SNVS549C June   2009  – February 2016 LM3554

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Specifications
    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 Timing Requirements
    7. 5.7 Typical Characteristics
  6. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Start-Up
      2. 6.3.2  Overvoltage Protection
      3. 6.3.3  Current Limit
      4. 6.3.4  Flash Termination (Strobe-Initiated Flash)
      5. 6.3.5  Flash Termination (I2C-Initiated Flash)
      6. 6.3.6  Flash Timeout
      7. 6.3.7  Torch Mode
      8. 6.3.8  TX1/Torch
      9. 6.3.9  ENVM/TX2/GPIO2
        1. 6.3.9.1 ENVM/TX2/GPIO2/INT as an Interrupt Output
      10. 6.3.10 Indicator LED/Thermistor (LEDI/NTC)
        1. 6.3.10.1 LED Indicator Mode (LEDI)
        2. 6.3.10.2 Thermal Comparator Mode (NTC)
      11. 6.3.11 Alternative External Torch (AET Mode)
      12. 6.3.12 Input Voltage Monitor
      13. 6.3.13 LM3554 Timing Diagrams
      14. 6.3.14 Flags Register and Fault Indicators
      15. 6.3.15 Thermal Shutdown
      16. 6.3.16 LED Fault
      17. 6.3.17 Flash Timeout
      18. 6.3.18 LED Thermal Fault
      19. 6.3.19 Input Voltage Monitor Fault
      20. 6.3.20 TX1 And TX2 Interrupt Flags
      21. 6.3.21 Light Load Disable
    4. 6.4 Device Functional Modes
      1. 6.4.1 Flash Mode
      2. 6.4.2 Pass Mode
      3. 6.4.3 Voltage-Output Mode
    5. 6.5 Programming
      1. 6.5.1 I2C-Compatible Interface
        1. 6.5.1.1 Start and Stop Conditions
        2. 6.5.1.2 I2C-Compatible Chip Address
        3. 6.5.1.3 Transferring Data
    6. 6.6 Register Maps
      1. 6.6.1 Register Descriptions
        1. 6.6.1.1 Torch Brightness Register
        2. 6.6.1.2 Flash Brightness Register
        3. 6.6.1.3 Flash Duration Register
        4. 6.6.1.4 Flags Register
        5. 6.6.1.5 Configuration Register 1
        6. 6.6.1.6 Configuration Register 2
        7. 6.6.1.7 GPIO Register
        8. 6.6.1.8 VIN Monitor Register
  7. 7 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 Output Capacitor Selection
        2. 7.2.2.2 Input Capacitor Selection
        3. 7.2.2.3 Inductor Selection
        4. 7.2.2.4 NTC Thermistor Selection
        5. 7.2.2.5 NTC Thermistor Placement
        6. 7.2.2.6 Maximum Load Current (Voltage Mode)
        7. 7.2.2.7 Maximum Output Power
          1. 7.2.2.7.1 Voltage-Output Mode
          2. 7.2.2.7.2 LED Boost Mode
          3. 7.2.2.7.3 LED Pass Mode
      3. 7.2.3 Application Curves
  8. 8 Power Supply Recommendations
  9. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Community Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

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

5 Specifications

5.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)(3)
MIN MAX UNIT
VIN, VSW, VOUT –0.3 6 V
VSCL, VSDA, VHWEN, VSTROBE, VTX1/TORCH, VENVM/TX2, VLED1, VLED2, VLEDI/NTC 0.3 V to (VIN + 0.3 V)
w/ 6 V max
Continuous power dissipation(4) Internally limit
Junction temperature, TJ-MAX 150 °C
Maximum lead temperature (soldering) See(5)
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) If Military/Aerospace specified devices are required, contact the Texas Instruments Sales Office/ Distributors for availability and specifications.
(4) 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).
(5) For detailed soldering specifications and information, refer to AN1112 DSBGA Wafer Level Chip-Scale Package (SNVA009).

5.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

5.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)(1)
MIN NOM MAX UNIT
Input voltage, VIN 2.5 5.5 V
Junction temperature, TJ –30 125 °C
Ambient temperature, TA(2) –30 85 °C
(1) All voltages are with respect to the potential at the GND pin.
(2) 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).

5.4 Thermal Information

THERMAL METRIC(1) LM3554 UNIT
YFQ (DSBGA)
16 PINS
RθJA Junction-to-ambient thermal resistance 75.8 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 0.5 °C/W
RθJB Junction-to-board thermal resistance 16.5 °C/W
ψJT Junction-to-top characterization parameter 0.3 °C/W
ψJB Junction-to-board characterization parameter 16.4 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

5.5 Electrical Characteristics

Unless otherwise specified, typical limits are for TA = 25°C, minimum and maximum limits in apply over the full operating ambient temperature range (–30°C ≤ TA ≤ +85°C), VIN = 3.6 V, and VHWEN = VIN. (1)(2)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
CURRENT SOURCE SPECIFICATIONS
ILED Current source accuracy 600-mA flash LED setting, VOUT = VIN ILED1 and ILED2 1128 1200 1284 mA
ILED1 or ILED2 541 600 657
17-mA torch current setting
VHR = 500 mV		 ILED1 and ILED2 30.4 33.8 37.2
VHR Current source regulation voltage (VOUT – VLED) 600-mA setting, VOUT = 3.75 V 300 mV
IMATCH LED Current Matching 600-mA setting, VLED = 3.2 V 0.35%
STEP-UP DC-DC CONVERTER
VREG Output voltage accuracy 2.7 V ≤ VIN ≤ 4.2 V, IOUT = 0 mA
VENVM = VIN, OV bit = 0		 4.8 5 5.2 V
VOVP Output overvoltage protection trip point(3) On threshold, 2.7 V ≤ VIN ≤ 5.5 V 5.4 5.6 5.7 V
Off threshold 5.3
RPMOS PMOS switch on-resistance IPMOS = 1 A 150 mΩ
RNMOS NMOS switch on-resistance INMOS = 1 A 150 mΩ
ICL Switch current limit(4) CL bits = 00 0.711 1.05 1.373 A
CL bits = 01 1.295 1.51 1.8
CL bits = 10 1.783 1.99 2.263
CL bits = 11 2.243 2.45 2.828
IOUT_SC Output short-circuit current limit VOUT < 2.3 V 550 mA
ILED/NTC Indicator current LEDI/NTC bit = 0 IND1, IND0 bits = 00 2.3 mA
IND1, IND0 bits = 01 4.6
IND1, IND0 bits = 10 6.9
IND1, IND0 bits = 11 8.2
VTRIP Comparator trip threshold LEDI/NTC bit = 1, 2.7 V ≤ VIN ≤ 5.5 V 0.947 1.052 1.157 V
ƒSW Switching frequency 2.7 V ≤ VIN ≤ 5.5 V 1.75 2 2.23 MHz
IQ Quiescent supply current Device not switching 630 µA
ISHDN Shutdown supply current 2.7 V ≤ VIN ≤ 5.5 V 3.5 6.6 µA
tTX Flash-to-torch LED current settling time TX_ Low to High, ILED1 + ILED2 = 1.2 A to 180 mA 20 µs
VIN_TH VIN monitor trip threshold VIN falling, VIN monitor register = 0x01
(enabled with VIN_TH = 3.1 V)		 2.95 3.09 3.23 V
TX1/TORCH/GPIO1, STROBE, HWEN, ENVM/TX2/GPIO2 VOLTAGE
VIL Input logic low 2.7 V ≤ VIN ≤ 5.5 V 0 0.4 V
VIH Input logic high 2.7 V ≤ VIN ≤ 5.5 V 1.2 VIN V
VOL Output logic low ILOAD = 3 mA, 2.7 V ≤ VIN ≤ 5.5 V 400 mV
RTX1/TORCH Internal pulldown resistance at TX1/TORCH 300 kΩ
RSTROBE Internal pulldown resistance at STROBE 300 kΩ
I2C-COMPATIBLE VOLTAGE SPECIFICATIONS (SCL, SDA)
VIL Input logic low 2.7 V ≤ VIN ≤ 5.5 V 0 0.4 V
VIH Input logic high 2.7 V ≤ VIN ≤ 5.5 V 1.22 VIN V
VOL Output logic low (SCL) ILOAD = 3 mA, 2.7 V ≤ VIN ≤ 5.5 V 400 mV
(1) All voltages are with respect to the potential at the GND pin.
(2) Minimum (MIN) and maximum (MAX) limits are ensured by design, test, or statistical analysis. Typical (TYP) numbers are not ensured, but do represent the most likely norm. Unless otherwise specified, conditions for typical specifications are: VIN = 3.6 V and TA = 25°C.
(3) The typical curve for overvoltage protection (OVP) is measured in closed loop using the Typical Application Circuit. The OVP value is found by forcing an open circuit in the LED1 and LED2 path and recording the peak value of VOUT. The value given in Electrical Characteristics is found in an open-loop configuration by ramping the voltage at OUT until the OVP comparator trips. The closed loop data can appear higher due to the stored energy in the inductor being dumped into the output capacitor after the OVP comparator trips. At worst case is an open circuit condition where the output voltage can continue to rise after the OVP comparator trips by approximately IIN× sqrt (L/COUT).
(4) The typical curve for Current Limit is measured in closed loop using the Typical Application Circuit by increasing IOUT until the peak inductor current stops increasing. The value given in Electrical Characteristics is measured open loop and is found by forcing current into SW until the current limit comparator threshold is reached. Closed loop data appears higher due to the delay between the comparator trip point and the NFET turning off. This delay allows the closed-loop inductor current to ramp higher after the trip point by approximately 20 ns × VIN / L.

5.6 Timing Requirements

See Figure 1.
MIN NOM MAX UNIT
1 / t1 SCL clock frequency 400 kHz
t2 Data in setup time to SCL high 100 ns
t3 Data out stable after SCL low 0 ns
t4 SDA low setup time to SCL low (start) 160 ns
t5 SDA high hold time after SCL high (stop) 160 ns
LM3554 30042004.gif Figure 1. I2C Timing

5.7 Typical Characteristics

VIN = 3.6 V, LEDs are Lumiled PWF-4, COUT = 10 µF, CIN = 4.7 µF, L = FDSE0312-2R2 (2.2 µH, RL = 0.15 Ω), TA = 25°C, unless otherwise specified.
LM3554 30042057.png
VOUT = 5 V Voltage-Output Mode
Figure 2. VOUT vs IOUT
LM3554 30042094.png
VIN = 3.6 V VLED1, VLED2 = 3.2 V TA = –40°C to +85°C
Current Matching = Abs Value ((ILED1–ILED2)÷(ILED1+ILED2))×100
Figure 4. Torch Current Matching vs Code
LM3554 300420102.png
VLED1, VLED2 = 3.2 V 75-mA Setting TA = 85°C
Figure 6. Torch Current vs VIN
LM3554 30042095.png
VIN = 3.6 V VLED1, VLED2 = 3.2 V TA = –40°C To +85°C
Current Matching = Abs Value ((ILED1–ILED2)÷(ILED1+ILED2))×100
Figure 8. Flash Current Matching vs Code
LM3554 300420103.png
VLED1, VLED2 = 3.2 V 600-mA Setting TA = 85°C
Figure 10. Flash Current vs VIN
LM3554 30042089.png
Figure 12. Switching Frequency vs VIN
LM3554 30042074.png
VLED = 1.5 V
Figure 14. Active (Non-Switching) Supply Current vs VIN
LM3554 30042085.png Figure 16. Closed Loop Current Limit vs VIN
(Flash Duration Register Bits [6:5] = 00)(4))
LM3554 30042087.png Figure 18. Closed Loop Current Limit vs VIN
(Flash Duration Register Bits [6:5] = 10)(4))
LM3554 30042078.png
Figure 20. VIN Monitor Thresholds vs Temperature
LM3554 30042080.png
Figure 22. Short Circuit Current Limit vs VIN
LM3554 30042091.png
VLEDI = 2 V
Figure 24. Indicator Current vs VIN
(Torch Brightness Register Bits[7:6] = 01)
LM3554 30042093.png
VLEDI = 2 V
Figure 26. Indicator Current vs VIN
(Torch Brightness Register Bits[7:6] = 11)
LM3554 30042058.png
VOUT = 5 V Voltage-Output Mode
Figure 3. VOUT vs VIN
LM3554 30042096.png
VLED1, VLED2 = 3.2 V 75-mA Setting TA = 25°C
Figure 5. Torch Current vs VIN
LM3554 300420104.png
VLED1, VLED2 = 3.2 V 75-mA Setting TA = –40°C
Figure 7. Torch Current vs VIN
LM3554 30042097.png
VLED1, VLED2 = 3.2 V 600-mA Setting TA = 25°C
Figure 9. Flash Current vs VIN
LM3554 300420105.png
VLED1, VLED2 = 3.2 V 600-mA Setting TA = –40°C
Figure 11. Flash Current vs VIN
LM3554 300420101.png
VHWEN = 0 V
Figure 13. Shutdown Current vs VIN
LM3554 30042075.png
VOUT = 5 V IOUT = 400 mA
Figure 15. Active (Switching) Supply Current vs VIN
LM3554 30042086.png Figure 17. Closed Loop Current Limit vs VIN
(Flash Duration Register Bits [6:5] = 01)(4) )
LM3554 30042088.png Figure 19. Closed Loop Current Limit vs VIN
(Flash Duration Register Bits [6:5] = 11)(4))
LM3554 30042079.png
Figure 21. OVP Thresholds vs VIN(3)
LM3554 30042090.png
VLEDI = 2 V
Figure 23. Indicator Current vs VIN
(Torch Brightness Register Bits[7:6] = 00)
LM3554 30042092.png
VLEDI = 2 V
Figure 25. Indicator Current vs VIN
(Torch Brightness Register Bits[7:6] = 10)
LM3554 30042098.png
Figure 27. NTC Comparator Trip Threshold vs VIN