Driver IC

AL3644

Diodes Incorporated

DUAL 1.5A CURRENT SOURCE CAMERA FLASH LED DRIVER July 2019

Manufacturer: Diodes Incorporated

Document: 23 Pages / 792Kb

Request Quote Download Datasheet Read online HTML view

More from Diodes Incorporated Browse A parts

Online Datasheet

Read AL3644 online.

AL3644

Document overview

Manufacturer or author: Diodes Incorporated
PDF pages: 25

Technical content

Features

 Dual Independent 1.5A LED Current Source Programmability  Accurate and Programmable LED Current Range from 1.4mA to 1.5A  Torch Currents up to 360mA (AL3644TT)  Flash Timeout Values up to 1.6 Seconds (AL3644TT)  Optimized Flash LED Current During Low Battery Conditions (Input Voltage Flash Monitor)  > 85% Efficiency in Torch Mode (at 100mA) and Flash Mode (at 1A to 1.5A)  Grounded Cathode LED Operation for Improved Thermal Management  Small Solution Size: < 2.36mm2  Hardware Strobe Enable (STROBE)  Synchronization Input for RF Power Amplifier Pulse Events (TX)  Hardware Torch Enable (TORCH/TEMP)  Remote NTC Monitoring (TORCH/TEMP)  400kHz I2C-Compatible Interface – AL3644 (I2C Address = 0x63)  Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)  Halogen and Antimony Free. “Green” Device (Note 3)  For automotive applications requiring specific change control (i.e. parts qualified to AEC-Q100/101/104/200, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative. https://www.diodes.com/quality/product-definitions/ Pin Assignment Top View A2 A3 B2 B3 C2 C3 D2 D3 Pin A1 U-WLB1713-12

Applications

 Camera phone white LED flashes Notes: 1. No purposely added lead. Fully EU Directive 2002 /95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant . 2. See https://www.diodes.com/quality/lead-free/ for more information about Diodes Incorporated’s definitions of Halogen - and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlori ne (<1500ppm total Br + Cl) and <1000ppm antimony compounds.

Document number: DS41558 Rev. 2 - 2 2 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 Typical Applications Circuit TORCH/ TEMP GND AL3644 IN 2.5V to 5V LED1 1mH SW OUT LED2 STROBE HWEN TX SDA SCL 10mF 10mF Flash LED Flash LED Pin Descriptions Pin Number Pin Name Type Function A1 GND Ground Ground. A2 IN Power Input voltage connection. Connect IN to the input supply and bypass to GND with a 10μF or larger ceramic capacitor. A3 SDA I/O Serial data input/output in the I2C mode on AL3644. B1 SW Power Drain connection for internal nMOS and synchronous pMOS switches. B2 STROBE I/O Active high hardware flash to enable. Drive STROBE high to turn on Flash pulse. Internal pulldown resistor of 300kΩ between STROBE and GND. B3 SCL I/O Serial clock input for AL3644. C1 OUT Power Step-up DC-DC converter output. Connect a 10μF ceramic capacitor between this pin and GND. C2 HWEN I/O Active high enable pin. High = Standby, Low = Shutdown/Reset. Internal pulldown resistor of 300kΩ between HWEN and GND. C3 TORCH/TEMP I/O Torch terminal input or threshold detector for NTC temperature sensing and current scale back. D1 LED2 Power High-side current source output for flash LED. D2 TX I/O Configurable dual polarity power amplifier synchronization input. Internal pulldown resistor of 300kΩ between TX and GND. D3 LED1 Power High-side current source output for flash LED.

Document number: DS41558 Rev. 2 - 2 3 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 Functional Block Diagram IN TORCH/ TEMP OUT INTC UVLO Thermal Shutdown +150°C VOVP PWM Control Overvoltage Comparator Input Voltage Flash Monitor SW 86mW TX SDA LED1 NTC VTRIP OUT-VHR Slope Compensation I2C Interface FB SELECT Control Logic/Registers Soft-Start Current Sense/Current Limit HWEN SCL STROBE VREF 2/4 MHz Oscillator + GND 65mW LED1 LED2 + + Error Amplifier LED2 C2 B2 D2 A1

Document number: DS41558 Rev. 2 - 2 4 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) (Note 4) Symbol Parameter Rating Unit VIN, VSW, VOUT, VLED1, VLED2 Voltage at Input Pins -0.3 to 6 V VSDA, VSCL, VTX, VTORCH/TEMP, VHWEN, VSTROBE VOUT and SW Pin Voltage -0.3 to the Lesser of (VIN+0.3)V / 6V V θJA Junction-to-Ambient Thermal Resistance (Note 5) 201.5 °C/W θJC Junction-to-Case Thermal Resistance (Note 5) 46.6 °C/W TJ Operating Junction Temperature +150 °C TSTG Storage Temperature -65 to +150 °C ESD HBM 2000 V CDM 1500 V Notes: 4. Stresses greater than those listed under Absolute Maximum Ratings can cause permane nt 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 Ratings for extended periods can affect device reliability. 5. Device mounted on FR-4 substrate PC board (1" x 1"), with minimum recommended pad layout. Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.) Symbol Parameter Min Max Unit VIN Input Voltage 2.5 5.0 V TA Operating Ambient Temperature -40 +85 °C TJ Operating Junction Temperature -40 +125 °C

Document number: DS41558 Rev. 2 - 2 5 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 Electrical Characteristics (VIN = 3.6V, VHWEN = VIN, TA = +25°C, unless otherwise specified.) Symbol Parameter Conditions Min Typ Max Unit CURRENT SOURCE ILED1/2 Current Source Accuracy VOUT = 4V Flash Code = 0x7F = 1.5A Flash 1.395 1.5 1.605 A -7% — 7% VOUT = 4V Torch Code = 0x3F = 89.3mA Torch 80.37 89.3 98.23 mA -10% — 10% ILED1/2 Current Source Accuracy (AL3644TT) VOUT = 4V Torch Code = 0x3F = 180mA Torch 162 180 198 mA -10% — 10% VHR LED1 and LED2 Current Source Regulation Voltage ILED1/2 = 729mA Flash — 290 — mV ILED1/2 = 179mA Torch — 158 — VHR LED1 and LED2 Current Source Regulation Voltage (AL3644TT) ILED1/2 = 360mA Torch and Flash — 270 — mV VOVP Overvoltage Protection Threshold On Threshold 4.60 4.75 4.85 V Off Threshold — 4.65 — STEP-UP DC/DC CONVERTER IQ Quiescent Supply Current Device not Switching Pass Mode — 0.3 0.75 mA ISD Shutdown Supply Current Device Disabled, VHWEN = 0V 2.5V ≤ VIN ≤ 5V — 0.1 4 μA ISB Standby Supply Current Device Disabled, VHWEN = 1.8V 2.5V ≤ VIN ≤ 5V — 2.5 10 μA fSW Switching Frequency 2.5V ≤ VIN ≤ 5V 3.76 4 4.24 MHz -6% — 6% RPMOS PMOS Switch On-Resistance VIN = 3.6V — 86 — mΩ RNMOS NMOS Switch On-Resistance VIN = 3.6V — 65 — mΩ ICL Switch Current Limit Reg 0x07, bit[0] = 0 1.672 1.9 2.128 A -12% — 12% Reg 0x07, bit[0] = 1 2.464 2.8 3.136 -12% — 12% UVLO Undervoltage Lockout Threshold Falling VIN — 2.5 2.6 V VTRIP NTC Comparator Trip Threshold Reg 0x09, bits[3:1] = '100' 0.57 0.60 0.63 V -5% — 5% INTC NTC Current — 47 50 53 -6% 50 6% μA VIVFM Input Voltage Flash Monitor Trip Threshold Reg 0x02, bits[5:3] = '000' 2.813 2.9 2.987 -3% — 3% V HWEN, TORCH/TEMP, STROBE, TX VOLTAGE VIL Input Logic Low 2.5V ≤ VIN ≤ 5V 0 — 0.4 V VIH Input Logic High 1.2 — VIN V I2C-COMPATIBLE INTERFACE (SCL, SDA) VIL Input Logic Low 2.5V ≤ VIN ≤ 4.2V 0 — 0.4 V VIH Input Logic High 1.2 — VIN V VOL Output Logic Low ILOAD = 3mA — — 400 mV

Document number: DS41558 Rev. 2 - 2 7 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 -40 -20 0 20 40 60 80 100 120 150 175 200 225 250 275 300 325 350 VHR (mV) Ambient Temperature( o AL3644TT, ILED1/2=360mA Torch Mode Flash Mode Typical Performance Characteristics (@TA = +25°C, VIN = 3.6V, VHWEN = VIN, CIN = 2 x 10µF, COUT = 2 x 10µF and L = 1µH, unless otherwise specified.) Current Source Regulation Voltage vs. Temperature Current Source Regulation Voltage vs. Temperature NTC Comparator Trip Threshold vs. Temperature Over Voltage Protection Threshold vs. Temperature Under Voltage Lockout Threshold vs. Temperature Input Voltage Flash Monitor Trip Threshold vs. Temperature -40 -20 0 20 40 60 80 100 120 2.50 2.55 2.60 2.65 2.70 2.75 2.80 2.85 2.90 2.95 3.00 VIVFM=2.9V VIVFM (V) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 VUVLO (V) Ambient Temperature ( o ON Threshold OFF Threshold -40 -20 0 20 40 60 80 100 120 100 130 160 190 220 250 280 310 340 370 400 VHR (mV) Ambient Temperature ( o AL3644 Torch Mode, ILED1/2=179mA Flash Mode, ILED1/2=729mA -40 -20 0 20 40 60 80 100 120 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 VTRIP=0.6V VTRIP (V) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0 VOVP (V) Ambient Temperature ( o ON Threshold OFF Threshold Overvoltage Undervoltage

Document number: DS41558 Rev. 2 - 2 8 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 Typical Performance Characteristics (continued) (@TA = +25°C, VIN = 3.6V, VHWEN = VIN, CIN = 2 x 10µF, COUT = 2 x 10µF and L = 1µH, unless otherwise specified.) Switching Frequency vs. Temperature NTC Current vs. Temperature Inductor Current Limit 1 vs. Temperature Inductor Current Limit 2 vs. Temperature Standby Supply Current vs. Temperature Quiescent Supply Current vs. Temperature -40 -20 0 20 40 60 80 100 120 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 4.5 fSW=4MHz Switching Frequency (MHz) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 NTC Current (mA) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 0.50 0.55 0.60 0.65 0.70 0.75 0.80 Device Not Switching IQ (mA) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VHWEN=1.8V ISB (mA) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 1800 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000 Lower Current Limit (mA) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 2700 2720 2740 2760 2780 2800 2820 2840 2860 2880 2900 2920 2940 2960 2980 3000 Lower Current Limit (mA) Ambient Temperature ( o

Document number: DS41558 Rev. 2 - 2 9 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 Typical Performance Characteristics (continued) (@TA = +25°C, VIN = 3.6V, VHWEN = VIN, CIN = 2 x 10µF, COUT = 2 x 10µF and L = 1µH, unless otherwise specified.) Shutdown Supply Current vs. Temperature LED Torch Current vs. Temperature LED Torch Current vs. Temperature LED Flash Current vs. Temperature LED Torch Current vs. Brightness Code LED1 Torch Current vs. Input Voltage 100 ILED1 Torch (mA) VIN (V) BRC=0 BRC=7 BRC=15 BRC=23 BRC=31 BRC=39 BRC=47 BRC=55 BRC=63 0 16 32 48 64 80 96 112 128 100 120 140 160 180 200 ILED Torch (mA) Brightness Code AL3644 ILED1 ILED2 -40 -20 0 20 40 60 80 100 120 1400 1420 1440 1460 1480 1500 1520 1540 1560 1580 1600 LED Flash Current (mA) Ambient Temperature ( o Flash Code=0x7F=1.5A Flash ILED1 ILED2 -40 -20 0 20 40 60 80 100 120 160 165 170 175 180 185 190 195 200 AL3644TT Torch Code=0x3F=180mA Torch ILED1 ILED2 LED Torch Current (mA) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 100 AL3644 Torch Code=0x3F=89.3mA Torch ILED1 ILED2 LED Torch Current (mA) Ambient Temperature ( o -40 -20 0 20 40 60 80 100 120 0.0 0.5 1.0 1.5 2.0 2.5 3.0 VHWEN=0V ISD (mA) Ambient Temperature ( o

Document number: DS41558 Rev. 2 - 2 10 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 Typical Performance Characteristics (continued) (@TA = +25°C, VIN = 3.6V, VHWEN = VIN, CIN = 2 x 10µF, COUT = 2 x 10µF and L = 1µH, unless otherwise specified.) LED2 Torch Current vs. Input Voltage LED Torch Current vs. Input Voltage LED Efficiency vs. Input Voltage 100 LED Efficiency (%) VIN (V) ILED1=ILED2=180mA fSW=2MHz fSW=4MHz 160 165 170 175 180 185 190 195 200 ILED=180mA fSW=2MHz fSW=4MHz ILED Torch (mA) VIN (V) 100 ILED2 Torch (mA) VIN (V) BRC=0 BRC=7 BRC=15 BRC=23 BRC=31 BRC=39 BRC=47 BRC=55 BRC=63

Application Information

General Operation The AL3644 is a high-power white LED flash driver capable of delivering up to 1.5A in either of the two parallel LEDs. The device incorporates a 2MHz or 4MHz constant freque ncy-synchronous current-mode PWM boost converter and dual high -side current sources to regulate the LED current over the 2.5V to 5V input voltage range. The AL3644 PWM DC-DC boost converter switches and boosts the output to maintain at least V HR across each of the current sources (LED1/2). This minimum headroom voltage ensures that both current sources remain in regulation. If the input voltage is above the LED voltage plus current source headroom voltage, the device does not switch, but turns the pFET on continuously (Pass mode). In Pass mode the difference between (VIN − ILED × RPMOS) and the voltage across the LED is dropped across the current source. The AL3644 has three logic inputs including a hardware Flash Enable (STROBE), a hardware Torch Enable (TORCH/TEMP, TORCH = default), and a Flash Interrupt input (TX) designed to interrupt the flash pulse during high battery-current conditions. These logic inputs have internal 300kΩ (typical) pulldown resistors to GND. Additional features of the AL3644 include an internal comparator for LED thermal sensing via an external NTC thermistor and an input voltage monitor that can reduce the Flash current during low VIN conditions. It also has a Hardware Enable (HWEN) pin that can be used to reset the state of the device and the registers by pulling the HWEN pin to ground. Control is done via an I 2C-compatible interface. This includes adjustment of the Flash and Torch current levels, changing the Flash Timeout Duration, and changing the switch current limit. Additionally, there are flag and status bits that indicate flash current timeout, LED overtemperature condition, LED failure (open/short), device thermal shutdown, TX interrupt, and VIN undervoltage conditions. 2. Feature Description 2. 1 Flash Mode In Flash Mode, the LED current sources (LED1/2) provide 128 target current levels from 10.9mA to 1500mA. Once the Flash sequence is activated the current source (LED) ramps up to the programmed Flash current by stepping through all current steps until the programmed current is reached. The headroom in the two current sources can be regulated to provide 10.9mA to 1.5A on each of the two output pins. There is an option in the register settings to keep the two currents in the output pins the same. When the device is enabled in Flash Mode through the Enable Register, all mode bits in the Enable Register are cleared after a flash timeout event.

2.2 Torch Mode

In Torch mode, the LED current sources (LED1/2) provide 128 target current levels from 0.977mA to 179mA or 1.954mA to 360mA on AL3644TT. The Torch currents are adjusted via the LED1 and LED2 LED Torch Brightness Registers. Torch mode is activated by the Enable Register (setting M1, M0 to '10'), or by pulling the TORCH/TEMP pin HIGH when the pin is enabled (Enable Register) and set to Torch Mode. Once the TORCH sequence is activated, the active current sources (LED1/2) ramps up to the programmed Torch current by stepping through all current steps until the programmed current is reached. The rate at which the current ramps is determined by the value chosen in the Timing Register. Torch Mode is not affected by Flash Timeout or by a TX Interrupt event. When the AL3644 enters standby mode, it shuts down all internal analog blocks to save power. To enter Torch mode from standby, the proper sequence is to first issue an I2C command to enter IR mode (Mode Bits = <01>), wait a few milliseconds, then enter Torch mode.

2.3 IR Mode

In IR Mode, the target LED current is equal to the value stored in the LED1/2 Flash Brightness Registers. When the IR mode is enabled (setting M1, M0 to '01'), the boost conve rter turns on and set s the output equal to the input (pass-mode). At this point, toggling the STROBE pin enables and disables the LED1/2 current sources (if enabled). The strobe pin can only be set to be Level sensitive, meaning all timing of the IR pulse is externally controlled. In IR Mode, the current sources do not ramp the LED outputs to the target. The current transitions immediately from off to on and then on to off.

2.4 Standby Mode

When the device enters “Standby Mode”, it shuts down all the inte rnal analog blocks including bandgap reference voltage and SYNC booster converter to save power. When the device wakes up from standby mode into active mode, it needs a proper power -up sequence and some delay to stable power blocks before customer turns on “Torch Mode” thru I2C command. 3. Device Functioning Modes

3.1 Startup (Enabling the Device)

Turning on of the AL3644 Torch and Flash modes can be done through the Enable Register. On startup, when VOUT is less than VIN the internal synchronous pFET turns on as a current source and delivers 200mA (typical) to the output capacitor. During this time the current source (LED) is off. When the voltage across the output capacitor reaches 2.2V (typical) the current source turns on. At turn -on the current sourc e steps through each FLASH or TORCH level until the target LED current is reached. This gives the device a controlled turn -on and limits the inrush current from the VIN supply.

3.2 Pass Mode

The AL3644 starts up in Pass Mode and stays there until Boost Mode is needed to maintain regulation. If the voltage difference between VOUT and VLED falls below VHR, the device switches to Boost Mode. In Pass Mode the boost converter does not switch, and the synchronous pMOS turns fully on bringing VOUT up to VIN − ILED × RPMOS. In Pass Mode the inductor current is not limited by the peak current limit.

3.3 Power Amplifier Synchronization (TX)

The TX pin is a Power Amplifier Synchronization input. This is designed to reduce the flash LED current and thus limit the battery current during high battery current conditions such as PA transmit events. When the AL3644 is engaged in a Flash event, and the TX pin is pulled high, the LED current is forced into Torch Mode at the programmed Torch current setting. If the TX p in is then pulled low before the Flash pulse terminates, the LED current returns to the previous Flash current level. At the end of the Flash timeout, whether the TX pin is high or low, the LED current turns off.

3.4 Input Voltage Flash Monitor (IVFM)

The AL3644 has the ability to adjust the flash current based upon the voltage level present at the IN pin utilizing the Input Voltage Flash Monitor (IVFM). The adjustable threshold IVFM -D ranges from 2.9V to 3.6V in 100mV steps, with three different usage mo des (Stop and Hold, Adjust Down Only, Adjust Up and Down). The Flags2 Register has the IVFM flag bit set when the input voltage crosses the IVFM -D value. Additionally, the IVFM-D threshold sets the input voltage boundary that forces the AL3644 to either stop ramping the flash current during startup (Stop and Hold Mode) or to start decreasing the LED current during the flash (Down Adjust Only and Up and Down Adjust). In Adjust Up and Down mode, the IVFM-D value plus the hysteresis voltage threshold set the input voltage boundary that forces the AL3644 to start ramping the flash current back up towards the target.

3.5 Fault/Protections

3.5.1 Fault Operation

AL3644 re-enters the fault state and enters standby again.

3.5.2 Flash Timeout

timeout levels ranging from 10ms to 400ms or 40ms to 1.6s on AL3644TT (see Timing Configuration Register (0x08) for more details).

3.5.3 Overvoltage Protection (OVP)

from forcing the device to shut down.

3.5.4 Current Limit

the overcurrent condition persists, the device operates continuously in current limit. during output short-circuit conditions. The mode bits are not cleared upon a Current Limit event, but a flag is set.

3.5.5 NTC Thermistor Input (TORCH/TEMP)

disabled via the Enable Register. If enabled, the NTC block turns on and off during the start and stop of a Flash/Torch event. detections can be individually disabled/enabled via the NTC Open Fault Enable bit and the NTC Short Fault Enable bit. Figure 6. Temp Detection Diagram

3.5.6 Undervoltage Lockout (UVLO)

can resume if the input voltage is greater than 2.5V.

3.5.7 Thermal Shutdown (TSD)

3.5.8 LED and/or VOUT Short Fault

4.1 Control Truth Table

4.2 I2C-Compatible Interface

4.2.1 Data Validity

Figure 7. Data Validity Data

4.2.2 Start and Stop Conditions

Figure 8. Start and Stop Conditions

4.2.3 Transferring Data

generates an acknowledgement after each byte is received. There is no acknowledge created after data is read from the device. register to which the data is written. The third byte contains data to write to the selected register. Figure 9. Write Cycle W = Write (SDA = "0") R = Read (SDA = "1") Ack = Acknowledge

4.2.4 I2C-Compatible Chip Address

selects the register address to which the data is written. The third byte contains the data for the selected register. Figure 10. I2C-Compatible Chip Address

5.1 Enable Register (0x01) (Note 6)

Note: 6. Edge Strobe Mode is not valid in IR Mode. Switching between Level and Edge Strobe Types while the device is enabled is not recommended. In Edge or Level Strobe Mode, it is recommended that the trigger pulse width be set greater than 1ms to ensure proper turn-on of the device.

5.2 IVFM Register (0x02) (Note 7)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RFU UVLO Circuitry (Default) 0 = Disabled (Default) 1 = Enabled IVFM Levels 000 = 2.9V (Default) 001 = 3V 010 = 3.1V 011 = 3.2V 100 = 3.3V 101 = 3.4V 110 = 3.5V 111 = 3.6V IVFM Hysteresis 0 = 0mV (Default) 1 = 50mV IVFM Selection 00 = Disabled 01 = Stop and Hold Mode (Default) 10 = Down Mode 11 = Up and Down Mode Note: 7. IVFM Mode Bits are static once the AL3644 is enabled in Torch, Flash or IR modes. If the IVFM mode needs to be updated, disable the device and then change the mode bits to the desired state.

5.3 LED1 Flash Brightness Register (0x03)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 LED2 Flash Current Override 0 = LED2 Flash Current is not set to LED1 Flash Current 1 = LED2 Flash Current is set to LED1 Flash Current (Default) LED1 Flash Brightness Levels IFLASH1/2 (mA) ≈ (Brightness Code × 11.725mA) + 10.9mA 0000000 = 10.9mA 0111111 = 750mA (Default) 1111111 = 1.5A

5.4 LED2 Flash Brightness Register (0x04)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RFU LED2 Flash Brightness Levels IFLASH1/2 (mA) ≈ (Brightness Code × 11.725mA) + 10.9mA 0000000 = 10.9mA 0111111 = 750mA (Default) 1111111 = 1.5A

5.5 LED1 Torch Brightness Register (0x05)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 LED2 Torch Current Override 0 = LED2 Torch Current is not set to LED1 Torch Current 1 = LED2 Torch Current is set to LED1 Torch Current (Default) LED1 Torch Brightness Levels ITORCH1/2 (mA) ≈ (Brightness Code × 1.4mA) + 0.977mA or ITORCH1/2 (mA) ≈ (Brightness Code × 2.8mA) + 1.954mA (AL3644TT) 0000000 = 0.977mA or 1.954mA for AL3644TT 0111111 = 89.3mA (Default) or 178.6mA for AL3644TT 1111111 = 179mA or 360mA for AL3644TT

5.6 LED2 Torch Brightness Register (0x06)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RFU LED2 Torch Brightness Levels ITORCH1/2 (mA) ≈ (Brightness Code × 1.4mA) + 0.977mA or ITORCH1/2 (mA) ≈ (Brightness Code × 2.8mA) + 1.954mA (AL3644TT) 0000000 = 0.977mA or 1.954mA for AL3644TT 0111111 = 89.3mA (Default) or 178.6mA for AL3644TT 1111111 = 179mA or 360mA for AL3644TT

5.7 Boost Configuration Register (0x07)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Software Reset Bit 0 = Not Reset (Default) 1 = Reset RFU RFU RFU LED Pin Short Fault Detect 0 = Disabled 1 = Enabled (Default) Boost Mode 0 = Normal (Default) 1 = Pass Mode Only Boost Frequency Select 0 = 2MHz (Default) 1 = 4MHz Boost Current Limit Setting 0 = 1.9A 1 = 2.8A (Default)

5.8 Timing Configuration Register (0x08) (Note 8)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RFU Torch Current Ramp Time 000 = No Ramp 001 = 1ms (Default) 010 = 32ms 011 = 64ms 100 = 128ms 101 = 256ms 110 = 512ms 111 = 1024ms Flash Timeout Duration 0000 = 10ms or 40ms (AL3644TT) 0001 = 20ms or 80ms (AL3644TT) 0010 = 30ms or 120ms (AL3644TT) 0011 = 40ms or 160ms (AL3644TT) 0100 = 50ms or 200ms (AL3644TT) 0101 = 60ms or 240ms (AL3644TT) 0110 = 70ms or 280ms (AL3644TT) 0111 = 80ms or 320ms (AL3644TT) 1000 = 90ms or 360ms (AL3644TT) 1001 = 100ms or 400ms (AL3644TT) 1010 = 150ms (Default) or 600ms (AL3644TT) 1011 = 200ms or 800ms (AL3644TT) 1100 = 250ms or 1000ms (AL3644TT) 1101 = 300ms or 1200ms (AL3644TT) 1110 = 350ms or 1400ms (AL3644TT) 1111 = 400ms or 1600ms (AL3644TT) Note: 8. On the AL3644TT, special care must be taken with regards to thermal management when using timeout values greater than 400ms. Depending on the PCB layout, input voltage and output current, it is possible to have the internal thermal shutdown circuit trip prior to reaching the desired flash timeout value.

5.9 TEMP Register (0x09) (Note 9)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RFU TORCH Polarity 0 = Active High (Default) (Pulldown Resistor Enabled) 1 = Active Low (Pulldown Resistor Disabled) NTC Open Fault Enable 0 = Disabled (Default) 1 = Enabled NTC Short Fault Enable 0 = Disabled (Default) 1 = Enabled TEMP Detect Voltage Threshold 000 = 0.2V 001 = 0.3V 010 = 0.4V 011 = 0.5V 100 = 0.6V (Default) 101 = 0.7V 110 = 0.8V 111 = 0.9V TORCH/TEMP Function Select 0 = TORCH (Default) 1 = TEMP Note: 9. The Torch Polarity bit is static once the AL3644 is enabled in T orch, Flash or IR modes. If the Torch Polarity bit needs to be updated, disable the device and then change the Torch Polarity bit to the desired state.

5.10 Flags1 Register (0x0A)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 TX Flag VOUT Short Fault VLED1 Short Fault VLED2 Short Fault Current Limit Flag Thermal Shutdown (TSD) Fault UVLO Fault Flash Timeout Flag

5.11 Flags2 Register (0x0B)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RFU RFU RFU NTC Short Fault NTC Open Fault IVFM Trip Flag OVP Fault TEMP Trip Fault

5.12 Device ID Register (0x0C)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RFU RFU Device ID '000' Silicon Revision Bit '010' or '100' for AL3644TT

5.13 Last Flash Register (0x0D)

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RFU The value stored is always the last current value the IVFM detection block set. ILED = IFLASH – TARGET × ((Code + 1) / 128). Design Tools Resource  Evaluation Board User Guides  Spice Models (PSPICE Digital Simulation)  Evaluation Board GUI

Ordering Information

Torch Current Product Name Blank : Low Torch Current 7 : 7" Tape & Reel AL3644 X X– X Packing TT: High Torch Current Package CH12 : U-WLB1713-12 Part Number Part Number Suffix Package Packing Qty. Carrier AL3644CH12-7 -7 U-WLB1713-12 (Note 10) 3,000 Tape & Reel AL3644TTCH12-7 -7 U-WLB1713-12 (Note 10) 3,000 Tape & Reel Note: 10. For packaging details, go to our website at https://www.diodes.com/design/support/packaging/diodes -packaging/. Marking Information U-WLB1713-12 Y : Year : 0 to 9 (ex: 3 = 2023) XX : Identification Code W : Week : A to Z : week 1 to 26; a to z : week 27 to 52; z represents week 52 and 53 X X Y W X (Top View) X : Internal Code Part Number Package Identification Code AL3644CH12-7 U-WLB1713-12 2A AL3644TTCH12-7 U-WLB1713-12 2B

Document number: DS41558 Rev. 2 - 2 24 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 Package Outline Dimensions Please see http://www.diodes.com/package-outlines.html for the latest version. U-WLB1713-12 E D Pin #1 ID By Marking e e 12x-Ø b SD A2 A SEATING PLANE SE A B C D 123 U-WLB1713-12 Dim Min Max Typ A 0.525 0.625 0.575 A1 0.185 0.235 0.210 A2 0.340 0.390 0.365 b 0.220 0.300 0.260 D 1.690 1.750 1.720 D1 1.150 1.250 1.200 E 1.290 1.350 1.320 E1 0.750 0.850 0.800 e 0.400 BSC SD 0.200 BSC SE 0.000 BSC All Dimensions in mm Suggested Pad Layout Please see http://www.diodes.com/package-outlines.html for the latest version. U-WLB1713-12 C C 12x-Ø D 321 A B C D t t1 Ø D2 Solder Mask Opening Solder Mask Opening Metal Under Solder Mask Ø D1 Metal Non-Solder Mask Defined (PREFERRED) Solder Mask Defined SOLDER MASK DETAILS (Not to Scale) Dimensions Value (in mm) C 0.40 D 0.20 D1 0.20 D2 0.20 t 0.05 Max t1 0.05 Min Mechanical Data  Moisture Sensitivity: Level 1 per J-STD-020  Terminals: SnAgCu Balls, Solderable per IPC/JEDEC J-STD-609  Weight: 0.00265 grams (Approximate)

Document number: DS41558 Rev. 2 - 2 25 of 25 www.diodes.com December 2023 © 2023 Copyright Diodes Incorporated. All Rights Reserved. AL3644 IMPORTANT NOTICE 1. DIODES INCORPORATED (Diodes) AND ITS SUBSIDIARIES MAKE NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO ANY INFORMATION CONTAINED IN THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). 2. The Information contained herein is for informational purpose only and is provided only to illustrate the operation of Diodes ’ products described herein and application examples. Diodes does not assume any liability arising out of the application or use of this document or any product described herein. This document is intended for skilled and technically trained engineering custom ers and users who design with Diodes’ products. Diodes’ products may be used to facilitate safety-related applications; however, in all instances customers and users are responsible for (a) selecting the appropriate Diodes products for their applications, (b) evaluating the suitability of Diodes’ products for their intended applications, (c) ensuring their applications, which incorporate Diodes’ products, comply the applicable legal and regulatory requirements as well as safety and functional-safety related standards, and (d) ensuring they design with appropriate safeguards (including testing, validation, quality co ntrol techniques, redundancy, malfunction prevention, and appropriate treatment for aging degradation) to minimize the risks associated wit h their applications. 3. Diodes assumes no liability for any application -related information, support, assistance or feedback t hat may be provided by Diodes from time to time. Any customer or user of this document or products described herein will assume all risks and liabilities associated with such use, and will hold Diodes and all companies whose products are represented herein or on Diodes’ websites, harmless against all damages and liabilities. 4. Products described herein may be covered by one or more United States, international or foreign patents and pending patent applications. Product names and markings noted herein ma y also be covered by one or more United States, international or foreign trademarks and trademark applications. Diodes does not convey any license under any of its intellectual property rights or the rights of any third parties (including third parties whose products and services may be described in this document or on Diodes’ website) under this document. 5. Diodes’ products are provided subject to Diodes’ Standard Terms and Conditions of Sale (https://www.diodes.com/about/company/terms-and-conditions/terms-and-conditions-of-sales/) or other applicable terms. This document does not alter or expand the applicable warranties provided by Diodes. Diodes d oes not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel. 6. Diodes’ products and technology may not be used for or incorporated into any products or systems whose manufacture, use or sa le is prohibited under any applicable laws and regulations. Should customers or users use Diodes’ products in contravention of any applicable laws or regulations, or for any unintended or unauthorized application, customers and users will (a) be solely resp onsible for any damages, losses or penalties arising in connection therewith or as a result thereof, and (b) indemnify and hold Diodes and its representatives a nd agents harmless against any and all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim relating to any noncompliance with the applicable laws and regulations, as well as any unintended or unauthorized application. 7. While efforts have been made to ensure the information contained in this document is ac curate, complete and current, it may contain technical inaccuracies, omissions and typographical errors. Diodes does not warrant that information contained in this docume nt is error-free and Diodes is under no obligation to update or otherwise correct this information. Notwithstanding the foregoing, Diodes reserves the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any produ ct described herein. This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the final and determinative format released by Diodes. 8. Any unauthorized copying, modification, distribution, transmission, display or other u se of this document (or any portion hereof) is prohibited. Diodes assumes no responsibility for any losses incurred by the customers or users or any third parties arising f rom any such unauthorized use. 9. This Notice may be periodically updated with the most recent version available at https://www.diodes.com/about/company/terms-and- conditions/important-notice The Diodes logo is a registered trademark of Diodes Incorporated in the United States and other countries. All other trademarks are the property of their respective owners. © 2023 Diodes Incorporated. All Rights Reserved. www.diodes.com

Product Information

AL3644 specifications and overview.

Summary

DUAL 1.5A CURRENT SOURCE CAMERA FLASH LED DRIVER July 2019

Description

DUAL 1.5A CURRENT SOURCE CAMERA FLASH LED DRIVER July 2019

Source title AL3644 Datasheet(PDF) - Diodes Incorporated

Related Parts

More parts from the same family.

Browse manufacturer