NXP Semiconductors
FRDM33772BTPLEVB
Featuring the MC33772B battery cell controller IC
FRDM33772BTPLEVBUG
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© NXP B.V. 2018. All rights reserved.
User guide
Rev. 1.0 — 22 June 2018
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4.10 GPIO configuration
The FRDM33772BTPLEVB offers seven customizable GPIOs [GPIO_0...GPIO_6] for
measuring external temperature with on-board or off-board NTCs. The off-board NTC
connection is described in
Section 6.5 "Off-board NTC configuration "
.
4.11 Cell terminal voltage measurement
The differential measurement of each cell terminal input is designed to function in
conjunction with an external low path filter.
4.12 Fault detection
The FRDM33772BTPLEVB uses an optocoupler to detect a fault that is dependent on
user defined internal or external faults.
The fault signal can be chained between EVBs and can be made available on the
controller inputs. With two FRDM33772BTPLEVB boards, the fault is chained as shown
in
Section 6.4 "Fault chain connection"
.
4.13 Current sensing
The FRDM33772BTPLEVB supports current sense function with off-board shunt resistor.
The off-board shunt resistor shall be connected between X1-31 (IS_P) and X1-32 (IS_N).
On-board current sensing filter and protection circuits can be found in EVB schematic
shared via NXP DocStore (NDA required).
4.14 Bus terminal communication
The transformers isolate communication between the MC33772B and the pack controller
and between each MC33772B. They are protected against ESD. There are significant
advantages to using transformers for isolation and communication:
•
High degree of voltage isolation
•
Communication rates of 2.0 MHz with very low radiated emissions
•
Ability to force the secondary signals to be true differential reducing radiated emissions
•
Ability to loop the network back to the pack controller
Detailed schematic, component selection, and layout recommendations can be obtained
from the NXP DocStore (NDA required).
[6]
5 Accessory transceiver board
The FRDM33772BTPLEVB kit is designed for use with the FRDM33664BEVB in high-
voltage isolated applications that provide a SPI-to-high-speed isolated communication
interface. The FRDM33664BEVB includes an MC33664 isolated network high speed
transceiver. MCU SPI data bits are directly converted to pulse bit information.
