SLVS950I July   2009  – May 2018 TPS65070 , TPS65072 , TPS65073 , TPS650731 , TPS650732

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Block Diagram
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Options
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
  8. 8 Specifications
    1. 8.1  Absolute Maximum Ratings
    2. 8.2  ESD Ratings
    3. 8.3  Recommended Operating Conditions
    4. 8.4  Thermal Information
    5. 8.5  Electrical Characteristics
    6. 8.6  Electrical Characteristics - DCDC1 Converter
    7. 8.7  Electrical Characteristics - DCDC2 Converter
    8. 8.8  Electrical Characteristics - DCDC3 Converter
    9. 8.9  Electrical Characteristics - VLDO1 and VLDO2 Low Dropout Regulators
    10. 8.10 Electrical Characteristics - wLED Boost Converter
    11. 8.11 Electrical Characteristics - Reset, PB_IN, PB_OUT, PGood, Power_on, INT, EN_EXTLDO, EN_wLED
    12. 8.12 Electrical Characteristics - ADC Converter
    13. 8.13 Electrical Characteristics - Touch Screen Interface
    14. 8.14 Electrical Characteristics - Power Path
    15. 8.15 Electrical Characteristics - Battery Charger
    16. 8.16 Timing Requirements
    17. 8.17 Dissipation Ratings
    18. 8.18 Typical Characteristics
  9. 9 Parameter Measurement Information
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
      1. 10.3.1  Battery Charger and Power Path
      2. 10.3.2  Power Down
      3. 10.3.3  Power-On Reset
      4. 10.3.4  Power-Path Management
        1. 10.3.4.1 SYS Output
      5. 10.3.5  Battery Charging
        1. 10.3.5.1 I-PRECHARGE
        2. 10.3.5.2 ITERM
        3. 10.3.5.3 Battery Detection and Recharge
        4. 10.3.5.4 Charge Termination On/Off
        5. 10.3.5.5 Timers
        6. 10.3.5.6 Dynamic Timer Function
        7. 10.3.5.7 Timer Fault
      6. 10.3.6  Battery Pack Temperature Monitoring
      7. 10.3.7  Battery Charger State Diagram
      8. 10.3.8  DC-DC Converters and LDOs
        1. 10.3.8.1 Operation
        2. 10.3.8.2 DCDC1 Converter
        3. 10.3.8.3 DCDC2 Converter
        4. 10.3.8.4 DCDC3 Converter
      9. 10.3.9  Power Save Mode
        1. 10.3.9.1 Dynamic Voltage Positioning
        2. 10.3.9.2 100% Duty Cycle Low Dropout Operation
        3. 10.3.9.3 Undervoltage Lockout
      10. 10.3.10 Short-Circuit Protection
        1. 10.3.10.1 Soft Start
      11. 10.3.11 Enable
        1. 10.3.11.1 RESET (TPS65070, TPS65073, TPS650731, TPS650732 Only)
        2. 10.3.11.2 PGOOD (Reset Signal For Applications Processor)
        3. 10.3.11.3 PB_IN (Push-Button IN)
        4. 10.3.11.4 PB_OUT
        5. 10.3.11.5 POWER_ON
        6. 10.3.11.6 EN_wLED (TPS65072 Only)
        7. 10.3.11.7 EN_EXTLDO (TPS65072 Only)
      12. 10.3.12 Short-Circuit Protection
      13. 10.3.13 Thermal Shutdown
        1. 10.3.13.1 Low Dropout Voltage Regulators
        2. 10.3.13.2 White LED Boost Converter
        3. 10.3.13.3 A/D Converter
        4. 10.3.13.4 Touch Screen Interface (only for TPS65070, TPS65073, TPS650731, TPS650732)
          1. 10.3.13.4.1 Performing Measurements Using the Touch Screen Controller
    4. 10.4 Device Functional Modes
    5. 10.5 Programming
      1. 10.5.1 I2C Interface Specification
        1. 10.5.1.1 Serial interface
    6. 10.6 Register Maps
      1. 10.6.1  PPATH1. Register Address: 01h
      2. 10.6.2  INT. Register Address: 02h
      3. 10.6.3  CHGCONFIG0. Register Address: 03h
      4. 10.6.4  CHGCONFIG1. Register Address: 04h
      5. 10.6.5  CHGCONFIG2. Register Address: 05h
      6. 10.6.6  CHGCONFIG3. Register Address: 06h
      7. 10.6.7  ADCONFIG. Register Address: 07h
      8. 10.6.8  TSCMODE. Register Address: 08h
      9. 10.6.9  ADRESULT_1. Register Address: 09h
      10. 10.6.10 ADRESULT_2. Register Address: 0Ah
      11. 10.6.11 PGOOD. Register Address: 0Bh
      12. 10.6.12 PGOODMASK. Register Address: 0Ch
      13. 10.6.13 CON_CTRL1. Register Address: 0Dh
      14. 10.6.14 CON_CTRL2. Register Address: 0Eh
      15. 10.6.15 CON_CTRL3. Register Address: 0Fh
      16. 10.6.16 DEFDCDC1. Register Address: 10h
      17. 10.6.17 DEFDCDC2_LOW. Register Address: 11h
      18. 10.6.18 DEFDCDC2_HIGH. Register Address: 12h
      19. 10.6.19 DEFDCDC3_LOW. Register Address: 13h
      20. 10.6.20 DEFDCDC3_HIGH. Register Address: 14h
      21. 10.6.21 DEFSLEW. Register Address: 15h
      22. 10.6.22 LDO_CTRL1. Register Address: 16h
      23. 10.6.23 DEFLDO2. Register Address: 17h
      24. 10.6.24 WLED_CTRL1. Register Address: 18h
      25. 10.6.25 WLED_CTRL2. Register Address: 19h
  11. 11Application and Implementation
    1. 11.1 Application Information
      1. 11.1.1 Power Solutions For Different Application Processors
        1. 11.1.1.1 Default Settings
        2. 11.1.1.2 Starting TPS6507x
    2. 11.2 Typical Applications
      1. 11.2.1 General PMIC Application
        1. 11.2.1.1 Design Requirements
        2. 11.2.1.2 Detailed Design Procedure
          1. 11.2.1.2.1 Output Filter Design (Inductor and Output Capacitor)
            1. 11.2.1.2.1.1 Inductor Selection
            2. 11.2.1.2.1.2 Output Capacitor Selection
            3. 11.2.1.2.1.3 Input Capacitor Selection/Input Voltage
            4. 11.2.1.2.1.4 Output Voltage Selection
            5. 11.2.1.2.1.5 Voltage Change on DCDC2 and DCDC3
          2. 11.2.1.2.2 LDOs
            1. 11.2.1.2.2.1 Output Capacitor Selection
            2. 11.2.1.2.2.2 Input Capacitor Selection
            3. 11.2.1.2.2.3 Output Voltage Change For LDO1 and LDO2
            4. 11.2.1.2.2.4 Unused LDOs
          3. 11.2.1.2.3 White-LED Boost Converter
            1. 11.2.1.2.3.1 LED-Current Setting/Dimming
            2. 11.2.1.2.3.2 Setup
            3. 11.2.1.2.3.3 Setting the LED Current
            4. 11.2.1.2.3.4 Inductor Selection
            5. 11.2.1.2.3.5 Diode Selection
            6. 11.2.1.2.3.6 Output Capacitor Selection
            7. 11.2.1.2.3.7 Input Capacitor Selection
          4. 11.2.1.2.4 Battery Charger
            1. 11.2.1.2.4.1 Temperature Sensing
            2. 11.2.1.2.4.2 Changing the Charging Temperature Range (Default 0°C to 45°C)
        3. 11.2.1.3 Application Curves
      2. 11.2.2 Powering OMAP-L138
        1. 11.2.2.1 Design Requirements
        2. 11.2.2.2 Detailed Design Procedure
      3. 11.2.3 Powering Atlas IV
        1. 11.2.3.1 Design Requirements
        2. 11.2.3.2 Detailed Design Procedure
          1. 11.2.3.2.1 Prima SLEEP Mode and DEEP SLEEP Mode Support
          2. 11.2.3.2.2 SLEEP Mode
          3. 11.2.3.2.3 DEEP SLEEP Mode
      4. 11.2.4 OMAP35xx (Supporting SYS-OFF Mode)
        1. 11.2.4.1 Design Requirements
        2. 11.2.4.2 Detailed Design Procedure
      5. 11.2.5 TPS650731 for OMAP35xx
        1. 11.2.5.1 Design Requirements
        2. 11.2.5.2 Detailed Design Procedure
      6. 11.2.6 Powering AM3505 Using TPS650732
        1. 11.2.6.1 Design Requirements
        2. 11.2.6.2 Detailed Design Procedure
  12. 12Power Supply Recommendations
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
  14. 14Device and Documentation Support
    1. 14.1 Device Support
      1. 14.1.1 Third-Party Products Disclaimer
    2. 14.2 Documentation Support
      1. 14.2.1 Related Documentation
    3. 14.3 Related Links
    4. 14.4 Receiving Notification of Documentation Updates
    5. 14.5 Community Resources
    6. 14.6 Trademarks
    7. 14.7 Electrostatic Discharge Caution
    8. 14.8 Glossary
  15. 15Mechanical, Packaging, and Orderable Information

Package Options

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

11.2.1.2.3.4 Inductor Selection

The inductor in a boost converter serves as an energy storage element. The energy stored equals ½ L × I2. Therefore, the inductor must not be saturated as the inductance will drop and the energy stored will be reduced causing bad efficiency. The converter operates with typically 15-µH to 22-µH inductors. A design example for an application powering 6LEDs in one string given below:

Vin = 2.8 V — minimum input voltage for the boost converter
Vo = 6 × 3.2 V = 19.2 V — assuming a forward voltage of 3.2 V per LED
Vf = 0.5 V — forward voltage of the Schottky diode
Io = 25 mA maximum LED current
Fsw = 1.125 MHz — switching frequency — T=890 ns
Rds(on) = 0.6R — drain-source resistance of the internal NMOS switch
Vsw — voltage drop at the internal NMOS switch
IAVG — average current in NMOS when turned on

The duty cycle for a boost converter is:

Equation 10. TPS65070 TPS65072 TPS65073 TPS650731 TPS650732 eq10_d_lvs950.gif

With:

Equation 11. TPS65070 TPS65072 TPS65073 TPS650731 TPS650732 eq11_vsw_lvs950.gif

A different approach to calculate the duty cycle is based on the efficiency of the converter. The typical number can be found in the graphs, or as a first approach, we can assume to get an efficiency of about 80% as a typical value.

Equation 12. TPS65070 TPS65072 TPS65073 TPS650731 TPS650732 eq12_d_lvs950.gif

With the values given above

Equation 13. TPS65070 TPS65072 TPS65073 TPS650731 TPS650732 eq13_d2_lvs950.gif

ton = T × D = 890 ns × 0.89 = 792 ns

toff = 890 ns – 792 ns = 98ns

Equation 14. TPS65070 TPS65072 TPS65073 TPS650731 TPS650732 eq14_vsw2_lvs950.gif

When the NMOS switch is turned on, the input voltage is forcing a current into the inductor. The current slope can be calculated with:

Equation 15. TPS65070 TPS65072 TPS65073 TPS650731 TPS650732 eq15_di_lvs950.gif
Equation 16. TPS65070 TPS65072 TPS65073 TPS650731 TPS650732 eq16_lavg_lvs950.gif

The minimum and maximum inductor current can be found by adding half of the inductor current ripple (di) to the average value, which gives:

Equation 17. TPS65070 TPS65072 TPS65073 TPS650731 TPS650732 eq17_lmax_lvs950.gif

Given the values above, an inductor with a current rating greater than 290 mA is needed. Plenty of margin should be kept to the rating in the inductor vendors data sheets as the maximum current is typically specified at a inductance drop of 20% or even 30%. A list of tested inductors is given in Table 13 with the following test conditions.

Test conditions:

  • Vin = 2.8 V
  • Vf = 3.2 V (per LED)
  • Vf = 0.5 V (Schottky diode)
  • Iout = 25 mA per string; no dimming

Table 13. Tested Inductors

LED CONFIGURATION INDUCTOR TYPE INDUCTOR VALUE SUPPLIER
1 × 6LEDs LPS3015 18 µH Coilcraft
2 × 6LEDs LPS4018 47 µH Coilcraft
1 × 10LEDs LPS4018 47 µH Coilcraft

Other inductors, with lower or higher inductance values can be used. A higher inductance will cause a lower inductor current ripple and therefore will provide higher efficiency. The boost converter will also stay in continuous conduction mode over a wider load current range. The energy stored in an inductor is given by E=1/2L × I2 where I is the peak inductor current. The maximum current in the inductor is limited by the internal current limit of the device, so the maximum power is given by the minimum peak current limit (see electrical specifications) times the inductance value. For highest output power, a large inductance value is needed. The minimum inductor value possible is limited by the energy needed to supply the load. The limit for the minimum inductor value is given during the on-time of the switch such that the current limit is not reached.

Example for the minimum inductor value:

Vin = 4.2 V, Vout = 19.7 V, Iout = 5 mA, Vsw =0.1 V
→ D = 79%
→ ton = 703 ns

During the on-time, the inductor current should not reach the current limit of 1.4 A.

With V… voltage across the inductor (V = Vin–Vsw)

→ L = V × dt/di = (4.2 V–0.1 V) × 703 ns/1.4 A = 2µH