SNVS967A August   2014  – November 2014 LM3643

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematic
  5. 5 Revision History
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 Handling Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Switching Characteristics
    8. 8.8 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Flash Mode
      2. 9.3.2 Torch Mode
      3. 9.3.3 IR Mode
    4. 9.4 Device Functioning Modes
      1. 9.4.1 Start-Up (Enabling The Device)
      2. 9.4.2 Pass Mode
      3. 9.4.3 Power Amplifier Synchronization (TX)
      4. 9.4.4 Input Voltage Flash Monitor (IVFM)
      5. 9.4.5 Fault/Protections
        1. 9.4.5.1 Fault Operation
        2. 9.4.5.2 Flash Time-Out
        3. 9.4.5.3 Overvoltage Protection (OVP)
        4. 9.4.5.4 Current Limit
        5. 9.4.5.5 NTC Thermistor Input (Torch/Temp)
        6. 9.4.5.6 Undervoltage Lockout (UVLO)
        7. 9.4.5.7 Thermal Shutdown (TSD)
        8. 9.4.5.8 LED and/or VOUT Short Fault
    5. 9.5 Programming
      1. 9.5.1 Control Truth Table
      2. 9.5.2 I2C-Compatible Interface
        1. 9.5.2.1 Data Validity
        2. 9.5.2.2 Start and Stop Conditions
        3. 9.5.2.3 Transferring Data
        4. 9.5.2.4 I2C-Compatible Chip Address
    6. 9.6 Register Descriptions
      1. 9.6.1  Enable Register (0x01)
      2. 9.6.2  IVFM Register (0x02)
      3. 9.6.3  LED1 Flash Brightness Register (0x03)
      4. 9.6.4  LED2 Flash Brightness Register (0x04)
      5. 9.6.5  LED1 Torch Brightness Register (0x05)
      6. 9.6.6  LED2 Torch Brightness Register (0x06)
      7. 9.6.7  Boost Configuration Register (0x07)
      8. 9.6.8  Timing Configuration Register (0x08)
      9. 9.6.9  TEMP Register (0x09)
      10. 9.6.10 Flags1 Register (0x0A)
      11. 9.6.11 Flags2 Register (0x0B)
      12. 9.6.12 Device ID Register (0x0C)
      13. 9.6.13 Last Flash Register (0x0D)
  10. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Output Capacitor Selection
        2. 10.2.2.2 Input Capacitor Selection
        3. 10.2.2.3 Inductor Selection
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Related Documentation
      1. 13.2.1 Related Links
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

8 Specifications

8.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN MAX UNIT
IN, SW, OUT, LED1, LED2 −0.3 6 V
SDA, SCL, TX, TORCH/TEMP, HWEN, STROBE −0.3 to the lesser of (VIN+0.3) w/ 6 V max
Continuous power dissipation(3) Internally limited
Junction temperature (TJ-MAX) 150 °C
Maximum lead temperature (soldering) Note (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) All voltages are with respect to the potential at the GND terminal.
(3) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ = 150°C (typ.) and disengages at TJ = 135°C (typ.). Thermal shutdown is ensured by design.
(4) For detailed soldering specifications and information, please refer to TI Application Note DSBGA Wafer Level Chip Scale Package (SNVA009).

8.2 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) −2500 2500 V
Charged device model (CDM), per JEDEC specification JESD22-C101, all pins(2) −1500 1500
(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.

8.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN MAX UNIT
VIN 2.5 5.5 V
Junction temperature (TJ) −40 125 °C
Ambient temperature (TA) (3) −40 85
(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. 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 terminal.
(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).

8.4 Thermal Information

THERMAL METRIC(1) LM3643 UNIT
DSBGA
12 PINS
RθJA Junction-to-ambient thermal resistance 67.8 °C/W
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

8.5 Electrical Characteristics

Typical limits tested at TA = 25°C. Minimum and maximum limits apply over the full operating ambient temperature range (−40°C ≤ TA ≤ 85°C). Unless otherwise specified, VIN = 3.6 V, HWEN = VIN.(1)(2)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
CURRENT SOURCE SPECIFICATIONS
ILED1/2 Current source accuracy VOUT = 4 V, flash code = 0x7F = 1.5 A flash –7% 1.5 7% A
VOUT = 4 V, torch code = 0x3F = 89.3 mA torch –10% 89.3 10% mA
VHR LED1 and LED2 current source regulation voltage ILED1/2 = 729 mA Flash 290 mV
ILED1/2 = 179 mA Torch 158
VOVP ON threshold 4.86 5 5.1 V
OFF threshold 4.75 4.88 4.99
STEP-UP DC/DC CONVERTER SPECIFICATIONS
RPMOS PMOS switch on-resistance 86 mΩ
RNMOS NMOS switch on-resistance 65
ICL Switch current limit Reg 0x07, bit[0] = 0 –12% 1.9 12% A
Reg 0x07, bit[0] = 1 –12% 2.8 12%
UVLO Undervoltage lockout threshold Falling VIN –2% 2.5 2% V
VTRIP NTC comparator trip threshold Reg 0x09, bits[3:1] = '100' –5% 0.6 5% V
INTC NTC current –6% 50 6% µA
VIVFM Input voltage flash monitor trip threshold Reg 0x02, bits[5:3] = '000' –3% 2.9 3% V
IQ Quiescent supply current Device not switching pass mode 0.3 0.75 mA
ISD Shutdown supply current Device disabled, HWEN = 0 V
2.5 V ≤ VIN ≤ 5.5 V		 0.1 4 µA
ISB Standby supply current Device disabled, HWEN = 1.8 V
2.5 V ≤ VIN ≤ 5.5 V		 2.5 10 µA
HWEN, TORCH/TEMP, STROBE, TX VOLTAGE SPECIFICATIONS
VIL Input logic low 2.5 V ≤ VIN ≤ 5.5 V 0 0.4 V
VIH Input logic high 1.2 VIN
I2C-COMPATIBLE INTERFACE SPECIFICATIONS (SCL, SDA)
VIL Input logic low 2.5 V ≤ VIN ≤ 4.2 V 0 0.4 V
VIH Input logic high 1.2 VIN
VOL Output logic low ILOAD = 3 mA 400 mV
(1) Minimum (Min) and Maximum (Max) limits are specified by design, test, or statistical analysis. Typical (typ.) numbers are not verified, but do represent the most likely norm. Unless otherwise specified, conditions for typical specifications are: VIN = 3.6 V and TA = 25°C.
(2) All voltages are with respect to the potential at the GND pin.

8.6 Timing Requirements

MIN NOM MAX UNIT
t1 SCL clock period 2.4 µs
t2 Data in set-up time to SCL high 100 ns
t3 Data out stable After SCL low 0
t4 SDA low set-up time to SCL Low (start) 100
t5 SDA high hold time after SCL high (stop) 100

8.7 Switching Characteristics

over operating free-air temperature range (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
ƒSW Switching frequency 2.5 V ≤ VIN ≤ 5.5 V –6% 4 6% MHz
30171819.gifFigure 1. I2C-Compatible Interface Specifications

8.8 Typical Characteristics

Ambient temperature is 25°C, input voltage is 3.6 V, HWEN = VIN, CIN = COUT = 2 × 10 µF and L = 1 µH, unless otherwise noted .
D001_SNVS967.gif
Figure 2. LED1 Flash Current vs Brightness Code
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Figure 4. LED1 Torch Current vs Brightness Code
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Figure 6. LED1 Current vs Input Voltage
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Figure 8. LED2 Current vs Input Voltage
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ILED = 1.5 A ƒSW = 2 MHz Flash
Figure 10. LED1/2 Current vs Input Voltage
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ILED = 1 A ƒSW = 2 MHz Flash
Figure 12. LED1/2 Current vs Input Voltage
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ILED = 179 mA ƒSW = 2 MHz Torch
Figure 14. LED Current vs Input Voltage
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ILED = 179 mA ƒSW = 2 MHz Torch
Figure 16. LED1 and LED2 Current vs Input Voltage
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HWEN = VIN I2C = VIN
Figure 18. Standby Current vs Input Voltage
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HWEN = 1.8 V I2C = 1.8 V
Figure 20. Standby Current vs Input Voltage
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ILED = 1.5 A ƒSW = 4 MHz VLED = 4.5 V
ICL = 1.9 A
Figure 22. Inductor Current Limit vs Input Voltage
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ILED = 1.5 A ƒSW = 4 MHz VLED = 4.5 V
ICL = 2.8 A
Figure 24. Inductor Current Limit vs Input Voltage
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Figure 26. 4-MHz Switching Frequency vs Input Voltage
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Figure 3. LED2 Flash Current vs Brightness Code
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Figure 5. LED2 Torch Current vs Brightness Code
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Figure 7. LED1 Current vs Input Voltage
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Figure 9. LED2 Current vs Input Voltage
D022_SNVS967.gif
ILED = 1.5 A ƒSW = 4 MHz Flash
Figure 11. LED1/2 Current vs Input Voltage
D024_SNVS967.gif
ILED = 730 mA ƒSW = 2 MHz Flash
Figure 13. LED1 and LED2 Current vs Input Voltage
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ILED = 179 mA ƒSW = 4 MHz Torch
Figure 15. LED Current vs Input Voltage
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HWEN = 0 V I2C = 0 V
Figure 17. Shutdown Current vs Input Voltage
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HWEN = 1.8 V I2C = 0 V
Figure 19. Standby Current vs Input Voltage
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ILED = 1.5 A ƒSW = 2 MHz VLED = 4.5 V
ICL = 1.9 A
Figure 21. Inductor Current Limit vs Input Voltage
D013_SNVS967.gif
ILED = 1.5 A ƒSW = 2 MHz VLED = 4.5 V
ICL = 2.8 A
Figure 23. Inductor Current Limit vs Input Voltage
D017_SNVS967.gif
Figure 25. 2-MHz Switching Frequency vs Input Voltage