MLX91231
Smart IVT Sensor IC
Datasheet
REVISION 1.0 – DEC 07, 2023
DOC. № 3901091231
1. Features and Benefits
▪ IVT battery measurements:
o Shunt based current sensor
o Voltage measurement
▪ Internal dividers for 12V or 24V/48V batteries
▪ External divider required for HV batteries
o Internal (PTAT) temperature sensor
▪ 16-bit MCU with 32 KB Flash, 128 B Flash CS,
20 KB ROM, 2 KB RAM and 512 B EEPROM
Memory
▪ LIN/UART communication interfaces
o LIN Physical Layer compliant to
ISO17987-4 and SAE J2602
o UART as CAN MCU bridge
o Wake-up on LIN and UART or on internal
timer
▪ Overcurrent detection functionality (<500µs)
▪ Sensing range of 256mV
▪ Possible Automatic Gain Control (AGC) for
higher dynamic range
▪ Low level SW libraries provided by Melexis
▪ User programmable transfer characteristic
▪ Supply voltage: 4.5 to 18V (5V regulated
supply or 12V battery supply capability)
▪ Low current consumption (<21mA),
programmable duty cycled sleep mode (RAM
content maintained at <100µA)
▪ Ambient temperature from -40°C to 125°C
▪ ASIL compliant SEooC (Safety Element out of
Context) according to ISO26262
▪ AEC-Q100 Grade 1 automotive qualified
▪ RoHS compliant package SOIC8 (DC)
2. Application Examples
▪ Battery Terminal Sensor 12V/ 24V
Battery Management System 48V/ HV
o Primary current measurement
o Redundant current measurement
(homogenous or heterogenous sensing
technology)
o Diagnosable Overcurrent Detection
▪ SoC/ SoH/ SoF + R
int
(pre)calculations
▪ Smart Battery Disconnect Unit, Junction
Box or Power Relay Assembly
▪ Smart Pyrofuses, HV relays or contactors
▪ HV DC FastCharge current sensor
▪ Zone controller
▪ DC/DC converter
▪ Power Distribution Unit
3. Description
The MLX91231 is the first Melexis smart Shunt-
based current sensor and is part of Gen3 portfolio.
With a measurement capability of three physical
quantities: Current, Voltage and Temperature,
Overcurrent detection alongside a dedicated 32 KB
Flash memory on a single IC, this ASIL-compliant
chip is ideal for safety applications. With its
diagnostics, the MLX91231 is removing an
important part of the burden from the integrator in
developing all the safety mechanisms. The
MLX91231 comes with 0.25% accuracy over
temperature (-40°C to 125°C) and over lifetime all-
in, hence boosting the accuracy of Shunt DC current
sensing. The IC’s MCU enables automatic gain
control to cover higher dynamic ranges, and its on-
board flash memory supports custom software,
extensive compensation of system imperfections
and low power modes. Supplied with a regulated
5V or directly connected to the 12V battery, the
MLX91231 outputs measurements and diagnostics
either on LIN bus or via UART.
MLX91231
Smart IVT Sensor IC
Datasheet
Page 2 of 29
REVISION 1.0 –DEC 07, 2023
DOC. № 3901091231
Contents
1. Features and Benefits .............................................................................................. 1
2. Application Examples .............................................................................................. 1
3. Description .............................................................................................................. 1
4. Ordering Information .............................................................................................. 3
5. Functional Diagram ................................................................................................. 4
6. Functional Safety ..................................................................................................... 4
7. References .............................................................................................................. 4
8. Glossary of Terms .................................................................................................... 5
9. Pin description, Pin Definitions and Pinout .............................................................. 6
10. Maximum Ratings ............................................................................................ 6
11. Operating Ranges ............................................................................................. 8
12. General Timing Specification ............................................................................ 9
13. Analog Front End ........................................................................................... 10
13.1. Shunt current measurement ............................................................. 10
13.2. Automatic gain control ...................................................................... 11
13.3. Overcurrent detection ....................................................................... 13
PWM digital OCD on TX_OCD pin ...................................................... 15
PWM digital OCD on LIN_OCD pin ..................................................... 17
13.4. VSENSE voltage measurement .......................................................... 18
LVBAT (12V) measurement ................................................................ 18
HVBAT (24V/48V) measurement ....................................................... 18
Direct voltage (HV) measurement ..................................................... 19
13.5. Internal die Temperature measurement ........................................... 20
13.6. VDD voltage measurement ................................................................ 20
14. Electrical specifications .................................................................................. 21
14.1. LIN ...................................................................................................... 21
14.2. UART .................................................................................................. 21
RX ....................................................................................................... 21
TX ....................................................................................................... 21
14.3. Supply system .................................................................................... 22
14.4. Internal Clock Generation .................................................................. 22
15. Recommended Application Diagrams ............................................................. 23
15.1. Application diagram for LIN and UART communications .................. 23
15.2. OCD external circuit example (PWM) ................................................ 25
16. Package, IC handling and assembly ................................................................. 27
16.1. Package information .......................................................................... 27
16.2. Storage and handling of plastic encapsulated ICs ............................. 28
16.3. Assembly of encapsulated ICs ........................................................... 28
16.4. Environment and sustainability ......................................................... 28
17. Revision History Table .................................................................................... 29
18. Disclaimer ...................................................................................................... 29