SNVSA68D October   2014  – November 2016 LM3648

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 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 Flash Mode
      2. 7.3.2 Torch Mode
      3. 7.3.3 IR Mode
    4. 7.4 Device Functioning Modes
      1. 7.4.1 Start-Up (Enabling The Device)
      2. 7.4.2 Pass Mode
      3. 7.4.3 Power Amplifier Synchronization (TX)
      4. 7.4.4 Input Voltage Flash Monitor (IVFM)
      5. 7.4.5 Fault/Protections
        1. 7.4.5.1 Fault Operation
        2. 7.4.5.2 Flash Time-Out
        3. 7.4.5.3 Overvoltage Protection (OVP)
        4. 7.4.5.4 Current Limit
        5. 7.4.5.5 NTC Thermistor Input (Torch/Temp)
        6. 7.4.5.6 Undervoltage Lockout (UVLO)
        7. 7.4.5.7 Thermal Shutdown (TSD)
        8. 7.4.5.8 LED and/or VOUT Short Fault
    5. 7.5 Programming
      1. 7.5.1 Control Truth Table
      2. 7.5.2 I2C-Compatible Interface
        1. 7.5.2.1 Data Validity
        2. 7.5.2.2 Start and Stop Conditions
        3. 7.5.2.3 Transferring Data
        4. 7.5.2.4 I2C-Compatible Chip Address
    6. 7.6 Register Descriptions
      1. 7.6.1  Enable Register (0x01)
      2. 7.6.2  IVFM Register (0x02)
      3. 7.6.3  LED Flash Brightness Register (0x03)
      4. 7.6.4  LED Torch Brightness Register (0x05)
      5. 7.6.5  Boost Configuration Register (0x07)
      6. 7.6.6  Timing Configuration Register (0x08)
      7. 7.6.7  TEMP Register (0x09)
      8. 7.6.8  Flags1 Register (0x0A)
      9. 7.6.9  Flags2 Register (0x0B)
      10. 7.6.10 Device ID Register (0x0C)
      11. 7.6.11 Last Flash Register (0x0D)
  8. 8 Applications 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 Output Capacitor Selection
        2. 8.2.2.2 Input Capacitor Selection
        3. 8.2.2.3 Inductor 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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
      2. 11.2.2 Related Links
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN MAX UNIT
IN, SW, OUT, LED −0.3 6 V
SDA, SCL, TX, TORCH/TEMP, HWEN, STROBE −0.3 (VIN+ 0.3) w/ 6 V max
Continuous power dissipation(3) Internally limited
Junction temperature (TJ-MAX) 150 °C
Maximum lead temperature (soldering) See(4)
Storage temperature, Tstg −65 150 °C
(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 pin.
(3) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ = 150°C (typical) and disengages at TJ = 135°C (typical). Thermal shutdown is ensured by design.
(4) For detailed soldering specifications and information, refer to Texas Instruments Application Note 1112: DSBGA Wafer Level Chip Scale Package (SNVA009).

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2500 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±150
(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.

6.3 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 °C
(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).

6.4 Thermal Information

THERMAL METRIC(1) LM3648 UNIT
YFF (DSBGA)
12 PINS
RθJA Junction-to-ambient thermal resistance 90.2 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 0.5 °C/W
RθJB Junction-to-board thermal resistance 40.0 °C/W
ΨJT Junction-to-top characterization parameter 3.0 °C/W
ΨJB Junction-to-board characterization parameter 39.2 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics.

6.5 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
ILED Current source accuracy VOUT = 4 V, flash code = 0x3F = 1.5 A flash –7% 1.5 7% A
VOUT = 4 V, torch code = 0x3F = 178.6 mA torch –10% 178.6 10% mA
ILED Current source accuracy (LM3648TT) VOUT = 4 V, torch code = 0x3F = 357.2 mA torch –10% 357.2 10% mA
VHR LED current source regulation voltage ILED = 1.5 A Flash 290 mV
ILED = 178.6 mA Torch 158
VHR LED current source regulation voltage (LM3648TT) ILED = 357.2 mA Torch and flash 270 mV
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%
VUVLO 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 V
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.

6.6 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 ns
t4 SDA low set-up time to SCL low (start) 100 ns
t5 SDA high hold time after SCL high (stop) 100 ns

6.7 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
LM3648 LM3648TT 30171819.gif Figure 1. I2C-Compatible Interface Specifications

6.8 Typical Characteristics

TA = 25°C, VIN = 3.6 V, HWEN = VIN, CIN = COUT = 2 × 10 µF and L = 1 µH, unless otherwise noted.
LM3648 LM3648TT D001_SNVSA68.gif
Figure 2. LED Flash Current vs Brightness Code
LM3648 LM3648TT D031_SNVSA68.gif
LM3648TT
Figure 4. LED Torch Current vs Brightness Code
LM3648 LM3648TT D015_SNVSA68.gif
Figure 3. LED Torch Current vs Brightness Code
LM3648 LM3648TT D021_SNVSA68.gif
ƒSW = 2 MHz Flash
Brightness Code = 0x3F
Figure 5. LED Current vs Input Voltage
LM3648 LM3648TT D022_SNVSA68.gif
ƒSW = 4 MHz Flash
Brightness Code = 0x3F
Figure 6. LED Current vs Input Voltage
LM3648 LM3648TT D025_SNVSA68.gif
ƒSW = 2 MHz Torch
Brightness Code = 0x7F
Figure 8. LED Current vs Input Voltage
LM3648 LM3648TT D026_SNVSA68.gif
ƒSW = 4 MHz Torch
Brightness Code = 0x7F
Figure 10. LED Current vs Input Voltage
LM3648 LM3648TT D007_SNVS967.gif
HWEN = 0 V I2C = 0 V
Figure 12. Shutdown Current vs Input Voltage
LM3648 LM3648TT D008_SNVS967.gif
HWEN = 1.8 V I2C = 0 V
Figure 14. Standby Current vs Input Voltage
LM3648 LM3648TT D011_SNVS967.gif
ƒSW = 2 MHz Flash VLED = 4.5 V
Brightness Code = 0x3F ICL = 1.9 A
Figure 16. Inductor Current Limit vs Input Voltage
LM3648 LM3648TT D013_SNVS967.gif
ƒSW = 2 MHz Flash VLED = 4.5 V
Brightness Code = 0x3F ICL = 2.8 A
Figure 18. Inductor Current Limit vs Input Voltage
LM3648 LM3648TT D017_SNVS967.gif
Figure 20. 2-MHz Switching Frequency vs Input Voltage
LM3648 LM3648TT D023_SNVSA68.gif
ƒSW = 2 MHz Flash
Brightness Code = 0x2B
Figure 7. LED Current vs Input Voltage
LM3648 LM3648TT D032_SNVSA68.gif
LM3648TT ƒSW = 2 MHz Torch
Brightness Code = 0x59
Figure 9. LED Current vs Input Voltage
LM3648 LM3648TT D033_SNVSA68.gif
LM3648TT ƒSW = 4 MHz Torch
Brightness Code = 0x59
Figure 11. LED Current vs Input Voltage
LM3648 LM3648TT D009_SNVS967.gif
HWEN = VIN I2C = VIN
Figure 13. Standby Current vs Input Voltage
LM3648 LM3648TT D010_SNVS967.gif
HWEN = 1.8 V I2C = 1.8 V
Figure 15. Standby Current vs Input Voltage
LM3648 LM3648TT D012_SNVS967.gif
ƒSW = 4 MHz Flash VLED = 4.5 V
Brightness Code = 0x3F ICL = 1.9 A
Figure 17. Inductor Current Limit vs Input Voltage
LM3648 LM3648TT D014_SNVS967.gif
ƒSW = 4 MHz Flash VLED = 4.5 V
Brightness Code = 0x3F ICL = 2.8 A
Figure 19. Inductor Current Limit vs Input Voltage
LM3648 LM3648TT D018_SNVS967.gif
Figure 21. 4-MHz Switching Frequency vs Input Voltage