JAJSP58 September   2022 TPS544C26

ADVANCE INFORMATION  

  1. 特長
  2. アプリケーション
  3. 概要
  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
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Internal VCC LDO and Using an External Bias on VCC/VDRV Pin
      2. 7.3.2  Input Undervoltage Lockout (UVLO)
        1. 7.3.2.1 Fixed VCC UVLO
        2. 7.3.2.2 Fixed VDRV UVLO
        3. 7.3.2.3 Programmable PVIN UVLO
        4. 7.3.2.4 Enable
      3. 7.3.3  Differential Remote Sense and Internal Feedback Divider
      4. 7.3.4  Set the Output Voltage and VID Table
      5. 7.3.5  Startup and Shutdown
      6. 7.3.6  Dynamic Voltage Slew Rate
      7. 7.3.7  Adaptive Voltage Positioning (Droop) and DC Load Line (DCLL)
      8. 7.3.8  Loop Compensation
      9. 7.3.9  Set Switching Frequency
      10. 7.3.10 Switching Node (SW)
      11. 7.3.11 Overcurrent Limit and Low-side Current Sense
      12. 7.3.12 Negative Overcurrent Limit
      13. 7.3.13 Zero-Crossing Detection
      14. 7.3.14 Input Overvoltage Protection
      15. 7.3.15 Output Overvoltage and Undervoltage Protection
      16. 7.3.16 Overtemperature Protection
      17. 7.3.17 VR Ready
      18. 7.3.18 Catastrophic Fault Alert: CAT_FAULT#
      19. 7.3.19 Telemetry
      20. 7.3.20 I2C Interface General Description
        1. 7.3.20.1 Setting the I2C Address
        2. 7.3.20.2 I2C Write Protection
        3. 7.3.20.3 I2C Registers With Special Handling
    4. 7.4 Device Functional Modes
      1. 7.4.1 Forced Continuous-Conduction Mode
      2. 7.4.2 Auto-Skip Eco-mode™ Light Load Operation
    5. 7.5 Programming
      1. 7.5.1 Supported I2C Registers
      2. 7.5.2 Support of Intel SVID Interface
    6. 7.6 Register Maps
      1. 7.6.1  (01h) OPERATION
      2. 7.6.2  (02h) ON_OFF_CONFIG
      3. 7.6.3  (03h) CLEAR_FAULTS
      4. 7.6.4  (15h) STORE_USER_ALL
      5. 7.6.5  (16h) RESTORE_USER_ALL
      6. 7.6.6  (33h) FREQUENCY_SWITCH
      7. 7.6.7  (35h) VIN_ON
      8. 7.6.8  (36h) VIN_OFF
      9. 7.6.9  (40h) VOUT_OV_FAULT_LIMIT
      10. 7.6.10 (41h) VOUT_OV_FAULT_RESPONSE
      11. 7.6.11 (42h) VOUT_OV_WARN_LIMIT
      12. 7.6.12 (43h) VOUT_UV_WARN_LIMIT
      13. 7.6.13 (44h) VOUT_UV_FAULT_LIMIT
      14. 7.6.14 (45h) VOUT_UV_FAULT_RESPONSE
      15. 7.6.15 (46h) IOUT_OC_FAULT_LIMIT
      16. 7.6.16 (4Fh) OT_FAULT_LIMIT
      17. 7.6.17 (50h) OT_FAULT_RESPONSE
      18. 7.6.18 (51h) OT_WARN_LIMIT
      19. 7.6.19 (55h) VIN_OV_FAULT_LIMIT
      20. 7.6.20 (60h) TON_DELAY
      21. 7.6.21 (61h) TON_RISE
      22. 7.6.22 (64h) TOFF_DELAY
      23. 7.6.23 (65h) TOFF_FALL
      24. 7.6.24 (6Bh) PIN_OP_WARN_LIMIT
      25. 7.6.25 (7Ah) STATUS_VOUT
      26. 7.6.26 (7Bh) STATUS_IOUT
      27. 7.6.27 (7Ch) STATUS_INPUT
      28. 7.6.28 (7Dh) STATUS_TEMPERATURE
      29. 7.6.29 (80h) STATUS_MFR_SPECIFIC
      30. 7.6.30 (88h) READ_VIN
      31. 7.6.31 (89h) READ_IIN
      32. 7.6.32 (8Bh) READ_VOUT
      33. 7.6.33 (8Ch) READ_IOUT
      34. 7.6.34 (8Dh) READ_TEMPERATURE_1
      35. 7.6.35 (97h) READ_PIN
      36. 7.6.36 (A0h) SYS_CFG_USER1
      37. 7.6.37 (A2h) I2C_ADDR
      38. 7.6.38 (A3h) SVID_ADDR
      39. 7.6.39 (A4h) IMON_CAL
      40. 7.6.40 (A5h) IIN_CAL
      41. 7.6.41 (A6h) VOUT_CMD
      42. 7.6.42 (A7h) VID_SETTING
      43. 7.6.43 (A8h) I2C_OFFSET
      44. 7.6.44 (A9h) COMP1_MAIN
      45. 7.6.45 (AAh) COMP2_MAIN
      46. 7.6.46 (ABh) COMP1_ALT
      47. 7.6.47 (ACh) COMP2_ALT
      48. 7.6.48 (ADh) COMP3
      49. 7.6.49 (AFh) DVS_CFG
      50. 7.6.50 (B0h) DVID_OFFSET
      51. 7.6.51 (B1h) REG_LOCK
      52. 7.6.52 (B3h) PIN_SENSE_RES
      53. 7.6.53 (B4h) IOUT_NOC_LIMIT
      54. 7.6.54 (B5h) USER_DATA_01
      55. 7.6.55 (B6h) USER_DATA_02
      56. 7.6.56 (BAh) STATUS1_SVID
      57. 7.6.57 (BBh) STATUS2_SVID
      58. 7.6.58 (BCh) CAPABILITY
      59. 7.6.59 (BDh) EXT_CAPABILITY_VIDOMAX_H
      60. 7.6.60 (BEh) VIDOMAX_L
      61. 7.6.61 (C0h) ICC_MAX
      62. 7.6.62 (C1h) TEMP_MAX
      63. 7.6.63 (C2h) PROTOCOL_ID_SVID
      64. 7.6.64 (C6h) VENDOR_ID
      65. 7.6.65 (C8h) PRODUCT_ID
      66. 7.6.66 (C9h) PRODUCT_REV_ID
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Application
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Inductor Selection
        2. 8.2.3.2 Input Capacitor Selection
        3. 8.2.3.3 Output Capacitor Selection
        4. 8.2.3.4 VCC/VRDV Bypass Capacitor
        5. 8.2.3.5 BOOT Capacitor Selection
        6. 8.2.3.6 RSENSE Selection
        7. 8.2.3.7 VINSENP and VINSENN Capacitor Selection
        8. 8.2.3.8 VRRDY Pullup Resistor Selection
        9. 8.2.3.9 I2C Address Resistor Selection
      4. 8.2.4 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
        1. 8.4.2.1 Thermal Performance on TPS544C26EVM
  9. Device and Documentation Support
    1. 9.1 Documentation Support
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 サポート・リソース
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  10. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Tape and Reel Information

パッケージ・オプション

メカニカル・データ(パッケージ|ピン)
サーマルパッド・メカニカル・データ
発注情報

Overcurrent Limit and Low-side Current Sense

For a synchronous buck converter, the inductor current increases at a linear rate determined by the input voltage, the output voltage, and the output inductor value during the high-side MOSFET on-time (ON time). During the low-side MOSFET on-time (OFF time), this inductor current decreases linearly per slew rate determined by the output voltage and the output inductor value. The inductor during the OFF time, even with a negative slew rate, usually flows from the device SW node to the load the device which is said to be sourcing current and the output current is declared to be positive. This section describes the overcurrent limit feature based on the positive low-side current. The next section describes the overcurrent limit feature based on the negative low-side current.

The positive overcurrent limit (OCL) feature in the TPS544C26 device is implemented to clamp low-side valley current on a cycle-by-cycle basis. The inductor current is monitored during the OFF time by sensing the current flowing through the low-side MOSFET. When the sensed low-side MOSFET current remains above the selected OCL threshold, the low-side MOSFET stays ON until the sensed current level becomes lower than the selected OCL threshold. This operation extends the OFF time and pushes the next ON time (where the high-side MOSFET turns on) out. As a result, the OCL bit in (7Bh) STATUS_IOUT is set, also the average output current sourced by the device is reduced. As long as the load pulls a heavy load where the sensed low-side valley current exceeds the selected OCL threshold, the device continuously operates in this clamping mode which extends the current OFF time and pushes the next ON time out. The device does not implement a fault response circuit directly tied to the overcurrent limit circuit, instead, the VOUT Tracking UVF function is utilized to shuts the device down under an overcurrent fault. During an overcurrent event, the current sunk by the load (IOUT) exceeds the current sourced by the device to the output capacitors, thus, the output voltage tends to decrease. Eventually, when the output voltage falls below the selected undervoltage fault threshold, the VOUT Tracking UVF comparator detects and shuts down the device after the UVF Response Delay (programmable in (45h) VOUT_UV_FAULT_RESPONSE register). The device then responds to the Tracking UVF trigger per bit[3] RESTART selection in (45h) VOUT_UV_FAULT_RESPONSE register. With the RESTART bit unset (value "0"), the device latches OFF both high-side and low-side drivers. The latch is cleared with a reset of VCC or by toggling the EN pin. With the RESTART bit set (value "1"), the device enters hiccup mode and re-starts automatically after a hiccup sleep time of 56 ms, without limitation on the number of restart attempts. In other words, the response to an overcurrent fault is set by the programmed UVF response.

If an OCL condition happens during a soft-start ramp the device still operates with the cycle-by-cycle current limit based on the sensed low-side valley current. This operation can limit the energy charged into the output capacitors thus the output voltage likely ramps up slower than the desired soft-start slew rate. During the soft-start, the VOUT Tracking UVF comparator is disabled thus the device does not respond to a UVF event. Upon the completion of the soft-start, the VOUT Tracking UVF comparator is enabled, then the device starts responding to the UVF event.

The OCL feature in the device is implemented by detecting the low-side valley current through analog circuitries and has no relationship with the integrated Analog-to-Digital converter (ADC). The telemetry analog-front-end gets an input from the low-side current sense circuit and average low-side MOSFET current from the start to the end of each low-side MOSFET on time. By this method, the telemetry sub-system reports the load current (IOUT) which is the average value of the inductor current but not peak or valley values.