SLVSFH6C January   2021  – December 2021 TPS61094


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  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 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
      1. 7.1.1 The Configuration of VCHG Pin, ICHG Pin, and OSEL Pin
        1. OSEL: Output Voltage Selection
        2. VCHG: Charging Termination Voltage Selection
        3. ICHG: Charging Output Current Selection
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Undervoltage Lockout
      2. 7.3.2 Enable and Soft Start
      3. 7.3.3 Active Pulldown for the EN and MODE Pins
      4. 7.3.4 Current Limit Operation
      5. 7.3.5 Output Short-to-Ground Protection
      6. 7.3.6 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation Mode Setting
      2. 7.4.2 Forced Bypass Mode Operation
      3. 7.4.3 True Shutdown Mode Operation
      4. 7.4.4 Forced Buck Mode Operation
      5. 7.4.5 Auto Buck or Boost Mode Operation
        1. Three States (Boost_on, Buck_on, and Supplement) Transition
        2. Boost, Bypass, and Pass-Through
        3. PWM, PFM, and Snooze Modes in Boost Operation
          1. PWM Mode
          2. PFM Mode
          3. Snooze Mode
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application – 3.6-V Output Boost Converter with Bypass
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. Programming the Output Voltage
        2. Maximum Output Current
        3. Inductor Selection
        4. Output Capacitor Selection
        5. Input Capacitor Selection
      3. 8.2.3 Application Curves
      4. 8.2.4 Typical Application – 3.3-V Output Boost Converter with Automatic Buck or Boost Function
        1. Design Requirements
        2. Detailed Design Procedure
          1. Programming the Voltage and Current
        3. Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Forced Buck Mode Operation

When the TPS61094 is enabled working in Buck mode (EN = high, MODE = low), the TPS61094 works in constant output current control scheme with the bypass switch always turned on. The TPS61094 supports sixteen internally set options for the charging termination voltage (VCHG) and charging current (ICHG) by connecting a resistor between the VCHG pin, ICHG pin, and ground.

When VOUT voltage is above the 1.7-V UVLO rising threshold, the buck function starts working to charge the supercap at the SUP pin. The typical charging operation (VCHG < VIN-800 mV) works as shown in Figure 7-1. At t0, the TPS61094 starts to charge the SUP pin by constant current. From t0 to t1, when the SUP pin voltage is lower than VSUP_UVLO, typically 0.85 V, the TPS61094 charges the SUP pin by the constant current (ICHG_PRE), which is smaller than or equal to 250 mA. From t1 to t2, when the SUP pin voltage reaches VSUP_UVLO, the TPS61094 charges the SUP pin by constant current (ICHG), which is set by the ICHG pin. At t2, the SUP pin voltage reaches VCHG (charging termination voltage) and the TPS61094 reduces the charging current to ICHG_TERM, the device stops switching until the SUP voltage reaches VCHG without the supercap ESR voltage drop. This can be avoided if the supercap is not fully charged when the SUP pin reaches VCHG in high charging current because of supercap ESR voltage drop. The TPS61094 starts switching when the SUP voltage drops 75 mV below the target value (VCHG).

If VCHG > VIN-500 mV, the TPS61094 will decrease the charging current when the SUP pin voltage is close to VIN.

Figure 7-1 Typical Charging Operation
  1. ICHG_PRE is 250 mA when ICHG is equal or larger than 250 mA; ICHG_PRE is ICHG when ICHG is lower than 250 mA.
  2. ICHG_TERM is 10 mA when ICHG is equal or larger than 10 mA; ICHG_TERM is 2.5 mA when ICHG is lower than 10 mA.