JAJSEF5L July   2012  – May 2019 LP8556

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
    1.     概略回路図
  3. 3 概要
  4. 4 改訂履歴
  5. 5 Device Options
  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  Electrical Characteristics — Boost Converter
    7. 7.7  Electrical Characteristics — LED Driver
    8. 7.8  Electrical Characteristics — PWM Interface
    9. 7.9  Electrical Characteristics — Logic Interface
    10. 7.10 I2C Serial Bus Timing Parameters (SDA, SCL)
    11. 7.11 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Boost Converter
        1. 8.3.1.1 Boost Converter Operation
        2. 8.3.1.2 Setting Boost Switching Frequency
        3. 8.3.1.3 Output Voltage Control
          1. 8.3.1.3.1 Adaptive Control
          2. 8.3.1.3.2 Manual Control
        4. 8.3.1.4 EMI Reduction
      2. 8.3.2 Brightness Control
        1. 8.3.2.1  BRT_MODE = 00
        2. 8.3.2.2  BRT_MODE = 01
        3. 8.3.2.3  BRT_MODE = 10
        4. 8.3.2.4  BRT_MODE = 11
        5. 8.3.2.5  Output Dimming Schemes
          1. 8.3.2.5.1 PWM Control
          2. 8.3.2.5.2 Pure Current Control
          3. 8.3.2.5.3 Adaptive Control
        6. 8.3.2.6  Setting Full-Scale LED Current
        7. 8.3.2.7  Setting PWM Dimming Frequency
        8. 8.3.2.8  Phase Shift PWM Scheme
        9. 8.3.2.9  Slope and Advanced Slope
        10. 8.3.2.10 Dithering
      3. 8.3.3 Fault Detection
        1. 8.3.3.1 LED Fault Detection
          1. 8.3.3.1.1 Open Detect
          2. 8.3.3.1.2 Short Detect
        2. 8.3.3.2 Undervoltage Detection
        3. 8.3.3.3 Overcurrent Protection
        4. 8.3.3.4 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Active Mode
    5. 8.5 Programming
      1. 8.5.1 I2C-Compatible Serial Bus Interface
        1. 8.5.1.1 Interface Bus Overview
        2. 8.5.1.2 Data Transactions
        3. 8.5.1.3 Acknowledge Cycle
        4. 8.5.1.4 Acknowledge After Every Byte Rule
        5. 8.5.1.5 Addressing Transfer Formats
        6. 8.5.1.6 Control Register Write Cycle
        7. 8.5.1.7 Control Register Read Cycle
        8. 8.5.1.8 Register Read and Write Detail
    6. 8.6 Register Maps
      1. 8.6.1 Register Bit Explanations
        1. 8.6.1.1 Brightness Control
        2. 8.6.1.2 Device Control
        3. 8.6.1.3 Status
        4. 8.6.1.4 Direct Control
        5. 8.6.1.5 LED String Enable
      2. 8.6.2 EPROM Bit Explanations
        1. 8.6.2.1  LP8556TM (DSBGA) Configurations and Pre-Configured EPROM Settings
        2. 8.6.2.2  LP8556TM (DSBGA) Configurations and Pre-configured EPROM Settings Continued
        3. 8.6.2.3  LP8556SQ (WQFN) Configurations and Pre-configured EPROM Settings
        4. 8.6.2.4  CFG98
        5. 8.6.2.5  CFG9E
        6. 8.6.2.6  CFG0
        7. 8.6.2.7  CFG1
        8. 8.6.2.8  CFG2
        9. 8.6.2.9  CFG3
        10. 8.6.2.10 CFG4
        11. 8.6.2.11 CFG5
        12. 8.6.2.12 CFG6
        13. 8.6.2.13 CFG7
        14. 8.6.2.14 CFG9
        15. 8.6.2.15 CFGA
        16. 8.6.2.16 CFGE
        17. 8.6.2.17 CFGF
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Using LP8556 With I2C Host
        1. 9.1.1.1 Setting Boost Switching and PWM Dimming Frequencies
        2. 9.1.1.2 Setting Full-Scale LED Current
      2. 9.1.2 Using LP8556 With Configuration Resistors and IO Pins
        1. 9.1.2.1 Setting Boost Switching and PWM Dimming Frequencies
        2. 9.1.2.2 Setting Full-Scale LED Current
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Recommended Inductance for the Boost Power Stage
        2. 9.2.2.2 Recommended Capacitances for the Boost and LDO Power Stages
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Examples
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 ドキュメントの更新通知を受け取る方法
    2. 12.2 コミュニティ・リソース
    3. 12.3 商標
    4. 12.4 静電気放電に関する注意事項
    5. 12.5 Glossary
  13. 13メカニカル、パッケージ、および注文情報

9.1.2.1 Setting Boost Switching and PWM Dimming Frequencies

Boost switching and PWM dimming frequencies can be set via resistor when BOOST_FSET_EN = 1 and PWM_FSET_EN = 1. Available options are shown in Table 14.

Table 14. Configuring PWM Dimming Frequency With an External Resistor

RFSET [kΩ]
(TOLERANCE)		 ƒSW [kHz]
BOOST_FSET_EN = 1		 ƒPWM [Hz] (RESOLUTION)
PWM_FSET_EN = 1
Floating or FSET pin pulled HIGH 1250 9616 (10-bit)
470 k - 1 M (±5%) 312 2402 (12-bit)
300 k, 330 k (±5%) 312 4808 (11-bit)
200 k (±5%) 312 6010 (10-bit)
147 k, 150k, 154 k, 158k (±1%) 312 9616 (10-bit)
121 k (±1%) 312 12020 (9-bit)
100 k (±1%) 312 14424 (9-bit)
86.6 k (±1%) 312 16828 (9-bit)
75 k (±1%) 312 19232 (9-bit)
63.4 k (±1%) 625 2402 (12-bit)
52.3 k, 53.6 k (±1%) 625 4808 (11-bit)
44.2k, 45.3 k (±1%) 625 6010 (10-bit)
39.2 k (±1%) 625 9616 (10-bit)
34 k (±1%) 625 12020 (9-bit)
30.1k (±1%) 625 14424 (9-bit)
26.1 k (±1%) 625 16828 (9-bit)
23.2 k (±1%) 625 19232 (9-bit)
20.5 k (±1%) 1250 2402 (12-bit)
18.7 k (±1%) 1250 4808 (11-bit)
16.5k (±1%) 1250 6010 (10-bit)
14.7 k (±1%) 1250 9616 (10-bit)
13 k (±1%) 1250 12020 (9-bit)
11.8k (±1%) 1250 14424 (9-bit)
10.7 k (±1%) 1250 16828 (9-bit)
9.76 k (±1%) 1250 19232 (9-bit)
FSET pin shorted to GND 1250 Same as PWM input frequency