Supertex inc. HV9801A Switch Dimmable LED Driver Features General Description Applications Through switch dimming, the lamp can be adjusted to four discrete brightness levels by rapid cycling of the light switch. The brightness levels are traversed in up and down manner. Brightness resumes at the highest level when power is removed for more than a second. ►► ►► ►► ►► ►► Four level switch dimming Very accurate current regulator Output over-current / short circuit protection IC over-temperature protection Available in 8L-SOIC and 16L-SOIC packages The HV9801A LED driver is ideally suited for switch dimmable applications using LED bulbs and fixtures. ►► Switch dimmable LED bulbs and fixtures The device can be powered directly from rectified AC through an internal VDD regulator rated at 450V. Typical Application Circuit VIN BUS AC L VIN GATE HV9801A CS GND VDD CDD Supertex inc. RT RT RCS ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com HV9801A Ordering Information Pin Description Package Options Device 8-Lead SOIC 16-Lead SOIC 4.90x3.90mm body 1.75mm height (max) 1.27mm pitch 9.90x3.90mm body 1.75mm height (max) 1.27mm pitch HV9801ALG-G HV9801ANG-G HV9801A VIN 1 16 DNC DNC 2 15 DNC DNC 3 14 RT CS 4 13 DNC 8 RT GND 5 12 VDD CS 2 7 DNC DNC 6 11 DNC GND 3 6 VDD DNC 7 10 DNC GATE 4 5 DNC GATE 8 VIN 1 -G indicates package is RoHS compliant (‘Green’) 8-Lead SOIC (LG) 9 DNC 16-Lead SOIC (NG) Caution! DNC means Do Not Connect! Absolute Maximum Ratings Parameter Value VVIN 470V VVDD 12V VCS, VLD, VPWMD, VGATE Product Marking 9801A LLLL -0.3V to (VVDD +0.3V) Junction temperature range -40°C to +150°C Storage temperature range -65°C to +150°C Continuous power dissipation (TA = +25°C) 8-Lead SOIC 16-Lead SOIC Y = Last Digit of Year Sealed WW = Week Sealed L = Lot Number = “Green” Packaging YWW Package may or may not include the following marks: Si or 8-Lead SOIC (LG) Top Marking Y = Last Digit of Year Sealed WW = Week Sealed L = Lot Number C = Country of Origin* A = Assembler ID* = “Green” Packaging HV9801ANG 650mW 1000mW YWW LLLLLLLL Bottom Marking Stresses beyond those listed under “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 the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. CCCCCCCCC AAA *May be part of top marking Package may or may not include the following marks: Si or 16-Lead SOIC (NG) Electrical Characteristics (Specifications are at TA = 25°C, VVIN = 15V unless otherwise noted) Sym Description Min Typ Max Unit Conditions Input VVIN Input voltage T 15 - 450 V --- IVIN Input current - - 1 2 mA --- Supply current, OTP shutdown G - - 500 μA --- IVIN,OT VDD Regulator VUVLO Undervoltage lockout threshold T 6.45 6.70 7.10 V VVIN rising ΔVUVLO Undervoltage lockout hysteresis - - 500 - mV VVIN falling Maximum input current, limited by UVLO G 3.5 - - mA TA = 25°C 1.5 - - mA TA = 125°C IUVLO Notes: G Not production tested; guaranteed by design or characterization. T Specifications apply over the full operating ambient temperature range of -40°C < TA < +125°C. Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com 2 HV9801A Electrical Characteristics (Specifications are at T A Sym Description = 25°C, VVIN = 15V unless otherwise noted) Min Typ Max Unit Conditions VDD Regulator (cont.) VVDD Output voltage - 7.25 7.50 7.75 V CGATE = 500pF; RRT = 226kΩ ΔVLINE Line regulation - - - 1 V VIN = 15 to 450V; CGATE = 500pF; RRT = 226kΩ ΔVDD(UV) VDD Voltage margin T 500 - - mV ΔVDD(UV) = VDD - UVLO ΔVLOAD Load regulation - - - 100 mV IVDD = 0 to 1mA; CGATE = 500pF; RRT = 226kΩ Switch Dimming IVDDX Supply current after power loss T - - 700 μA --- VUVLO Undervoltage lockout during VIN power loss - - 3.5 - V --- TPL1 Power loss, qualification-time - - 7 - ms TPL2 Power loss, time to reset G - 1 - s FPWM PWM dimming frequency - - 1.2 - kHz --- VVIN falling below VUVLO LED Current Regulator VCST Current sense threshold T 236 250 256 mV --- TLEB Leading edge blanking time T 110 - 260 ns --- TONX Minimum on-time - - - 760 ns VCS = VCST + 30mV DMAX Maximum duty cycle maintaining regulation - 80 - - % LED current falls beyond this duty cycle Short Circuit Protection VCSH Hiccup threshold - - 440 - mV --- TDLY VCS high to GATE low delay - - - 180 ns VCS = VCST + 30mV TSCH Hiccup time - - 750 - μs --- TONX Minimum on-time - - - 430 ns CS = VDD - 32 40 48 - 8.0 10 12 TOFF Timer TOFF Off-time μs RRT = 1MΩ RRT = 226kΩ GATE Driver ISRC Sourcing current - 165 - - mA VGATE = 0V ISINK Sinking current - 165 - - mA VGATE = VDD tRISE Rise time - - 30 50 ns CGATE = 500pF tFALL Fall time - - 30 50 ns CGATE = 500pF Trip temperature G - 140 - °C --- Hysteresis G - 20 - °C --- Over-temperature Protection TTRIP ΔTTRIP Notes: G Not production tested; guaranteed by design or characterization. T Specifications apply over the full operating ambient temperature range of -40°C < TA < +125°C. Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com 3 HV9801A Functional Block Diagram VIN GND VDD Regulator OTP VDD CS UVLO Leading Edge Blanking 250mV OR Hiccup 440mV S Q R Q OFF Time Generator HV9801A Current Mirror from VDD Rail Application Information Current Control Continuous Conduction Mode The HV9801A is designed for control of a buck converter operating in continuous conduction mode. CCM operation is characterized by converter operation with non-zero inductor current throughout the switching cycle. Such operation can be achieved by selection of the inductance. LED Current The HV9801A regulates the LED current with an accuracy far superior to that of competing peak current mode controllers. Average LED current is set by the current sense resistor RCS and the current regulator reference voltage : V = (I) • (R) 250mV = (ILED ) • (RRCS ) For example, a 2Ω resistor correponds to a 125mA (average) LED current. Current Control Performance The control method of the HV9801A virtually eliminates the regulation errors associated with peak current mode controllers, such as errors caused by: inductor tolerance; propagation delay of the current sense comparator; tolerance in the oscillator frequency or off-timer; and changes in line and load voltage. Fig. 1 compares the load regulation of the HV9801A and that of a device with peak current control. The difference in load regulation between the HV9801A and the HV9910B, a peak current regulator, is clearly visible. Output Characteristics 0.60 VIN = 170VDC 0.55 LED Current, A RT GATE AND Average Current Regulator HV9801A 0.50 0.45 0.40 HV9910B 0.35 0.30 0.25 0 10 20 30 40 Output Voltage, V 50 60 Fig.1. Typical output characteristic of the HV9801A LED driver. Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com 4 HV9801A Duty Cycle, Off-time, On-time, Inductor Duty cycle The duty cycle (D) is related to the load voltage (VLED) and input voltage (VBUS) by the simple relation: VOUT = (D) • (VIN ) Off-time The HV9801A employs constant off-time control. Operation with constant off-time suppresses subharmonic oscillation. Switching period and switching frequency are related to ontime and off-time as follows: TSW = (TON + TOFF ) FSW = 1 / TSW On-time is related to off-time and duty cycle as follows: (L) • (ΔI) = (V) • (ΔT) (L) • (PPR) • (ILED ) = (VLED ) • (TOFF ) For instance, 30% PPR on 350mA average current equates to 105mA ripple, which together with 5µs off-time, and 30V LED string voltage corresponds to 1.43mH inductance. VLED = (D) • (VBUS ) Inductance can be calculated from the current drop during off-time: D = (TON ) / (TON + TOFF ) A design with 30V LED voltage and with 150V bus voltage corresponds to 20% duty cycle; respectively, with a 120V bus voltage to 25% duty cycle. 20% duty cycle corresponds to 1.25µs on-time, 25% duty cycle corresponds to 1.67µs. Hence, the switching frequency is 167kHz at 150V bus voltage and 150kHz at 120V bus voltage. Maximum Duty Cycle Duty cycle should be limited to the specified maximum (80%). Accordingly, the LED string voltage and the bus voltage are limited to the same ratio. Operation at a larger duty cycle results in an LED current lower than programmed. With a given TOFF, the HV9801A dynamically adjusts TON to regulate the LED current. Specifically, TON adapts to the duty cycle associated with given VBUS and VLED. Minimum Duty Cycle Duty cycle is limited on the low side by the minimum on-time specification (760ns). Operation at a smaller on-time causes the LED current to exceed the programmed value. Off-time Programming Off-time is programmed by the RT resistor: LED string voltage can not be made arbitrarily low. Minimum LED voltage can be determined from the following: TOFF = (A) • (RRT) + B where A = 40ps / Ω and B = 300ns VLED = (DMIN ) • (VBUS ) For instance, a 200kΩ resistor corresponds to 8.3μs off-time. An acceptable range for RT is 30kΩ to 1MΩ, corresponding to an off-time range between 1.5µs and 40.3µs. Inductor The converter should operate in continuous conduction mode. As such, the inductor current should not fall to zero within a switching cycle, and inductor current ripple should be sized accordingly. A common choice for peak-to-peak Inductor current ripple (PPR) is 30 to 40% of nominal LED current. Supertex inc. DMIN = (TONX ) / (TOFF + TONX ) For instance, with 5µs off-time, the duty cycle should be kept above 13%. Such a duty cycle corresponds to an LED string voltage of 19.5V at 150V bus voltage. A design requiring a lower LED string voltage requires change to a longer off-time. Short Circuit Protection A rise of the LED current sense signal above 440mV (176% of nominal) trips the short circuit comparator thereby causing the converter to switch to hiccup mode. In hiccup mode, off-time is lengthened to about 750µs to allow the inductor current to drop to a safe level. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com 5 HV9801A Without the extended off-time the inductor current increases with every switching cycle, thereby causing over-current damage to the converter. The extension of the off-time can be observed in Fig.2: 440mV/RCS S illustration below. The sequence starts at 100% and adjusts to a lower level with the following step. Upon reaching the highest or lowest level the direction of the sequence reverses. When power is removed for more than one second, the dimming sequence is terminated and brightness is reset to 100% upon turn-on of the light switch. VDD Capacitor The VDD voltage should be maintained for at least one second and above the 3.5V level after loss of VIN power to allow certain timing circuits to function. ~750µs Fig.2. Short-circuit inductor current. Leading Edge Blanking The MOSFET drain current, and thereby the current sense signal, exhibits a spike at the start of a switching cycle which arises from the MOSFET gate charging current and the current required for discharge of the MOSFET drain node. These two currents typically exceed the inductor by quite a margin. The current sense signal is blanked at the start of the switching cycle in order to avoid a premature trigger of the current sense and the short circuit protection comparators. VDD Regulator The VDD regulator generates a source of regulated voltage for operation of internal and external circuits from the power applied at the VIN pin. Alternatively, the VDD voltage can be supplied from a source directly connected to the VDD pin. The VDD regulator will turn off. Switch Dimming The minimum required capacitance can be calculated from: (C) • (ΔV) = (I) • (ΔT) (CCDD) • (7.5 - 3.5V) = (IVDDX) • (1s) With 700µA of IVDDX the bypass capacitance should be 175µF. Detection of Power Cycling The presence of AC line power is detected at the VIN pin. To this end, loss of AC power should result in a rapidly falling voltage at the output of the bridge rectifier. The VVIN voltage drops due to the current draw from the VDD regulator. In order to facilitate a quick fall of the voltage, a diode should be added to isolate the bus capacitor from the VIN pin as shown in the Typical Application Circuit. AC Line Power ON/OFF cycle time 1second (max.) ON General Lamp brightness can be adjusted to one of four discrete levels by rapidly cycling power with the light switch. The brightness levels are traversed in an up and down manner, the levels being 100%, 50%, 25% and 12.5%. Brightness resumes at the highest level when power is removed for more than a second. Brightness 100% 50% 25% 12.5% 25% Fig.3. LED brightness and AC line power. Reduction of LED current is accomplished through PWM dimming with a PWM dimming frequency of about 1kHz. The PWM frequency is generated by an internal oscillator and the duty cycle by means of digital logic. Turning the light switch off and on within one second adjusts LED current to the next higher or lower level, see the Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com 6 100% HV9801A Pin Description Pin # 8-Lead SOIC 16-Lead SOIC Function Description 1 1 VIN Connect to bridge rectifier output. Supplies power to the VDD regulator. Detects light switch power-off event through loss of bridge rectifier output voltage. Do not connect excessive capacitance before or after the bridge so as to allow VIN to drop rapidly after loss of power. 2 4 CS Current sense input. 3 5 GND Ground. 4 8 GATE Gate driver output. 6 12 VDD VDD regulator output. Connect a high frequency bypass and a hold-up capacitor at VDD. Bypass capacitor to be 100nF minimum. See applications section for hold-up capacitance. 8 14 RT 5, 7 2, 3, 6, 7, 9, 10, 11, 13, 15, 16 DNC Supertex inc. Off-time programming input. Connect programming resistor to GND. Caution! DNC means Do Not Connect! ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com 7 HV9801A 8-Lead SOIC (Narrow Body) Package Outline (LG) 4.90x3.90mm body, 1.75mm height (max), 1.27mm pitch D θ1 8 E E1 L2 Note 1 (Index Area D/2 x E1/2) L 1 θ L1 Top View Gauge Plane Seating Plane View B A View B Note 1 h h A A2 Seating Plane b e A1 A Side View View A-A Note: 1. This chamfer feature is optional. A Pin 1 identifier must be located in the index area indicated. The Pin 1 identifier can be: a molded mark/identifier; an embedded metal marker; or a printed indicator. Symbol Dimension (mm) A A1 A2 b MIN 1.35* 0.10 1.25 0.31 NOM - - - - MAX 1.75 0.25 1.65* 0.51 D E E1 4.80* 5.80* 3.80* 4.90 6.00 3.90 5.00* 6.20* 4.00* e 1.27 BSC h L 0.25 0.40 - - 0.50 1.27 L1 1.04 REF L2 0.25 BSC JEDEC Registration MS-012, Variation AA, Issue E, Sept. 2005. * This dimension is not specified in the JEDEC drawing. Drawings are not to scale. Supertex Doc. #: DSPD-8SOLGTG, Version I041309. Supertex inc. ● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com 8 θ θ1 0O 5O - - 8O 15O HV9801A 16-Lead SOIC (Narrow Body) Package Outline (NG) 9.90x3.90mm body, 1.75mm height (max), 1.27mm pitch D 16 θ1 E1 E Note 1 (Index Area D/2 x E1/2) Gauge Plane L2 1 L Top View View B A A A2 e A1 View B h Note 1 h Seating Plane Seating Plane θ L1 b Side View View A-A A Note: 1. This chamfer feature is optional. If it is not present, then a Pin 1 identifier must be located in the index area indicated. The Pin 1 identifier can be: a molded mark/identifier; an embedded metal marker; or a printed indicator. Symbol Dimension (mm) A A1 A2 b D E E1 MIN 1.35* 0.10 1.25 0.31 9.80* 5.80* 3.80* NOM - - - - 9.90 6.00 MAX 1.75 0.25 1.65* 0.51 3.90 10.00* 6.20* 4.00* e 1.27 BSC h L 0.25 0.40 - - 0.50 1.27 L1 L2 1.04 0.25 REF BSC θ θ1 0O 5O - - 8O 15O JEDEC Registration MS-012, Variation AC, Issue E, Sept. 2005. * This dimension is not specified in the JEDEC drawing. Drawings are not to scale. Supertex Doc. #: DSPD-16SONG, Version G041309. (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to http://www.supertex.com/packaging.html.) Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com) Supertex inc. ©2011 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited. Doc.# DSFP-HV9801A A122111 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com 9