AS3685A/AS3685B Ultra Small High Efficiency 1000mA Charge Pump for White LED Flash General Description The AS3685 is low noise high efficiency capacitive charge pump with 1:1, 1:1.5 and 1:2 operating modes in a small 3x3mm DFN10 or a tiny 2x1.5mm WL-CSP (Wafer Level Chip Scale Package) package. It can drive one flash LED at up to 1000mA current. It supports flash/torch and indicator mode for the flash LED. Additionally the AS3685 limits the flash time automatically to protect the flash LED. Ordering Information and Content Guide appear at end of datasheet. Key Benefits & Features The benefits and features of AS3685A/AS3685B, Ultra Small High Efficiency 1000mA Charge Pump for White LED Flash are listed below: Figure 1: Added Value Of Using AS3685A/AS3685B Benefits Features • System safety • High efficiency capactive charge pump with 1:1, 1:1.5 and 1:2 modes therefore maximum input current is exactly controlled. • Overtemperature protection • Automatic 800ms flash timeout to protect the flash LED • Drive LED at high brightness for better pictures • Up to 1000mA LED Current • Flexible selection of interface type • Two device variants: • AS3685A: Direct control to select three currents • AS3685B: Single pin interface or two pin interface with strobe input; 17 different currents can be selected • Flexible package options • DFN10 (3x3mm) 10 pins + exposed pad • WL-CSP (2x1.5mm) 3x4 balls 0.5mm pitch ams Datasheet [v2-23] 2016-Mar-30 Page 1 Document Feedback AS3685A/AS3685B − General Description Applications The AS3685A/AS3685B, Ultra Small High Efficiency 1000mA Charge Pump for White LED Flash is ideal for Flash / Torch for Mobile Phones, Digital Cameras and PDAs. Figure 2: Application Diagram of AS3685A/AS3685B CFLY1 1.0 F CFLY2 1.0 F C1+ C1- C2+ C2VBAT CBAT 2.2 F VBAT VCP AS3685A AS3685B EN1 ILED EN2 CVCP 2.2 F DLED ISET VSS RTXMASK Page 2 Document Feedback RISET ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Pin Assignment Pin Assignment DFN10 (3x3mm) Figure 3: Pin Diagram DFN10 (3x3mm) 3 10 8 1 C1+ C1- C2+ C22 VCP AS3685A EN1 AS3685B ILED EN2 VBAT 5 7 4 9 ISET VSS 6 Exposed Pad Figure 4: Pin Description DFN10 (3x3mm) Pin Number Pin Name Type Description 1 C2- AI/O Flying Capacitor 2 connection – connect 1μF ceramic capacitor CFLY2 between C2- and C2+ 2 VBAT S 3 C1+ AI/O Flying Capacitor 1 connection – connect 1μF ceramic capacitor CFLY1 between C1- and C1+ 4 VCP AI/O Charge Pump Output voltage – connect flash LED anode to this pin and add CVCP capacitor with 2.2μF to VSS 5 EN1 DI 6 ISET AI/O 7 EN2 DI ams Datasheet [v2-23] 2016-Mar-30 Battery Supply Voltage Digital Control Signal EN1 Current Generator input pin – connect current set resistor RISET between this pin and VSS (and optional RTXMASK) Digital Control Signal EN2 Page 3 Document Feedback AS3685A/AS3685B − Pin Assignment Pin Number Pin Name Type Description 8 C2+ AI/O Flying Capacitor 2 connection – connect 1μF ceramic capacitor CFLY2 between C2- and C2+ 9 ILED AI/O Current Source input pin – connect flash LED cathode to this pin 10 C1- AI/O Flying capacitor 1 connection – connect 1μF ceramic capacitor CFLY1 between C1- and C1+ Exposed Pad VSS S Ground Connection – a proper thermal connection with several vias to the ground plane is recommended Note(s): 1. Pin Type Descriptions: AI/O: Analog Pin DI: Digital Input S: Supply Pin WL-CSP (2x1.5mm) Figure 5: WL-CSP (2x1.5mm) Pin Diagram B1 D2 C2 D1 C1+ C1- C2+ C2C1 VBAT VCP B2 A1 AS3685A EN1 AS3685B ILED EN2 C3 B3 ISET VSS A3 Page 4 Document Feedback A2,D3 ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Pin Assignment Figure 6: Pin Description WL-CSP (2x1.5mm) Pin Number Pin Name Type A1 EN1 DI Digital Control Signal EN1 A2 VSS S Ground Connection – a proper thermal connection to the ground plane is recommended A3 ISET AI/O Current Generator input pin – connect current set resistor RISET between this pin and VSS (and optional RTXMASK) B1 C1+ AI/O Flying Capacitor 1 connection – connect 1μF ceramic capacitor CFLY1 between C1- and C1+ B2 VCP AI/O Charge Pump Output voltage – connect flash LED anode to this pin and add CVCP capacitor with 2.2μF to VSS B3 EN2 DI Digital Control Signal EN2 C1 VBAT S Battery Supply Voltage C2 C2+ AI/O Flying Capacitor 2 connection – connect 1μF ceramic capacitor CFLY2 between C2- and C2+ C3 ILED AI/O Current Source input pin – connect flash LED cathode to this pin D1 C2- AI/O Flying Capacitor 2 connection – connect 1μF ceramic capacitor CFLY2 between C2- and C2+ D2 C1- AI/O Flying capacitor 1 connection – connect 1μF ceramic capacitor CFLY1 between C1- and C1+ D3 VSS S Description Ground Connection – a proper thermal connection to the ground plane is recommended Note(s): 1. Pin Type Descriptions WL-CSP (2x1.5mm): AI/O: Analog Pin DI: Digital Input S: Supply Pin ams Datasheet [v2-23] 2016-Mar-30 Page 5 Document Feedback AS3685A/AS3685B − Absolute Maximum Ratings Absolute Maximum Ratings Stresses beyond those listed in 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 in Electrical Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Figure 7: Absolute Maximum Ratings Symbol Parameter Min Max Units VBATMAX Maximum Supply Voltage -0.3 7.0 V IIN Input Pin Current without causing latchup -25 +25 mA TSTRG Storage Temperature Range -55 125 °C RHNC Relative Humidity (non-condensing) 5 85 % ESDHBM PT PDERATE Electrostatic Discharge (Human Body Model) ±1000 Total Continuous Power Dissipation At 25°C, according to JEDEC 17 V MIL 883 E Method 3015 1.14 W DFN10 (3x3mm), TAMB = 70°C (1) 1.02 W WL-CSP (2x1.5mm), TAMB = 70°C (1) 16.3 mW/ °C DFN10 (3x3mm) 14.7 mW/ °C WL-CSP (2x1.5mm) PT Derating Factor (2) TJUNC Junction Temperature 150 °C TBODY Body Temperature during Soldering 260 °C MSL Comments According to IPC/JEDEC J-STD-020C 1 WLCSP package; Represents a max. floor life time of unlimited hours 3 DFN package; Represents a max. floor life time of 168 hours Moisture sensitivity level Note(s): 1. Depending on actual PCB layout and PCB used; for peak power dissipation during flashing see document ‘AS3685 Thermal Measurements’. For 1A flash current see application notes ‘AN3685_1Aflash’ and ‘AN3685_1Aflash_thermal_1v0’. 2. The PT derating factor changes the total continuous power dissipation, if the ambient temperature is different to 70°C. Therefore for e.g. 85°C calculate PT85°C = PT – P DERATE * (85°C to 70°C). Page 6 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Electrical Characteristics All limits are guaranteed. The parameters with minimum and maximum values are guaranteed with production tests or SQC (Statistical Quality Control) methods. Electrical Characteristics Figure 8: Operating Conditions Symbol Parameter Min Typ Max Units VBAT Battery Supply Voltage 3.0 3.6 5.5 V Supply voltage range VBATFUNC Battery Supply Voltage (functionally working) 2.6 V AS3685 functionally working, but not all parameters fulfilled 0.4 A Depending on load current and charge pump mode 2.0 A Limited lifetime, max 20,000s 25 85 °C 1.0 4.0 μA EN1 = 0, EN2 = 0; VBAT ≤ 4.2V 0.85 mA 1:1 Mode 6.6 mA 1:1.5 Mode 8.1 mA 1:2 Mode IBAT Operating Current TAMB Ambient Temperature IOFF Off Mode Current IOPERATING Note -30 Power Consumption (without load) Figure 9: Charge Pump Characteristics Symbol Parameter VCPOUT V(VCP) Output Voltage (without load – do not short to VSS) Min Output Limitation RCP Eta VRIPPLE Charge Pump Effective Resistance Efficiency Output Ripple Voltage ams Datasheet [v2-23] 2016-Mar-30 Typ Max Units VBAT x CPmode V 5.4 5.6 0.28 0.53 Note CP-mode is 1, 1.5 or 2 (automatically selected) Internally limited Ω 1:1 Mode VBAT = 3.6V, ICPOUT = 200mA 1.37 2.00 Ω 1:1.5 Mode VBAT = 3.3V, ICPOUT = 500mA, TJUNCTION ≤ 85°C 1.95 2.44 Ω 1:2 Mode VBAT = 3.0V, ICPOUT=700mA, TJUNCTION ≤ 85°C 93 % Vin=3.0V-4.5V, Iout=100mA (charge pump alone) mVpp Vin=3.0-4.5V, Iout=350mA, 75 100 Page 7 Document Feedback AS3685A/AS3685B − Electrical Characteristics Symbol Parameter Min Typ Max Units fclk Operating Frequency -20% 1.0 +20% MHz tUP_DEB_LONG Initial Mode Switching Debounce Time tUP_DEB Mode Switching Debounce Time Note 256 μs Mode switching up-debounce time after enabling of the charge pump or after mode switching between 1:1 to 1:1.5 16 μs Mode switching up-debounce time in normal operation Figure 10: Current Source (Sink) Characteristics Symbol ILED IACCURACY Parameter Min Output Current Range Current Setting Accuracy VISET Current Generator Set Point Voltage (pin ISET) IISET Current Generator Operating Range -10% Typ Max Units 700 1000 mA 700mA: RISET = 14.2kΩ 1000mA: RISET = 10kΩ 500 +10% mA Measured with RISET = 19.9kΩ and maximum flash current 1.3 10.0 130 IFLASH2ISET Flash Current to Bias Current Ratio 7650 ITORCH2ISET Torch Current to Bias Current Ratio 1639 VSWITCH Mode Switching Threshold on V(ILED) between 1:1 → 1:1.5 and 1:1.5 → 1:2 Page 8 Document Feedback V 400 150 200 250 μA Note IISET = VISET / RISET if the resulting bias current is higher than 200μA (typ.), the current source is disabled A/A AS3685A, EN1=1, EN2=1 or AS3685B at full flash current (700mA with RISET = 14.2kΩ) A/A AS3685A, EN1=0, EN2=1 (150mA with RISET = 14.2kΩ) mV AS3685A, EN1=1, EN2=1 or AS3685B with ILED>350mA (with RISET = 14.2kΩ) mV All lower currents ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Electrical Characteristics Figure 11: Digital Interface Characteristics Symbol Parameter Min VIH High Level Input Voltage VIL ILEAKAGE tPULSEWIDTH Typ Max Units 1.5 VBAT V Low Level Input Voltage 0.0 0.5 V Input Pin Leakage Current -10 10 μA Pulsewidth for Signals on EN1 and EN2 (high or low pulses) 1.0 unlimited μs Note For Pins EN1 and EN2 Do not leave EN1 and EN2 floating (47kΩ pulldowns can be used) Figure 12: Protection Functions Symbol TOVTEMP Parameter Min Overtemperature Protection TOVTEMPHYST Overtemperature Protection Hysteresis tFLASHTIMEOUT Flash Timeout Time ams Datasheet [v2-23] 2016-Mar-30 -20% Typ Max Units 140 °C 5 °C 800 +20% ms Note If the junction temperature exceeds TOVTEMP , the current sink will be disabled and the charge pump switched back into 1:1 mode until the temperature drops below TOVTEMP - TOVTEMPHYST AS3685A, EN1=1, EN2=1 or AS3685B flash modes Page 9 Document Feedback AS3685A/AS3685B − Typical Operating Characteristics Typical Operating Characteristics Figure 13: Efficiency vs. Battery Voltage (with Lumiled PWF1) 100 Efficiency of Charge Pump [%] ILED=50m ILED=100m ILED=200m ILED=300m ILED=400m 90 ILED=500m 80 70 ILED=600m 60 ILED=700m 50 40 2.8 3.2 3.6 4.0 4.4 4.8 5.2 VBAT [V] Figure 14: Battery Current vs. Battery Voltage (with Lumiled PWF1) 1.6 1.4 1.2 IBAT [A] 1.0 0.8 ILED=700m ILED=600m 0.6 ILED=500m ILED=400m ILED=300m 0.4 ILED=200m 0.2 ILED=50m ILED=100m 0.0 2.8 3.2 3.6 4.0 4.4 4.8 5.2 VBAT [V] Page 10 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Typical Operating Characteristics Figure 15: LED Current I(ILED) vs. Battery Voltage (with Lumiled PWF1) 0.8 ILED=700m 0.7 ILED=600m 0.6 ILED=500m ILED [A] 0.5 ILED=400m 0.4 ILED=300m 0.3 ILED=200m 0.2 ILED=100m 0.1 ILED=50m 0.0 2.8 3.2 3.6 4.0 4.4 4.8 5.2 VBAT [V] Figure 16: Linearity of Current Sink 0.8 ILED=700m 0.7 0.6 ILED=600m ILED [A] 0.5 ILED=500m ILED=400m 0.4 ILED=300m 0.3 ILED=200m 0.2 ILED=100m 0.1 ILED=50m 0.0 0.0 0.5 1.0 1.5 2.0 2.5 VILED [V] ams Datasheet [v2-23] 2016-Mar-30 Page 11 Document Feedback AS3685A/AS3685B − Typical Operating Characteristics Figure 17: I(ILED) vs. R(ISET) (Flash and Torch Mode of AS3685A) 1200 1000 Flash Mode ILED [mA] 800 600 400 200 Torch Mode 0 0k 20k 40k 60k 80k 100k 120k 140k R ISET [Ohm] Figure 18: Startup of AS3685A -- ILED Current ILED 500mA/div 100μs/div VBAT=3.3V, ILED=700mA Page 12 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Typical Operating Characteristics Figure 19: Startup of AS3685A -- IBAT Current IBAT 500mA/div 100μs/div VBAT=3.3V, ILED=700mA Figure 20: Shutdown of AS3685A -- IBAT Current IBAT 500mA/div 100μs/div VBAT=3.3V, ILED=700mA ams Datasheet [v2-23] 2016-Mar-30 Page 13 Document Feedback AS3685A/AS3685B − Typical Operating Characteristics Figure 21: Typical Operating Waveforms 1:1.5 Mode VCP ac-coupled, 100mV/div 1μs/div VBAT=3.3V, ILED=500mA Figure 22: Typical Operating Waveforms 1:2 Mode VCP ac-coupled, 50mV/div 250ns/div VBAT=3.3V, ILED=500mA Page 14 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Detailed Description Detailed Description Figure 23: Internal Circuit Diagram of AS3685A/AS3685B C1+ VBAT C1- C2+ C2- Low Noise Charge Pump 1:1, 1:1.5, 1:2 Modes VBAT VCP clk mode soft_limit 1MHz 5.3V Overtemp Detect Vswitch EN1 EN2 EN1 EN2 ILED Digital Control 1.3V Different Control Logic for AS3685A and AS3685B TXMask AS3685 ISET VSS Low Noise Charge Pump The AS3685 charge pump uses two external flying capacitors to generate output voltages higher than the battery voltage. The charge pump can operate in three different modes: • 1:1 Bypass Mode or Off Mode • Battery input and output are connected by a low-impedance switch • Battery current = output current • 1:1.5 Mode • The output voltage is 1.5 times the battery voltage (without load) • Battery current = 1.5 times output current • 1:2 Mode • The output voltage is 2 times the battery voltage (without load) • Battery current = 2 times output current The flying capacitors are switched at the fixed frequency fclk. ams Datasheet [v2-23] 2016-Mar-30 Page 15 Document Feedback AS3685A/AS3685B − Detailed Description Mode Switching The AS3685 monitors the voltage at the current sink V(ILED) and if this voltage falls below VSWITCH, for a time longer than the debounce time, the charge pump automatically switches into a higher mode. The debounce time is set to tUP_DEB_LONG at enabling of the charge pump or immediately after a 1:1 to 1:1.5 mode change. Afterwards the debounce time is reduced to t UP_DEB. (This allows the LED current to settle properly on startup or after a mode change). The charge pump enters always 1:1 mode in off mode or in case of overtemperature. It is possible to avoid the 1:2 mode (factory programmable) to limit the battery current to 1.5 times the output (=LED) current. Soft Start The soft start mechanism reduces the inrush current. Battery current is smoothed when switching the charge pump on and also at each switching condition. This precaution reduces electromagnetic radiation significantly. Current Source (Sink) The AS3685 operates in three different modes: • Indicator Mode: A small (average) current is used to obtain an indication function with the flash LED (e.g. indication for camera operation). • Torch Mode: A moderate current of e.g. 150mA allows the use of the flash LED as a torch or video light. • Flash Mode: A high current of e.g. 700mA (up to 1000mA) is set for a high brightness flash. Only in this mode, the flash timeout timer limits the total flash time. • Pulsed Indicator Mode (only AS3685A): The control device sends a short sequence to the AS3685A and the AS3685A enables the flash LED for a defined fixed duration (torch current setting). This duration is controlled by the AS3685A and the control device does not need to start an internal timer function. The current through the LED and the operating mode is controlled by the two digital pins EN1 and EN2. There are two versions of the AS3685 available: AS3685A and AS3685B. The only difference between these versions is the digital interface as shown below: Page 16 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Detailed Description AS3685A Current Setting For the AS3685A, the operating mode and the current through the LED is defined by the following table: Figure 24: AS3685A Current Settings EN1 0 EN2 0 ILED for RISET = Mode Percent of Full Scale ILED/IISET 14.2kΩ 10kΩ Off 0mA 0mA 0% 0 (Off ) 6.7mA average (=214mA with 1/32 duty cycle (1)) 0.67% (=21.4% / 32) 52.2 (=ITORCH2ISET/32) 1 0 Indicator 4.7mA average (=150mA with 1/32 duty cycle (1)) 0 1 Torch 150mA 214mA 21.4% 1639 (=ITORCH2ISET ) 1 1 Flash 700mA 1000mA 100% 7650 (=IFLASH2ISET ) Note(s): 1. The on-time for indicator mode is 1μs, off time 31μs (32μs = 32.25kHz). Where I ISET is: (EQ1) V ISET 1.3V I ISET = --------------- = --------------R ISET R ISET Application Hint: To obtain higher torch currents use the following circuit: Figure 25: AS3685A Increasing Torch Current VBAT VBAT AS3685A EN1 EN1 EN2 EN2 ISET RTORCH RISET ams Datasheet [v2-23] 2016-Mar-30 Page 17 Document Feedback AS3685A/AS3685B − Detailed Description AS3685A Pulsed Indicator Mode The torch mode is controlled by EN1=0 and EN2=1 as following figure shows: Figure 26: AS3685A Torch Mode EN1 EN2 ILED Torch Current typ. 64μs off off t To allow an indication function using short pulses (with torch current settings), the pulsed indicator mode can be used. The control device sends a setup sequence (total time required: less than 128μs) to ‘program’ the AS3685A, and the AS3685A enables its current sink for the duration t TORCH (the current used is exactly the torch current setting). Therefore the control does not need to setup a timer to accurately define the duration of the indicator pulse. The duration t TORCH can be setup from 1ms to 15ms depending on the number of pulses on EN2 as shown in the following figure and table: Figure 27: AS3685A Pulsed Indicator Mode Set duration of Torch-Pulse (tTORCH) with number of pulses on pin EN2 EN1 EN2 max. 128μs ILED min tPULSEWIDTH (1μs) Torch Current typ. 64μs off Page 18 Document Feedback tTORCH off t ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Detailed Description Figure 28: AS3685A tTORCH Timings ams Datasheet [v2-23] 2016-Mar-30 H-L Pulses on EN2 tTORCH 1,2 0ms ignored (noise filter) 3 1ms 4 2ms 5 3ms 6 4ms 7 5ms 8 6ms 9 7ms 10 8ms 11 9ms 12 10ms 13 11ms 14 12ms 15 13ms 16 14ms ≥17 15ms Page 19 Document Feedback AS3685A/AS3685B − Detailed Description AS3685B Current Setting The current through the LED (I LED) can be set in several steps using the following waveforms: Figure 29: AS3685B Current Setting Method A Define Method A Set current with number of pulses EN1 EN2 Current can be increased if required min. tPULSEWIDTH ILED typ. 64μs Flash/Strobe/Indicatior function dependent on number of pulses off off t For method A, the current is started after a certain time after the first rising edge of EN1. The AS3685B chooses method A, if EN1 is high at the first rising edge of EN2. Figure 30: AS3685B Current Setting Method B Define Method B Set current with number of pulses EN1 EN2 Current can be increased if required ILED no time limit off min tPULSEWIDTH typ. 64μs Flash/Strobe/Indicatior function dependent on number of pulses off t For method B, the current is started after the second rising edge of EN2. The AS3685B chooses method B, if EN1 is low at the first rising edge of EN2. Any high or low level duration for EN1 or EN2 should not be shorter than t PULSEWIDTH. The actual number of pulses on the pin EN1 (applies for methods A and B) define the mode and the current settings for the AS3685B: Page 20 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Detailed Description Figure 31: AS3685B Current Settings H-L-H Pulses on EN1 Mode ILED (for RISET =14.2kΩ) ILED (for RISET = 10kΩ) ILED/IISET EN1=EN2=0 Off 0mA 0% 0 (Off) 4.7mA average 6.7mA 1 (=150mA with 1/32 duty cycle(1) ) (=214mA with 1/32 duty cycle(1) ) (=ITORCH2ISET/32) 2 41mA 60mA 448 85mA 120mA 929 4 129mA 180mA 1410 5 173mA 250mA 1891 217mA 310mA 2371 7 261mA 370mA 2852 8 305mA 440mA 3333 9 349mA 500mA 3814 10 393mA 560mA 4295 11 437mA 620mA 4776 481mA 690mA 5257 13 525mA 750mA 5737 14 569mA 810mA 6218 15 613mA 880mA 6699 16 657mA 940mA 7180 17 700mA 1000mA 7650 (=IFLASH2ISET ) 0 Indicator 3 52.2 Torch 6 12 Flash Flash Note(s): 1. The on-time for indicator mode is 1μs, off time 31μs (32μs = 32.25kHz). Where I ISET is: (EQ2) ams Datasheet [v2-23] 2016-Mar-30 V ISET 1.3V I ISET = --------------- = --------------R ISET R ISET Page 21 Document Feedback AS3685A/AS3685B − Detailed Description AS3685B Single Wire Interface Using the following application schematic, a single GPIO pin can be used to control the mode and current of the AS3685B: Figure 32: AS3685B Single Wire Interface Vbat VBAT AS3685B EN1 EN1 EN2 CSINGLE 1nF RSINGLE single GPIO Pin to set indicator/torch/flash mode ISET An example driving waveform can be (this uses method A as shown above in section ‘AS3685B Current Settings’): Figure 33: AS3685B Example Single Wire Interface Driving Waveform EN1 (EN2) off Set current with number of pulses Flash/Strobe/Indicatior function dependent on number of previous pulses off The low time of the pulses on EN1 for setting the current should be kept short. Then the (generated) signal on pin EN2 will stay at a high level during this time ensuring correct operation. R SINGLE should be chosen to fit to the actual driving waveform on EN1. Page 22 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Detailed Description AS3685B Two Wire Interface with Strobe Input Using the following application schematic, the AS3685B current and mode can be set accurately and the camera can directly control the exact strobe time: Figure 34: AS3685B Two Wire Interface with Strobe Input Vbat VBAT AS3685B Two GPIO Pins to set current and mode EN1 EN1 EN2 EN2 ISET STROBE RSTROBE Optional Strobe Input An example driving waveform can be (this uses method B as shown above in section AS3685B Current Setting): Figure 35: AS3685B Example Two Wire Interface Driving Waveform Enable/Disable current directly by the camera module using the 'STROBE' input EN1 EN2 STROBE off Set current with number of pulses Flash/Strobe/Indicatior function dependent on number of previous pulses GPIO output driving EN2 directly is tristated and 'STROBE' defines input EN2 ams Datasheet [v2-23] 2016-Mar-30 off GPIO output driving EN2 directly defines input EN2 Page 23 Document Feedback AS3685A/AS3685B − Detailed Description AS3685A and AS3685B TXMask Function If the battery has to supply two high currents at the same time (e.g. the AS3685 flash and a RF-power amplifier) it is possible, that the total current causes a high voltage drop on the battery resulting in a shutdown of the complete system. In order to avoid this shutdown, the AS3685 (AS3685A or AS3685B) can reduce its current with the signal ‘TXMask’ using the following circuit: Figure 36: TXMask Function of the AS3685 VBAT VBAT EN1 EN1 EN2 EN2 AS3685A AS3685B ISET RTXMASK TXMask RISET The TXMask signal is connected to e.g. the (RF-) power amplifier enable pin (active high if the PA is enabled). This reduces the flash current if the power amplifier is enabled and avoids the unexpected shutdown of the system. Note(s): The internal flash timeout timer (tFLASHTIMEOUT ) to limit the total flash duration, is not affected by the TXMask function (see also section Flash Timeout). The I ISET current (current into the pin ISET) for TXMask = 0 can be calculated with: V ISET V ISET 1.3V 1.3V I ISET, TXMASK = 0 = --------------- + ------------------------- = --------------- + ------------------------R ISET R TXMASK R ISET R TXMASK (EQ3) For TXMask = 1 the current IISET is reduced to: (EQ4) I ISET, TXMASK = 1 V – V ( TXMASK ) V ISET 1.3V 1.3V – V ( TXMASK ) ISET = ------------------ + ------------------------------------------------------------- = ------------------ + ------------------------------------------------------R R R R TXMASK ISET TXMASK ISET V(TXMask) is the actual voltage for the high level (‘1’) for the signal TXMask Page 24 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Detailed Description The maximum flash current ILEDMAX for TXMask=0 or 1 can be calculated according to the following formula using the above obtained I ISET values: (EQ5) I LEDMAX = I FLASH2BIAS I ISET = 7650 ⋅ I ISET Choose the values for R ISET and R TXMASK according to your application requirements. Protection Functions Overtemperature Protection If the AS3685 junction temperature exceeds TOVTEMP , the current sink will be disabled and the charge pump forced into 1:1 mode. If the junction temperature drops below TOVTEMP – TOVTEMPHYST , the device enables the current sink again and the charge pump resumes normal operation. LED Shortcircuit Protection If the LED is shorted (VCP to ILED), then depending on the set current and the resulting high power dissipation inside the AS3685, the overtemperature protection will trigger. This protects the AS3685 and the system against damage. If the AS3685 is in off-mode, then shorting of the diode will have no influence on the system. Note(s): Do not short VCP to VSS if the supply is not current limited (e.g. by an internal protection inside the battery), as there is an internal diode between VBAT (anode) and VCP (cathode). Flash Timeout The flash duration of a single flash is limited automatically to t FLASHTIMEOUT (applies only for ‘Flash’ mode(s)). This protects the flash LED against thermal damage. ams Datasheet [v2-23] 2016-Mar-30 Page 25 Document Feedback AS3685A/AS3685B − Detailed Description Layout Recommendations To improve the heat dissipation, use a massive ground plane. Figure 37: AS3685 DFN10 (3x3mm) Layout Recommendation CFLY1 CFLY2 AS3685 ILED 1 2 3 4 5 VBAT EN1 CBAT VSS 10 9 8 7 6 EN2 Top Layer Bottom Layer RISET VIA, which is connected to the ground plane, too CVCP Use ground place connected to VSS 'Normal' VIA VCP Figure 38: AS3685 WL-CSP (2x1.5mm) Layout Recommendation Use ground plane connected to VSS CVCP VCP EN1 CBAT VSS VBAT A1 A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3 CFLY2 RISET EN2 ILED AS3685 CFLY1 Top Layer Inner Layer Bottom Layer VIA, which is connected to the ground plane, too 'Normal' VIA Micro VIA between Page 26 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − External Components External Components Capacitor and Resistor Selection Use low-ESR ceramic capacitors with X7R or X5R dielectric. These capacitors allow good filtering and have a wide temperature range. The connections of all external capacitors should be kept as short as possible. All resistors should have a tolerance of ±1%. Usage of PCB Wire Inductance The inductance between the battery and pin VBAT can be used as a filter to reduce disturbance on the battery. Instead of using one capacitor (C BAT ) it is recommended to split C BAT into C BAT1 and C BAT2 with the capacitance of (EQ6) C BAT1 = C BAT2 = C BAT It is recommended to apply a minimum of 20nH (maximum 200nH) with low impedance. This inductance can be realized on the PCB without any discrete coil. Assuming that a 1mm signal line corresponds to approximately 1nH (valid if the length (L) is significantly bigger than the width (W) of the line (L/W <10)), a line length of (EQ7) 20mm < L < 200mm Figure 39: PCB Wire Inductance Example1 L Battery Connector CBAT1 VSS ams Datasheet [v2-23] 2016-Mar-30 AS3685 Pin VBAT CBAT2 LTOTAL = L VSS Page 27 Document Feedback AS3685A/AS3685B − External Components Figure 40: PCB Wire Inductance Example2 L1 CBAT2 CBAT1 VSS L2 AS3685 Pin VBAT Battery Connector LTOTAL = L1 + 10*L2 VSS External Component Specifications Figure 41: External Components List Value Part Min Typ Max Tol (Min) Rating (Max) Notes Package (Min) CBAT (1) 2.2μf ±20% 6.3V Ceramic, X5R e.g. Murata GRM21BR71A225KA01L CFLY1, CFLY2 1.0μf ±20% 6.3V Ceramic, X5R e.g. Murata GRM188R60J105K CVCP 2.2μf ±20% 6.3V Ceramic, X5R e.g. Murata GRM21BR71A225KA01L 0603 ±1% Current Set Resistor 0201 ±1% TXMask Set Resistor 0201 RISET 10kΩ 130kΩ RTXMASK See section ‘TXMask function’ DLED Flash LED 0603 0603 (0402,0405) Note(s): 1. See section Usage of PCB Wire Inductance. Page 28 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Package Drawings & Markings Package Drawings & Markings DFN10 (3 × 3mm) Figure 42: DFN10 (3x3mm) Package Drawing RoHS Green REF. MIN NOM MAX A A1 A3 L L1 b D E e D2 E2 aaa bbb ccc ddd eee fff N 0.80 0 0.90 0.02 0.20 REF 0.40 0.25 3.00 BSC 3.00 BSC 0.50 BSC 2.50 1.70 0.15 0.10 0.10 0.05 0.08 0.10 10 1.00 0.05 0.35 0.18 2.40 1.60 - 0.45 0.15 0.30 2.60 1.80 - Note(s): 1. Dimensioning & toleranceing confirm to ASME Y14.5M-1994 2. All dimensions are in millimeters. Angles are in degrees. 3. Dimension b applies to metallized terminal and is measured between 0.25mm to 0.30mm from terminal tip. dimension L1 represents terminal full back from package edge up to 0.1mm is acceptable. 4. Coplanarity applies to the exposed heat slug as well as the terminal. 5. Radius on the terminal optional. 6. N is the total number of terminals. ams Datasheet [v2-23] 2016-Mar-30 Page 29 Document Feedback AS3685A/AS3685B − Package Drawings & Markings Figure 43: DFN Package Marking YYWW XZZ AS8A Note(s): 1. AS8A for AS3685A or AS8B for AS3685B. Figure 44: DFN Package Code YYWWXZZ YY WW X ZZ Last two digits of the manufacturing year Manufacturing week Plant identifier Letters for free choice Page 30 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Package Drawings & Markings WL-CSP (2 x 1.5mm) Figure 45: WL-CSP (2x1.5mm) Package Drawing RoHS ams Datasheet [v2-23] 2016-Mar-30 Green Page 31 Document Feedback AS3685A/AS3685B − Package Drawings & Markings Figure 46: WL-CSP Package Marking AS3685A YYWWGZZ Figure 47: WL-CSP Package Code YYWWGZZ YY WW G ZZ Last two digits of the manufacturing year Manufacturing week Plant identifier Letters for free choice Page 32 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Ordering & Contact Information Ordering & Contact Information The devices are available as the standard products shown in Figure 48. Figure 48: Ordering Information Ordering Code Description Marking Package Delivery Form Delivery Quantity AS3685AZWLT-2N80 AS3685A interface version, 800ms flash timeout, 1:2 mode locked AS3685A WL-CSP 2x1.5mm Tape & Reel 6000 pcs/reel AS3685AZWLT-2Y80 AS3685A interface version, 800ms flash timeout, 1:2 mode enabled (1) AS3685A2 WL-CSP 2x1.5mm Tape & Reel 6000 pcs/reel AS3685AZDFT-2Y80 AS3685A interface version, 800ms flash timeout, 1:2 mode enabled (1) AS8A DFN 10 3x3mm Tape & Reel 6000 pcs/reel AS3685BZDFT-2Y80 AS3685B interface version, 800ms flash timeout, 1:2 mode enabled AS8B DFN 10 3x3mm Tape & Reel 6000 pcs/reel Note(s): 1. If 1000mA flash LED current is used it is usually required to allow 1:2 mode (due to the high forward voltage of the LED). Description: AS3685V-ZPPT-2X80 V … AS3685 Interface Version: A = AS3685A: Direct control to select three different currents. B = AS3685B: Single or two pin interface with strobe; 17 different current settings. Z … Temperature Range: Z = -30°C to 85°C PP … Package: WL = Wafer Level Chip Scale Package DF = DFN10 T … 2X … Delivery Form: T = Tape & Reel Charge Pump Mode Locking: 2N = 1:2 mode locked (device can only use 1:1 and 1:1.5 mode) 2Y = 1:2 mode available (device can use 1:1, 1:1.5 and 1:2 mode) 80 … ams Datasheet [v2-23] 2016-Mar-30 Flash Timeout Time Programming 80 = 800ms flash timeout time Page 33 Document Feedback AS3685A/AS3685B − Ordering & Contact Information Buy our products or get free samples online at: www.ams.com/ICdirect Technical Support is available at: www.ams.com/Technical-Support Provide feedback about this document at: www.ams.com/Document-Feedback For further information and requests, e-mail us at: [email protected] For sales offices, distributors and representatives, please visit: www.ams.com/contact Headquarters ams AG Tobelbaderstrasse 30 8141 Premstaetten Austria, Europe Tel: +43 (0) 3136 500 0 Website: www.ams.com Page 34 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − RoHS Compliant & ams Green Statement RoHS Compliant & ams Green Statement RoHS: The term RoHS compliant means that ams AG products fully comply with current RoHS directives. Our semiconductor products do not contain any chemicals for all 6 substance categories, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, RoHS compliant products are suitable for use in specified lead-free processes. ams Green (RoHS compliant and no Sb/Br): ams Green defines that in addition to RoHS compliance, our products are free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material). Important Information: The information provided in this statement represents ams AG knowledge and belief as of the date that it is provided. ams AG bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. ams AG has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. ams AG and ams AG suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. ams Datasheet [v2-23] 2016-Mar-30 Page 35 Document Feedback AS3685A/AS3685B − Copyrights & Disclaimer Copyrights & Disclaimer Copyright ams AG, Tobelbader Strasse 30, 8141 Premstaetten, Austria-Europe. Trademarks Registered. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. Devices sold by ams AG are covered by the warranty and patent indemnification provisions appearing in its General Terms of Trade. ams AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein. ams AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by ams AG for each application. This product is provided by ams AG “AS IS” and any express or implied warranties, including, but not limited to the implied warranties of merchantability and fitness for a particular purpose are disclaimed. ams AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of ams AG rendering of technical or other services. Page 36 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Document Status Document Status Document Status Product Preview Preliminary Datasheet Datasheet Datasheet (discontinued) ams Datasheet [v2-23] 2016-Mar-30 Product Status Definition Pre-Development Information in this datasheet is based on product ideas in the planning phase of development. All specifications are design goals without any warranty and are subject to change without notice Pre-Production Information in this datasheet is based on products in the design, validation or qualification phase of development. The performance and parameters shown in this document are preliminary without any warranty and are subject to change without notice Production Information in this datasheet is based on products in ramp-up to full production or full production which conform to specifications in accordance with the terms of ams AG standard warranty as given in the General Terms of Trade Discontinued Information in this datasheet is based on products which conform to specifications in accordance with the terms of ams AG standard warranty as given in the General Terms of Trade, but these products have been superseded and should not be used for new designs Page 37 Document Feedback AS3685A/AS3685B − Revision Information Revision Information Changes from 2.20 to current revision 2-23 (2016-Mar-30) Page 2.20 to 2-21 (2016-Mar-08) Content of austriamicrosystems datasheet was updated to latest ams design Updated product name 1 Added benefits to Figure 1 1 Updated Package Drawings & Markings section 29 2-21 (2016-Mar-08) to 2-22 (2016-Mar-23) Updated Figure 7 6 Updated Figure 42 29 Updated Figure 46 32 2-22 (2016-Mar-23) to 2-23 (2016-Mar-30) Updated Figure 7 6 Note(s): 1. Page and figure numbers for the previous version may differ from page and figure numbers in the current revision. 2. Correction of typographical errors is not explicitly mentioned. Page 38 Document Feedback ams Datasheet [v2-23] 2016-Mar-30 AS3685A/AS3685B − Content Guide Content Guide ams Datasheet [v2-23] 2016-Mar-30 1 1 2 General Description Key Benefits & Features Applications 3 3 4 Pin Assignment DFN10 (3x3mm) WL-CSP (2x1.5mm) 6 7 10 Absolute Maximum Ratings Electrical Characteristics Typical Operating Characteristics 15 15 16 16 16 17 20 24 25 25 25 26 Detailed Description Low Noise Charge Pump Mode Switching Soft Start Current Source (Sink) AS3685A Current Setting AS3685B Current Setting AS3685A and AS3685B TXMask Function Protection Functions Overtemperature Protection Flash Timeout Layout Recommendations 27 27 27 28 External Components Capacitor and Resistor Selection Usage of PCB Wire Inductance External Component Specifications 29 29 31 Package Drawings & Markings DFN10 (3 × 3mm) WL-CSP (2 x 1.5mm) 33 35 36 37 38 Ordering & Contact Information RoHS Compliant & ams Green Statement Copyrights & Disclaimer Document Status Revision Information Page 39 Document Feedback