SLVSGS5A December   2023  – June 2024 DRV3946-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 SPI Timing Requirements
    7. 5.7 Timing Diagrams
    8. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Recommended External Components
      2. 6.3.2  Power Supplies and Monitors
        1. 6.3.2.1 PVDD and VDD Power Supplies
        2. 6.3.2.2 PVDD Monitor
        3. 6.3.2.3 VDD Monitor
        4. 6.3.2.4 RESET (nPOR)
        5. 6.3.2.5 Device Safety Layer
      3. 6.3.3  Output Driver
        1. 6.3.3.1 Retry Wait
        2. 6.3.3.2 Over Current Protection
        3. 6.3.3.3 Thermal Protection
      4. 6.3.4  Start-up Sequencing
      5. 6.3.5  Current Control
        1. 6.3.5.1 Internal Regulation Mode
          1. 6.3.5.1.1 Current Thresholds
          2. 6.3.5.1.2 PWM Cycle Control
        2. 6.3.5.2 Fixed Frequency, Variable Duty Cycle Mode
        3. 6.3.5.3 Fixed Duty Cycle, Variable Frequency Mode
        4. 6.3.5.4 Quick Turn Off
        5. 6.3.5.5 PWM Frequency
        6. 6.3.5.6 Minimum and Maximum Duty Cycle
      6. 6.3.6  EN/EN1 and DIS/EN2 pins
      7. 6.3.7  Diagnostics Features
        1. 6.3.7.1 On State Diagnostics
          1. 6.3.7.1.1 PWM Cycle Warnings
          2. 6.3.7.1.2 Timer Based Warnings
        2. 6.3.7.2 Off-state Diagnostics
      8. 6.3.8  nFAULT/NAD Pin
      9. 6.3.9  Fault Table
      10. 6.3.10 Programming
        1. 6.3.10.1 SPI Interface
        2. 6.3.10.2 Addressable SPI
        3. 6.3.10.3 SPI Error Indicators
        4. 6.3.10.4 SPI Format
        5. 6.3.10.5 SPI Watchdog Monitor
  8. 7 Register Maps
    1. 7.1 STATUS Registers
      1. 7.1.1 STATUS0 Register (Address = 1h) [Reset = 2500h]
      2. 7.1.2 STATUS1 Register (Address = 2h) [Reset = 0803h]
      3. 7.1.3 STATUS2 Register (Address = 3h) [Reset = 0000h]
      4. 7.1.4 STATUS3 Register (Address = 4h) [Reset = 0000h]
      5. 7.1.5 STATUS4 Register (Address = Ah) [Reset = 0000h]
      6. 7.1.6 STATUS5 Register (Address = Bh) [Reset = 0000h]
    2. 7.2 MEAS Registers
      1. 7.2.1 MEAS0 Register (Address = 5h) [Reset = 0000h]
      2. 7.2.2 MEAS1 Register (Address = 6h) [Reset = 0000h]
      3. 7.2.3 MEAS2 Register (Address = 7h) [Reset = 0000h]
      4. 7.2.4 MEAS3 Register (Address = 8h) [Reset = 0000h]
      5. 7.2.5 MEAS4 Register (Address = 9h) [Reset = 0000h]
      6. 7.2.6 MEAS5 Register (Address = Ch) [Reset = 0000h]
      7. 7.2.7 MEAS6 Register (Address = Dh) [Reset = 0000h]
    3. 7.3 CONFIG A Registers
      1. 7.3.1 CONFIG_A0 Register (Address = 10h) [Reset = C040h]
      2. 7.3.2 CONFIG_A1 Register (Address = 11h) [Reset = C040h]
      3. 7.3.3 CONFIG_A2 Register (Address = 12h) [Reset = 2424h]
      4. 7.3.4 CONFIG_A3 Register (Address = 13h) [Reset = 0088h]
      5. 7.3.5 CONFIG_A4 Register (Address = 14h) [Reset = 130Ch]
      6. 7.3.6 CONFIG_A5 Register (Address = 15h) [Reset = 8000h]
      7. 7.3.7 CONFIG_A6 Register (Address = 16h) [Reset = 0000h]
    4. 7.4 CONFIG B Registers
      1. 7.4.1 CONFIG_B0 Register (Address = 17h) [Reset = 2623h]
      2. 7.4.2 CONFIG_B1 Register (Address = 18h) [Reset = 0040h]
      3. 7.4.3 CONFIG_B2 Register (Address = 19h) [Reset = 0B0Bh]
      4. 7.4.4 CONFIG_B3 Register (Address = 1Ah) [Reset = 8000h]
      5. 7.4.5 CONFIG_B4 Register (Address = 1Bh) [Reset = 0000h]
    5. 7.5 CMD Registers
      1. 7.5.1 CMD0 Register (Address = 1Ch) [Reset = 8000h]
      2. 7.5.2 CMD1 Register (Address = 1Dh) [Reset = 0000h]
      3. 7.5.3 CMD2 Register (Address = 1Eh) [Reset = 0000h]
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Transient Thermal Impedance and Current Capability
      3. 8.2.3 Application Performance Plots
      4. 8.2.4 PVDD Capacitance Value Estimation
    3. 8.3 Initialization Setup
      1. 8.3.1 Device Initialization – NAD
      2. 8.3.2 Device Initialization – Configuration
      3. 8.3.3 System Initialization
        1. 8.3.3.1 EN/EN1 and DIS/EN2 Function Check
        2. 8.3.3.2 nFAULT Signalling Check
        3. 8.3.3.3 Device Timing Check
        4. 8.3.3.4 Secondary Logic Check
      4. 8.3.4 Turn On Relay
      5. 8.3.5 Turn Off Relay
        1. 8.3.5.1 Using Target Device Command
        2. 8.3.5.2 Using Broadcast Command
    4. 8.4 Power Supply Recommendations
      1. 8.4.1 PVDD Supply Requirements
      2. 8.4.2 PVDD Undervoltage Transients - Contactor Chatter or Weld Prevention
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Package Option Addendum
    2. 11.2 Tape and Reel Information

6.3.1 Recommended External Components

Table 6-2 lists the recommended external components for the DRV3946-Q1.

Table 6-2 External Components
Pin Component Purpose

Suggested Value

IPROPI1

Resistor to GND

Sets the range for the peak and hold current for output 1. This resistor needs to be in the specified range, else RIPROPI1_W warning flag will be set. Range allows for ~4X scaling of current based on relay type.

4.7kΩ to 20kΩ, 0.063W, 1%
IPROPI1

Capacitor to GND

 Optional - filter capacitor on IPROPI1 pin

10pF ceramic capacitor

IPROPI2

Resistor to GND

Sets the range for the peak and hold current for output 2. This resistor needs to be in the specified range, else RIPROPI2_W warning flag will be set. Range allows for ~4X scaling of current based on relay type.

4.7kΩ to 20kΩ,0.063W, 1%
IPROPI2 Capacitor to GND Optional - filter capacitor on IPROPI2 pin 10 pF ceramic capacitor

SDO

Resistor to VDD

Pull up resistor to ensure that SDO output is registered as high when not driven by the device.

10 kΩ, 0.063 W, 10%

nFAULT/NAD

Resistor to VDD

Sets the unique node address for SPI communication. This resistor needs to be one of the four resistor values allowed, else NAD_ERR flag will be set and SPI communication will be affected.

5.6kΩ/ 12kΩ/ 27kΩ/ 56kΩ, 0.063W, 1%

PVDD

Bulk capacitor to GND

Local bulk capacitor on PVDD to handle transients

≥ 10μF, 35V

PVDD

Diode to GND

Optional – Diode to GND on PVDD to handle inductive current during load de-energization

35V, ≥ 1A

PVDD

Bypass capacitor to GND

Local high frequency bypass capacitor on PVDD

0.1μF, 35V, low ESR ceramic capacitor

VDD

Bypass cap to GND

Optional – Local high frequency bypass capacitor on VDD

0.1μF, 6.3V, low ESR ceramic capacitor

OUT1

EMC cap across load

Optional - High frequency EMC capacitor across load on output 1

≤ 0.1μF, low ESR ceramic capacitor

OUT2

EMC cap across load

Optional - High frequency EMC capacitor across load on output 2

≤ 0.1μF, low ESR ceramic capacitor

When a redundant High-Side (HS) switch is used to cut-off the 12V supply, the output of the HS switch (PVDD pin) needs to have sufficient capacitance to guarantee:

  • dV/dt < 2V/µs on PVDD when HS switch is closed
  • Ability to source the transient load current (inductive fly back) in case of:
    • Clamping function is NOT handled by DRV3946-Q1
    • Fault condition: When the HS switch is opened with the loads energized and one of the outputs shorted to GND (loss of clamping function for DRV3946-Q1).

The capacitance on PVDD is meant to prevent the violation of the ABS MIN on this pin during this transient. An optional diode from PVDD to GND is recommended to help with the inductive current sourced from PVDD during the clamping time to reduce the capacitor size. Depending on the current levels, half-bridge drivers could be an option to combine both the high-side switch cutoff function and discrete diode recirculation function to dissipate the inductive energy when the switch is opened.