DATA SHEET SKY81290: 1.2 A Single Flash LED Driver With AS2C Interface Applications Description LED photo flash/torch devices The SKY81290 is a high-efficiency, 1.2 A high current boost converter with a programmable constant current sink. It is an ideal power solution for LED photo flash applications in all single cell, Li-ion powered products. Camera-enabled mobile devices Cellphones/smartphones Multimedia mobile phones Features Input voltage range: 2.7 V to 5.5 V Single channel flash output Up to 1.2 A regulated output current Up to 88% efficiency Switching frequency: 2.0 MHz Separate flash enable Single resistor sets Flash and Movie Mode current Flash safety timer AS Cwire single wire programming: Movie Mode current Flash/Movie Mode current ratio Maximum flash current ratio 2 True Load Disconnect Soft start and input current limit Over voltage (open LED, open circuit), short circuit, and over-temperature protection TDFN (14-pin, 3 x 3 mm and 3 x 2 mm) packages (MSL1, 260 C per JEDEC J-STD-020) Skyworks Green™ products are compliant with all applicable legislation and are halogen-free. For additional information, refer to Skyworks Definition of Green™, document number SQ04-0074. The SKY81290 maintains output current regulation by switching the internal high-side and low-side switch transistors. The transistor switches are pulse-width modulated at a fixed frequency of 2.0 MHz. The high switching frequency allows the use of a small external inductor and output capacitor, which makes the SKY81290 ideally suited for small battery-powered applications. Skyworks proprietary Advanced Simple Serial Control (AS2Cwire™) digital interface is used to enable, disable, configure, and program the operation of the SKY81290. Using the AS2Cwire interface, the Movie Mode current level for each LED, flash safety timer, and the flash-to-Movie-Mode current ratio can be programmed to one of 16 levels. The SKY81290 includes a separate flash enable input (FLEN) to initiate the flash operation. Also included is a flash inhibit pin (FLINH) that reduces the flash current to Movie Mode levels during high battery demand. The maximum Flash and Movie Mode current is set by one external resistor where the ratio of Flash to Movie Mode current is set at approximately 7:1. The SKY81290 contains a thermal management system to protect the device in the event of an output short-circuit condition. Builtin circuitry prevents excessive inrush current during start-up. The shutdown feature reduces quiescent current to less than 1.0 μA. The SKY81290 is available in a 14-pin, 3 x 3 mm TDFN package and a 14-pin, 3 x 2 mm TDFN package. A typical application circuit is shown in Figure 1. The pin configuration and packages are shown in Figure 2. Signal pin assignments and functional pin descriptions are provided in Table 1. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 1 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE L1 1 μH SW OUT IN VBATT = 2.9 V to 5.5 V COUT 2.2 μF CIN 2.2 μF Flash LED SKY81290 Enable/Set Input EN / SET Flash Enable FL FLEN RSET RSET Flash Inhibit FLINH PGND AGND FLGND S3419 Figure 1. Typical Application Circuit N/C 1 14 RSET EN/SET 2 13 FL FLEN 3 12 AGND 4 IN N/C 1 14 RSET EN/SET 2 13 FL FLGND FLEN 3 12 FLGND 11 N/C AGND 4 11 N/C 5 10 FLINH IN 5 10 FLINH SW 6 9 AGND SW 6 9 AGND PGND 7 8 OUT PGND 7 8 OUT 3x3 mm TDFN 3x2 mm TDFN S3267 Figure 2. SKY81290 Pinout – 14-Pin TDFN Packages (Top View) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 2 September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Table 1. SKY81290 Signal Descriptions Pin Name Description Pin Name Description 1 N/C No connect. 8 OUT Power output of the boost converter. Connect a 10 V, X7R 2.2 μF or larger ceramic capacitor from OUT to PGND, and locate as close to the device as possible. Connect OUT to the anode of the flash LED. 2 EN/SET Enable and serial control input. This pin is the AS2Cwire addressing and programming input to adjust the Movie Mode current level, select the Flash-to-Movie-Mode ratio, and set the flash safety timer. This pin has an internal 675 kΩ pull-down resistor. 9 AGND Analog ground pin. Connect AGND to PGND and FLGND at a single point as close to the device as possible. 3 FLEN Flash enable pin. A low-to-high transition on this pin initiates a flash pulse and a high-to-low transition terminates a flash pulse. This pin has an internal 225 kΩ pull-down resistor. 10 FLINH Flash inhibit pin. FLINH is an active high control input with an internal 225 kΩ resistor to AGND. A low-to-high transition on the FLINH pin reduces FL pin sink current to the maximum (default) Movie Mode current level. 4 AGND Analog ground pin. Connect AGND to PGND and FLGND at a single point as close to the device as possible. 11 N/C No connect. 5 IN Flash output boost converter power input. Connect IN to the input power source. Connect a 10 V, X7R 2.2 μF or larger ceramic capacitor from IN to PGND, and locate as close to the device as possible for optimum performance. 12 FLGND Flash ground pin. Connect FLGND to PGND and AGND at a single point as close to the device as possible. 6 SW Boost converter switching node. Connect a 1 μH inductor between the SW and IN pins. 13 FL LED flash current sink pin. Connect the cathode of the flash LED to this pin. 7 PGND 14 RSET Flash current set pin. Connect a resistor from RSET to AGND to program the desired flash current for the current sink pin (FL). Power ground. Connect PGND to the same single point as AGND and located as close to the device as possible. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 3 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Table 2. SKY81290 Absolute Maximum Ratings Parameter Symbol Maximum voltage rating Minimum Maximum Units IN, OUT, SW –0.3 +6.0 V EN/SET, FLEN, FLINH, RSET, FL –0.3 VIN + 0.3 V Storage temperature TS –65 +150 C Junction operating temperature TJ –20 +150 C +300 C Soldering temperature (at leads, 10 sec) TLEAD Thermal resistance (as mounted on an FR4 board, measured according to EIA/JESD 51 series): 3 x 3 TDFN 3 x 2 TDFN ΘJA Maximum power dissipation @ 25 C: 3 x 3 TDFN 3 x 2 TDFN PD Note: 35 41 C/W C/W 3.29 2.80 W W Exposure to maximum rating conditions for extended periods may reduce device reliability. There is no damage to device with only one parameter set at the limit and all other parameters set at or below their nominal value. Exceeding any of the limits listed here may result in permanent damage to the device. CAUTION: Although this device is designed to be as robust as possible, electrostatic discharge (ESD) can damage this device. This device must be protected at all times from ESD. Static charges may easily produce potentials of several kilovolts on the human body or equipment, which can discharge without detection. Industry-standard ESD precautions should be used at all times. Table 3. SKY81290 Recommended Operating Conditions Parameter Symbol Minimum Typical Maximum Units Input voltage VIN 2.7 5.5 V Operating temperature TOP –40 +85 C Electrical and Mechanical Specifications The absolute maximum ratings of the SKY81290 are provided in Table 2. Recommended operating conditions are specified in Table 3. Electrical specifications are provided in Table 4. Typical performance characteristics of the SKY81290 are illustrated in Figures 3 to 19. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 4 September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Table 4. SKY81290 Electrical Specifications (Note 1) (VIN = 3.6 V, CIN = COUT = 2.2 μF, RSET = 162 kΩ, L = 1 μH, TA = –40 C to +85 C [Typical Values are TA = +25 C], Unless Otherwise Noted) Parameter Symbol Test Condition Min Typical Max Units 5.5 V Power Supply, Current Sinks Input voltage range (Note 2) VIN Supply current IIN(Q) 2.7 EN/SET = FLEN = IN, FL load = 1 A 1.40 EN/SET = IN, FLEN = AGND 0.23 Input shutdown current ISHDN EN/SET and FLEN = AGND Maximum flash current IFL(MAX) RSET = 135 kΩ, VF = 3.3 V, VIN = 4.2 V Boost switch current limit ILIMIT IFL(ACC) IFL = 1 A Total output current, Movie Mode IMM(LOAD) Move Mode current set to 100%, IFL = 1 A Movie Mode current accuracy IMM(ACC) Flash to Movie Mode ratio IFL/IMM Switching frequency fOSC Over-temperature shutdown threshold TSD mA 1 1.2 2.8 –8 +8 143 –8 1.5 +8 2.0 A % mA 7 TA = 25 °C μA A 1.8 Flash current accuracy mA % – 2.5 MHz C 140 Output over-voltage limitation VOVP 5.3 V Open LED, short circuit protection threshold VFL_FLT 150 mV Protection delay time tFLT_DEL 1.4 ms EN/SET, FLEN, FLINH Logic threshold: Low High VIL VIH Internal pull-down resistance (EN/SET) REN/SET_PUDN 675 kΩ Internal pull-down resistance (FLEN, FLINH) RPUDN 225 kΩ 0.4 1.4 0.3 75 V V μs Serial interface low time (EN/SET) tEN/SET(LO) Minimum EN/SET high time tEN/SET(HI-MIN) Maximum EN/SET high time tEN/SET(HI-MAX) EN/SET off timeout time EN/SET latch timeout time FLEN delay time: On Off tFLEN(ON) tFLEN(OFF) 40 10 μs μs FLINH on delay time tFLENH(ON) 93 μs 50 ns 75 μs tEN/SET(OFF) 500 μs tEN/SET(LAT) 500 μs EN/SET = AGND Auto Disable Function Shorted LED detection voltage VLED(DETECT) VIN = 3.6 V, ILED = 2.4 mA 1.7 V Note 1: Performance is guaranteed only under the conditions listed in this table. Note 2: Flash mode operation may be limited by the boost switch current limit. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 5 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Typical Performance Characteristics (VIN = 3.6 V, CIN = COUT = 2.2 μF, RSET = 162 kΩ, L = 1 μH, TA = –40 C to +85 C [Typical Values are TA = +25 C], Unless Otherwise Noted) 95 90 IMM = 174 mA IMM = 142 mA 90 80 Efficiency (%) Efficiency (%) 85 80 75 70 65 70 60 50 IFL nom = 1.2 A IFL nom = 1.0 A IFL nom = 700 mA IFL nom = 540 mA 60 40 55 50 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 30 5.5 3.2 3.3 3.4 3.5 Input Voltage (V) 3.6 3.7 3.8 3.9 4.0 4.1 4.2 4.3 4.4 Input Voltage (V) Figure 3. Movie Mode Efficiency vs Input Voltage Figure 4. Flash Mode Efficiency vs Input Voltage 0 +0.6 +0.4 –0.2 +0.2 Accuracy (%) Accuracy (%) –0.4 –0.6 –0.8 –1.0 –1.2 0 –0.2 –0.4 –0.6 –0.8 –1.0 –1.4 –1.2 –1.6 –60 –40 –20 0 +20 +40 +60 +80 –1.4 –60 +100 –40 –20 +20 +40 +60 +1.5 +100 Flash On Time Delay (ms) 30 +1.0 +0.5 0 –0.5 –1.0 25 20 15 10 TA = +85 °C TA = +25 °C TA = –40 °C 5 0 –1.5 2.7 3.1 3.5 3.9 4.3 4.7 5.1 Input Voltage (V) Figure 7. Movie Mode Current Accuracy vs Input Voltage (IMM = 142 mA, L = 1 μH) 5.5 2.7 3.1 3.5 3.9 4.3 4.7 5.1 Input Voltage (V) Figure 8. Flash On Time Delay vs Input Voltage Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 6 +80 Figure 6. Movie Mode Current Accuracy vs Temperature (IMM = 142 mA, VIN = 3.6 V, L = 1 μH) Figure 5. Flash Mode Current Accuracy vs Temperature (IFL = 1 A, VIN = 3.6 V, L = 1 μH) Accuracy (%) 0 Temperature (°C) Temperature (°C) September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H 5.5 DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE 80 EN/SET Latch Timeout (ms) EN/SET Off Timeout (ms) 70 60 50 40 30 TA = +85 °C TA = +25 °C TA = –40 °C 20 10 0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 70 60 50 40 30 TA = +85 °C TA = +25 °C TA = –40 °C 20 10 0 2.7 5.5 3.1 3.5 1.4 4.7 5.1 5.5 1.2 1.0 0.8 0.6 TA = +85 °C TA = +25 °C TA = –40 °C 0.4 0.2 1.4 1.2 1.0 0.8 0.6 TA = +85 °C TA = +25 °C TA = –40 °C 0.4 0.2 0 3.1 3.5 3.9 4.3 4.7 5.1 5.5 2.7 3.1 3.5 Input Voltage (V) 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Figure 11. EN/SET, FLEN Low Threshold Voltage vs Input Voltage Figure 12. EN/SET, FLEN High Threshold Voltage vs Input Voltage 3.0 2.16 2.14 Supply Current (mA) Boost Switching Frequency (MHz) 4.3 Figure 10. EN/SET Latch Timout vs Input Voltage EN/SET, FLEN High Threshold Voltage (V) EN/SET, FLEN Low Threshold Voltage (V) Figure 9. EN/SET Off Timeout vs Input Voltage 0 2.7 3.9 Input Voltage (V) Input Voltage (V) 2.10 2.10 2.08 2.06 2.04 2.02 2.5 2.0 1.5 1.0 0.5 2.00 1.98 2.7 3.1 3.5 3.9 4.3 4.7 5.1 Input Voltage (V) Figure 13. Boost Switching Frequency vs Input Voltage (TA = 25 °C, L = 1 μH) 5.5 0 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Figure 14. Supply Current vs Input Voltage (VEN/SET = VFLEN = VIN, IFL = 0 mA, Non-Switching) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 7 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE VSW (2 V/div) VSW (2 V/div) VOUT (10 mV/div) VOUT (50 mV/div) ISW (100 mA/div) ISW (1 A/div) Time (400 ns/div) Time (400 ns/div) Figure 15. Movie Mode Ripple (IMM = 142 mA, COUT = 2.2 μF, VIN = 3.6 V, L = 1 μH) Figure 16. Flash Mode Ripple (IFL = 1 A, COUT = 2.2 μF, VIN = 3.6 V, L = 1 μH) VFLEN (4 V/div) VFLEN (4 V/div) VOUT (2 V/div) VOUT (2 V/div) VSINK (2 V/div) VSINK (1 V/div) IFL (1 A/div) IFL (1 A/div) Time (100 µs/div) Figure 17. Flash Turn On (VOUT = 3.6 V, IFL = 1 A) Time (100 µs/div) Figure 18. Movie Mode to Flash Turn On (VOUT = 3.6 V, IFL = 174 mA to 1.2 A) VEN/SET (5 V/div) VOUT (2 V/div) VSINK (2 V/div) IFL (100 mA/div) Time (200 µs/div) Figure 19. Movie Mode Turn On (VOUT = 3.6 V, IFL = 142 mA) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 8 September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE SW OUT (to Flash LED) FL IN EN/SET FLEN System Control Enable and AS2C Interface FLGND RSET FLINH AGND PGND S3170 Figure 20. SKY81290 Functional Block Diagram Functional Description Move (Torch) Mode The SKY81290 is a boost converter with a current-regulated output designed to drive high current, white LEDs used in camera flash applications. The SKY81290 has a constant current sink channel to accurately regulate the current flow through a high current, high intensity white flash LED. The Movie (Torch) Mode current level is programmed by the SKY81290 AS2Cwire interface using the EN/SET pin. The Movie Mode current level can be adjusted to one of 16 steps using a logarithmic scale where each code level is 1 dB below the previous code. The maximum Movie Mode current is fixed at 1/7th of the maximum programmed flash current set by the RSET resistor. The manual FLEN signal has priority over Movie Mode operation. The SKY81290 has two basic operating modes: a Flash Mode controlled by the FLEN pin, and a Movie/Torch Mode controlled through the AS2Cwire interface. A functional block diagram is shown in Figure 20. Flash Mode A flash pulse is initiated by strobing the FLEN input pin low-tohigh. The maximum flash current in the SKY81290 is set by an external resistor (RSET) that sets the flash current and the maximum Movie Mode current. The maximum flash current is limited by the boost switch current limit. For mobile GSM systems where the phone remains in constant contact with the base station by regular communication, a FLINH pin is provided to prevent both the camera flash and PA transmission pulses from occurring simultaneously. This avoids potential dips to the Li-ion battery voltage below the system’s cut off voltage. During a flash event, strobing the FLINH pin low-to-high reduces the LED current to the default Movie Mode current level for the duration of FLINH. Strobing FLINH high-to-low instructs the SKY81290 to revert the flash LED current to its maximum level, assuming that the FLEN pin is still active (high). The FLEN signal overrides the Movie Mode operation when toggled to a logic high level. The SKY81290 does not reenter Movie Mode when FLEN is brought low. To reenter Movie Mode after a flash event, the device must be cycled off and back on to reset the Movie Mode and reprogrammed with the AS2Cwire interface to the desired Movie Mode operation. Open LED or Short Circuit Protection The SKY81290 features open LED protection and short circuit protection. When the FL pin voltage drops below 150 mV, the boost output reaches the overprotection level (typically 5.3 V). After the output voltage reaches the overprotection level, if the FL voltage is kept below 150 mV for more than 1.4 msec (typical), the SKY81290 triggers the open LED/short circuit protection and latches off the device. The output is also disconnected from the input supply. To restart the device requires cycling the input power or EN pin. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 9 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Flash Safety Timer The SKY81290 is equipped with a flash safety timer that will turn off the flash according to the programmed safety time in Flash Mode. The default safety time is set as 1 sec but can be programmed between 0.25 sec and 1.75 sec. The safety timer can also be disabled through AS2Cwire programming. default Movie Mode current level appears at the FL channel. The default Movie Mode current level is maintained on FL as long as the FLINH and FLEN pins are asserted. Besides setting the flash current using the RSET resistor, the flash current can be changed after FLEN is asserted by programming the Movie Mode current register. Short LED Protection AS2Cwire Control of Movie Mode Operation The SKY81290 is equipped with an auto-disable feature for the flash LED channel. After the device is enabled and system start up commences, a test current of 2.4 mA (typical) is forced through the sink channel. The channel is disabled if the voltage of the FL pin does not drop to a predetermined threshold (1.7 V minimum). Movie Mode operation is managed by programming the AS2Cwire interface. This interface relies on the number of rising edges of the EN/SET pin to address and load internal data registers as indicated in Table 5. This feature is very convenient for disabling the current sink when the flash LED fails to a short circuit. This small test current is added to the set output current in both Flash and Movie Mode conditions. Register 0 controls the Movie Mode current level as a percentage of the maximum Movie Mode current. Table 5 also shows the default values for each of the address registers. AS2Cwire Serial Interface Over-Temperature Protection The SKY1290 has internal thermal protection circuitry to latch off the device if the internal power dissipation exceeds a preset thermal limit for over 1.4 ms. The junction over-temperature threshold is 140 °C. During Flash or Movie Mode operation, if an environmental condition, flash current sink, or the boost converter causes the internal die temperature to rise above 140 °C, the device latches off and disconnects the output from the input circuit. Flash Mode LED Current Flash sink current can be programmed up to a maximum of 1.2 A. The maximum flash current is set by the RSET resistor. For the desired flash current, the resistor value can be calculated using the following equation: I FL 162 k A 162 k 1.2 A RSET 135 k The AS2Cwire interface latches data or an address after the EN/SET pin has been held high for longer than tLAT (500 μs). Address or data are differentiated by the number of EN/SET rising edges. Since the data registers are 4 bits each, the differentiating number of pulses is 24 or 16, so that Register/address 0 is signified by 17 rising edges and Register/address 3 by 20 rising edges (refer to Table 5). Data in Register/address 0 is inclusively applied to any number of rising edges between 1 and 16. A typical write protocol is a burst of EN/SET rising edges that signify a particular address followed by a pause with EN/SET held high for the prescribed tLAT timeout period, then a burst of rising edges signifying data, and a tLAT timeout for the data registers. Once an address is set, then multiple writes to the corresponding data register are allowed. Address 0 is the default address on the first rising edge after the SKY81290 has been disabled. A flash event is initiated by asserting the FLEN pin. A flash event is automatically terminated when FLEN is de-asserted or the flash safety timer expires. Whenever the FLINH pin is asserted, the Table 5. AS2Cwire Serial Interface Addressing Register/Address EN/SET Rising Edges Function Default (No Programming) 0 17 Movie Mode current 100% 1 18 Flash safety timer time 1 second 2 19 Output enable control On 3 20 Flash current ratio (Flash/Movie Mode current ratio is fixed at 1:7) 100% Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 10 September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Address tLO Data tHI tLAT tLAT EN/SET 1 Address 2 16 17 1 2 n ≤ 16 0 Data Register 1 1 0 n S3090 Figure 21. AS2Cwire Serial Interface Timing Diagram When EN/SET is transitioned from high to low and held low longer than tOFF (500 μs), the device enters a shutdown mode and draws less than 1 μA from the input supply. All data and addresses are cleared (reset to 0) during shutdown. AS2Cwire addressing controls the Movie Mode output current and the ratio of Movie Mode current to flash current. If there are no programmed write instructions applied to the EN/SET pin before the assertion of the FLEN pin, and the device is enabled, then all registers are loaded with the default values shown in Table 5. If the number of rising edges applied at the EN/SET pin is fewer than 17, the internal state machine interprets the instruction to program the output currents to the desired current level for Movie Mode operation. A timing diagram for the AS2Cwire interface is shown in Figure 21. Register 0: Movie Mode Current The SKY81290 Movie Mode current settings are controlled using the AS2Cwire interface. The ratio between the flash current level and maximum Movie Mode current level is fixed at 1:7. For example, if an RSET value of 135 kΩ is chosen, then the flash current is set to 1200 mA. For Movie Mode operation, the maximum current available is then: IFL(MAX) = 162 kΩ/RSET × 1000 mA IMOVIEMODE = IFL(MAX)/7 = 1200 mA/7 = 171 mA Register/address 0 controls precise Movie Mode current levels. The Movie Mode current can be adjusted in a logarithmic fashion to one of 16 steps represented as a fraction of the maximum Movie Mode current as noted in Table 6. Table 6. Register/Address 0: Movie Mode Current Programming Data Percentage of Maximum Movie Mode Current Data Percentage of Maximum Movie Mode Current 1 (default) 100.0 9 49.5 2 93.7 10 43.2 3 87.4 11 36.9 4 81.1 12 30.6 5 74.8 13 24.3 6 68.4 14 18.0 7 62.1 15 11.7 8 55.8 16 5.5 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 11 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Table 7. Register/Address 1: Flash Safety Timer Data Flash Safety Timer Time (seconds) Data Flash Safety Timer Time (seconds) 1 Disables the timer 5 (default) 1.00 2 0.25 6 1.25 3 0.50 7 1.50 4 0.75 8 1.75 Table 8. Register/Address 2: Movie Mode Enable Control Data Movie Mode Enable Data Movie Mode Enable 1 Off 3 On 2 Off 4 (default) On Table 9. Register/Address 3: Flash Current Ratio Data Maximum Flash Current Ratio Data Maximum Flash Current Ratio 1 (default) 100% 3 70% 2 84% 4 62% Register 1: Flash Safety Timer The SKY81290 is equipped with a flash safety timer. This timer limits the operation time in Flash Mode to thermal issues. The safety timer can be adjusted from 0.25 seconds to 1.75 seconds as noted in Table 7. Register 2: Movie Mode Enable Control To enable or disable Movie Mode, a write instruction to address 2 is applied to the EN/SET pin (see Table 8). If no write instruction is applied, the default value for address 2 is “on.” During a flash event, the LED is enabled regardless of the Movie Mode setting. Register 3: Flash Current Ratio During flash start up, the maximum peaked sustained flash current level is programmable using Register/address 3. This level is a fraction of the maximum flash current set by RSET. The ratio can vary from 100 percent to 62 percent in 4 steps as shown in Table 9. Shutdown section enters shutdown mode and draws less than 1 μA from the input power source. All data and address registers for the Flash and/or Movie Mode are cleared (reset to 0) during shutdown. Evaluation Board Description The SKY81290 Evaluation Board is used to test the performance of the SKY81290 LED Driver. An Evaluation Board schematic diagram is provided in Figure 22. Layer details for the Evaluation Board are shown in Figure 23. Table 10 provides the Bill of Materials (BOM) for Evaluation Board components. Package Dimensions The PCB layout footprint for the SKY81290 is provided in Figure 24 (3 x 3 TDFN) and Figure 25 (3 x 2 TDFN). Typical case markings are shown in Figure 26. Package dimensions, and tape and reel dimensions for the 14pin, 3 x 3 mm TDFN package are shown in Figures 27 and 28, respectively. Package dimensions, and tape and reel dimensions for the 14-pin, 3 x 2 mm TDFN package are shown in Figures 29 and 30, respectively. Since the flash current sink is the only power return for the flash LED load, there is no leakage current to load if all the sink switches are disabled. When the EN/SET pin is held low for greater than tOFF (500 μs), the SKY81290 flash boost converter Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 12 September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Package and Handling Information Instructions on the shipping container label regarding exposure to moisture after the container seal is broken must be followed. Otherwise, problems related to moisture absorption may occur when the part is subjected to high temperature during solder assembly. additional information, refer to the Skyworks Application Note, Solder Reflow Information, document number 200164. Care must be taken when attaching this product, whether it is done manually or in a production solder reflow environment. Production quantities of this product are shipped in a standard tape and reel format. The SKY81290 is rated to Moisture Sensitivity Level 1 (MSL1) at 260 C. It can be used for lead or lead-free soldering. For DC + FLINH JP6 1 2 3 MCU R5 R6 R7 10 kΩ 10 kΩ 10 kΩ SW 1 MMC 2 4 1 3 5 SW 2 Flash Current Ratio 2 4 U2 1 2 3 4 VDD GP 5 GP 4 GP 3 VSS GP 0 GP 1 GP 2 8 7 6 5 2 4 FLEN 2 4 1 3 5 2 4 SW 4 SW 5 1 3 5 JP4 2 JP3 2 1 1 R4 100 kΩ VOUT R3 100 kΩ LED 1 RED D1 LED 2 Green SW 3 Movie ON /OFF R10 10 kΩ R8 330 Ω R9 330 Ω PIC 12F 675 1 3 5 C3 1 μF JP2 0Ω 1 3 5 JP1 0Ω U1 DC JP5 1 2 3 R2 100 kΩ EN /SET C1 2.2 μF L1 1 μH 1 2 3 4 5 6 7 JP8 FLINH 1 3 5 7 9 N/C EN /SET FLEN AGND IN SW PGND RSET FL FLGND N/C FLINH AGND OUT 14 13 12 11 10 9 8 R1 162 kΩ C2 2.2 μF 2 4 6 8 10 S3265 Figure 22. SKY81290 Evaluation Board Schematic Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 13 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Top Layer Bottom Layer Figure 23. SKY81290 Evaluation Board Layer Details Table 10. SKY81290 Evaluation Board Bill of Materials (BOM) Component Description Manufacturer Part # C1, C2 2.2 μF, 10 V, X7R, 0603 Murata GRM188R71A225KE15 C3 1 μF, 10 V, X5R, 0805 Murata GRM216R61A105KA01 D1 White flash LED Seoul Semiconductor SSC-FCW401Z4 JP3, JP4, JP5, JP6 Connecting header, 2mm zip Sullins Electronics PRPN401PAEN L1 1 μH, 3 A, 45 mΩ, 2.5 mm x 2 mm TOKO DFE252012C LED1 Red LED, 1206 Chicago Miniature Lighting CMD15-21SRC/TR8 LED2 Green LED, 1206 Chicago Miniature Lighting CMD15-21VGC/TR8 JP1, JP2 0 Ω, 1% Vishay Chip resistor R1 162 kΩ, 1%, 0402 Vishay Chip resistor R2, R3, R4 100 kΩ, 1%, 0603 Vishay Chip resistor R5, R6, R7, R10 10 kΩ, 1%, 0603 Vishay Chip resistor R8, R9 330 Ω, 1%, 0603 Vishay Chip resistor SW1 to SW5 Switches, SPST, 5 mm ITT Industries PTS645TL50 U1 1.2 A step-up current regulator for flash LEDs Skyworks SKY81290 U2 8-bit CMOS, flash-based I/C (8-pin PDIP package) Microchip PIC12F675 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 14 September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Pin 1 Indicator 0.3 X 45° 3.00 0.40 Pitch 2.55 14X 0.200 14X 0.800 15X Exposed Solder Area 1.70 All dimensions are in millimeters S3417 Figure 24. SKY81290 PCB Layout Footprint (3 x 3 TDFN) 15X Exposed Solder Area 2.50 2.00 0.85 14X 0.75 Pin 1 Indicator 0.3 X 45° 0.40 Pitch 14X 0.20 All dimensions are in millimeters S3418 Figure 25. SKY81290 PCB Layout Footprint (3 x 2 TDFN) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 15 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Pin 1 Indicator Skyworks P/N Lot # TDFN 3x3 Package Skyworks P/N Lot # Pin 1 Indicator TDFN 3x2 Package Figure 26. Typical Case Markings (Top View) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 16 September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Pin 1 Indicator 3.00 ± 0.05 0.203 Ref. Pin 1 Indicator 0.30 X 45° 1.65 ± 0.05 Exp. DAP 0.18 ± 0.05 0.400 BSC 2.5 ± 0.05 Exp. Pad 2.40 Ref 3.00 ± 0.05 0.00/0.05 0.425 ± 0.05 0.75 ± 0.05 Top View Side View Bottom View All measurements are in millimeters. S3266 Figure 27. SKY81290 14-Pin TDFN Package Dimensions (3 x 3 mm) ø1.50 +0.10/–0 4.00 ± 0.10 3.30 ± 0.10 (Bo) A Pin 1 Indicator 1.75 ± 0.10 5.50 ± 0.05 B A 12.00 ± 0.30 2.00 ± 0.05 0.30 ± 0.05 0.10 ± 0.10 1.10 ± 0.10 (Ko) 8.00 ± 0.10 B 0.10 ± 0.10 B Notes: 1. Carrier tape material: black conductive polystyrene. 2. Cover tape material: transparent conductive material. 3. Cover tape size: 9.2 mm width 4. ESD surface resistivity is ≤ 1 x 1010 Ohms/square per EIA, JEDEC tape and reel specification. 5. Ao and Bo measured on a plane 0.30 mm above the bottom of the pocket. 6. All measurements are in millimeters R0.30 ø1.50 Min. 3.30 ± 0.10 (Ao) A S3416 Figure 28. SKY81290 Tape and Reel Dimensions (3 x 3 mm Package) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 17 DATA SHEET • SKY81290 1.2: A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE 2.50 ± 0.05 Exp. Pad 0.18 ± 0.05 3.00 ± 0.05 0.33 ± 0.05 0.75 ± 0.05 0.80 ± 0.05 Exp. Pad 2.00 ± 0.05 0.00/0.05 0.203 Ref. 0.40 BSC Pin 1 Indicator Pin #1 Identification Chamfer C0.30 X 45° 2.40 Ref. Top View Side View Bottom View S3268 All measurements are in millimeters. Figure 29. SKY81290 14-Pin TDFN Package Dimensions (3 x 2 mm) 4.00 2.00 ± 0.05 ø1.5 + 0.1/–0 ø1.00 Min. Pin 1 Indicator 1.75 ± 0.10 4.00 (Note 1) 3.50 R0.20 Max. 3.30 (Bo) A 1.05 (Ko) 2.30 (Ao) R0.25 Typ. A Notes: 1. Sprocket hole pitch cumulative tolerance ±0.2. 2. Carrier tape material: black conductive polystyrene. 3. Pocket position relative to sprocket hole measured as true position of pocket, not pocket hole. 4. Cover tape material: transparent conductive material. 5. All measurements are in millimeters. Figure 30. SKY81290 Tape and Reel Dimensions (3 x 2 mm Package) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 18 September 4, 2014 • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • 202388H S3415 8.0 + 0.3/–0.1 A 0.30 ± 0.05 DATA SHEET • SKY81290: 1.2 A SINGLE FLASH LED DRIVER WITH AS2C INTERFACE Ordering Information Model Name SKY81290 Single Flash LED Driver Manufacturing Part Number Evaluation Board Part Number TDFN, 3 x 3 mm: SKY81290-11-564LF SKY81290-11-564LF-EVB1 TDFN, 3 x 2 mm: SKY81290-11-563LF SKY81290-11-563LF-EVB2 TDFN, 3 x 2 mm: SKY81290-11-563LFJ SKY81290-11-563LFJ-EVB1 Copyright © 2012-2014 Skyworks Solutions, Inc. All Rights Reserved. Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Skyworks may change its documentation, products, services, specifications or product descriptions at any time, without notice. Skyworks makes no commitment to update the materials or information and shall have no responsibility whatsoever for conflicts, incompatibilities, or other difficulties arising from any future changes. No license, whether express, implied, by estoppel or otherwise, is granted to any intellectual property rights by this document. Skyworks assumes no liability for any materials, products or information provided hereunder, including the sale, distribution, reproduction or use of Skyworks products, information or materials, except as may be provided in Skyworks Terms and Conditions of Sale. THE MATERIALS, PRODUCTS AND INFORMATION ARE PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, INCLUDING FITNESS FOR A PARTICULAR PURPOSE OR USE, MERCHANTABILITY, PERFORMANCE, QUALITY OR NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT; ALL SUCH WARRANTIES ARE HEREBY EXPRESSLY DISCLAIMED. SKYWORKS DOES NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE MATERIALS. SKYWORKS SHALL NOT BE LIABLE FOR ANY DAMAGES, INCLUDING BUT NOT LIMITED TO ANY SPECIAL, INDIRECT, INCIDENTAL, STATUTORY, OR CONSEQUENTIAL DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS THAT MAY RESULT FROM THE USE OF THE MATERIALS OR INFORMATION, WHETHER OR NOT THE RECIPIENT OF MATERIALS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Skyworks products are not intended for use in medical, lifesaving or life-sustaining applications, or other equipment in which the failure of the Skyworks products could lead to personal injury, death, physical or environmental damage. Skyworks customers using or selling Skyworks products for use in such applications do so at their own risk and agree to fully indemnify Skyworks for any damages resulting from such improper use or sale. Customers are responsible for their products and applications using Skyworks products, which may deviate from published specifications as a result of design defects, errors, or operation of products outside of published parameters or design specifications. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product design, or damage to any equipment resulting from the use of Skyworks products outside of stated published specifications or parameters. Skyworks and the Skyworks symbol are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for identification purposes only, and are the property of their respective owners. Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202388H • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • September 4, 2014 19