LTM8005EY#PBF

LTM8005 38VIN Boost µModule Regulator for LED Drive with 10A Switch FEATURES DESCRIPTION Wide Input Voltage Range: 5V to 38V nn Supports Boost or SEPIC Power Topologies nn Adjustable LED Current Up to 1.6A nn 40V 10A Internal Power Switch nn Wide Temperature Range: –40°C to 150°C nn Input and Output Current Reporting nn Internal Switch for PWM and Output Disconnect nn Internal Spread Spectrum Frequency Modulation nn 3000:1 True Color PWM™ Dimming nn Open LED Protection with OPENLED Flag nn Short-Circuit Protection and SHORTLED Flag nn Soft-Start with Programmable Fault Restart Timer nn 9mm × 11.25mm × 2.22mm BGA The LTM®8005 is a 38VIN, 38VOUT boost µModule (power micromodule) LED driver designed to regulate current or voltage and is ideal for driving LEDs. The fixed frequency and current mode architecture result in stable operation over a wide range of supply and output voltages. Spread spectrum frequency modulation (SSFM) can be activated for improved electromagnetic compatibility (EMC) performance. The ground-referred voltage FB pin serves as the input for several LED protection features, and also allows the converter to operate as a constant voltage source. The PWM input provides LED dimming ratios of up to 3000:1, and the CTRL inputs provide additional analog dimming capability. nn The low profile package enables utilization of unused space on the bottom of PC boards. The LTM8005 is packaged in thermally enhanced, compact over-molded Ball Grid Array (BGA) package suitable for automated assembly by standard surface mount equipment. The LTM8005 is RoHS compliant. APPLICATIONS nn nn High Power LED, High Voltage LED Accurate Current-Limited Voltage Regulators All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION 350mA at 30.5V to 35.5V LED String from 6V to 27V VIN (Boost) with Spread Spectrum L 8.2µH VIN 6V TO 27V VIN 1M CIN 2× 4.7µF 50V IVINP IVINN SW DA EN/UVLO COUT 2× 4.7µF 50V VOUT 93.1k OVLO ISN 19.1k LTM8005 LED PWM AUX VREF 374k CTRL1 FB 100k ISMON CTRL2 18.7k L: COILCRAFT XAL7030-822ME CIN, COUT: MURATA GRM31CR71H475KA12 PIN NOT USED IN THIS CIRCUIT: IVINCOMP SS VC 0.1µF RT 4.7k 10nF GND 12.4k OPENLED SHORTLED RAMP 23.2k f = 350kHz LED STRING 0.1µF 6.8nF 8005 TA01a Rev. B Document Feedback For more information www.analog.com 1 LTM8005 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) OPENLED SHORTLED RAMP TOP VIEW VIN, EN/UVLO, IVINN, IVINP......................................50V ISN Above LED...........................................................40V SW, ISN, LED, VOUT, VOUT-DA...................................40V CTRL1, CTRL2 ………………....................................15V PWM, SHORTLED, OPENLED....................................12V FB, OVLO.....................................................................8V Maximum Junction Temperature (E-Grade, I-Grade)............................................. 125°C Maximum Junction Temperature (H-Grade)........... 150°C Storage Temperature............................................. 150°C Peak Solder Reflow Body Temperature.................. 260°C GND 8 BANK 4 VOUT BANK 5 BANK 6 PWM CTRL2 7 ISN LED VREF 6 CTRL1 BANK 3 DA 5 RT BANK 1 4 SS GND BANK 2 3 VC AUX IVINN IVINP SW 2 FB ISMON VIN EN/UVLO 1 A B C D F E G OVLO GND J H K IVINCOMP BGA PACKAGE 80-Pad (11.25mm × 9mm × 2.22mm) θJA = 19.3°C/W, θJCBOTTOM = 3.0°C/W, θJCTOP = 16.3°C/W, θJB = 7.2°C/W, WEIGHT = 0.4g θ VALUES DETERMINED PER JEDEC 15-9, 51-12 ORDER INFORMATION Part Number Terminal Finish LTM8005EY#PBF Part Marking* Package Type MSL Rating Temperature Range e1 BGA 3 –40°C to 125°C LTM8005 e1 BGA 3 –40°C to 125°C LTM8005 e1 BGA 3 –40°C to 150°C Device Finish Code SAC305 (RoHS) LTM8005 LTM8005IY#PBF SAC305 (RoHS) LTM8005HY#PBF SAC305 (RoHS) Contact the factory for parts specified with wider operating temperature ranges. *Device temperature grade is identified by a label on the shipping container. Pad or ball finish code is per IPC/JEDEC J-STD-609. • Recommended LGA and BGA PCB Assembly and Manufacturing Procedures • LGA and BGA Package and Tray Drawings Rev. B 2 For more information www.analog.com LTM8005 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating temperature range, otherwise specifications are at TA = 25°C. CTRL1 = CTRL2 = PWM = 5V, unless otherwise noted (Note 2). PARAMETER CONDITIONS Minimum Input Voltage LED DC Current MIN 1.65 0.8 0.16 10 12 ISMON Voltage ILED = 1.5A Quiescent Current into VIN EN/UVLO = 0V (Disabled), PWM = 0V EN/UVLO = 1.15V, PWM = 0V RT = 82.5K to GND, FB = 1.5V (Not Switching) VREF Voltage IREF = –100µA VREF Line Regulation 5V < VIN < 48V VREF Load Regulation –100µA < IREF < 0µA SS Current Sourcing, SS = 0V Sinking, ILED Overcurrent 0.88 l 1.95 ILED Overcurrent Threshold ISN-LED RDS(ON) VC Output Impedance VC Standby Input Bias Current PWM = 0V VC Pin Current VC = 1.2V, Sourcing VC = 1.2V, Sinking Voltage at FB pin 2.00 14 1.23 0.96 V 35 40 3.5 µA µA mA 2.08 V % 1 % 28 2.8 µA µA 2.4 A 53 mΩ 2000 kΩ 20 1.25 Current Out of Pin, FB = VFB FB OPENLED Threshold OPENLED Falling FB Overvoltage Threshold 1.27 nA 1.176 1.222 V 1.26 1.34 V 350 mV SHORTLED Falling 300 0.16 IVINCOMP Voltage IVINP – IVINN = 60mV Switching Frequency RT = 82.5k RT = 26.1k RT = 6.65k Switching Frequency Modulation RAMP = 2V V µS 200 LED Current C/10 Threshold IVINP – IVINN nA µA µA 500 FB Pin Input Bias Current A mΩ 10 30 l V 0.1 –20 FB Amplifier gm UNITS A A A 19 SW RDS(ON) Input Current Limit Threshold MAX 5 CTRL1 = 1.5V CTRL1 = 0.6V CTRL1 = 0.2V SW Current Limit FB SHORTLED Threshold TYP l 53 A 67 mV 125 360 1200 kHz kHz kHz 1.2 85 240 800 105 300 1000 V 70 % RAMP Input Low Threshold 1 V RAMP Input High Threshold 2 V RAMP Pin Source Current RAMP = 0.4V 12 µA RAMP Pin Sink Current RAMP = 1.6V 12 µA CTRL1, CTRL2 Pin Current CTRL1, CTRL2 = 1V 200 nA PWM Input Threshold Rising 1 V PWM Pin Bias Current 10 µA Rev. B For more information www.analog.com 3 LTM8005 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating temperature range, otherwise specifications are at TA = 25°C. CTRL1 = CTRL2 = PWM = 5V, unless otherwise noted (Note 2). PARAMETER CONDITIONS MIN TYP MAX UNITS EN/UVLO Threshold Voltage Falling 1.22 V EN/UVLO Threshold Voltage Rising 1.24 V EN/UVLO Pin Bias Current EN/UVLO = 1.15V, VIN = 12V OPENLED Output Low IOPENLED = 0.5mA 0.3 V SHORTLED Output Low ISHORTLED  =  0.5mA 0.3 V OVLO Threshold Voltage Rising Falling 1.30 1.26 V V Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTM8005E is guaranteed to meet performance specifications from 0°C to 125°C internal. Specifications over the full –40°C to 125°C internal operating temperature range are assured by design, characterization and correlation with statistical process controls. The LTM8005I is guaranteed to meet specifications over the full –40°C to 125°C internal operating temperature range. The LTM8005MP is guaranteed to meet specifications over the full –55°C to 125°C internal operating temperature range. The LTM8005H is guaranteed to meet specifications over the full –40°C to 150°C internal operating temperature range. Note that the maximum internal temperature is determined by specific operating conditions in conjunction with board layout, the rated package thermal resistance and other environmental factors. 19 1.21 1.17 µA Note 3: The LTM8005 contains over-temperature protection that is intended to protect the device during momentary overload conditions. The internal temperature exceeds the maximum operating junction temperature when the over-temperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. Rev. B 4 For more information www.analog.com LTM8005 TYPICAL PERFORMANCE CHARACTERISTICS LED Current vs CTRL2 1.6 1.6 1.2 0.8 0.4 1.2 0.8 0.25 0.50 0.75 1 CTRL1 VOLTAGE (V) 1.25 1.50 0 0 0.25 0.50 0.75 1 CTRL2 VOLTAGE (V) 1.25 8005 G01 2.5 1.50 0 0 0.3 0.6 0.9 VFB (V) 8005 G02 1.2 1.5 8005 G03 Switching Frequency vs SS Voltage VREF vs Load 350 VREF vs Load Current RT = 23.2k 280 FREQUENCY (kHz) 2.0 1.5 1.0 0.5 0 1.0 0.5 0.4 0 LED Current vs FB (CTRL1 = CTRL2 = VREF) 1.5 210 140 70 0 45 90 135 LOAD CURRENT (µA) 0 180 0 0.3 8005 G04 Demonstration Circuit DC2257A Output Current Ripple 34V at 1.2A LED, 12VIN 0.6 0.9 VSS (V) 1.2 1.5 8005 G05 DC2257A Conducted EMI with and without Spread Spectrum Enabled 100 SPREAD SPECTRUM DISABLED SPREAD SPECTRUM ENABLED CRAMP = 22nF 80 EMISSIONS (dBµV) 0 2.0 LED CURRENT (A) 2.0 LED CURRENT (A) 2.0 VREF (V) LED CURRENT (A) LED Current vs CTRL1 TA = 25°C, unless otherwise noted. CURRENT RIPPLE 50mA/DIV 1µs/DIV 8005 G06 60 41 21 1 0.1 1.1 2.1 3.0 FREQUENCY (MHz) 4.0 5.0 8005 G07 Rev. B For more information www.analog.com 5 LTM8005 TYPICAL PERFORMANCE CHARACTERISTICS DC2257A CISPR 22 Radiated Results With Spread Spectrum 40 40 30 30 EMISSIONS (dBµV/m) EMISSIONS (dBµV/m) DC2257A CISPR 22 Radiated Results Without Spread Spectrum 20 10 TA = 25°C, unless otherwise noted. 20 10 SPREAD SPECTRUM DISABLED 0 0 250 500 750 FREQUENCY (MHz) 1000 SPREAD SPECTRUM ENABLED 0 0 250 500 750 FREQUENCY (MHz) 8005 G08 1000 8005 G09 Output Disconnect Response (Short Circuit) Output Disconnect Response (Input > Output) VOUT 10V/DIV VIN 10V/DIV VLED 10V/DIV VOUT 10V/DIV ILED 10A/DIV VLED 10V/DIV 500ns/DIV 8005 G10 1ms/DIV 8005 G11 Rev. B 6 For more information www.analog.com LTM8005 PIN FUNCTIONS GND (Bank 1, Pin K1, Pin K8): Tie these GND pins to a local ground plane below the LTM8005 and the circuit components. In most applications, the bulk of the heat flow out of the LTM8005 is through these pads, so the printed circuit design has a large impact on the thermal performance of the part. See the PCB Layout and Thermal Considerations sections for more details. Return the feedback divider to this net. SW (Bank 2): Power Switch Node. This is the drain of the internal power switching MOSFET. For boost, buck-boost mode and buck mode topologies, connect this bank to the inductor and the DA bank. For a SEPIC, connect this bank to an inductor winding and the positive coupling capacitor terminal. DA (Bank 3): Power Diode Anode. For boost, buck-boost mode and buck mode topologies, connect this bank to the inductor and the SW bank. For a SEPIC, connect this bank to an inductor winding and the negative coupling capacitor terminal. VOUT (Bank 4): Power Output Pins. Apply the output filter capacitor between these pins and the GND pins. ISN (Bank 5): Output Current Sense Resistor. The LTM8005 incorporates a sense resistor between VOUT and ISN to set the output current regulation point and for output current monitoring. If a larger output current is required, apply an external resistor between VOUT and ISN. Keep this pin voltage within 0.3V of VOUT. LED (Bank 6): LED Current Output. Connect the anode of the LED string to this bank. VIN (Pin F1): Input Power. The VIN pin supplies current to the LTM8005’s internal regulators and circuitry, and must be bypassed with a 0.22µF (or larger) capacitor placed close to the LTM8005. IVINN (Pin F2): Input Sense Resistor Signal. Apply an external sense resistor between IVINP and IVINN to set the maximum input current and for input current monitoring. If this function is not required, tie both IVINP and IVINN to VIN. Keep this pin voltage within 0.3V of VIN. EN/UVLO (Pin G1): Enable and Precision UVLO. An accurate 1.22V falling threshold with externally programmable hysteresis detects when power is OK to enable switching. Rising hysteresis is generated by the external resistor divider, an internal 499kΩ resistor between EN/UVLO and VIN and an accurate internal 3µA pull-down current. Above the threshold, EN/UVLO input bias current is sub-µA. Below the falling threshold, a 3µA pull-down current is enabled so the user can optimize the hysteresis with the external resistor selection. An undervoltage condition resets soft-start. The EN/UVLO pin may be connected directly to VIN, but do not drive this pin directly from another low impedance voltage source. If EN/UVLO must be driven from a voltage source, do so with at least a 50Ω series resistor. IVINP (Pin G2): Input Sense Resistor Signal. Apply an external sense resistor between IVINP and IVINN to set the maximum input current and for input current monitoring. If this function is not required, tie both IVINP and IVINN to VIN. Keep this pin voltage within 0.3V of VIN. OVLO (Pin H1): Input Overvoltage Lockout Pin. An accurate 1.25V rising threshold detects when power is OK to enable switching. If not used, tie this pin to GND. IVINCOMP (Pin H2): Input Current Sense Amplifier Output Pin. The voltage at IVINCOMP pin is proportional to IIN as VIVINCOMP = IIN • RINSNS • 20. A 10nF capacitor to GND is provided internally at this pin to compensate the input current loop. Do not load this pin with a current and do not drive this pin with an external source, although additional capacitance may be added externally. SHORTLED (Pin H7): An open-collector pull-down on SHORTLED asserts when any of the following conditions happen: 1. FB < 0.3V after SS pin reaches 1.7V at start-up. 2. LED overcurrent (ILED > 2.4A). To function, the pin requires an external pull-up resistor. SHORTLED status is only updated during PWM high state and latched during PWM low state. SHORTLED remains asserted until the SS pin is discharged below 0.2V. If not used, leave floating or tie to GND. OPENLED (Pin H8): Fault Indicator. An open-collector pull-down on OPENLED asserts if the FB input is above 1.20V (typical), and the LED current is less than 0.16A (typical). To function, the pin requires an external pull-up Rev. B For more information www.analog.com 7 LTM8005 PIN FUNCTIONS resistor. OPENLED status is updated only during PWM high state and latched during PWM low state. If not used, leave floating or tie to GND. ISMON (Pin J1): LED Current Report Pin. The LED current is reported as VISMON = (LED current)/1.6. Leave the ISMON pin unconnected if not used. When PWM is low, ISMON is driven to ground. Bypass with a 47nF capacitor or higher if needed. Do not drive this pin with an external source. AUX (Pin J2): Auxiliary Pin. This pin is internally connected to VOUT to ease layout. Conveniently located next to FB, it is provided to simplify layout of the output voltage feedback network. VREF (Pin J6): Voltage Reference Output Pin. Typically 2V. This pin drives a resistor divider for the CTRL pins, either for analog dimming or for temperature limit/compensation of the LED load. It can supply up to 100µA. Do not drive this pin with an external source. PWM (Pin J7): PWM Input Signal Pin. A low signal turns off switching, idles the oscillator, disconnects the VC pin from all internal loads, and disconnects the output load from VOUT. PWM has an internal 500kΩ pull-down resistor. If not used, connect to VREF. RAMP (Pin J8): The RAMP pin is used for spread spectrum frequency modulation. The internal switching frequency is spread out to 70% of the original value, where the modulation frequency is set by 12µA/(2 • 1V • CRAMP). If not used, tie this pin to GND. FB (Pin K2): Voltage Loop Feedback Pin. FB is intended for constant-voltage regulation or for LED protection/open LED detection. The internal transconductance amplifier with output VC regulates FB to 1.25V (nominal) through the DC/DC converter. If the FB input is regulating the loop, and LED current is less than 0.15A (typical), the OPENLED pull-down is asserted. This action may signal an open LED fault. If FB is driven above 1.3V (by an external power supply spike, for example), the internal N-Channel MOSFET is turned off and the load is disconnected from VOUT to protect the LEDs from an overcurrent event. Do not tie this pin to GND as the SHORTLED will be asserted and the part will be shut down. VC (Pin K3): Transconductance Error Amplifier Output Pin. Used to stabilize the control loop with an RC network. This pin is high impedance when PWM is low, a feature that stores the demanded current state variable for the next PWM high transition. Connect a capacitor between this pin and GND; a resistor in series with the capacitor is recommended for fast transient response. Do not leave this pin open, and do not drive this pin with an external source. SS (Pin K4): Soft-Start Pin. This pin modulates oscillator frequency and compensation pin voltage (VC). The softstart interval is set with an external capacitor. The pin has a 28µA (typical) pull-up current source to an internal 2.5V rail. This pin can be used as fault timer. Provided the SS pin has exceeded 1.7V to complete a blanking period at start-up, the pull-up current source is disabled and a 2.8µA pull-down current is enabled when any one of the following fault conditions happen: 1. LED overcurrent (ILED > 2.4A) 2. Output short (FB < 0.3V after start-up) 3. Thermal limit The SS pin must be discharged below 0.2V to re-initiate a soft-start cycle. Switching is disabled until SS begins to recharge. It is important to select a capacitor large enough that FB can exceed 0.3V under normal load conditions before SS exceeds 1.7V. Do not leave this pin open and do not drive this pin with an external source. RT (Pin K5): Switching Frequency Adjustment Pin. Set the frequency using a resistor to GND. Do not leave the RT pin open. Do not drive this pin with an external source. CTRL1, CTRL2 (Pin K6, K7): Current Sense Threshold Adjustment. CTRL1 and CTRL2 have identical functions. The output current is regulated by CTRL1 or CTRL2. The pin with the lowest voltage takes precedence. For 0.1V