SLUSEQ9D July   2022  – April 2024 TPS1211-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Charge Pump and Gate Driver Output (VS, PU, PD, BST, SRC)
      2. 8.3.2 Capacitive Load Driving
        1. 8.3.2.1 FET Gate Slew Rate Control
        2. 8.3.2.2 Using Precharge FET - (with TPS12111-Q1 Only)
      3. 8.3.3 Overcurrent and Short-Circuit Protection
        1. 8.3.3.1 Overcurrent Protection with Auto-Retry
        2. 8.3.3.2 Overcurrent Protection with Latch-Off
        3. 8.3.3.3 Short-Circuit Protection
      4. 8.3.4 Analog Current Monitor Output (IMON)
      5. 8.3.5 Overvoltage (OV) and Undervoltage Protection (UVLO)
      6. 8.3.6 Remote Temperature Sensing and Protection (DIODE)
      7. 8.3.7 Output Reverse Polarity Protection
      8. 8.3.8 TPS1211x-Q1 as a Simple Gate Driver
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application: Driving Zonal Controller Loads on 12-V Line in Power Distribution Unit
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
    3. 9.3 Typical Application: Reverse Polarity Protection with TPS12110-Q1
      1. 9.3.1 Design Requirements
      2. 9.3.2 External Component Selection
      3. 9.3.3 Application Curves
    4. 9.4 Power Supply Recommendations
    5. 9.5 Layout
      1. 9.5.1 Layout Guidelines
      2. 9.5.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

8.3.4 Analog Current Monitor Output (IMON)

TPS1211x-Q1 features an accurate analog load current monitor output (IMON) with adjustable gain. The current source at IMON terminal is configured to be proportional to the current flowing through the RSNS current sense resistor. This current can be converted to a voltage using a resistor RIMON from IMON terminal to GND terminal. This voltage, computed using Equation 11 can be used as a means of monitoring current flow through the system.

Use Equation 11 to calculate the V(IMON).

Equation 11. V ( I M O N )   =   ( V S N S   +   V ( O S _ S E T ) )   ×   G a i n

Where VSNS = I_LOAD × RSNS and V(OS_SET) is the input referred offset (± 200 µV) of the current sense amplifier (VSNS to V(IMON) scaling). Use the following equation to calculate gain.

Equation 12. GUID-20220112-SS0I-SD0R-M34N-C1MGDHZHLGZR-low.svg
Where 0.9 is the current mirror factor between the current sense amplifier and the IMON pass FET.

The maximum voltage range for monitoring the current (V(IMONmax)) is limited to minimum([V(VS) – 0.5V], 5.5V) to ensure linear output. This puts limitation on maximum value of RIMON resistor. The IMON pin has an internal clamp of 6.5 V (typical).

Accuracy of the current mirror factor is < ± 1%. Use the following equation to calculate the overall accuracy of V(IMON).

Equation 13. % V(IMON) = V(OS_SET)VSNS × 100

Figure 8-14 shows external connections and simplified block diagram of current sensing and overcurrent protection implementation.

GUID-20220704-SS0I-60ZT-RW8M-Z5M8JLLNGSCB-low.svg Figure 8-12 Current Sensing and Overcurrent Protection

In TPS12110-Q1 and TPS12111-Q1, IMON amplifer output is turned OFF when PD is pulled low to SRC (due to INP pulled low or fault event) whereas IMON output remains enabled in TPS12112-Q1 even if PD is pulled low to SRC. In TPS12112-Q1, IMON output gets disabled only when the device is disabled by pulling EN/UVLO low below V(ENF) or V(VS) below V(VS_PORF).

TPS12112-Q1 can be used in applications where grouped IMON output is desired as shown in Figure 8-13:

GUID-20230929-SS0I-WDX7-Q889-QLGZXVKMCZLH-low.svg Figure 8-13 TPS12112-Q1 Application Circuit with Grouped IMON Output