SNVS693E September   2011  – September 2014 LP8552

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Default EEPROM Values
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  Handling Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics
    6. 7.6  Boost Converter Electrical Characteristics
    7. 7.7  LED Driver Electrical Characteristics
    8. 7.8  PWM Interface Characteristics
    9. 7.9  Undervoltage Protection
    10. 7.10 Logic Interface Characteristics
    11. 7.11 I2C Serial Bus Timing Parameters (SDA, SCLK)
    12. 7.12 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Clock Generation
      2. 8.3.2 Brightness Control Methods
        1. 8.3.2.1  PWM Input Duty Cycle
        2. 8.3.2.2  Brightness Register Control
        3. 8.3.2.3  PWM Direct Control
        4. 8.3.2.4  PWM Calculation Data Flow
        5. 8.3.2.5  PWM Detector
        6. 8.3.2.6  Brightness Control
        7. 8.3.2.7  Resolution Selector
        8. 8.3.2.8  Sloper
        9. 8.3.2.9  PWM & Current Control
        10. 8.3.2.10 Dither
        11. 8.3.2.11 PWM Comparator
        12. 8.3.2.12 Current Setting
        13. 8.3.2.13 PWM Frequency Setting
        14. 8.3.2.14 Phase Shift PWM Scheme
        15. 8.3.2.15 Slope And Dithering
        16. 8.3.2.16 Driver Headroom Control
      3. 8.3.3 Boost Converter
        1. 8.3.3.1 Operation
        2. 8.3.3.2 Protection
        3. 8.3.3.3 Manual Output Voltage Control
        4. 8.3.3.4 Adaptive Boost Control
      4. 8.3.4 Fault Detection
        1. 8.3.4.1 LED Fault Detection
        2. 8.3.4.2 Undervoltage Detection
        3. 8.3.4.3 Overcurrent Protection
        4. 8.3.4.4 Device Thermal Regulation
        5. 8.3.4.5 Thermal Shutdown
    4. 8.4 Device Functional Modes
    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
      2. 8.5.2 EEPROM
    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 Fault
        4. 8.6.1.4 Identification
        5. 8.6.1.5 Direct Control
        6. 8.6.1.6 Temp MSB
        7. 8.6.1.7 Temp LSB
        8. 8.6.1.8 EEPROM Control
      2. 8.6.2 EEPROM Bit Explanations
        1. 8.6.2.1 EEPROM Address 0
        2. 8.6.2.2 EEPROM Address 1
        3. 8.6.2.3 EEPROM Address 2
        4. 8.6.2.4 EEPROM Address 3
        5. 8.6.2.5 EEPROM Address 4
        6. 8.6.2.6 EEPROM Address 5
        7. 8.6.2.7 EEPROM Address 6
        8. 8.6.2.8 EEPROM Address 7
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Typical Application Using Internal LDO
        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
          3. 9.2.1.2.3 LDO Capacitor
          4. 9.2.1.2.4 Output Diode
          5. 9.2.1.2.5 Resistors for Setting the LED Current and PWM Frequency
          6. 9.2.1.2.6 Filter Component Values
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Typical Application for Low Input Voltage
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 Typical Application for Three Channels and Low Input Voltage
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 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 Trademarks
    2. 12.2 Electrostatic Discharge Caution
    3. 12.3 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7 Specifications

7.1 Absolute Maximum Ratings(1)(2)

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
VIN –0.3 24 V
VLDO –0.3 6
Voltage on logic pins (VSYNC, PWM, EN, SCLK, SDA) –0.3 6
Voltage on logic pin (FAULT) –0.3 VVDDIO + 0.3
Voltage on analog pins (FILTER, VDDIO, ISET, FSET) –0.3 6
V (OUT1...OUT6, SW, FB) –0.3 44
Continuous power dissipation (3) Internally Limited
Junction temperature (TJ-MAX) 125 °C
Maximum lead temperature (soldering) See (4)
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications.
(3) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ = 150°C (typ.) and disengages at TJ = 130°C (typ.).
(4) For detailed soldering specifications and information, please refer to Application Report AN-1112 DSBGA Wafer Level Chip Scale Package (SNVA009).

7.2 Handling Ratings

MIN MAX UNIT
Tstg Storage temperature range –65 150 °C
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) -2 2 kV
Charged device model (CDM), per JEDEC spec. JESD22-C101, all pins(2) –200 200 V
Machine model –1 1 kV
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

7.3 Recommended Operating Conditions(1)(2)

over operating free-air temperature range (unless otherwise noted)
MIN NOM MAX UNIT
VIN (Figure 27) Input voltage 5.5 22 V
VIN + VLDO (Figure 31) 4.5 5.5
VDDIO 1.65 5
V(OUT1...OUT6, SW, FB) 0 40
TJ Junction temperature –30 125 °C
TA(3) Ambient temperature –30 85
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) All voltages are with respect to the potential at the GND pins.
(3) In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may have to be derated. Maximum ambient temperature (TA-MAX) is dependent on the maximum operating junction temperature (TJ-MAX-OP = 125°C), the maximum power dissipation of the device in the application (PD-MAX), and the junction-to ambient thermal resistance of the part/package in the application (RθJA), as given by the following equation: TA-MAX = TJ-MAX-OP – (RθJA × PD-MAX).

7.4 Thermal Information

THERMAL METRIC(1) DSBGA UNIT
25 PINS
RθJA Junction-to-ambient thermal resistance (2) 40 - 73 °C/W
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
(2) Junction-to-ambient thermal resistance is highly application and board-layout dependent. In applications where high maximum power dissipation exists, special care must be paid to thermal dissipation issues in board design.

7.5 Electrical Characteristics(1)(2)

Limits are for TA = 25°C (unless otherwise specified); VIN = 12 V, VDDIO = 2.8 V, CVLDO = 1 μF, L1 = 15 μH, CIN = 10 μF, COUT = 10 μF. RISET = 16 kΩ, unless otherwise specified. (3)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
IIN Standby supply current Internal LDO disabled
EN=L and PWM=L
1 (4) μA
Normal mode supply current LDO enabled, boost enabled, no current going through LED outputs
5-MHz PLL Clock
3 mA
10-MHz PLL Clock 3.7
20-MHz PLL Clock 4.7
40-MHz PLL Clock 6.7
fOSC Internal oscillator frequency accuracy –4%
–7% (4)
4%
7%(4)
VLDO Internal LDO voltage 4.5 (4) 5 5.5 (4) V
ILDO Internal LDO external loading 5 mA
(1) All voltages are with respect to the potential at the GND pins.
(2) Minimum (MIN) and Maximum (MAX) limits are specified by design, test, or statistical analysis. Typical numbers represent the most likely norm.
(3) Low-ESR Surface-Mount Ceramic Capacitors (MLCCs) used in setting electrical characteristics.
(4) Limits apply over the full operating ambient temperature range (–30°C ≤ TA ≤ 85°C).

7.6 Boost Converter Electrical Characteristics

Limits are for TA = 25°C (unless otherwise specified); VIN = 12 V, VDDIO = 2.8 V, CVLDO = 1 μF, L1 = 15 μH, CIN = 10 μF, COUT = 10 μF. RISET = 16 kΩ, unless otherwise specified. (1)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
RDSON Switch ON resistance ISW = 0.5 A 0.12 Ω
VMAX Boost maximum output voltage 40 V
ILOAD Maximum continuous load current 9 V ≤ VBATT, VOUT = 35 V 450 mA
6 V ≤ VBATT, VOUT = 35 V 300
3 V ≤ VBATT, VOUT = 25 V 180
VOUT/VIN Conversion ratio fSW = 1.25 MHz 10
fSW Switching frequency BOOST_FREQ = 00
BOOST_FREQ = 01
BOOST_FREQ = 10
BOOST_FREQ = 11
156
312
625
1250
kHz
VOV Overvoltage protection voltage VBOOST + 1.6V V
tPULSE Switch pulse minimum width no load 50 ns
tSTARTUP Start-up time Note  (2) 6 ms
IMAX SW pin current limit BOOST_IMAX = 0
BOOST_IMAX = 1
1.4
2.5
A
(1) Low-ESR Surface-Mount Ceramic Capacitors (MLCCs) used in setting electrical characteristics.
(2) Start-up time is measured from the moment boost is activated until the VOUT crosses 90% of its target value.

7.7 LED Driver Electrical Characteristics

Limits are for TA = 25°C (unless otherwise specified); VIN = 12 V, VDDIO = 2.8 V, CVLDO = 1 μF, L1 = 15 μH, CIN = 10 μF, COUT = 10 μF. RISET = 16 kΩ, unless otherwise specified. (1)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
ILEAKAGE Leakage current Outputs OUT1 to OUT6, VOUT = 40 V 0.1 1 μA
IMAX Maximum source current OUT1 to OUT6 EN_I_RES = 0, CURRENT[7:0] = FFh 30 mA
EN_I_RES = 1, CURRENT[7:0] = FFh 50
IOUT Output current accuracy (2) Output current set to 23 mA, EN_I_RES = 1 –3%
-4%(3)
3%
4%(3)
IMATCH Matching(2) Output current set to 23 mA, EN_I_RES = 1 0.5%
PWMRES PWM output resolution (4) fLED = 5 kHz, fPLL = 5 MHz 10 bits
fLED = 10 kHz, fPLL = 5 MHz 9
fLED = 20 kHz, fPLL = 5 MHz 8
fLED = 5 kHz, fPLL = 40 MHz 13
fLED = 10 kHz, fPLL = 40 MHz 12
fLED = 20 kHz, fPLL = 40 MHz 11
fLED LED switching frequency(4) PWM_FREQ[4:0] = 00000b
PLL clock 5 MHz
600 Hz
PWM_FREQ[4:0] = 11111b
PLL clock 5 MHz
19.2k
VSAT Saturation voltage(5) Output current set to 20 mA 105 220(3) mV
Output current set to 30 mA 160 290(3)
(1) Low-ESR Surface-Mount Ceramic Capacitors (MLCCs) used in setting electrical characteristics.
(2) Output Current Accuracy is the difference between the actual value of the output current and programmed value of this current. Matching is the maximum difference from the average. For the constant current sinks on the part (OUT1 to OUT6), the following are determined: the maximum output current (MAX), the minimum output current (MIN), and the average output current of all outputs (AVG). Two matching numbers are calculated: (MAX-AVG)/AVG and (AVG-MIN/AVG). The largest number of the two (worst case) is considered the matching figure. The typical specification provided is the most likely norm of the matching figure for all parts. Note that some manufacturers have different definitions in use.
(3) Limits apply over the full operating ambient temperature range (–30°C ≤ TA ≤ 85°C).
(4) PWM output resolution and frequency depend on the PLL settings. Please see PWM Frequency Setting section for full description.
(5) Saturation voltage is defined as the voltage when the LED current has dropped 10% from the value measured at 1 V.

7.8 PWM Interface Characteristics

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
fPWM PWM frequency range 0.1 25 kHz
tMIN_ON Minimum pulse ON time 1 μs
tMIN_OFF Minimum pulse OFF time 1
tSTARTUP Turnon delay from standby to backlight on PWM input active, EN pin rise from low to high 6 ms
TSTBY Turn off delay PWM input low time for turn off, slope disabled 50 ms
PWMRES PWM input resolution fIN < 9 kHz
fIN < 4.5 kHz
fIN < 2.2 kHz
fIN < 1.1 kHz
10
11
12
13
bits

7.9 Undervoltage Protection

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VUVLO VIN UVLO threshold voltage UVLO[1:0] = 00 Disabled V
UVLO[1:0] = 01, falling 2.55 2.70 2.94
UVLO[1:0] = 01, rising 2.62 2.76 3.00
UVLO[1:0] = 10, falling 5.11 5.40 5.68
UVLO[1:0] = 10, rising 5.38 5.70 5.98
UVLO[1:0] = 11, falling 7.75 8.10 8.45
UVLO[1:0] = 11, rising 8.36 8.73 9.20

7.10 Logic Interface Characteristics

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
LOGIC INPUT EN
VIL Input low level 0.4(1) V
VIH Input high level 1.2(1) V
II Input current -1(1) 1(1) μA
LOGIC INPUT VSYNC
VIL Input low level 0.4(1) V
VIH Input high level 2.2(1) V
II Input current –1(1) 1(1) μA
fVSYNC Frequency range 58 60 55000 Hz
LOGIC INPUT PWM
VIL Input low level 0.2xVDDIO(1) V
VIH Input high level 0.8xVDDIO(1) V
II Input current –1(1) 1(1) μA
LOGIC INPUTS SCL, SDA
VIL Input low level 0.2xVDDIO(1) V
VIH Input high level 0.8xVDDIO(1) V
II Input current –1(1) 1(1) μA
LOGIC OUTPUTS SDA, FAULT
VOL Output low level IOUT = 3 mA (pull-up current) 0.3 0.5(1) V
IL Output leakage current VOUT = 2.8 V –1(1) 1(1) μA
(1) Limits apply over the full operating ambient temperature range (–30°C ≤ TA ≤ 85°C).

7.11 I2C Serial Bus Timing Parameters (SDA, SCLK) (1)

MIN MAX UNIT
fCLK Clock frequency 400 kHz
1 Hold time (repeated) START condition 0.6 μs
2 Clock low time 1.3 μs
3 Clock high time 600 ns
4 Setup time for a repeated START condition 600 ns
5 Data hold time 50 ns
6 Data setup time 100 ns
7 Rise time of SDA and SCL 20+0.1Cb 300 ns
8 Fall time of SDA and SCL 15+0.1Cb 300 ns
9 Setup time for STOP condition 600 ns
10 Bus free time between a STOP and a START condition 1.3 μs
Cb Capacitive load parameter for each bus line
Load of 1 pF corresponds to 1 ns.
10 200 ns
(1) Specified by design. Not production tested. VDDIO = 1.65 V to 5.5 V.
30138198.pngFigure 1. I2C Timing Diagram

7.12 Typical Characteristics

Unless otherwise specified: VBATT = 12 V, CVLDO = 1 μF, L1 = 33 μH, CIN = 10 μF, COUT = 10 μF
30138110.gif
fLED = 9.6 kHz
Figure 2. LED Drive Efficiency
30116312.gif
Figure 4. Boost Converter Efficiency
301163101.gif
Figure 6. ILED vs. RISET
30138108.gif
Figure 8. Optical Efficiency With 15-inch Panel
30116302.gif
Figure 10. Luminance vs. PWM Input
30138111.gif
fLED = 9.6 kHz L1 = 15 µH
Figure 3. LED Drive Efficiency
30138109.gif
Figure 5. Battery Current
30138184.png
Figure 7. Boost Line Transient Response
30138107.gif
Figure 9. Input Power vs. Luminance
30138101.gif
Figure 11. Power Saved with PWM & Current Mode Compared to PWM Mode