Texas Instruments bq76PL455A-Q1, User Manual

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Registers
Control
Squeeze
Resistors
Threshold Set
NPN Regulator
EQ
Control
WinComp
VP
N
PN
B
T
O
P
V
5
VAO
VD
IG
VM
C
H
M
C
H
P
OSC
MUX
OV DAC
UV DAC
10 V ALWAYS ON
4.5V
VREF
5.3 V REF
NPN PROTECT
VP CLAMP
1k
2.5V
VREF
O
U
T
2
O
U
T
1
LPF
RX
ADC
MUX
ADC
VR
EF
Registers
I/O
TSD
OV
UV
OV
UV
OV
UV
OV
UV
VDIG
VP
VIO
VDD18
V5VAO
ANALOG DIE DIGITAL DIE
VDD18
TX
TX / RX
TX / RX
V5VAO VDIG
Charge
Pump
VDIG
VP
VM
HIGHEST
CELL
EEPROM
VREG1.8
5 V
ALWAYS
ON
Comms
Interface
AUX0
AUX7
FAULTH-
FAULTL-
COMMH-
COMMH+
COMML-
COMML+
WAKEUP
RX
TX
POR
VP POR
V5VAO POR
1.8V POR
VIO POR
VDIG POR
POR
VP POR
VDIG POR
VM POR
G
PI
O
5
G
PI
O
0
F
AU
L
T
_
N
VI
O
C
G
N
D
D
G
N
D
AG
N
D
2
AG
N
D
1
Temp
Sensor
AFE
VSENSE0
EQ1
VSENSE1
VSENSE2
EQ2
VSENSE15
EQ16
VSENSE16
Temp
Sensor
Checksum
Engine
EEC Decoder
AUX Pullup
AUXPUEN
Digital
Comparators
Stack
Monitor
AG
N
D
3
VTOP
AGND
NPN PROTECT
!
TSD
!
WAKE
WAKEUP
V5VAO
Wakeup
Control
Registers
Control
WAKEUP
WAKE
Application
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Figure 2. bq76PL455A-Q1 Functional Block Diagram
4.1 Cell Voltage Monitoring
The TI bq76PL455A-Q1 integrated balancing solution supports high-accuracy, high-speed cell voltage
measurement. The whole measurement subsystem is designed for high-accuracy measurements while
providing low-power operation. The cell monitoring block utilizes a high-voltage, high-accuracy AFE and a
14-bit ADC. The bq76PL455A-Q1 is capable of monitoring up to 16 cells from a minimum stack voltage of
16 V up to a maximum stack voltage of 79.2 V. Each channel is capable of measuring cell voltage over an
operating range of 1 V to 5 V.
The bq76PL455A-Q1 can be programmed to sample any combination of its selected channels in
descending order, with sampling times between 4.13
μ s and 1000.08 μ s. To reduce noise on
measurements, set the bq76PL455A-Q1 to oversample up to 32 times and respond back with the average
sampled value from each channel during the averaging. Using the PC GUI, set the bq76PL455EVM to
continuously poll the programmed channels at various rates, depending on the averaging period selected.
Whenever user-specified under- or over-voltage thresholds are exceeded by measured cell voltages, fault
register bits are set indicating one or more faults. Active faults can be selectively programmed to trigger
the bq76PL455A-Q1 FAULT output pin, if a limit is exceeded.
6 bq76PL455EVM and GUI User Guide SLUUBA7A – April 2015 – Revised July 2015
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