austriamicrosystems AG is now ams AG The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30 8141 Unterpremstaetten, Austria Tel: +43 (0) 3136 500 0 e-Mail: [email protected] Please visit our website at www.ams.com austriamicrosystems AS3685A/AS3685B Datasheet Datasheet AS3685A/AS3685B 1 General Description Overtemperature Protection Automatic 800ms Flash Timeout to protect the flash LED 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 am lc s on A te G nt st il Additionally the AS3685 limits the flash time automatically to protect the flash LED. lv 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. al id Ultra Small High Efficiency 1000mA Charge Pump for White LED Flash 2 Key Features High Efficiency capactive charge pump with 1:1, 1:1.5 and 1:2 modes − 1:2 Mode can be disabled (different device versions available) Up to 1000mA Led Current Automatic Charge Pump Mode switching (Up) LED cathode disconnect in Shutdown Package − DFN10 3x3mm (10 pins + exposed pad) − WL-CSP (Wafer Level Chip Scale Package) 3x4 balls 0.5mm pitch (2x1.5mm) 3 Applications Flash / Torch for Mobile Phones, Digital Cameras and PDA 4 Application Diagram Figure 1 – Application Diagram of AS3685A/AS3685B ni ca CFLY1 1.0 F CBAT 2.2 F Te ch VBAT www.austriamicrosystems.com/AS3685 (ptr) CFLY2 1.0 F C1+ C1- C2+ C2VBAT VCP AS3685A AS3685B EN1 ILED EN2 CVCP 2.2 F DLED ISET VSS RTXMASK RISET Revision 2.2 1 - 24 AS3685A/AS3685B Datasheet Table of Contents General Description........................................................................................................................................... 1 Key Features ..................................................................................................................................................... 1 Applications ....................................................................................................................................................... 1 Application Diagram .......................................................................................................................................... 1 Characteristics................................................................................................................................................... 3 5.1 Absolute Maximum Ratings..................................................................................................................... 3 5.2 Operating Conditions .............................................................................................................................. 3 5.3 Electrical Characteristics ......................................................................................................................... 4 6 Typical Operation Characteristics...................................................................................................................... 6 7 Detailed Functional Description ......................................................................................................................... 8 7.1 Low Noise Charge Pump ........................................................................................................................ 8 7.1.1 Mode Switching........................................................................................................................ 8 7.1.2 Soft Start .................................................................................................................................. 9 7.2 Current Source (Sink).............................................................................................................................. 9 7.2.1 AS3685A Current Setting ......................................................................................................... 9 7.2.2 AS3685B Current Setting ....................................................................................................... 12 7.2.3 AS3685A and AS3685B TXMask Function ............................................................................ 15 7.3 Protection Functions.............................................................................................................................. 16 7.3.1 Overtemperature Protection ................................................................................................... 16 7.3.2 Flash Timeout ........................................................................................................................ 16 7.4 Layout Recommendations..................................................................................................................... 16 8 External Components ...................................................................................................................................... 17 8.1 Capacitor and Resistor Selection .......................................................................................................... 17 8.2 Usage of PCB Wire Inductance............................................................................................................. 17 8.3 External Component Specifications ...................................................................................................... 17 9 Pinout and Packaging...................................................................................................................................... 18 9.1 DFN10 3x3mm ...................................................................................................................................... 18 9.1.1 Pin Assignments DFN10 3x3mm ........................................................................................... 18 9.1.2 Pin Descriptions DFN10 3x3mm ............................................................................................ 18 9.1.3 Package Drawings and Marking DFN10 3x3.......................................................................... 19 9.2 WL-CSP 2x1.5mm (Wafer Level Chip Scale Package) ......................................................................... 21 9.2.1 Pin Assignments WL-CSP 2x1.5mm...................................................................................... 21 9.2.2 Pin Descriptions WL-CSP 2x1.5mm....................................................................................... 21 9.2.3 Package Drawings and Marking WL-CSP 2x1.5mm .............................................................. 22 10 Ordering Information........................................................................................................................................ 23 Te ch ni ca am lc s on A te G nt st il lv al id 1 2 3 4 5 www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 2 - 24 AS3685A/AS3685B Datasheet 5 Characteristics 5.1 Absolute Maximum Ratings Stresses beyond those listed in Table 1 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 Section 5 Electrical Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameter Min Max Unit 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 Humidity 5 85 % VESD Electrostatic Discharge -1000 1000 V PT Total Continuous Power Dissipation TBODY Notes: 1. Non condensing Norm: MIL 883 E Method 3015 W DFN10 3x3mm, TA = 70°C 1 1.02 W WL-CSP 2x1.5mm, TA = 70°C 1 16.3 mW/ °C DFN10 3x3mm 14.7 mW/ °C WL-CSP 2x1.5mm Junction Temperature 150 °C Body Temperature during Soldering 260 °C am lc s on A te G nt st il TJUNC At 25ºC, Norm: Jedec 17 1.14 PT Derating Factor 2 PDERATE Note lv Symbol al id Table 1 – Absolute Maximum Ratings according to IPC/JEDEC JSTD-020C 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’. 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 – PDERATE * (85°C – 70 °C) 2. ca 5.2 Operating Conditions Table 2 – Operating Conditions VBAT Parameter Min Typ Max Unit Note Battery Supply Voltage 3.0 3.6 5.5 V Supply voltage range 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 ni Symbol ch VBATFUNC Te IBAT Operating Current TAMB Ambient Temperature IOFF Off mode current www.austriamicrosystems.com/AS3685 (ptr) -30 Revision 2.2 EN1 = 0, EN2 = 0; VBAT<=4.2V 3 - 24 AS3685A/AS3685B Datasheet Table 2 – Operating Conditions IOPERATING Min Power Consumption without load Typ Max Unit Note 0.85 mA 1:1 Mode 6.6 mA 1:1.5 Mode 8.1 mA 1:2 Mode Max Unit Note VBAT * CPmode V CP-mode is 1, 1.5 or 2 (automatically selected) 5.3 Electrical Characteristics Table 3 – Charge Pump Characteristics Parameter VCPOUT V(VCP) Output voltage without load – do not short to VSS Output limitation Min Charge Pump effective Resistance RCP Eta Typ 5.4 5.6 internally limited 0.28 0.53 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, am lc s on A te G nt st il Symbol al id Parameter lv Symbol Efficiency 75 Output ripple voltage fclk Operating Frequency tUP_DEB_LONG Initial Mode Switching Debounce Time 256 μs tUP_DEB Mode Switching Debounce Time 16 μs ca VRIPPLE 100 -20% 1.0 +20% MHz Mode switching up-debounce time after enabling of the charge pump or after mode switching between 1:1 to 1:1.5 Mode switching up-debounce time in normal operation Table 4 – Current Source (Sink) Characteristics ILED Parameter ni Symbol Output Current Range Current Setting Accuracy VISET Current Generator Set Point Voltage (pin ISET) ch IACCURACY IISET Current Generator operating range IFLASH2ISET Flash Current to Bias Current Ratio Te Min www.austriamicrosystems.com/AS3685 (ptr) -10% Typ Max Unit Note 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 V 130 7650 μA A/A IISET = VISET / RISET if the resulting bias current is higher than 200μA (typ.), the current source is disabled AS3685A, EN1=1, EN2=1 or AS3685B at full flash current (700mA with RISET = 14.2kΩ) Revision 2.2 4 - 24 AS3685A/AS3685B Datasheet Table 4 – Current Source (Sink) Characteristics ITORCH2ISET Torch Current to Bias Current Ratio VSWITCH Mode Switching Threshold on V(ILED) between 1:1 -> 1:1.5 and 1:1.5 -> 1:2 Min Typ Max Unit Parameter AS3685A, EN1=0, EN2=1 1639 A/A 400 mV AS3685A, EN1=1, EN2=1 or AS3685B with ILED>350mA (with RISET = 14.2kΩ) (150mA with RISET = 14.2kΩ) 150 200 250 mV All lower currents Min Typ Max Unit Note For Pins EN1 and EN2 Table 5 –Digital Interface characteristics Symbol Note High Level Input voltage 1.5 VBAT V VIL Low Level Input voltage 0.0 0.5 V ILEAKAGE Input pin leakage current -10 10 μA tPULSEWIDTH Pulsewidth for signals on EN1 and EN2 (high or low pulses) 1.0 unlimited μs Max Unit Do not leave EN1 and EN2 floating; (47kΩ pulldowns can be used) am lc s on A te G nt st il VIH al id Parameter lv Symbol Table 6 – Protection Functions Symbol Parameter Min Typ TOVTEMP Overtemperature protection 140 °C TOVTEMPHYST Overtemperature protection Hysteresis 5 °C tFLASHTIMEOUT Flash Timeout Time 800 +20% ms AS3685A, EN1=1, EN2=1 or AS3685B flash modes Te ch ni ca -20% 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 www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 5 - 24 AS3685A/AS3685B Datasheet 6 Typical Operation Characteristics Figure 2 – Efficiency vs. Battery Voltage (with Lumiled PWF1) Figure 3 – Battery Current vs. Battery Voltage (with Lumiled PWF1) 1.6 100 ILED=100m ILED=200m ILED=300m ILED=400m 90 1.4 1.2 ILED=500m 80 70 ILED=700m ILED=600m 0.6 ILED=700m ILED=500m ILED=400m ILED=300m 0.4 50 ILED=200m 0.2 ILED=50m ILED=100m lv ILED=600m 60 0.8 0.0 40 2.8 3.2 3.6 4.0 4.4 4.8 2.8 5.2 3.2 3.6 4.0 5.2 Figure 5 – Linearty of Current Sink 0.8 0.7 ILED=700m 0.6 0.6 ILED=500m 0.3 ILED [A] ILED=300m ILED=100m 0.1 0.4 ILED=300m ILED=200m 0.2 ILED=100m 0.1 ILED=50m ILED=50m 0.0 2.8 ILED=500m ILED=400m 0.3 ILED=200m 0.2 ILED=600m 0.5 ILED=400m 0.4 ILED=700m 0.7 ILED=600m 0.5 ILED [A] 4.8 am lc s on A te G nt st il Figure 4 – LED current I(ILED) vs. Battery Voltage (with Lumiled PWF1) 3.2 3.6 4.0 4.4 4.8 0.0 5.2 0.0 VBAT [V] 0.5 1.0 1.5 2.0 2.5 VILED [V] Figure 6 –I(ILED) vs. R(ISET) (Flash and Torch Mode of AS3685A) Figure 7 – Startup of AS3685A -- ILED Current ca 1200 1000 ni Flash Mode 800 600 ch ILED [mA] 4.4 VBAT [V] VBAT [V] 0.8 al id 1.0 IBAT [A] Efficiency of Charge Pump [%] ILED=50m 400 200 Te Torch Mode 0 0k 20k 40k 60k 80k 100k 120k 140k ILED 500mA/div 100µs/div VBAT=3.3V, ILED=700mA R ISET [Ohm] www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 6 - 24 AS3685A/AS3685B Datasheet Figure 9 – Shutdown of AS3685A -- IBAT Current lv al id Figure 8 – Startup of AS3685A -- IBAT Current IBAT 500mA/div 100µs/div VBAT=3.3V, ILED=700mA am lc s on A te G nt st il IBAT 500mA/div 100µs/div VBAT=3.3V, ILED=700mA Figure 10 – Typical Operating Waveforms 1:1.5 Mode Figure 11 – Typical Operating Waveforms 1:2 Mode VCP ac-coupled, 50mV/div 250ns/div VBAT=3.3V, ILED=500mA Te ch ni ca VCP ac-coupled, 100mV/div 1µs/div VBAT=3.3V, ILED=500mA www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 7 - 24 AS3685A/AS3685B Datasheet 7 Detailed Functional Description Figure 12 – Internal Circuit Diagram of AS3685A/AS3685B C2+ C2- Low Noise Charge Pump 1:1, 1:1.5, 1:2 Modes VBAT VCP al id VBAT C1- clk mode soft_limit 1MHz 5.3V Overtemp Detect Vswitch EN1 EN2 Digital Control ILED am lc s on A te G nt st il EN2 EN1 lv C1+ 1.3V Different Control Logic for AS3685A and AS3685B TXMask AS3685 ISET VSS 7.1 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: ni 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 ca ch The flying capacitors are switched at the fixed frequency fclk. 7.1.1 Mode Switching Te 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 tUP_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. www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 8 - 24 AS3685A/AS3685B Datasheet 7.1.2 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. 7.2 Current Source (Sink) lv al id 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. am lc s on A te G nt st il 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: 7.2.1 AS3685A Current Setting For the AS3685A, the operating mode and the current through the LED is defined by the following table: Table 7 – AS3685A Current Settings ILED EN1 EN2 0 1 0 0 1 1 1 Notes: ILED/IISET 0 (Off) 10kΩ 0mA 0mA 0% 4.7mA average 6.7mA average 0.67% Indicator (=150mA with 1/32 duty cycle1)) (=214mA with 1/32 duty cycle1)) (=21.4% / 32) (=ITORCH2ISET/32) Torch 150mA 214mA 21.4% 1639 (=ITORCH2ISET) Flash 700mA 1000mA 100% 7650 (=IFLASH2ISET) 52.2 The on-time for indicator mode is 1μs, off time 31μs (32μs = 32.25kHz) ni 1) Off Percent of Full Scale 14.2kΩ ca 0 for RISET = Mode Where IISET is: ch VISET RISET 1.3 V RISET Te IISET www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 9 - 24 AS3685A/AS3685B Datasheet Application Hint: To obtain higher torch currents use the following circuit: Figure 13 – AS3685A Increasing Torch Current VBAT VBAT AS3685A EN1 EN1 EN2 EN2 ISET al id RTORCH 7.2.1.1 AS3685A Pulsed Indicator Mode am lc s on A te G nt st il The torch mode is controlled by EN1=0 and EN2=1 as following figure shows: lv RISET Figure 14 – AS3685A Torch Mode EN1 EN2 ILED Torch Current typ. 64µs off off t ca 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 tTORCH (the current used is exactly the torch current setting). Therefore the control does not need to setup an timer to accurately define the duration of the indicator pulse. Te ch ni The duration tTORCH can be setup from 1ms to 15ms depending on the number of pulses on EN2 as shown in the following figure and table: www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 10 - 24 AS3685A/AS3685B Datasheet Figure 15 – 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) tTORCH typ. 64µs off Table 8 – AS3685A tTORCH timings H-L Pulses on EN2 4 5 6 7 8 9 10 11 12 13 14 15 16 ignored (noise filter) 1ms 2ms 3ms 4ms 5ms 6ms 7ms 8ms 9ms 10ms 11ms 12ms 13ms 14ms 15ms Te ch ni ≥17 0ms am lc s on A te G nt st il 3 tTORCH ca 1,2 t lv off al id Torch Current www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 11 - 24 AS3685A/AS3685B Datasheet 7.2.2 AS3685B Current Setting The current through the LED (ILED) can be set in several steps using the following waveforms: Figure 16 – AS3685B Current Setting Method A Define Method A Set current with number of pulses EN1 EN2 min. tPULSEWIDTH ILED typ. 64µs al id Current can be increased if required Flash/Strobe/Indicatior function dependent on number of pulses off t lv off am lc s on A te G nt st il 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 17 – AS3685B Current Setting Method B Set current with number of pulses Define Method B EN1 EN2 Current can be increased if required ILED no time limit off typ. 64µs Flash/Strobe/Indicatior function dependent on number of pulses min tPULSEWIDTH 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 tPULSEWIDTH. ca 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: Table 9 – AS3685B Current Settings Mode ni H-L-H Pulses on EN1 EN1=EN2=0 Off ch 0 1 Indicator Te 2 3 4 Torch 5 6 www.austriamicrosystems.com/AS3685 (ptr) Flash ILED (for RISET = 14.2kΩ) ILED (for RISET = 10kΩ) ILED/IISET 0mA 0% 0 (Off) 4.7mA average 6.7mA (=150mA with 1/32 duty cycle1) ) (=214mA with 1/32 duty cycle1)) (=ITORCH2ISET/32) 41mA 60mA 448 85mA 120mA 929 129mA 180mA 1410 173mA 250mA 1891 217mA 310mA 2371 Revision 2.2 52.2 12 - 24 AS3685A/AS3685B Datasheet Table 9 – AS3685B Current Settings Mode ILED (for RISET = 14.2kΩ) ILED (for RISET = 10kΩ) ILED/IISET 7 Flash 261mA 370mA 2852 8 305mA 440mA 3333 9 349mA 500mA 3814 10 393mA 560mA 4295 11 437mA 620mA 4776 12 481mA 690mA 13 525mA 750mA 14 569mA 810mA 15 613mA 880mA 16 657mA 940mA 17 700mA 1000mA Where IISET is: IISET 5257 5737 6218 lv 6699 7180 7650 (=IFLASH2ISET) am lc s on A te G nt st il Notes: 1) The on-time for indicator mode is 1μs, off time 31μs (32μs = 32.25kHz) al id H-L-H Pulses on EN1 VISET RISET 1.3 V RISET 7.2.2.1 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 18 – AS3685B Single Wire Interface Vbat VBAT AS3685B EN1 EN1 ca RSINGLE ISET ni single GPIO Pin to set indicator/torch/flash mode EN2 CSINGLE 1nF ch An example driving waveform can be (this uses method A as shown above in section ‘AS3685B Current Settings’): Te Figure 19 – AS3685B Example Single Wire Interface driving waveform EN1 (EN2) off Set current with number of pulses www.austriamicrosystems.com/AS3685 (ptr) Flash/Strobe/Indicatior function dependent on number of previous pulses Revision 2.2 off 13 - 24 AS3685A/AS3685B Datasheet 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. RSINGLE should be chosen to fit to the actual driving waveform on EN1. 7.2.2.2 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: Vbat al id Figure 20 – AS3685B Two Wire Interface with strobe input VBAT Two GPIO Pins to set current and mode EN1 EN2 EN2 ISET STROBE RSTROBE am lc s on A te G nt st il Optional Strobe Input lv AS3685B EN1 An example driving waveform can be (this uses method B as shown above in section ‘AS3685B Current Settings’): Figure 21 – 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 defines input EN2 Te ch ni ca GPIO output driving EN2 directly is tristated and 'STROBE' defines input EN2 off www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 14 - 24 AS3685A/AS3685B Datasheet 7.2.3 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 22 – TXMask function of the AS3685 VBAT EN1 EN1 EN2 EN2 AS3685A AS3685B al id VBAT ISET RTXMASK lv TXMask am lc s on A te G nt st il 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: 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 IISET current (current into the pin ISET) for TXMask = 0 can be calculated with: IISET , TXMask 0 V ISET VISET R ISET RTXMASK 1.3 V RISET 1.3 V R TXMASK For TXMask = 1 the current IISET is reduced to: IISET , TXMask 1 V ISET V ISET V TXMask R ISET R TXMASK 1.3 V RISET 1.3 V V TXMask RTXMASK V(TXMask) is the actual voltage for the high level (‘1’) for the signal TXMask ca The maximum flash current ILEDMAX for TXMask=0 or 1 can be calculated according to the following formula using the above obtained IISET values: ILEDMAX IFLASH2BIAS IISET 7650 I ISET Te ch ni Choose the values for RISET and RTXMASK according to your application requirements. www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 15 - 24 AS3685A/AS3685B Datasheet 7.3 Protection Functions 7.3.1 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. 7.3.1.1 LED Shortcircuit protection al id 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: 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). 7.3.2 Flash Timeout am lc s on A te G nt st il lv The flash duration of a single flash is limited automatically to tFLASHTIMEOUT (applies only for ‘Flash’ mode(s)). This protects the flash LED against thermal damage. 7.4 Layout Recommendations To improve the heat dissipation, use a massive ground plane. Figure 23 – AS3685 DFN10 3x3mm Layout Recommendation CFLY1 CFLY2 AS3685 VBAT EN1 VSS 1 2 3 4 5 CBAT ILED 10 9 8 7 6 EN2 RISET VIA, which is connected to the ground plane, too CVCP 'Normal' VIA VCP ca Use ground place connected to VSS Top Layer Bottom Layer ni Figure 24 – AS3685 WL-CSP 2x1.5mm Layout Recommendation Use ground plane connected to VSS ch VSS CBAT CVCP EN1 Te VBAT A1 A1 A2 A3 B1 B2 B3 VCP RISET EN2 ILED C1 C2 C3 D1 D2 D3 CFLY2 AS3685 CFLY1 Top Layer Inner Layer Bottom Layer VIA, which is connected to the ground plane, too 'Normal' VIA Micro VIA between www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 16 - 24 AS3685A/AS3685B Datasheet 8 External Components 8.1 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%. 8.2 Usage of PCB Wire Inductance al id 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 (CBAT) it is recommended to split CBAT into CBAT1 and CBAT2 with the capacitance of CBAT1 = CBAT2 = CBAT lv 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 20mm < L < 200mm is recommended. The shape of the line is not important. am lc s on A te G nt st il Figure 25 – PCB Wire Inductance Example1 L Battery Connector AS3685 Pin VBAT CBAT1 VSS LTOTAL = L CBAT2 VSS Figure 26 – PCB Wire Inductance Example2 L1 CBAT1 VSS AS3685 Pin VBAT CBAT2 L2 Battery Connector LTOTAL = L1 + 10*L2 VSS ca 8.3 External Component Specifications Table 10 – External Components List Tol (Min) Rating (Max) 2.2μF +/-20% 6.3V CFLY1, CFLY2 1.0μF +/-20% 6.3V CVCP 2.2μF +/-20% 6.3V Min Te ch CBAT 1 RISET RTXMASK DLED Notes: Value Typ ni Part 10kΩ Max 130kΩ See section ‘TXMask function’ Notes Package (min) Ceramic, X5R 0603 e.g. Murata GRM21BR71A225KA01L Ceramic, X5R e.g. Murata GRM188R60J105K Ceramic, X5R e.g. Murata GRM21BR71A225KA01L 0603 (0402, 0405) 0603 +/-1% Current Set Resistor 0201 +/-1% TXMask Set Resistor 0201 Flash Led 1. See section ‘Usage of PCB Wire Inductance’ www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 17 - 24 AS3685A/AS3685B Datasheet 9 Pinout and Packaging 9.1 DFN10 3x3mm 9.1.1 Pin Assignments DFN10 3x3mm Figure 27 –Pin Assignments DFN10 3x3mm 8 1 C1+ C1- C2+ C22 VBAT VCP 4 5 AS3685A EN1 AS3685B ILED EN2 9 7 ISET VSS Exposed Pad am lc s on A te G nt st il 6 al id 10 lv 3 9.1.2 Pin Descriptions DFN10 3x3mm Table 11 – Pin Type Descriptions DFN10 3x3mm Pin Type Description AI/O Analog Pin DI Digital Input S Supply Pin Table 12 – Pin Descriptions 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+ VBAT S C1+ AI/O 2 ca 3 4 6 EN1 DI ISET AI/O EN2 DI ch 7 AI/O ni 5 VCP Battery Supply Voltage Flying Capacitor 1 connection – connect 1μF ceramic capacitor CFLY1 between C1- and C1+ Charge Pump Output voltage – connect flash LED anode to this pin and add CVCP capacitor with 2.2μF to VSS 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 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 Te 8 www.austriamicrosystems.com/AS3685 (ptr) Ground Connection – a proper thermal connection with several vias to the ground plane is recommended Revision 2.2 18 - 24 AS3685A/AS3685B Datasheet 9.1.3 Package Drawings and Marking DFN10 3x3 am lc s on A te G nt st il Top View lv AYWW XZZ AS8x al id Figure 28 – DFN10 – 3x3mm Pacakge Drawing ch ni ca Bottom View (rotated) Te Marking: Line 1: AYWW A = Pb-Free Identifier Y = Year WW = Week Line 2: XZZ X = Plant Identifier ZZ = Letters of Free Choice Line 3: AS8A for AS3685A or AS8B for AS3685B www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 19 - 24 AS3685A/AS3685B Datasheet Te ch ni ca am lc s on A te G nt st il lv al id Figure 29 – DFN10 – 3x3mm Detail Dimensions www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 20 - 24 AS3685A/AS3685B Datasheet 9.2 WL-CSP 2x1.5mm (Wafer Level Chip Scale Package) 9.2.1 Pin Assignments WL-CSP 2x1.5mm Figure 30 – WL-CSP 2x1.5mm Pin Assignments B1 D2 C2 D1 VBAT VCP B2 A1 AS3685A EN1 AS3685B ILED EN2 C3 B3 ISET VSS A3 A2,D3 am lc s on A te G nt st il 9.2.2 Pin Descriptions WL-CSP 2x1.5mm lv C1 al id C1+ C1- C2+ C2- Table 13 – Pin Type Descriptions WL-CSP 2x1.5mm Pin Type Description AI/O Analog Pin DI Digital Input S Supply Pin Table 14 – Pin Descriptions WL-CSP 2x1.5mm Pin Number Pin Name Type A1 EN1 DI Digital Control Signal EN1 VSS S Ground Connection – a proper thermal connection to the ground plane is recommended ISET AI/O Current Generator input pin – connect current set resistor RISET between this pin and VSS (and optional RTXMASK) C1+ AI/O Flying Capacitor 1 connection – connect 1μF ceramic capacitor CFLY1 between C1- and C1+ VCP AI/O Charge Pump Output voltage – connect flash LED anode to this pin and add CVCP capacitor with 2.2μF to VSS EN2 DI Digital Control Signal EN2 VBAT S Battery Supply Voltage C2+ AI/O Flying Capacitor 2 connection – connect 1μF ceramic capacitor CFLY2 between C2- and C2+ A2 A3 B1 ca B2 C1 ch C2 ni B3 Description 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 Te C3 www.austriamicrosystems.com/AS3685 (ptr) Ground Connection – a proper thermal connection to the ground plane is recommended Revision 2.2 21 - 24 AS3685A/AS3685B Datasheet 9.2.3 Package Drawings and Marking WL-CSP 2x1.5mm lv al id Figure 31 – WL-CSP 2x1.5mm Package Drawing Marking: austriamicrosystems logo AS3685x x = A for AS3685A, B for AS3685B, A2 for AS3685A with 1:2 mode, B2 for AS3685A with 1:2 mode AYWWIZZ A = Pb-Free Identifier Y = Year WW = Week I = Plant Identifier ZZ = Letters of Free Choice am lc s on A te G nt st il Line 1: Line 2: Line 3: Te ch ni ca Figure 32 – WL-CSP 2x1.5mm Detail Dimensions www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 22 - 24 AS3685A/AS3685B Datasheet 10 Ordering Information Table 15 – Delivery Information AS3685A-ZWLT2Y80 WL-CSP 2x1.5mm AS3685A2 AS8A DFN 10 3x3mm Delivery Form Description Tape&Reel AS3685A Interface Wafer Level Chip Scale Package, Size 2x1.5mm, 4x3 balls, 0.5mm pitch, RoHS compliant / Pb-free, 800ms flash timeout, 1:2 mode locked Tape&Reel AS3685A Interface Wafer Level Chip Scale Package, Size 2x1.5mm, 4x3 balls, 0.5mm pitch, RoHS compliant / Pb-free, 800ms flash timeout, 1:2 mode enabled 1 Tape&Reel AS3685A Interface DFN Package, 3x3mm, 10 pins, 0.4mm pitch, RoHS compliant / Pb-free, 800ms flash timeout, 1:2 mode enabled1 am lc s on A te G nt st il Description: WL-CSP 2x1.5mm AS3685A AS3685A-ZDFT2Y80 AS3685B-ZDFT2Y80 Package Type al id AS3685A-ZWLT2N80 Marking lv Part Number AS8B DFN 10 3x3mm Tape&Reel AS3685B Interface DFN Package, 3x3mm, 10 pins, 0.4mm pitch, Pb-Free, 800ms flash timeout, 1:2 mode enabled AS3685V-ZPPT-2X80 AS3685 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 – 85°C PP … Package: WL = Wafer Level Chip Scale Package DF = DFN10 - T … 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) ni - ca … V … ch 2X … Flash Timeout time programming 80 = 800ms flash timeout time Te 80 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). www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 23 - 24 AS3685A/AS3685B Datasheet Copyright Copyright © 1997-2010, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, AustriaEurope. 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. All products and companies mentioned are trademarks or registered trademarks of their respective companies. Diclaimer ni ca am lc s on A te G nt st il lv al id Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. austriamicrosystems 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 austriamicrosystems AG for current information. This product is intended for use in normal 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 austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location. The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems 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 austriamicrosystems AG rendering of technical or other services ch Contact Information Te Headquarters austriamicrosystems AG Tobelbaderstrasse 30 Schloss Premstätten A-8141 Austria Tel: Fax: +43 (0) 3136 500 0 +43 (0) 3136 525 01 For Sales Offices, Distributors and Representatives, please visit: http://www.austriamicrosystems.com/contact www.austriamicrosystems.com/AS3685 (ptr) Revision 2.2 24 - 24