Supertex inc. HV9910C Universal High Brightness LED Driver Features ►► Switch mode controller for single switch LED drivers ►► Enhanced drop-in replacement to the HV9910B ►► Open loop peak current controller ►► Internal 15 to 450V linear regulator ►► Constant frequency or constant off-time operation ►► Linear and PWM dimming capability ►► Requires few external components for operation ►► Over-temperature protection Applications ►► ►► ►► ►► ►► ►► DC/DC or AC/DC LED driver applications RGB backlighting LED driver Back lighting of flat panel displays General purpose constant current source Signage and decorative LED lighting Chargers General Description The HV9910C is an open loop, current mode, control LED driver IC. The HV9910C can be programmed to operate in either a constant frequency or constant off-time mode. It includes a 15 – 450V linear regulator which allows it to work from a wide range of input voltages without the need for an external low voltage supply. HV9910C includes a TTL compatible PWM dimming input that can accept an external control signal with a duty ratio of 0 – 100% and a frequency of up to a few kilohertz. It also includes a 0 – 250mV linear dimming input which can be used for linear dimming of the LED current. As opposed to the HV9910B, the HV9910C is equipped with built-in thermalshutdown protection. The HV9910C is ideally suited for buck LED drivers. Since the HV9910C operates in open loop current mode control, the controller achieves good output current regulation without the need for any loop compensation. Also, being an open loop controller, PWM dimming response is limited only by the rate of rise of the inductor current, enabling a very fast rise and fall times of the LED current. The HV9910C requires only three external components (apart from the power stage) to produce a controlled LED current making it an ideal solution for low cost LED drivers. Typical Application Circuit CIN CO D1 CDD L1 VIN VDD HV9910C LD GATE PWMD RT ROSC Doc.# DSFP-HV9910C NR041813 Q1 CS GND RCS Supertex inc. www.supertex.com HV9910C Ordering Information Pin Description Part Number Package Option Packing VIN 1 16 NC HV9910CLG-G 8-Lead SOIC 2500/Reel NC 2 15 NC HV9910CNG-G 16-Lead SOIC 45/Tube NC 3 14 RT HV9910CNG-G M934 16-Lead SOIC 2500/Reel -G denotes a lead (Pb)-free / RoHS compliant package Absolute Maximum Ratings CS 4 13 LD VIN 1 8 RT GND 5 12 VDD CS 2 7 LD NC 6 11 NC 6 VDD NC 7 10 NC GATE 8 9 PWMD GND 3 Parameter Value VIN to GND -0.5V to +470V VDD to GND 12V CS, LD, PWMD, GATE GATE 4 8-Lead SOIC -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 9910C LLLL Package may or may not include the following marks: Si or 8-Lead SOIC 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. Top Marking HV9910CNG YWW LLLLLLLL Bottom Marking Thermal Resistance CCCCCCCCC AAA θja 8-Lead SOIC 101OC/W 16-Lead SOIC 83OC/W Y = Last Digit of Year Sealed WW = Week Sealed L = Lot Number C = Country of Origin* A = Assembler ID* = “Green” Packaging *May be part of top marking Package may or may not include the following marks: Si or 16-Lead SOIC Electrical Characteristics (The specifications are at T = 25°C and V A Sym Y = Last Digit of Year Sealed WW = Week Sealed L = Lot Number = “Green” Packaging YWW 650mW 1300mW Package 16-Lead SOIC Product Marking -0.3V to (VDD +0.3V) Junction temperature range 5 PWMD Description IN = 15V, unless otherwise noted.) Min Typ Max Units Conditions Input VINDC Input DC supply voltage range1 * 15 - 450 V IIN(MAX) Supply current - - 0.8 1.5 mA Pin PWMD to VDD, no capacitance at GATE Shut-down mode supply current - - 0.5 1.0 mA Pin PWMD to GND IINSD DC input voltage Notes: 1. Also limited by package power dissipation limit, whichever is lower. * Denotes the specifications which apply over the full operating ambient temperature range of -40°C < TA < +125°C. # Guaranteed by design. Doc.# DSFP-HV9910C NR041813 2 Supertex inc. www.supertex.com HV9910C Electrical Characteristics (cont.) (The specifications are at T = 25°C and V A Sym Description IN = 15V, unless otherwise noted.) Min Typ Max Units Conditions Internal Regulator Internally regulated voltage - 7.25 7.50 7.75 V VIN = 15V, IDD(ext) = 0, PWMD = VDD, 500pF at GATE; ROSC = 249kΩ ΔVDD, line Line regulation of VDD - 0 - 1.0 V VIN = 15 - 450V, IDD(ext) = 0, PWMD = VDD, 500pF at GATE; ROSC = 249kΩ ΔVDD, load Load regulation of VDD - 0 - 0.1 V IDD(ext) = 0 - 1.0mA, PWMD = VDD, 500pF at GATE; ROSC = 249kΩ UVLO VDD undervoltage lockout threshold * 6.45 6.70 6.95 V VDD rising ∆UVLO VDD undervoltage lockout hysteresis - - 500 - mV VDD falling Maximum regulator current # 5.0 - - mA VDD = UVLO - ∆UVLO VDD IIN(MAX) PWM Dimming VEN(lo) PWMD input low voltage * - - 1.0 V VIN = 15 - 450V VEN(hi) PWMD input high voltage * 2.4 - - V VIN = 15 - 450V Internal pull-down resistance at PWMD - 50 100 150 kΩ VPWMD = 5.0V Current sense pull-in threshold voltage - 225 250 275 mV -40°C < TA < +125°C VOFFSET Offset voltage for LD comparator * -12 - +12 mV --- TBLANK Current sense blanking interval * 150 215 280 ns VCS = 0.55VLD, VLD = VDD tDELAY Delay to output - - 80 150 ns VIN = 15V, VLD = 0.15, VCS = 0 to 0.22V after tBLANK - 20 25 30 - 80 100 120 Maximum GATE sourcing current - 0.165 - - A VGATE = 0V ISINK Maximum GATE sinking current - 0.165 - - A VGATE = VDD tRISE GATE output rise time # - 30 50 ns CGATE = 500pF tFALL GATE output fall time # - 30 50 ns CGATE = 500pF Shut-down temperature - 128 - 150 O Hysteresis - 10 - 30 TSD-mode VIN current - - - 350 REN Current Sense Comparator VCS Oscillator fOSC Oscillator frequency kHz ROSC = 1.00MΩ ROSC = 249kΩ GATE Driver ISOURCE Over-Temperature Protection TSD ∆TSD ISD C --- O C --- μA --- Notes: 1. Also limited by package power dissipation limit, whichever is lower. * Denotes the specifications which apply over the full operating ambient temperature range of -40°C < TA < +125°C. # Guaranteed by design. Doc.# DSFP-HV9910C NR041813 3 Supertex inc. www.supertex.com HV9910C Application Information The HV9910C is optimized to drive buck LED drivers using open-loop peak current mode control. This method of control enables fairly accurate LED current control without the need for high side current sensing or the design of any closed loop controllers. The IC uses very few external components and enables both Linear and PWM dimming of the LED current. and any external resistor dividers needed to control the IC. The VDD pin must be bypassed by a low ESR capacitor to provide a low impedance path for the high frequency current of the output GATE driver. The HV9910C can also be operated by supplying a voltage at the VDD pin greater than the internally regulated voltage. This will turn off the internal linear regulator of the IC and the HV9910C will operate directly off the voltage supplied at the VDD pin. Please note that this external voltage at the VDD pin should not exceed 12V. A resistor connected to the RT pin programs the frequency of operation (or the off-time). The oscillator produces pulses at regular intervals. These pulses set the SR flip-flop in the HV9910C which causes the GATE driver to turn on. The same pulses also start the blanking timer which inhibits the reset input of the SR flip flop and prevent false turn-offs due to the turn-on spike. When the FET turns on, the current through the inductor starts ramping up. This current flows through the external sense resistor Rcs and produces a ramp voltage at the CS pin. The comparators are constantly comparing the CS pin voltage to both the voltage at the LD pin and the internal 250mV. Once the blanking timer is complete, the output of these comparators is allowed to reset the flip flop. When the output of either one of the two comparators goes high, the flip flop is reset and the GATE output goes low. The GATE goes low until the SR flip flop is set by the oscillator. Assuming a 30% ripple in the inductor, the current sense resistor Rcs can be set using: RCS = Although the VIN pin of the HV9910C is rated up to 450V, the actual maximum voltage that can be applied is limited by the power dissipation in the IC. For example, if an 8-lead SOIC (junction to ambient thermal resistance Rθj-a = 101°C/W) HV9910C draws about IIN = 2.0mA from the VIN pin, and has a maximum allowable temperature rise of the junction temperature limited to ΔT = 75°C, the maximum voltage at the VIN pin would be: VIN(MAX) = = ● Rθja 1 IIN 75OC 101 C/W O ● 1 2mA = 371V 0.25V (or VLD ) 1.15 • ILED In these cases, to operate the HV9910C from higher input voltages, a Zener diode can be added in series with the VIN pin to divert some of the power loss from the HV9910C to the Zener diode. In the above example, using a 100V zener diode will allow the circuit to easily work up to 450V. Note: The Zener diode will increase the minimum input voltage required to turn on the HV9910C to 115V. Constant frequency peak current mode control has an inherent disadvantage – at duty cycles greater than 0.5, the control scheme goes into subharmonic oscillations. To prevent this, an artificial slope is typically added to the current sense waveform. This slope compensation scheme will affect the accuracy of the LED current in the present form. However, a constant off-time peak current control scheme does not have this problem and can easily operate at duty cycles greater than 0.5 and also gives inherent input voltage rejection making the LED current almost insensitive to input voltage variations. But, it leads to variable frequency operation and the frequency range depends greatly on the input and output voltage variation. HV9910C makes it easy to switch between the two modes of operation by changing one connection (see oscillator section). The input current drawn from the VIN pin is a sum of the 1.5mA (maximum) current drawn by the internal circuit and the current drawn by the GATE driver (which in turn depends on the switching frequency and the GATE charge of the external FET). IIN = 1.5mA + Qg • fs In the above equation, fs is the switching frequency and Qg is the GATE charge of the external FET (which can be obtained from the datasheet of the FET). Input Voltage Regulator The HV9910C can be powered directly from its VIN pin and can work from 15 - 450VDC at its VIN pin. When a voltage is applied at the VIN pin, the HV9910C maintains a constant 7.5V at the VDD pin. This voltage is used to power the IC Doc.# DSFP-HV9910C NR041813 ΔT Current Sense The current sense input of the HV9910C goes to the noninverting inputs of two comparators. The inverting terminal 4 Supertex inc. www.supertex.com HV9910C of one comparator is tied to an internal 250mV reference whereas the inverting terminal of the other comparator is connected to the LD pin. The outputs of both these comparators are fed into an OR GATE and the output of the OR GATE is fed into the reset pin of the flip-flop. Thus, the comparator which has the lowest voltage at the inverting terminal determines when the GATE output is turned off. ► Linear dimming may be desired to adjust the current level to reduce the intensity of the LEDs. In these cases, an external 0-250mV voltage can be connected to the LD pin to adjust the LED current during operation. The outputs of the comparators also include a 150-280ns blanking time which prevents spurious turn-offs of the external FET due to the turn-on spike normally present in peak current mode control. In rare cases, this internal blanking might not be enough to filter out the turn-on spike. In these cases, an external RC filter needs to be added between the external sense resistor (RCS) and the CS pin. Note: Although the LD pin can be pulled to GND, the output current will not go to zero. This is due to the presence of a minimum on-time (which is equal to the sum of the blanking time and the delay to output time) which is about 450ns. This will cause the FET to be on for a minimum of 450ns and thus the LED current when LD = GND will not be zero. This current is also dependent on the input voltage, inductance value, forward voltage of the LEDs and circuit parasitics. To get zero LED current, the PWMD pin has to be used. To use the internal 250mV, the LD pin can be connected to VDD. Please note that the comparators are fast (with a typical 80ns response time). A proper layout minimizing external inductances will prevent false triggering of these comparators. PWM Dimming PWM Dimming can be achieved by driving the PWMD pin with a low frequency square wave signal. When the PWM signal is zero, the GATE driver is turned off and when the PWMD signal if high, the GATE driver is enabled. Since the PWMD signal does not turn off the other parts of the IC, the response of the HV9910C to the PWMD signal is almost instantaneous. The rate of rise and fall of the LED current is thus determined solely by the rise and fall times of the inductor current. Oscillator The oscillator in the HV9910C is controlled by a single resistor connected at the RT pin. The equation governing the oscillator time period Tosc is given by: Tosc (µs) = Rosc (kΩ) 25 If the resistor is connected between RT and GND, HV9910C operates in a constant frequency mode and the above equation determines the time-period. If the resistor is connected between RT and GATE, the HV9910C operates in a constant off-time mode and the above equation determines the off-time. To disable PWM dimming and enable the HV9910C permanently, connect the PWMD pin to VDD. Over-Temperature Protection The auto-recoverable thermal shutdown at 140°C (typ.) junction temperature with 20°C hysteresis is featured to avoid thermal runaway. When the junction temperature reaches TSD = 140°C (typ.), the HV9910C enters a low power consumption shut-down mode with IIN <350µA. GATE Output The gate output of the HV9910C is used to drive an external FET. It is recommended that the GATE charge of the external FET be less than 25nC for switching frequencies ≤ 100kHz and less than 15nC for switching frequencies > 100kHz. Linear Dimming The Linear Dimming pin is used to control the LED current. There are two cases when it may be necessary to use the Linear Dimming pin. ► In some cases, it may not be possible to find the exact RCS value required to obtain the LED current when the internal 250mV is used. In these cases, an external voltage divider from the VDD pin can be connected to the LD pin to obtain a voltage (less than 250mV) corresponding to the desired voltage across RCS. Doc.# DSFP-HV9910C NR041813 5 Supertex inc. www.supertex.com HV9910C Block Diagram VIN VDD + + LD CS POR 1.25V Bandgap Reference Blanking OTP R + - 250mV GATE Q S Oscillator GND RT PWMD Pin Description Pin # Function Description 8-Lead SOIC 16-Lead SOIC 1 1 VIN This pin is the input of an 15 - 450V linear regulator. 2 4 CS This pin is the current sense pin used to sense the FET current by means of an external sense resistor. When this pin exceeds the lower of either the internal 250mV or the voltage at the LD pin, the GATE output goes low. 3 5 GND Ground return for all internal circuitry. This pin must be electrically connected to the power ground. 4 8 GATE This pin is the output GATE driver for an external N-channel power MOSFET. 5 9 PWMD This is the TTL compatible PWM dimming input of the IC. When this pin is pulled to GND or left open, the GATE driver is turned off. When the pin is pulled high, the GATE driver operates normally. 6 12 VDD This is the power supply pin for all internal circuits. It must be bypassed with a low ESR capacitor to GND (≥0.1μF). 7 13 LD This pin is the linear dimming input and sets the current sense threshold as long as the voltage at the pin is less than 250mV (typ). 8 14 RT This pin sets the oscillator frequency. When a resistor is connected between RT and GND, the HV9910C operates in constant frequency mode. When the resistor is connected between RT and GATE, the IC operates in constant off-time mode. - 2, 3, 6, 7, 10, 11, 15, 16 NC No connection Doc.# DSFP-HV9910C NR041813 6 Supertex inc. www.supertex.com HV9910C 8-Lead SOIC (Narrow Body) Package Outline (LG) 4.90x3.90mm body, 1.75mm height (max), 1.27mm pitch θ1 D 8 Note 1 (Index Area D/2 x E1/2) E1 E L2 L 1 θ L1 Top View View B Note 1 Gauge Plane Seating Plane View B h A h A A2 Seating Plane A1 e b Side View View A-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 θ θ1 0O 5O - - 8O 15O 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. Doc.# DSFP-HV9910C NR041813 7 Supertex inc. www.supertex.com HV9910C 16-Lead SOIC (Narrow Body) Package Outline (NG) 9.90x3.90mm body, 1.75mm height (max), 1.27mm pitch D θ1 16 Note 1 (Index Area D/2 x E1/2) E1 E Gauge Plane L2 e 1 L1 b Top View Seating Plane θ View B A A2 A L View B h h Seating Plane A1 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. ©2013 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited. Doc.# DSFP-HV9910C NR041813 8 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com