FAN5645 Indicator LED Blinker with Single-Wire Interface Features Description Records and plays back blink patterns Single-wire digital control of LED blink rate and intensity Resistor-programmable LED maximum current High-side constant-current driver topology: - 20mA maximum output - 40mV typical dropout at 20mA 33µA operating current Standard 1.8V logic Short-circuit protection Thermal Shutdown Protection Under-Voltage Lockout Protection 6-pin 3.0 x 3.0mm MLP package The FAN5645 is a flexible and compact solution for a blinking LED indicator. The internal programmable blink algorithm eliminates any need for continual system processor control. This means longer battery life for the hand-held system because the system processor is not awakened from sleep mode just to blink an LED. Very low dropout of 40mV allows driving an LED without any inductors or switch capacitors. An external resistor sets the LED output current level. LED blink rate and intensity is controlled by a simple one-wire interface. In shutdown mode, the supply current is reduced to 0.3µA (typical). The FAN5645 is available in 6-pin molded leadless package (MLP). Applications Cell Phones, Smart-Phones ® Pocket PCs, Bluetooth Headsets PDA, DSC, PMP, and MP3 Players Laptop Computers Typical Application 2.7 to 5.5V VBAT LED+ GND ISET CTRL GND R SET C IN 0.1µF VIN Control Figure 1. Typical Application for the FAN5645 Ordering Information Part Number FAN5645MPX Package MLP-6 3.0 x 3.0mm Pb-Free Operating Temperature Range Packing Method -40°C to 85°C Tape and Reel Bluetooth® is a registered trademark of Motorola, Inc. © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 www.fairchildsemi.com FAN5645 — Indicator LED Blinker with Single-Wire Interface September 2007 Under-Voltage UVLO Lockout CTRL Thermal Shutdown Protection Input edge detector & timer Oscillator Bandgap reference Ref. current generator TSD Control logic & memory DATA LED ON Output current mirror LED+ VIN GND ISET RSET Figure 2. Block Diagram FAN5645 — Indicator LED Blinker with Single-Wire Interface Block Diagram Pin Configuration GND 1 LED+ 2 ISET 3 P1 (GND) 6 VIN 5 GND 4 CTRL Top View Figure 3. MLP Pin Assignments Pin Definitions Pin # Name Description 1 GND Ground. 0V reference for all voltages. 2 LED+ LED output. Connect to anode of LED. 3 ISET Current Set. Resistor to GND sets maximum LED current 1:400. 4 CTRL Digital single wire interface. Program STOP/TRAIN/RUN sequences. 5 GND Ground. 0V reference for all voltages. 6 VIN Power input. © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 www.fairchildsemi.com 2 Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbol Parameter Min. Max. Unit VIN, LED+, CTRL Voltage -0.3 +6.0 V ISET Voltage -0.3 VIN+0.2 V TJ Junction Temperature -40 150 °C TSTG Storage Temperature -65 150 °C 260 °C TL ESD Lead Soldering Temperature, 10 seconds Electrostatic Discharge Protection Level HBM 7 CDM 2 HBM (on LED+ pin) 8 kV Recommended Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not recommend exceeding them or designing to absolute maximum ratings. Symbol Parameter VIN Power Supply Voltage Range IOUT Output Current RSET Min. Max. Units 2.7 5.5 V 1 20 mA Resistor Used to Set LED Current 24.7 494.0 kΩ TA Operating Ambient Temperature Range -40 +85 °C TJ Operating Junction Temperature Range -40 +125 °C © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 FAN5645 — Indicator LED Blinker with Single-Wire Interface Absolute Maximum Ratings www.fairchildsemi.com 3 VIN = 2.7V to 5.5V, TA = -40°C to +85°C, Vf = 1.8V to (3.5V or VIN-0.1V, whichever is smaller). Typical values are at TA = 25°C, VIN = 3.6V, and Vf = 2.5V. Symbol Parameter Conditions Power Supplies Shutdown current in STOP ISD (sleep) mode VIN = 3.6V IIN Operating current in RUN,TRAINING, RUN_ONCE, RESET_FOLLOW modes VIH Control high-level input voltage VIL Control low-level input voltage IIH Control pin input current VUVLO Min. VIN = 3.6V, ILED = 0mA Max. Units 0.30 0.75 µA 33 55 µA 1.2 CTRL = 1.8V Under-voltage lockout threshold Typ. V 1 0.4 V 100 nA VIN Rising 2.5 V VIN Falling 2.2 V Regulation IOUT IOUT_RIPPLE ∆ISET Maximum regulated output current Sourced from LED+ pin Minimum regulated output current Sourced from LED+ pin mA Maximum LED ripple current ΔVIN = 700mV, trise = tfall = 10µs, T = 570µs ISET accuracy TA = 25°C, ILED = 1mA-20mA (1) ISET_LINEARITY ISET linearity 20 1 0.5 -3 ILED = 1mA-20mA % p-p +3 5 % % ∆IOUT_LOAD IOUT load regulation LED Vf = 1.8 to 3.5V, VIN = 3.6V -3 +3 % ∆IOUT_LINE IOUT line regulation VIN = 2.7 to 4.8V, Vf = 2.5V -3 +3 % VISET ISET_LIM VDROPOUT ISC TSD ISET voltage 24kΩ ≤ RSET ≤ 494kΩ 1.235 V ISET current limit VLED+ = 0V, VISET = 0V 150 μA Current mirror ratio IOUT / ISET 400 Dropout voltage ILED = 20mA, -10% drop 40 Short-circuit current limit RSET or IOUT w.r.t GND 60 Rising Temperature at Junction 150 °C Hysteresis 20 °C Thermal shutdown FAN5645 — Indicator LED Blinker with Single-Wire Interface Electrical Specifications mV 80 mA Timing fOSC Internal oscillator frequency TOSC Oscillator stability VIN = 3.6V 51 64 -3 tON LED on-time resolution (1) tOFF LED off-time resolution (1) 77 kHz 3 % 1 ms 10 ms Note: 1. Guaranteed by design; not tested in production. © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 www.fairchildsemi.com 4 1. Two control pulses, finished within TCMD1. The HIGH time of the control pulses should be greater than 2µs and less than 55µs. The LOW time between two control pulses should be greater than 2µs. Operational Modes At power up, the device is in STOP (“SLEEP”) mode until a rising edge of a CTRL signal is detected and the device goes into active mode. Depending upon the signal applied to CTRL, active mode can be TRAINING, RUN, RUN ONCE, or FOLLOW AFTER RESET. 2. CTRL held LOW, for at least TFTPR(MIN), but less than TFTPR(MAX), measured from the first rising edge of the control pulse. 3. Between one and three sets of training pulses, where a training pulse defines the LED’s on time TON and off-time TOFF. Initialization The reference and the circuit remain in SLEEP mode until VIN crosses the UVLO threshold and a rising edge on the CTRL pin is detected. When the IC is in SLEEP mode, all internal bias circuits are disabled. The training registers are all reset to 0 at power up. 4. Three control pulses finished within TCMD2 to signify end of training. The HIGH time of the control pulses should be greater than 2µs and less than 55µs. The LOW time between two control pulses should be greater than 2µs. Training Mode The IC can record a pattern of up to three distinct HIGH (TON) and LOW (TOFF) times. These times are recorded during training in six internal 8-bit counters, one counter for each distinct TON and TOFF time. If the training pulse ON or OFF time exceeds the maximum clock counts, the value is held at the maximum. 5. The IC enters STOP (SLEEP) mode and is able to receive a new command only after TCMD2 expires. 6. If no end-of-training controls pulses are received after TOFF3 maximizes out, the IC enters STOP (SLEEP) mode automatically. TRAINING mode contains the following sequence: TFTPR TCMD1 TCPHIGH T CMD2 CTRL TON1 TCPLOW TOFF1 TON2 TOFF2 TON3 TOFF3 FAN5645 — Indicator LED Blinker with Single-Wire Interface Circuit Description Figure 4. TRAINING Mode RUN Mode When CTRL is raised and held HIGH, and training registers are not all zeros, repetitive playback of the trained sequence commences. The delay between CTRL HIGH and LED on is TDLY1. When CTRL subsequently goes LOW, the IC turns off the LED and enters STOP (SLEEP) mode. After a TCMD2 time, a new command can be processed. T DLY CTRL Trained Sequence LED TON1 Figure 5. RUN Mode Run Once Mode When the IC receives four consecutive control pulses within TCMD1, followed by CTRL going HIGH after at least TFTPR(MIN), but less than TFTPR(MAX), the IC plays back the trained pattern once, then enters STOP (SLEEP) mode after the trained sequence is completed. This assumes that training registers are not all zeros. TFTPR TCMD1 TCPHIGH CTRL TCPLOW Trained Sequence LED TON1 Figure 6. RUN ONCE Mode © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 www.fairchildsemi.com 5 set of control pulses. When the CTRL signal goes LOW, LED current is turned off and the IC enters STOP (SLEEP) mode. A TCMD2 waiting period, after the last trailing edge of the CTRL input, is necessary before a new command can be received and processed. TTIMEOUT TCPHIGH Note that FOLLOW mode can be entered upon power up as well, because all registers are cleared on power up and the device acts as if in RESET mode. CTRL TCPLOW CTRL Figure 7. RESET Mode After the IC goes through RESET mode; if CTRL goes HIGH again for longer than TDLY, the IC begins Follow mode, which causes the LED to be turned ON when CTRL is HIGH. The IC delays turning on the LED after the rising edge of CTRL by TDLY to determine whether the CTRL rising edge is to be interpreted as a command to turn the LED ON or the beginning of a new TDLY LED Figure 8. FOLLOW Mode Timing Symbol Description Min. TCMD1 Maximum time window in which starting control pulses must be finished TFTPR Time window from first control pulse rising edge to first rising edge of training pulse TCMD2 Maximum time window in which ending control pulses must be finished TTIMEOUT Minimum time window CTRL line has to stay LOW after control pulses to enter and finish RESET mode (starting from the first rising edge of the control pulse) 4.0 TDLY Time delay in playback or follow mode b/t rising edge of CTRL line to when LED turns ON for the first time 0.95 1.5 TCPHIGH Control pulse HIGH width 2 TCPLOW Control pulse LOW width 2 TON1 LED ON time in Run modes 1.0 TOFF1 LED OFF time in Run modes 10 TRESTART Over-temperature or over-current fault time in Follow mode Typ. Max. Units 0.8 ms 1.7 ms 0.85 ms FAN5645 — Indicator LED Blinker with Single-Wire Interface RESET and FOLLOW Modes Reset mode consists of two control pulses, then CTRL goes LOW for longer than TTIMEOUT. The IC clears all training registers to zero, then enters STOP (SLEEP) mode. ms 1.10 1.45 ms μs 55 μs 255.0 2550 10 ms ms ms Over-Current, Over-Temperature, and Under-Voltage Faults on the ISET pin. If a short-circuit or over-temperature fault occurs during playback modes, playback is retried when the next playback pulse (TON) comes. If a shortcircuit or over-temperature fault occurs during Follow mode, the LED turns off for TRESTART, then Follow mode tries to resume the LED current according to the current state of the CTRL line. An over-current fault occurs if the ISET pin is shorted to GND or the RSET resistor value is too low. If the resulting LED current is greater than three times the maximum programmed output current (60mA), the IC shuts down its output current and disables the reference voltage developed on the ISET pin. An over-temperature fault occurs when the IC exceeds 150°C, which also causes the IC to shut down its output current and disable the reference voltage developed on the ISET pin until the IC cools by about 20°C. If an under-voltage fault occurs, the IC turns off the LED and enters SLEEP mode until the next control pulse comes, at which point the IC tries to wake up. If either fault occurs, the IC turns off the output LED current and disables the reference voltage developed © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 www.fairchildsemi.com 6 Setting the LED Current Selecting External Components The LED forward current is established by the external resistor, RSET, according to: A ceramic capacitor of 0.1µF or more can be added between VIN and GND to reduce the electrical noise at the power supply line. ILED = 400 • 1.235V / RSET where 1.235V = Typical ISET voltage, and 400 = Typical current mirror ratio. EQ.1 The minimum value of VIN should exceed Vf by as little as 40mV to ensure the LED current is regulated at the right value. Conversely, the LED should be selected to have the Vf at the specified current, at least 40mV lower than the minimum VIN. The ILED accuracy is determined by the tolerance of the above parameters over the input voltage and the ambient temperature range as well the tolerance of the RSET resistance. For best accuracy, RSET should be a precision resistor, connected close to the IC pins, so that the voltage across RSET is identical to the voltage between the ISET and GND pins. The LEDs utilized as blinking indicators, driven by the FAN5645, may be white or any color. The forward current voltage characteristics and the absolute maximum ratings are provided by the manufacturer in their technical specifications. The typical forward voltage at 15mA current is 1.9V for red and orange, 2V for yellow, 2.1V for green, and 3.3V for bright white, bright non-yellowish green, and most blue types. Programming the LED ON times below 20 - 30ms appears as a flash, rather than as a blink with an observable ON time, to the observer. The brightness of such a flash is determined by the energy delivered during the flash. It is possible to change the apparent brightness by varying the ON / OFF time ratio, keeping the frequency higher than 40Hz. Meet the maximum rated current of the LED only under favorable conditions with little or no heat buildup. Some LED current ratings assume really favorable test conditions - such as surrounded by air no warmer than 25°C and decent thermal conduction from where the leads are mounted. Running LEDs at specified laboratory conditions used for maximum current rating can cause LEDs to lose half the light output after rated life expectancy (20,000 to 100,000 hours), best-case. Since the resolution of the ON time is in 1ms increments, a dimming function for 20 discrete levels of brightness can be implemented via software. © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 FAN5645 — Indicator LED Blinker with Single-Wire Interface Application Information www.fairchildsemi.com 7 Unless otherwise noted, VIN = VEN = 3.6V, TA = 25°C, white LED with Vf = 3.3V at ILED = 20mA. 20.20 25 V f=2.1V -40°C 20.10 LED Current (mA) LED Current (mA) 20.15 20.05 20.00 +25°C 19.95 19.90 19.85 20 -40°C 15 +25°C 10 +85°C 5 +85°C 19.80 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 0 0.01 0.02 0.03 VIN(V) Figure 9. Line Regulation 430 20 425 18 0.06 0.07 0.08 0.09 0.10 -40°C 420 Current Mirror Ratio 16 ILED (mA) 0.05 Figure 10. LED Current vs. Headroom Voltage 22 14 12 10 8 6 4 2 0 0.04 VIN(V)-VOUT(V) 10 100 415 410 RSET(k ) +25°C 405 400 395 +85°C 390 385 0 1000 FAN5645 — Indicator LED Blinker with Single-Wire Interface Typical Performance Characteristics 2 4 6 8 10 12 14 16 18 20 LED Current (mA) Figure 11. LED Current vs. RSET Resistance Figure 12. Current Mirror Ratio vs. Output Current Vf=2.5V VCTRL=1.2V VIN=3.7V VCTRL=0.4V VIN=3.0V ILED=20mA ILED(AC), 0.1mA/div. on top of 20mA ILED=0mA Horizontal Scale: 500µs/div. Horizontal Scale: 20µs/div. Figure 13. Line Transient Response © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 Figure 14. Active Modes Delay www.fairchildsemi.com 8 FAN5645 — Indicator LED Blinker with Single-Wire Interface Physical Dimensions Figure 15. 6-Pin Molded Leadless Package © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 www.fairchildsemi.com 9 FAN5645 — Indicator LED Blinker with Single-Wire Interface © 2006 Fairchild Semiconductor Corporation FAN5645 • Rev. 1.0.0 www.fairchildsemi.com 10