SLVSLZ3 August   2026 TLV612901

PRODMIX  

  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 I2C Interface Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Output Voltage Setting
      2. 7.3.2 Switching Frequency and Spread Spectrum Function
    4. 7.4 Device Functional Modes
      1. 7.4.1  Enable and Start-Up
      2. 7.4.2  Operation Mode Setting
      3. 7.4.3  Bypass Mode
      4. 7.4.4  Boost Control Operation
      5. 7.4.5  Auto PFM Mode
      6. 7.4.6  Forced PWM Mode
      7. 7.4.7  Ultrasonic Mode
      8. 7.4.8  Output Discharge
      9. 7.4.9  Undervoltage Lockout
      10. 7.4.10 Current Limit Operation
      11. 7.4.11 Output Short-to-Ground Protection
      12. 7.4.12 Overvoltage Protection
      13. 7.4.13 Thermal Shutdown
      14. 7.4.14 Power-Good Indication Status
    5. 7.5 Programming
      1. 7.5.1 Data Validity
      2. 7.5.2 START and STOP Conditions
      3. 7.5.3 Byte Format
      4. 7.5.4 Acknowledge (ACK) and Not Acknowledge (NACK)
      5. 7.5.5 Target Address and Data Direction Bit
      6. 7.5.6 Single Read and Write
      7. 7.5.7 Multi-Read and Multi-Write
  9. 8 Register Maps
    1. 8.1 DeviceID Register
    2. 8.2 CONFIG Register
    3. 8.3 VOUTFLOORSET Register
    4. 8.4 ILIMBSTSET Register
    5. 8.5 VOUTROOFSET Register
    6. 8.6 STATUS Register
    7. 8.7 ILIMPTSET Register
    8. 8.8 BSTLOOP Register
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 TLV612901 With 2.5V – 4.85V VIN, 5.0V VOUT, 3A Output Current
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Inductor Selection
          2. 9.2.1.2.2 Output Capacitor
          3. 9.2.1.2.3 Input Capacitor
          4. 9.2.1.2.4 Checking Loop Stability
        3. 9.2.1.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
      3. 9.4.3 Thermal Information
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information
    1.     79

7.4.1 Enable and Start-Up

The TLV612901 automatically powers-up after an input voltage greater than 2.2V. After start-up, the input voltage can be reduced to 1.8V. The device has an internal soft-start circuit that limits the inrush current during start-up.

The first phase in the start-up procedure is to bias the output node close to the input level (also called down mode pre-charge phase). In this operation mode, when VIN exceeds 2.8V, the TLV612901 has three operating conditions:

  • When output voltage is lower than 0.8V, the inductor average current is limited to approximately 0.5A.
  • When the output voltage is higher than 0.8V but lower than the input voltage minus 2.0V, the inductor average current limit is increased to approx 1.5A.
  • When the output voltage is higher than the input voltage minus 2V but lower than the input voltage, the average inductor current limit is increased to the half of boost current limit (approximately 4A).

When VIN does not exceed 2.8V, the TLV612901 only has two operating conditions during the down mode pre-charge phase. Table 7-1 shows more details for this operation.

The second phase in start-up procedure is boost switching phase. In this operation mode, the output voltage is higher than input voltage, and the average inductor current limit is increased to boost current limit (default 8A).

Using this method, the loading capability during start-up is improved, and this improvement is helpful to reduce the inrush current during start-up. Table 7-1 and Table 7-2 show the relationship between average inductor current limit and output voltage in start-up phase.

Table 7-1 Average Inductor Current Limit Setting During Start-Up (VIN ≤ 2.8V)
PHASEAVERAGE INDUCTOR CURRENT LIMITOUTPUT VOLTAGE
Down mode pre-charge phase0.5A (typical)VOUT ≤ 0.8V
4A (typical)0.8V < VOUT ≤ VIN
Boost switching phase8A (typical)VIN < VOUT
Table 7-2 Average Inductor Current Limit Setting During Start-Up (VIN > 2.8V)
PHASEINDUCTOR AVERAGE CURRENT LIMITOUTPUT VOLTAGE
Down mode pre-charge phase0.5A (typical)VOUT ≤ 0.8V
1.5A (typical)0.8V < VOUT ≤ VIN – 2.0V
4A (typical)VIN – 2.0V < VOUT ≤ VIN
Boost switching phase8A (typical)VIN < VOUT

In down mode pre-charge phase, if the output voltage does not reach the input voltage after 1ms, the TLV612901 triggers protection and stops switching. Then the device remains in a waiting state for 19ms before attempting to restart again.

The TLV612901 is able to start up with 2.2V UVLO rising threshold. However, if the load during start-up is so heavy or the output capacitance is so large that the TLV612901 fails to charge the output voltage to target value, the TLV612901 does not start up successfully until the input voltage is increased or the load current is reduced. The total start-up time depends on input voltage, output capacitance and load current.