Datasheet

NXP Semiconductors

FRDM33772BSPIEVB

Featuring the MC33772B battery cell controller IC

User guide Rev. 1.0 — 22 June 2018

9 / 20

Pin # Connection Description

X1-31 ISENSE_P Current measurement input+ with external filter RC

X1-32 ISENSE_N Current measurement input– with external filter RC

X1-33 CT_REF

CB_1

Cell pin REF input with external LPF resistor.

Cell balance driver. Terminate to cell 1 cell balance load resistor.

X1-34 GND Negative_Battery

4.9 External EEPROM

The FRDM33772BSPIEVB has an integrated gateway communication link to an external

local EEPROM. The MC33772B's I

C Communication Interface manages communication

with the EEPROM.

After a reset, the EEPROM is not enabled. When the EEPROM is enabled, the device

can load the EEPROM calibration parameters into the MC33772B registers.

4.10 GPIO configuration

The FRDM33772BSPIEVB offers seven customizable GPIOs [GPIO_0...GPIO_6] for

measuring external temperature with a bridge divider. [GPIO_0] can be used as the input

for wake-up or fault daisy chain.

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 Current sensing

The FRDM33772BSPIEVB 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).

4.13 SPI communication interface

The MC33772B SPI interface is a standard SPI slave interface with a chip select (CSB),

clock (SCLK), Slave Out (SO), and Slave In (SI). The SI/SO shifting of the data follows a

first-in-first-out protocol, with both input and output words transferring the Most Significant

Bit (MSB) first.

All SPI communication to the MC33772B is controlled by the microcontroller. One 40-bit

in message sent by the MCU. For message integrity and communication robustness,

each SPI transmit message consists of six fields containing 40 bits.

The six transmit fields are defined as the following:

1. Cyclical redundancy check (8 bits)

2. Command field (4 bits)

3. Cluster ID field (4 bits)

4. Memory address field (7 bits)