SNVS256E November   2003  – October 2024 LP3943

PRODUCTION DATA  

  1.   1
  2. 1Features
  3. 2Applications
  4. 3Description
  5. 4Pin Configuration and Functions
    1.     Pin Functions
  6. 5Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 I2C Interface (SCL and SDA Pins) Timing Requirements
    7. 5.7 Typical Characteristic
  7. 6Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
    4. 6.4 Device Functional Modes
    5. 6.5 Programming
      1. 6.5.1 I2C Data Validity
      2. 6.5.2 I2C START and STOP Conditions
      3. 6.5.3 Transferring Data
      4. 6.5.4 Auto Increment
    6. 6.6 Register Maps
      1. 6.6.1 Binary Format for Input Registers (Read-only)—Address 0x00 and 0x01
      2. 6.6.2 Binary Format for Frequency Prescaler and PWM Registers — Address 0x02 to 0x05
      3. 6.6.3 Binary Format for Selector Registers — Address 0x06 to 0x09
  8.   Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Reducing IQ When LEDs are OFF
      3. 7.2.3 Application Curve
    3. 7.3 System Examples
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
  9. 7Device and Documentation Support
    1. 7.1 Receiving Notification of Documentation Updates
    2. 7.2 Community Resources
    3. 7.3 Trademarks
  10. 8Revision History
  11.   Mechanical, Packaging, and Orderable Information

Package Options

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

6.3 Feature Description

Some of the features of the LP3943 device are:

  1. 16 low-side switches to control the current in 16 strings of LEDs with a maximum of 25mA per switch or a maximum of 200mA total.
  2. Programmable internal PWM dimming:
    1. Duty cycle control (8 bits). Any of the 16 current switches can be mapped to either PWM0 register or PWM1 register. Each register offers 8-bit PWM duty cycle control.
    2. PWM Frequency control (8 bits). Any of the 16 current switches can be mapped to either PSC0 register or PSC1 register. Each register offers 8-bit PWM frequency control from 0.625Hz to 160Hz.
  3. RESET input.
  4. Auto increment for I2C writes to reduce number of I2C clock pulses .
  5. The LP3943 provides for an externally selectable I2C slave address via the ADR0, ADR1, and ADR2 inputs. See Figure 6-3.