SNVSB83B June   2019  – January 2020 LP8867-Q1 , LP8869-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
    2.     LED Backlight Efficiency
  4. 4 Revision History
  5. 5 Device Comparison Table
  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  Internal LDO Electrical Characteristics
    7. 7.7  Protection Electrical Characteristics
    8. 7.8  Current Sinks Electrical Characteristics
    9. 7.9  PWM Brightness Control Electrical Characteristics
    10. 7.10 Boost and SEPIC Converter Characteristics
    11. 7.11 Logic Interface Characteristics
    12. 7.12 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 Integrated DC-DC Converter
        1. 8.3.1.1 DC-DC Converter Parameter Configuration
          1. 8.3.1.1.1 Switching Frequency
          2. 8.3.1.1.2 Spread Spectrum and External SYNC
          3. 8.3.1.1.3 Recommended Component Value and Internal Parameters
          4. 8.3.1.1.4 DC-DC Converter Switching Current Limit
          5. 8.3.1.1.5 DC-DC Converter Light Load Mode
        2. 8.3.1.2 Adaptive Voltage Control
          1. 8.3.1.2.1 Using Two-Divider
          2. 8.3.1.2.2 Using T-Divider
          3. 8.3.1.2.3 Feedback Capacitor
      2. 8.3.2 Internal LDO
      3. 8.3.3 LED Current Sinks
        1. 8.3.3.1 LED Output Configuration
        2. 8.3.3.2 LED Current Setting
        3. 8.3.3.3 Brightness Control
      4. 8.3.4 Power-Line FET Control
      5. 8.3.5 LED Current Dimming With External Temperature Sensor
      6. 8.3.6 Fault Detections and Protection
        1. 8.3.6.1 Supply Fault and Protection
          1. 8.3.6.1.1 VIN Undervoltage Fault (VIN_UVLO)
          2. 8.3.6.1.2 VIN Overvoltage Fault (VIN_OVP)
          3. 8.3.6.1.3 VIN Overcurrent Fault (VIN_OCP)
        2. 8.3.6.2 Boost Fault and Protection
          1. 8.3.6.2.1 Boost Overvoltage Fault (BST_OVP)
          2. 8.3.6.2.2 SW Overvoltage Fault (SW_OVP)
        3. 8.3.6.3 LED Fault and Protection (LED_OPEN and LED_SHORT)
        4. 8.3.6.4 Thermal Fault and Protection (TSD)
        5. 8.3.6.5 Overview of the Fault and Protection Schemes
    4. 8.4 Device Functional Modes
      1. 8.4.1 STANDBY State
      2. 8.4.2 SOFT START State
      3. 8.4.3 BOOST START State
      4. 8.4.4 NORMAL State
      5. 8.4.5 FAULT RECOVERY State
      6. 8.4.6 State Diagram and Timing Diagram for Start-up and Shutdown
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Typical Application for 4 LED Strings
      2. 9.2.2 Design Requirements
      3. 9.2.3 Detailed Design Procedure
        1. 9.2.3.1 Inductor Selection
        2. 9.2.3.2 Output Capacitor Selection
        3. 9.2.3.3 Input Capacitor Selection
        4. 9.2.3.4 LDO Output Capacitor
        5. 9.2.3.5 Diode
      4. 9.2.4 Application Curves
      5. 9.2.5 SEPIC Mode Application
        1. 9.2.5.1 Design Requirements
        2. 9.2.5.2 Detailed Design Procedure
          1. 9.2.5.2.1 Inductor
          2. 9.2.5.2.2 Diode
          3. 9.2.5.2.3 Capacitor C1
        3. 9.2.5.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

6 Pin Configuration and Functions

LP8867-Q1 PWP Package
20-Pin HTSSOP With Exposed Thermal Pad
Top View
LP8867-Q1 LP8869-Q1 LP8867-PINOUT.gif
LP8869-Q1 PWP Package
20-Pin HTSSOP With Exposed Thermal Pad
Top View
LP8867-Q1 LP8869-Q1 pin-02-LP8869.gif

Pin Functions

PIN TYPE(1) DESCRIPTION
NO. NAME
1 VIN A Input power pin; input voltage OVP detection pin; input current sense positive input pin.
2 LDO A Output of internal LDO; connect a 1-μF decoupling capacitor between this pin and noise-free ground. Put the capacitor as close to the chip as possible.
3 FSET A DC-DC (boost or SEPIC) switching frequency setting resistor; for normal operation, resistor value from 24 kΩ to 219 kΩ must be connected between this pin and ground.
4 VDDIO/EN I Enable input for the device as well as supply input (VDDIO) for digital pins.
5 FAULT OD Fault signal output. If unused, the pin may be left floating.
6 SYNC I Input for synchronizing DC-DC converter. If synchronization is not used, connect this pin to ground to disable spread spectrum or to VDDIO/EN to enable spread spectrum.
7 PWM I PWM dimming input.
8 TSENSE A Input for NTC resistor divider. Refer to LED Current Dimming With External Temperature Sensor for proper connection. If unused, the pin must be left floating.
9 TSET A Input for NTC resistor divider. Refer to LED Current Dimming With External Temperature Sensor for proper connection. If unused, the pin must be connected to GND.
10 ISET A LED current setting resistor; for normal operation, resistor value from 20 kΩ to 129 kΩ must be connected between this pin and ground.
11 GND G Ground.
12 OUT4/GND A Current sink output for LP8867-Q1
This pin must be connected to ground if not used.

GND pin for LP8869-Q1
13 OUT3 A Current sink output.
This pin must be connected to ground if not used.
14 OUT2 A Current sink output.
This pin must be connected to ground if not used.
15 OUT1 A Current sink output.
This pin must be connected to ground if not used.
16 FB A DC-DC (boost or SEPIC) feedback input; for normal operation this pin must be connected to the middle of a resistor divider between VOUT and ground using feedback resistor values greater than 5kΩ.
17 PGND G DC-DC (boost or SEPIC) power ground.
18 SW A DC-DC (boost or SEPIC) switch pin.
19 SD A Power-line FET control. Open Drain (current sink type) Output. If unused, the pin may be left floating.
20 VSENSE_N A Input current sense negative input. Connect to VIN pin when input current sense resistor is not used.
(1) A: Analog pin, G: Ground pin, P: Power pin, I: Input pin, I/O: Input/Output pin, O: Output pin, OD: Open Drain pin