ZHCSCK8G May   2014  – October 2017 LP8860-Q1

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     系统效率
  4. 4 修订历史记录
  5. 5 器件比较表
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics
    6. 7.6  Current Sinks Electrical Characteristics
    7. 7.7  Boost Converter Characteristics
    8. 7.8  Logic Interface Characteristics
    9. 7.9  VIN Undervoltage Protection (VIN_UVLO)
    10. 7.10 VDD Undervoltage Protection (VDD_UVLO)
    11. 7.11 VIN Overvoltage Protection (VIN_OVP)
    12. 7.12 VIN Overcurrent Protection (VIN_OCP)
    13. 7.13 Power-Line FET Control Electrical Characteristics
    14. 7.14 External Temp Sensor Control Electrical Characteristics
    15. 7.15 I2C Serial Bus Timing Parameters (SDA, SCLK)
    16. 7.16 SPI Timing Requirements
    17. 7.17 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 Boost Controller
      2. 8.1.2 LED Output Configurations
      3. 8.1.3 Display Mode
      4. 8.1.4 Cluster Mode
      5. 8.1.5 Hybrid Dimming
      6. 8.1.6 Charge Pump and Square Waveform (SQW) Output
      7. 8.1.7 Power-Line FET
      8. 8.1.8 Protection Features
      9. 8.1.9 Advanced Thermal Protection Features
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Clock Generation
        1. 8.3.1.1 LED PWM Clock Generation With VSYNC
        2. 8.3.1.2 LED PWM Frequency and Resolution
      2. 8.3.2 Brightness Control (Display Mode)
        1. 8.3.2.1 PWM Input Duty Cycle Based Control
        2. 8.3.2.2 Brightness Register Control
        3. 8.3.2.3 PWM Input Duty × Brightness Register
        4. 8.3.2.4 PWM-Input Direct Control
        5. 8.3.2.5 Brightness Slope
        6. 8.3.2.6 LED Dimming Methods
        7. 8.3.2.7 PWM Calculation Data Flow for Display Mode
      3. 8.3.3 LED Output Modes and Phase Shift PWM (PSPWM) Scheme
      4. 8.3.4 LED Current Setting
      5. 8.3.5 Cluster Mode
      6. 8.3.6 Boost Controller
      7. 8.3.7 Charge Pump
      8. 8.3.8 Powerline Control FET
      9. 8.3.9 Protection and Fault Detection Modes
        1. 8.3.9.1 LED Fault Comparators and Adaptive Boost Control
        2. 8.3.9.2 LED Current Dimming With Internal Temperature Sensor
        3. 8.3.9.3 LED Current Limitation With External NTC Sensor
        4. 8.3.9.4 LED Current Dimming With External NTC Sensor
        5. 8.3.9.5 Protection Feature and Fault Summary
    4. 8.4 Device Functional Modes
      1. 8.4.1 Standby Mode
      2. 8.4.2 Active Mode
      3. 8.4.3 Fault Recovery State
      4. 8.4.4 Start-Up and Shutdown Sequences
    5. 8.5 Programming
      1. 8.5.1 EEPROM
      2. 8.5.2 Serial Interface
        1. 8.5.2.1 SPI Interface
        2. 8.5.2.2 I2C Serial Bus Interface
          1. 8.5.2.2.1 Interface Bus Overview
          2. 8.5.2.2.2 Data Transactions
          3. 8.5.2.2.3 Acknowledge Cycle
          4. 8.5.2.2.4 Acknowledge After Every Byte Rule
          5. 8.5.2.2.5 Addressing Transfer Formats
          6. 8.5.2.2.6 Control Register Write Cycle
          7. 8.5.2.2.7 Control Register Read Cycle
    6. 8.6 Register Maps
      1. 8.6.1 Register Bit Explanations
        1. 8.6.1.1  Display/Cluster1 Brightness Control MSB
        2. 8.6.1.2  Display/Cluster1 Brightness Control LSB
        3. 8.6.1.3  Display/Cluster1 Output Current MSB
        4. 8.6.1.4  Display/Cluster1 Output Current LSB
        5. 8.6.1.5  Cluster2 Brightness Control MSB
        6. 8.6.1.6  Cluster2 Brightness Control LSB
        7. 8.6.1.7  Cluster2 Output Current
        8. 8.6.1.8  Cluster3 Brightness Control MSB
        9. 8.6.1.9  Cluster3 Brightness Control LSB
        10. 8.6.1.10 Cluster3 Output Current
        11. 8.6.1.11 Cluster4 Brightness Control MSB
        12. 8.6.1.12 Cluster4 Brightness Control LSB
        13. 8.6.1.13 Cluster4 Output Current
        14. 8.6.1.14 Configuration
        15. 8.6.1.15 Status
        16. 8.6.1.16 Fault
        17. 8.6.1.17 LED Fault
        18. 8.6.1.18 Fault Clear
        19. 8.6.1.19 Identification
        20. 8.6.1.20 Temp MSB
        21. 8.6.1.21 Temp LSB
        22. 8.6.1.22 Display LED Current MSB
        23. 8.6.1.23 Display LED Current LSB
        24. 8.6.1.24 Display LED PWM MSB
        25. 8.6.1.25 Display LED PWM LSB
        26. 8.6.1.26 EEPROM Control
        27. 8.6.1.27 EEPROM Unlock Code
      2. 8.6.2 EEPROM Bit Explanations
        1. 8.6.2.1  EEPROM Register 0
        2. 8.6.2.2  EEPROM Register 1
        3. 8.6.2.3  EEPROM Register 2
        4. 8.6.2.4  EEPROM Register 3
        5. 8.6.2.5  EEPROM Register 4
        6. 8.6.2.6  EEPROM Register 5
        7. 8.6.2.7  EEPROM Register 6
        8. 8.6.2.8  EEPROM Register 7
        9. 8.6.2.9  EEPROM Register 8
        10. 8.6.2.10 EEPROM Register 9
        11. 8.6.2.11 EEPROM Register 10
        12. 8.6.2.12 EEPROM Register 11
        13. 8.6.2.13 EEPROM Register 12
        14. 8.6.2.14 EEPROM Register 13
        15. 8.6.2.15 EEPROM Register 14
        16. 8.6.2.16 EEPROM Register 15
        17. 8.6.2.17 EEPROM Register 16
        18. 8.6.2.18 EEPROM Register 17
        19. 8.6.2.19 EEPROM Register 18
        20. 8.6.2.20 EEPROM Register 19
        21. 8.6.2.21 EEPROM Register 20
        22. 8.6.2.22 EEPROM Register 21
        23. 8.6.2.23 EEPROM Register 22
        24. 8.6.2.24 EEPROM Register 23
        25. 8.6.2.25 EEPROM Register 24
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Typical Application for Display Backlight
        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 Selection
          3. 9.2.1.2.3  Input Capacitor Selection
          4. 9.2.1.2.4  Charge Pump Output Capacitor
          5. 9.2.1.2.5  Charge Pump Flying Capacitor
          6. 9.2.1.2.6  Diode
          7. 9.2.1.2.7  Boost Converter Transistor
          8. 9.2.1.2.8  Boost Sense Resistor
          9. 9.2.1.2.9  Power Line Transistor
          10. 9.2.1.2.10 Input Current Sense Resistor
          11. 9.2.1.2.11 Filter Component Values
            1. 9.2.1.2.11.1 Critical Components for Design
        3. 9.2.1.3 Application Performance Plots
      2. 9.2.2 Low VDD Voltage and Combined Output Mode Application
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Performance Plots
      3. 9.2.3 High Output Voltage Application
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Performance Plots
      4. 9.2.4 High Output Current Application
        1. 9.2.4.1 Design Requirements
        2. 9.2.4.2 Detailed Design Procedure
        3. 9.2.4.3 Application Performance Plots
      5. 9.2.5 Three-Channel Configuration Without Serial Interface
        1. 9.2.5.1 Design Requirements
        2. 9.2.5.2 Detailed Design Procedure
        3. 9.2.5.3 Application Performance Plots
      6. 9.2.6 Solution With Minimum External Components
        1. 9.2.6.1 Design Requirements
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 器件支持
      1. 12.1.1 第三方产品免责声明
    2. 12.2 文档支持
      1. 12.2.1 相关文档
    3. 12.3 接收文档更新通知
    4. 12.4 社区资源
    5. 12.5 商标
    6. 12.6 静电放电警告
    7. 12.7 Glossary
  13. 13机械、封装和可订购信息

封装选项

请参考 PDF 数据表获取器件具体的封装图。

机械数据 (封装 | 引脚)
  • VFP|32
散热焊盘机械数据 (封装 | 引脚)
订购信息

8.3.3 LED Output Modes and Phase Shift PWM (PSPWM) Scheme

The PSPWM scheme allows delaying the time when each LED output is active. When the LED outputs are not activated simultaneously, the peak load current from the boost output is greatly decreased. This reduces the ripple seen on the boost output and allows smaller output capacitors. Reduced ripple also reduces the output ceramic capacitor audible ringing. The PSPWM scheme also increases the load frequency seen on boost output up to 4 times, therefore transferring possible audible noise to a frequency above human hearing range. In addition, “optical ripple” through the LCD panel is reduced helping in waterfall noise reduction.

Figure 18 shows the available LED output modes. The number of LED outputs used can be one to four; outputs can be tied together to increase current for one string or all four strings can be independently controlled in the cluster mode.

In <LED_STRING_CONF[2:0]> = 000 the phase difference between channels is 90 degrees. This mode is intended for application in Figure 53. When <LED_STRING_CONF[2:0] > = 001 the phase difference between 3 channels in display mode is 120 degrees. This mode is intended for application shown in Figure 63. When <LED_STRING_CONF[2:0]> = 010 the phase difference between 2 channels in display mode is 180 degrees, channels 3 and 4 in cluster mode, intended for application illustrated by Figure 60. LED strings not used in Display mode can be used for Cluster mode, or not used. When <LED_STRING_CONF[2:0]> = 111 all strings are in cluster mode.

LP8860-Q1 PSPWM_mode_diags_snvsa21.gifFigure 18. Phase Shift Modes

Table 9. Description of the LED Output Modes

MODE LED_STRING_CONF[2:0] DESCRIPTION
0 000 4 separate LED strings with 90° phase shift
1 001 3 separate LED strings with 120° phase shift (String 4 in cluster mode or not used)
2 010 2 separate LED strings with 180° phase shift (Strings 3 and 4 in cluster mode or not used)
3 011 1 LED string. (Strings 2,3 and 4 in cluster mode or not used)
4 100 2 LED strings (1+2, 3+4) with 180° phase shift. Strings with same phase can be connected together.
5 101 1 LED string (1+2+3+4). All strings with same phase (can be tied together).
6 110 1 LED string (1+2). 1st and 2nd strings tied with same phase, strings 3 and 4 are in cluster mode or not used
7 111 All strings are used in cluster mode with 90° phase shift

Table 10. Output Mode Configuration

LED_STRING_CONF[2:0] 000 001 010 011 100 101 110 111
SETUP No. of Displ. Strings No. of Cluster Strings No. of Displ. Strings No. of Cluster Strings No. of Displ. Strings No. of Cluster Strings No. of Displ. Strings No. of Cluster Strings No. of Displ. Strings No. of Cluster Strings No. of Displ. Strings No. of Cluster Strings No. of Displ. Strings No. of Cluster Strings No. of Displ. Strings No. of Cluster Strings
4 0 3 1 2 1+1 1 1+1+1 2+2 0 same phase/
4 tied 		0 same phase/
2 tied 		1+1 0 1+1+1+1
Adaptive voltage control Y Y N Y N Y N Y Y Y N N
FAULT DETECTION
Open LED string Y Y Y Y Y Y Y Y Y Y Y Y
Short LED string Y Y Y Y Y N Y Y Y/N Y/N Y Y
OPTIONS
Sloper Y Y N Y N Y N Y Y Y N N
Dithering
Int. temp. current dimming
Ext. temp. current limit
Ext. temp. current dimming Y Y Y Y Y
Brightness modes All All Reg. only All Reg. only All Reg. only All All All Reg. only Reg. only
PMW dimming Y Y Y Y Y Y Y Y Y Y Y Y
Hybrid PWM and Current Dimming N N N N N
LED OUTPUT PARAMETERS (PLL Frequency 40 MHz)
ƒLED PWM min 4.9 kHz 4.9 kHz 4.9 kHz 4.9 kHz 4.9 kHz
Resolution at min ƒLED PWM 13 13 13 13 13
fLED PWM max 39 kHz 39 kHz 39 kHz 39 kHz 4.9 kHz
Resolution at max ƒLED PWM 10 10 10 10 13
Additional Dither for Display 4 4 N 4 N 4 N 4 4 4 N N
LED OUTPUT PARAMETERS (PLL Frequency 5 MHz/off
fLED PWM min 4.9 kHz 4.9 kHz 4.9 kHz 4.9 kHz 610 Hz
Resolution at min ƒLED PWM 10 10 10 10 13
ƒLED PWM Max 39 kHz 39 kHz 39 kHz 39 kHz 610 Hz
Resolution at max ƒLED PWM 7 7 7 13
Additional bits with dither 4 4 N 4 N 4 N 4 4 4 N N