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Texas Instruments BQ79631PAPRQ1
- Part No.:
- BQ79631PAPRQ1
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 64-PowerTQFP
- Datasheet:
-
BQ79631PAPRQ1.pdf
- Description:
- AUTOMOTIVE 16-S BATTERY JUNCTION
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
BQ79631PAPRQ1 from Texas Instruments is an automotive-grade UIR (Voltage, Current, and Insulation Resistance) sensor IC designed for high-voltage battery junction box (BJB) and battery disconnect unit (BDU) systems in EVs and PHEVs. It delivers differential voltage measurement across 16 high-side nodes (VS0–VS16), integrated ±100 mV current sensing via low-side shunt (SRP/SRN), and on-chip insulation resistance monitoring - all with ASIL D hardware and systematic capability per ISO 26262.
For engineers reviewing the BQ79631PAPRQ1 datasheet, BQ79631PAPRQ1 pinout, BQ79631PAPRQ1 application, or BQ79631PAPRQ1 equivalent, this device serves as a functional safety-compliant, isolated daisy-chainable sensor for HV battery safety monitoring - requiring precise voltage accuracy (±2.6 mV over –40°C to +125°C), synchronized current/voltage sampling, and UART + isolated differential communication interface support.
Technical Context
The BQ79631PAPRQ1 integrates three independent ADC subsystems: a 16-bit main ADC for high-accuracy differential voltage sensing (VS0–VS16, AUX0–AUX4), a 14-bit auxiliary ADC for diagnostics and thermistor inputs, and a dedicated 24-bit current-sense ADC with 14.9 nV/LSB resolution for SRP/SRN. All ADCs feature integrated digital low-pass filtering and support synchronized acquisition.
Its isolated daisy-chain interface uses transformer- or capacitor-based coupling with configurable ring architecture for fault-tolerant communication across stacked monitors; it also includes a built-in SPI master for peripheral control and UART host interface - eliminating need for external safety MCU or CAN transceivers in BJB/BDU topologies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Main ADC resolution | 16-bit ENOB; enables 190.73 µV/LSB voltage measurement precision for HV node monitoring |
| Current sense ADC resolution | 24-bit output with 14.9 nV/LSB; supports sub-milliamp current resolution at ±100 mV full-scale range |
| Voltage accuracy (VS) | ±2.6 mV over –40°C to +125°C; meets tight tolerance requirements for pack+, fuse, link+, and charge+ measurements |
| Insulation resistance monitoring | Integrated hardware-controlled switching and ADC-based Riso calculation; no external controller needed |
| Functional safety certification | AEC-Q100 Grade 1 (–40°C to +125°C ambient); ASIL D capable per ISO 26262 for system-level safety architecture |
| Communication interfaces | Isolated differential daisy-chain (capacitor/transformer-coupled) + UART; supports ring topology for single-point failure resilience |
| GPIO count & flexibility | 8 programmable GPIOs supporting thermistor sensing, relay control, ADC input, or SPI master I/O functions |
Pinout & Package
Package: HTQFP-64 (10.00 mm × 10.00 mm), thermally enhanced for automotive under-hood environments with RθJA = 21.6°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VS0–VS16, AUX0–AUX4 | Differential voltage sense inputs | Support direct connection to HV nodes (Pack+, Fuse, Link+, Charge+) with integrated LPF; VS0/VS1 handle low-side reference |
| SRP / SRN | Current sense differential inputs | Accept ±100 mV across low-side shunt; feed dedicated 24-bit CS ADC with <1.1 mV total channel error |
| COMHP / COMHN / COMLP / COMLN | Isolated daisy-chain I/O | Enable bidirectional transformer/capacitor-isolated stack communication; configurable as ring for fault containment |
| TX / RX | UART host interface | Direct TTL-level UART connection to host MCU; eliminates need for level-shifting or isolation in non-safety-critical paths |
| GPIO1–GPIO8 | Configurable I/O | Support thermistor bias (TSREF), analog voltage input, digital I/O, or SPI master signals - reducing external component count |
| NFAULT | Active-low fault indicator | Asserts on OV/UV, thermal shutdown, or communication error; directly interfaces with host safety MCU interrupt pin |
Key Features
| Feature | Design Value |
|---|---|
| Synchronized multi-channel acquisition | Simultaneous sampling of voltage, current, and temperature channels ensures time-aligned safety decisions in BMS fault detection |
| Integrated insulation resistance measurement | On-chip switching control and ADC processing eliminate external microcontroller involvement in Riso test sequences |
| Stackable daisy-chain with ring fallback | Single two-wire interface manages up to 16 devices; ring mode maintains host access even if one interconnect breaks |
| Built-in SPI master | Drives external peripherals (e.g., EEPROM, temperature sensors) without requiring host MCU resources or additional SPI controllers |
| ASIL D hardware capability | Includes dual-lockstep logic, memory ECC, watchdog timers, and diagnostic coverage >90% - verified per ISO 26262 Part 5 |
Applications
| Battery Junction Box (BJB) Monitoring | Battery Disconnect Unit (BDU) Safety Control |
|---|---|
|
Use Scenario: Real-time monitoring of Pack+, Fuse, Link+, and Charge+ voltages during DC fast charging and load switching in EV power distribution units. IC Role / Device Role / Timing Role: Primary HV voltage and current sensor; performs synchronized 16-channel voltage scans and shunt-based current measurement every 10 ms. Use Value: Enables accurate open-wire detection, precharge verification, and overvoltage/undervoltage protection with ±2.6 mV accuracy across automotive temperature range. |
Use Scenario: Controlling contactor sequencing and verifying isolation integrity before HV system energization in high-voltage battery disconnect circuits. IC Role / Device Role / Timing Role: Insulation resistance monitor and safety-critical voltage supervisor; initiates Riso test cycles and validates thresholds prior to main contactor closure. Use Value: Reduces BDU BOM by integrating Riso switching, timing, and ADC - meeting ISO 6469-1 requirements without external MCU coordination. |
| EV Powertrain Safety Architecture | Modular Battery Pack Management |
|
Use Scenario: Serving as the primary safety sensor in ASIL D–compliant battery management systems where functional safety decomposition requires dedicated UIR monitoring. IC Role / Device Role / Timing Role: Hardware-level safety element; provides diagnostic data (die temp, supply monitors, ADC self-test results) to safety MCU via daisy-chain or UART. Use Value: Delivers ASIL D systematic capability and hardware fault tolerance - including lockstep ADCs, memory ECC, and voltage supervisor redundancy - validated per ISO 26262. |
Use Scenario: Scalable monitoring of multi-module battery packs using daisy-chained BQ79631PAPRQ1 devices alongside cell monitors (e.g., BQ79616-Q1). IC Role / Device Role / Timing Role: Stack coordinator and HV interface; synchronizes measurements with adjacent cell monitors and relays status via isolated daisy-chain. Use Value: Eliminates CAN bus and safety MCU in module-level BJBs - reducing latency, cost, and EMI susceptibility while maintaining full diagnostic coverage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar UIR sensor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ79616-Q1 | 16-cell monitor with integrated voltage/current sensing but no insulation resistance measurement circuitry or dedicated UIR functionality | Designed for cell-level monitoring in battery modules; lacks HV node isolation testing and BJB-specific voltage ranges (e.g., Pack+, Fuse) | Select BQ79616-Q1 only when UIR capability is handled externally or not required; BQ79631PAPRQ1 is mandatory for ISO 6469-1 Riso compliance |
| MAX17853 | Automotive AEC-Q100 Grade 1 16-channel monitor with current sense and daisy-chain, but no on-chip insulation resistance measurement or ASIL D hardware certification | Used in non-safety-critical pack monitoring; requires external MCU and discrete components for Riso testing and fails ASIL D hardware capability assessment | Choose MAX17853 only for cost-sensitive, non-ASIL D designs; BQ79631PAPRQ1 is required where ISO 26262 ASIL D hardware capability is mandated |
Compared with BQ79616-Q1 and MAX17853, the BQ79631PAPRQ1 uniquely integrates certified ASIL D hardware, on-chip insulation resistance measurement, and BJB-optimized HV voltage sensing - making it the only qualified solution for functional safety-compliant HV battery junction box monitoring.
Availability
BQ79631PAPRQ1 is available at Aetrix Electronics and suitable for electric vehicle battery junction boxes, battery disconnect units, and ASIL D–compliant battery management systems requiring stable component supply, long-term automotive lifecycle support, and traceable sourcing.
Supply support for BQ79631PAPRQ1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with deep expertise in automotive-grade power management and battery monitoring solutions.
The BQ79631PAPRQ1 belongs to TI's BQ796xx-Q1 family of functional safety-compliant battery monitor ICs, engineered specifically for high-voltage battery safety applications in EVs, PHEVs, and HEVs - emphasizing insulation resistance, synchronized multi-parameter sensing, and ASIL D system integration.
FAQ
What is the primary function of the BQ79631PAPRQ1 in an EV battery system?
The BQ79631PAPRQ1 serves as a UIR (Voltage, Current, and Insulation Resistance) sensor IC in high-voltage battery junction boxes and disconnect units. It performs synchronized differential voltage measurements across 16 HV nodes (e.g., Pack+, Fuse, Link+), measures current via low-side shunt resistor, and executes on-chip insulation resistance tests - all with ASIL D hardware capability. Its role is critical for ISO 6469-1 compliance and functional safety in EV power distribution.
Does the BQ79631PAPRQ1 support daisy-chain communication with other battery monitors?
Yes, the BQ79631PAPRQ1 supports isolated differential daisy-chain communication with other UIR and cell monitors (e.g., BQ79616-Q1, BQ79656-Q1) using transformer- or capacitor-coupled interfaces. It also features configurable ring architecture to maintain host communication even if one interconnect fails - a key requirement for fault-tolerant BMS designs.
What is the accuracy of voltage measurement for the BQ79631PAPRQ1 over its full operating temperature range?
The BQ79631PAPRQ1 achieves ±2.6 mV total channel accuracy for VS measurements over –40°C to +125°C ambient temperature, with 16-bit ENOB and integrated digital low-pass filtering. This accuracy applies to differential inputs such as Pack+, Fuse, Link+, and Charge+ - meeting stringent requirements for HV node monitoring in automotive BJB/BDU applications.
How does the BQ79631PAPRQ1 implement insulation resistance monitoring?
The BQ79631PAPRQ1 implements insulation resistance monitoring using internal switching control and dedicated ADC resources. It drives external resistor networks, sequences voltage application and sampling, and computes Riso values on-chip - eliminating need for external MCU intervention. The process complies with ISO 6469-1 and supports configurable test timing and threshold validation.
Is the BQ79631PAPRQ1 pin-compatible with other devices in the BQ796xx-Q1 family?
No, the BQ79631PAPRQ1 is not pin-compatible with other BQ796xx-Q1 devices such as BQ79616-Q1 or BQ79656-Q1. It uses a unique 64-pin HTQFP package with dedicated pins for HV voltage sensing (VS0–VS16, AUX0–AUX4), insulation resistance control, and isolated daisy-chain I/O - reflecting its specialized UIR sensor role versus cell-monitoring variants.
BQ79631PAPRQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 64-PowerTQFP
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Battery Monitor
- Battery Chemistry:
- -
- Number of Cells:
- 1
- Fault Protection:
- -
- Interface:
- SPI, UART
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-HTQFP (10x10)
BQ79631PAPRQ1 FAQ
1.How can I place an order for BQ79631PAPRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ79631PAPRQ1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for BQ79631PAPRQ1 reliable?
The price and inventory of BQ79631PAPRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ79631PAPRQ1 is usually 5 days.
3.What payment methods are accepted for BQ79631PAPRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ79631PAPRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ79631PAPRQ1?
BQ79631PAPRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ79631PAPRQ1 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for BQ79631PAPRQ1?
For technical support, including BQ79631PAPRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ79631PAPRQ1 requirements.
6.How does Aetrix verify that BQ79631PAPRQ1 is sourced from the original manufacturer or authorized distributors?
All BQ79631PAPRQ1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BQ79631PAPRQ1 meets industry standards.
7.What is the process for return or replacement of BQ79631PAPRQ1?
All BQ79631PAPRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with BQ79631PAPRQ1, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The BQ79631PAPRQ1 part is unused and in its original packaging.
Return procedure for BQ79631PAPRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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