments subject to high dV/dt or dI/dt supply noise and
EMI noise. For example, the supply noise of a power
inverter driving a high horse-power motor produces a
large square wave at the battery terminals, even though
the battery is also a high-power battery. Typically, the
battery dominates the task of absorbing this noise, since
it is impractical to put hundreds of farads at the inverter.
The MAX11080/MAX11081 are designed with several
mechanisms to deal with extremely noisy environments.
First, the major power-supply inputs that see the full
battery-stack voltage are 80V tolerant. This is high
enough to handle the large voltage changes on the bat-
tery stack that can occur when the batteries transition
18
CELL STACK
______________________________________________________________________________________
SEE THE APPLICATION CIRCUIT
DIAGRAM FOR PROPER
CONNECTION LOCATION
TOP OF
DCIN
DLY
is used to supply the transient current
to result in a fault. The voltage drop from
DCIN
R
22Ω
22Ω
LIMIT
L
output is asserted as a fault indica-
provides the supply path during
C
0.1µF
DCIN
80V
5kΩ
100kΩ
SMCJ70
TO GND
TO DCIN
INPUT
INPUT
U
between charge and discharge conditions. Next, the
linear regulator has high PSRR to produce a clean low-
voltage power supply for the internal circuitry. This
allows DCIN to be connected directly to the stack volt-
age. Finally, GND
internal charge pump with its power and acts as the ref-
erence ground for the upper alarm communication port.
The charge pump creates a secondary low-voltage
supply that is referenced to GND
shifted supply VDD
upper alarm communication port glides smoothly on
GND
The upper alarm signal is internally shifted down to
AGND level where it is processed by the digital logic.
There are two connection methods that can be used for
GND
For the top module in a system, or where GND
be DC-coupled to the next higher module for other rea-
sons, GND
as DCIN. This connection is valid as long as the voltage
difference between the top of Stack(n) and the bottom
of Stack(n+1) during worst-case conditions does not
exceed the margin of the alarm pin signaling levels.
When GND
bus bar, it can be AC-coupled to the far side to main-
tain alarm communication when the bus bar is open-cir-
cuit. In that case, the two sides of the AC-coupling
capacitor can be at different DC potentials, but the
alarm communication signal continues to be passed
across the capacitor connection. It is recommended
that an AC- or DC-coupled version of GND
with the alarm signal through the communication bus
wiring, possibly by twisted pair wire, for maximum noise
immunity and minimum emissions.
The preferred connection to reject noise between mod-
ules is when a DC connection can be made from GND
to AGND of the next module. It is again recommended
that the DC-coupled GND
the alarm signal as part of the communication bus for
maximum noise immunity and minimum emissions.
The SHDN pin connections of the MAX11080/MAX11081
operate in a manner that allows the shutdown/wake-up
command to trickle up through the series of daisy-
chained packs. Because the internal linear regulator is
powered down during shutdown, the shutdown function
must operate when V
not depend on a Schmitt trigger input. A special low-cur-
rent, high-voltage circuit is used to detect the state of the
SHDN pin. The shutdown pin has a +2.1V minimum
threshold for the inactive state. When SHDN > 2.1V, the
MAX11080/MAX11081 turn on and begin regulating V
U
U
depending on application requirements.
and it is effectively immune to noise on GND
U
U
should be connected to the same location
is not DC-coupled to the far side of the
U
U
serves two purposes. It supplies the
AA
is referenced to GND
is absent and, therefore, it can-
U
signal is routed adjacent to
Shutdown Control
U
. Because the level-
U
U
, the entire
U
is paired
cannot
AA
U
U
.
,