General Description
42
bq76PL455EVM Schematic - Sheet 1
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43
bq76PL455EVM Schematic - Sheet 2
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bq76PL455EVM Schematic - Sheet 3
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bq76PL455EVM Schematic - Sheet 4
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List of Tables
1
Switch Settings for Sample Rates
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2
Battery Connector Pin Assignments
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3
J4 - Diff Comm Low Connector Pin Assignments
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4
J5 - Diff Comm High Connector Pin Assignments
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5
J3 - Serial Connector Pin Assignments
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6
J2 -Thermistor Connector Pin Assignments
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7
P1 - GPIO Header Pin Assignments
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8
bq76PL455EVM Test Points
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1
General Description
Texas Instruments’ passive balancing bq76PL455A-Q1 provides monitoring and balancing for a stack of
up to 16 series-connected lithium-ion battery cells. The bq76PL455A-Q1 operates on stack voltages from
a 16 V minimum to a 79.2 V maximum. In addition to 16 battery cell measurement channels, eight (8)
additional analog channels are provided for temperature or auxiliary signal sensing, and six (6) additional
digital channels are provided. As an option, configure the digital channels to generate faults when the level
changes state; either high to low, or low to high. Please refer to the bq76PL455A-Q1 data sheet
(
) for specification of channel voltage measurement accuracy over the 0 to 65°C and –40°C to
105°C operating temperature ranges. The passive cell balancing current is set by onboard resistors to 56
mA for a cell at 4.2 V.
For battery stacks with more than 16 cells, stack up to 6 bq76PL455EVMs, in series, to support up to 96
cells. Communication with stacked bq76PL455EVMs is via an isolated daisy chain differential bus capable
of withstanding 500 V. A stack of multiple bq76PL455EVMs can be woken from power down using a
single wake command from the GUI.
System Faults
are monitored and indicated in the GUI by simulated
LED fault indicators.
Control a single EVM or multiple stacked bq76PL455EVMs using a PC-hosted GUI. Communication
between the PC and the lowest in a stack of bq76PL455EVMs is via an FTDI USB-to-TTL (5V) serial
interface cable. Communication between all other EVMs in the stack is via the isolated, daisy chain
differential communication bus. The PC GUI allows configuration of the bq76PL455EVMs to monitor cells
and other analog data channels, control balancing, and monitor details of any faults.
The bq76PL455EVM (
) demonstrates the performance of Texas Instrument’s new highly
integrated bq76PL455A-Q1 16-cell, battery stack monitoring, passive balancing device. The bq76PL455A-
Q1 provides a highly accurate, reliable, and robust solution for battery management, integrating all of the
following components:
•
14-bit Analog-to-Digital Converter (ADC)
•
Precision voltage reference
•
Precision, high-voltage Analog Front End (AFE)
•
Universal asynchronous receiver/transceiver (UART) serial communication interface
•
LDO voltage regulator
•
Control logic for monitoring, balancing, and communication functions
2
Features
The features for the bq76PL455EVM include:
•
16-channel precision voltage cell monitoring and passive balancing
•
8-channel temperature or auxiliary signal monitoring
3
SLUUBA7A – April 2015 – Revised July 2015
bq76PL455EVM and GUI User Guide
Copyright © 2015, Texas Instruments Incorporated
