SNVS598B August   2010  – March 2018 LM3535

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Charge Pump
      2. 7.3.2 Diode Current Sinks
      3. 7.3.3 Ambient Light Sensing (ALS) And Interrupt
      4. 7.3.4 Dynamic Backlight Control Input (PWM Pin)
      5. 7.3.5 LED Forward Voltage Monitoring
      6. 7.3.6 Configurable Gain Transition Delay
      7. 7.3.7 Hardware Enable (HWEN)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
      2. 7.4.2 Standby
      3. 7.4.3 Active Mode
    5. 7.5 Programming
      1. 7.5.1 I2C Compatible Interface
        1. 7.5.1.1 Data Validity
        2. 7.5.1.2 Start and Stop Conditions
        3. 7.5.1.3 Transferring Data
        4. 7.5.1.4 I2C Compatible Chip Address
        5. 7.5.1.5 Internal Registers of LM3535
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Ambient Light Sensing
          1. 8.2.2.1.1 Ambient Light Sensor Block
          2. 8.2.2.1.2 ALS Operation
            1. 8.2.2.1.2.1 ALS Configuration Example
          3. 8.2.2.1.3 ALS Averaging Time
          4. 8.2.2.1.4 Ambient Light Current Control + PWM
            1. 8.2.2.1.4.1 ALS + PWM Example
        2. 8.2.2.2 LED Configurations
        3. 8.2.2.3 Maximum Output Current, Maximum LED Voltage, Minimum Input Voltage
          1. 8.2.2.3.1 Total Output Current Capability
        4. 8.2.2.4 Parallel Connected and Unused Outputs
        5. 8.2.2.5 Power Efficiency
        6. 8.2.2.6 Power Dissipation
        7. 8.2.2.7 Thermal Protection
        8. 8.2.2.8 Capacitor Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.5.1.5 Internal Registers of LM3535

REGISTERINTERNAL HEX ADDRESSPOWER ON VALUE
Diode Enable Register 0x10 0000 0000 (0x00)
Configuration Register 0x20 0000 0000 (0x00)
Options Register 0x30 0000 0000 (0x00)
ALS Zone Readback 0x40 1111 0000 (0xF0)
ALS Control Register 0x50 0000 0011 (0x03)
ALS Resistor Register 0x51 0000 0000 (0x00)
ALS Zone Boundary #0 0x60 0011 0011 (0x33)
ALS Zone Boundary #1 0x61 0110 0110 (0x66)
ALS Zone Boundary #2 0x62 1001 1001 (0x99)
ALS Zone Boundary #3 0x63 1100 1100 (0xCC)
ALS Brightness Zone #1 0x70 1001 1001 (0x99)
ALS Brightness Zone #2 0x71 1011 0110 (0xB6)
ALS Brightness Zone #3 0x72 1100 1100 (0xCC)
ALS Brightness Zone #4 0x73 1110 0110 (0xE6)
ALS Brightness Zone #5 0x74 1111 1111 (0xFF)
Group A Brightness Control Register 0xA0 1000 0000 (0x80)
Group B Brightness Control Register 0xB0 1100 0000 (0xC0)
Group C Brightness Control Register 0xC0 1111 1000 (0xF8)
LM3535 30082404.gifFigure 20. Diode Enable Register Description
Internal Hex Address: 0x10

Each ENx Bit controls the state of the corresponding current sink. Writing a 1 to these bits enables the current sinks. Writing a 0 disables the current sinks. In order for current to begin flowing through the BankA current sinks, the brightness codes stored in either the BankA Brightness register or the ALS Brightness registers (with ALS enabled) must be non-zero. The BankA current sinks can be disabled in two different manors. Writing 0 to the ENx bits when the current sinks are active will disable the current sinks without going through the ramp down sequence. Additionally, setting the BankA brightness code to 0 when the current sinks are active (ENx = 1) does force the diode current to ramp down. All ramping behavior is tied to the BankA Brightness or ALS Brightness Register settings. Any change in these values causes the LM3535 brightness state machine to ramp the diode current.

Writing a '1 to ENC, EN1B, EN62 and EN53 (when EN62 and EN53 are assigned to BankB) by default enables the corresponding current sinks and drive the LEDs to the current value stored in the BankB and BankC brightness registers. Writing a 0 to these bits immediately disables the current sinks.

The ENC and EN1B bits are ignored if the D1C/ALS pin is configured as an ALS input and if the D1B/INT is configured as an interrupt flag.

LM3535 30082405.gifFigure 21. Configuration Register Description
Internal Hex Address:0x20
  • PWM-EN: PWM Input Enable. Writing a 1 = Enable, and a 0 = Ignore (default).
  • PWM-P: PWM Input Polarity. Writing a 0 = Active High (default) and a 1 = Active Low.
  • 53A: Assign D53 diode to BankA. Writing a 0 assigns D53 to BankB (default) and a 1 assigns D53 to BankA.
  • 62A: Assign D62 diode to BankA. Writing a 0 assigns D62 to BankB (default) and a 1 assigns D62 to BankA.
  • ALS-ENA: Enable ALS on BankA. Writing a 1 enables ALS control of diode current and a 0 (default) forces the BankA current to the value stored in the BankA brightness register. The ALS-EN bit must be set to a 1 for the ALS block to control the BankA brightness.
  • ALS-ENB: Enable ALS on BankB. Writing a 1 enables ALS control of diode current and a 0 (default) forces the BankB current to the value stored in the BankB brightness register. The ALS-EN bit must be set to a 1 for the ALS block to control the BankB brightness. The ALS function for BankB is different than bankA in that the ALS will only enable and disable the BankB diodes depending on the ALS zone chosen by the user. BankA utilizes the 5 different zone brightness registers (Addresses 0x70 to 0x74).
  • ALS-EN: Enables ALS monitoring. Writing a 1 enables the ALS monitoring circuitry and a 0 disables it. This feature can be enabled without having the current sinks or charge pump active. The ALS value is updated in register 0x40 (ALS Zone Register)
  • ALSF: ALS Interrupt Enable. Writing a 1 sets the D1B/INT pin to the ALS interrupt pin and writing a 0 (default) sets the pin to a BankB current sink.
    • LM3535 30082406.gifFigure 22. Options Register
    Internal Hex Address: 0x30
  • RD0-RD2: Diode Current Ramp Down Step Time. : ‘000’ = 6 µs, ‘001’ = 0.77 ms, ‘010’ = 1.5 ms, ‘011’ = 3 ms, ‘100’ = 6 ms, ‘101’ = 12 ms, ‘110’ = 25ms, ‘111’ = 50ms
  • RU0-RU2: Diode Current Ramp Up Step Time. : ‘000’ = 6 µs, ‘001’ = 0.77 ms, ‘010’ = 1.5 ms, ‘011’ = 3 ms, ‘100’ = 6 ms, ‘101’ = 12 ms, ‘110’ = 25ms, ‘111’ = 50ms
  • GT0-GT1: Gain Transition Filter. The value stored in this register determines the filter time used to make a gain transition in the event of an input line step. Filter times = ‘00’ = 3-6 ms, ‘01’ = 0.8-1.5 ms, ‘10’ = 20 µs, On LM3535-2ALS, '11' = 1µs, On LM3535, ‘11’ = DO NOT USE

The Ramp-Up and Ramp-Down times follow the equatios: TRAMP = (NStart – NTarget) × Ramp-Step Time

LM3535 30082409.gif
LM3535 30082410.gif
LM3535 30082414.gifFigure 23. Brightness Control Register Description
Internal Hex Address: 0xa0 (Groupa), 0xb0 (Groupb), 0xc0 (Groupc)

NOTE

DxA6-DxA0: Sets Brightness for DxA pins (GroupA). 1111111 = Fullscale. Code 0 in this register disables the BankA current sinks.

DxB2-DxB0: Sets Brightness for DxB pins (GroupB). 111 = Fullscale

ALSZT2-ALSZT0: Sets the Brightness Zone boundary used to enable and disable BankB diodes based upon ambient lighting conditions.

DxC2-DxC0: Sets Brightness for D1C pin. 111 = Fullscale

The BankA Current can be approximated by Equation 1 where N = BRC = the decimal value stored in either the BankA Brightness Register or the five different ALS Zone Brightness Registers:

Equation 1. LM3535 30082418.gif

Table 1. ILED vs Brightness Register Data

BankA or ALS Brightness Data % of ILED_MAX BankA or ALS Brightness Data % of ILED_MAX BankA or ALS Brightness Data % of ILED_MAX BankA or ALS Brightness Data % of ILED_MAX
0000000 0.000% 0100000 0.803% 1000000 4.078% 1100000 20.713%
0000001 0.166% 0100001 0.845% 1000001 4.290% 1100001 21.792%
0000010 0.175% 0100010 0.889% 1000010 4.514% 1100010 22.928%
0000011 0.184% 0100011 0.935% 1000011 4.749% 1100011 24.122%
0000100 0.194% 0100100 0.984% 1000100 4.996% 1100100 25.379%
0000101 0.204% 0100101 1.035% 1000101 5.257% 1100101 26.701%
0000110 0.214% 0100110 1.089% 1000110 5.531% 1100110 28.092%
0000111 0.226% 0100111 1.146% 1000111 5.819% 1100111 29.556%
0001000 0.237% 0101000 1.205% 1001000 6.122% 1101000 31.096%
0001001 0.250% 0101001 1.268% 1001001 6.441% 1101001 32.716%
0001010 0.263% 0101010 1.334% 1001010 6.776% 1101010 34.420%
0001011 0.276% 0101011 1.404% 1001011 7.129% 1101011 36.213%
0001100 0.291% 0101100 1.477% 1001100 7.501% 1101100 38.100%
0001101 0.306% 0101101 1.554% 1001101 7.892% 1101101 40.085%
0001110 0.322% 0101110 1.635% 1001110 8.303% 1101110 42.173%
0001111 0.339% 0101111 1.720% 1001111 8.735% 1101111 44.371%
0010000 0.356% 0110000 1.809% 1010000 9.191% 1110000 46.682%
0010001 0.375% 0110001 1.904% 1010001 9.669% 1110001 49.114%
0010010 0.394% 0110010 2.003% 1010010 10.173% 1110010 51.673%
0010011 0.415% 0110011 2.107% 1010011 10.703% 1110011 54.365%
0010100 0.436% 0110100 2.217% 1010100 11.261% 1110100 57.198%
0010101 0.459% 0110101 2.332% 1010101 11.847% 1110101 60.178%
0010110 0.483% 0110110 2.454% 1010110 12.465% 1110110 63.313%
0010111 0.508% 0111011 2.582% 1010111 13.114% 1110111 66.611%
0011000 0.535% 0110111 2.716% 1011000 13.797% 1111000 70.082%
0011001 0.563% 0111000 2.858% 1011001 14.516% 1111001 73.733%
0011010 0.592% 0111001 3.007% 1011010 15.272% 1111010 77.574%
0011011 0.623% 0111010 3.163% 1011011 16.068% 1111011 81.616%
0011100 0.655% 0111011 3.328% 1011100 16.905% 1111100 85.868%
0011101 0.689% 0111100 3.502% 1011101 17.786% 1111101 90.341%
0011110 0.725% 0111101 3.684% 1011110 18.713% 1111110 95.048%
0011111 0.763% 0111111 3.876% 1011111 19.687% 1111111 100.000%

GroupB and GroupC Brightness Levels = 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 25mA

LM3535 30082407.gifFigure 24. Als Zone Register Description
Internal Hex Address: 0x40
  • ZONE0-ZONE2: ALS Zone information: '000’ = Zone0, ‘001’ = Zone1, ‘010’ = Zone2, ‘011’ = Zone3, ‘100’ = Zone4. Other combinations not used
  • FLAG: ALS Transition Flag. 1 = Transition has occurred. 0 = No Transition. The FLAG bit is cleared once the 0x40 register has been read.
LM3535 30082417.gifFigure 25. ALS Control / Silicon Revision Register Description
Internal Hex Address: 0x50
  • Rev0-Rev1 : Stores the Silicon Revision value. LM3535 = 11
  • AVE2-AVE0: Sets Averaging Time for ALS sampling. Need two to three Averaging periods to make transition decision. 000 = 25 ms, 001 = 50 ms, 010 = 100 ms 011 = 200 ms, 100 = 400 ms, 101 = 800 ms 110 = 1.6 s, 111 = 3.2s
LM3535 alsreg.gifFigure 26. ALS Resistor Control Register Description
Internal Hex Address: 0x51
  • R0-R3: Sets the internal ALS resistor value

Table 2. Internal ALS Resistor Table

R3R2R1R0ALS RESISTOR VALUE (Ω)
0 0 0 0 High Impedance
0 0 0 1 13.6 k
0 0 1 0 9.08 k
0 0 1 1 5.47 k
0 1 0 0 2.32 k
0 1 0 1 1.99 k
0 1 1 0 1.86 k
0 1 1 1 1.65 k
1 0 0 0 1.18 k
1 0 0 1 1.1 k
1 0 1 0 1.06 k
1 0 1 1 986
1 1 0 0 804
1 1 0 1 764
1 1 1 0 745
1 1 1 1 711
LM3535 30082415.gifFigure 27. Zone Boundary Register Descriptions
  • ZB7-ZB0: Sets Zone Boundary Lines with a Falling ALS voltage.
    • 0xFF w/ ALS Falling = 992.3 mV (typical).
    • VTRIP-LOW (typ) = [Boundary Code × 3.874mV] + 4.45mV
    • For boundary codes 2 to 255. Code 0 and Code1 are mapped to equal the Code2 value.
    • Each zone line has approx. 5.5mV of hysteresis between the falling and rising ALS trip points.
  • Zone Boundary 0 is the line between ALS Zone 0 and Zone 1. Default Code = 0x33 or approximately 200 mV
  • Zone Boundary 1 is the line between ALS Zone 1 and Zone 2. Default Code = 0x66 or approximately 400 mV
  • Zone Boundary 2 is the line between ALS Zone 2 and Zone 3. Default Code = 0x99 or approximately 600 mV
  • Zone Boundary 3 is the line between ALS Zone 3 and Zone 4. Default Code = 0xCC or approximately 800 mV
LM3535 30082416.gifFigure 28. Zone Brightness Region Register Description
  • B7-B0: Sets the ALS Zone Brightness Code. B7 always = 1 (unused). Use the formula found in the BankA Brightness Register Description (Figure 23) to set the desired target brightness. Default values can be overwritten
  • Zone0 Brightness Address = 0x70. Default = 0x99 (25) or 0.084 mA
  • Zone1 Brightness Address = 0x71. Default = 0xB6 (54) or 0.164 mA
  • Zone2 Brightness Address = 0x72. Default = 0xCC (76) or 1.45 mA
  • Zone3 Brightness Address = 0x73. Default = 0xE6 (102) or 6.17 mA
  • Zone4 Brightness Address = 0x74. Default = 0xFF (127) or 25 mA