MAX16800ATE/V+

19-3803; Rev 1; 4/09 High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver The MAX16800 current regulator operates from a 6.5V to 40V input voltage range and delivers up to a total of 350mA to one or more strings of high-brightness LEDs. The output current of the MAX16800 is adjusted by using an external current-sense resistor in series with the LEDs. An enable input allows wide-range “pulsed” dimming. Wave-shaping circuitry reduces EMI. The differential current-sense input increases noise immunity. The MAX16800 is well suited for applications requiring high-voltage input and is able to withstand automotive load-dump events up to 40V. An on-board pass element minimizes external components while providing ±3.5% output current accuracy. Additional features include a 5V regulated output and short-circuit and thermal protection. The MAX16800 is available in a thermally enhanced, 5mm x 5mm, 16-pin TQFN package and is specified over the automotive -40°C to +125°C temperature range. Applications Automotive Interior: Map, Courtesy, and Cluster Lighting Features ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ +6.5V to +40V Operating Range Adjustable Level (35mA to 350mA) ±3.5% Output Current Accuracy Integrated Pass Element with Low-Dropout Voltage (0.5V typ) Output Short-Circuit Protection +5V Regulated Output with 4mA Source Capability Thermal Shutdown Differential LED Current Sense High-Voltage Enable Pin for Dimming Interface Low Shutdown Supply Current (12μA typ) Low 204mV Current-Sense Reference Reduces Power Losses Wave-Shaped Soft Edges Reduce Radiated EMI During PWM Dimming Available in Small, Thermally Enhanced, 5mm x 5mm, 16-Pin TQFN Package -40°C to +125°C Operating Temperature Range Ordering Information Automotive Exterior: Tail Lights and CHMSL Warning Lights for Emergency Vehicles Navigation and Marine Indicators General Illumination Signage, Gasoline Canopies, Beacons PART TEMP RANGE -40°C to +125°C 16 TQFN-EP* MAX16800ATE/V+ -40°C to +125°C 16 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed paddle. /V denotes an automotive qualified part. GND V5 CS- CS+ Pin Configuration TOP VIEW 12 11 10 9 PIN-PACKAGE MAX16800ATE+ Simplified Diagram +6.5V TO +40V IN OUT 0.1μF 8 N.C. 13 +5V REG N.C. V5 LEDs 0.1μF N.C. 14 MAX16800 EN 15 OUT 16 + 7 N.C. 6 N.C. 5 N.C. MAX16800 CS+ RSENSE PWM DIMMING 2 3 4 OUT IN IN N.C. EN 1 CSGND TQFN ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX16800 General Description MAX16800 High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver ABSOLUTE MAXIMUM RATINGS Continuous Power Dissipation (TA = +70°C) 16-Pin TQFN 5mm x 5mm (derate 33.3mW/°C above +70°C)............................2666.7mW Operating Junction Temperature Range ...........-40°C to +125°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C IN, OUT, and EN to GND........................................-0.3V to +45V CS+, V5 to GND .......................................................-0.3V to +6V CS- to GND............................................................-0.3V to +0.3V OUT Short Circuited to GND Duration (at VIN = +16V) ........................................................60 minutes Maximum Current Into Any Pin (except VIN and OUT) .......±20mA 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. ELECTRICAL CHARACTERISTICS (VIN = +12V, EN = VIN, CV5 = 0.1µF to GND, IV5 = 0, CS- = GND, connect RSENSE = 0.58Ω between CS+ and CS-. Connect OUT to CS+ (Note 1). TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS Supply Voltage Range VIN (Note 1) Ground Current IG ILOAD = 350mA Shutdown Supply Current I SHDN VEN
0.6V Guaranteed Output Current I OUT RSENSE = 0.55 Output Current Accuracy Dropout Voltage (Note 3) MIN Output Current Slew Rate Short-Circuit Current MAX UNITS 40.0 V 1.4 3 mA 12 40 350 35mA < I OUT < 350mA VDO TYP 6.5 μA mA ±3.5 % I OUT = 350mA (current pulsed), 12V < VIN < 40V 0.5 1.2 V I OUT = 350mA (current pulsed), 6.5V < VIN < 40V 0.5 1.5 V Current rising 5.4 Current falling 90 VOUT = 0V, VIN = 12V 400 600 mA/μs 800 mA nA LOGIC INPUT EN Input Current I EN 100 EN Input Voltage High VIH 2.8 EN Input Voltage Low VIL Turn–On Time t ON 0.6 EN rising edge to 90% of OUT V V 135 350 μs 204 211 mV CURRENT SENSE (Note 4) Regulated RSENSE Voltage Input Current (CS+) Input Current (CS-) 2 VRSNS VSENSE = VCS+ - VCSVCS+ = 220mV 197 -14 VCS+ = 220mV _______________________________________________________________________________________ μA +84 μA High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver (VIN = +12V, EN = VIN, CV5 = 0.1µF to GND, IV5 = 0, CS- = GND, connect RSENSE = 0.58Ω between CS+ and CS-. Connect OUT to CS+ (Note 1). TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS THERMAL OVERLOAD Thermal-Shutdown Temperature +155 °C 23 °C Thermal-Shutdown Hysteresis +5V REGULATOR Output Voltage Regulation Output Voltage Change V5 5.0 V5 5.27 5.5 V 15 60  0 < ILOAD < 4mA (Note 5) V5 = 0V (Note 6) V5 Short-Circuit Current 30 mA Note 1: Resistors were added from OUT to CS+ to aid with the power dissipation during testing. Note 2: All devices 100% production tested at TA = +25°C. Limits over the operating temperature range are guaranteed by design. Note 3: Dropout is measured as follows: Connect RO = 27Ω from OUT to CS+. Connect RSENSE = 0.58Ω from CS+ to CS-. Set VIN = +12V (record VOUT as VOUT1). Reduce VIN until VOUT = 0.97 x VOUT1 (record as VIN2 and VOUT2). ΔVDO = VIN2 - VOUT2. Note 4: IV5 = 0mA. Note 5: Current regulation varies with V5 load (see the Typical Operating Characteristics). Note 6: Thermal shutdown does not function if the output of the 5V reference is shorted to ground. Typical Operating Characteristics (VIN = VEN = +12V, TA = +25°C, unless otherwise noted.) OUTPUT CURRENT vs. TEMPERATURE 300 250 ILOAD = 200mA 200 150 ILOAD = 100mA 100 50 ILOAD = 35mA 0.207 0.206 0.205 0.204 0.203 0.202 350 300 250 200 150 100 50 0.201 0.200 0 MAX16800 toc03 0.208 400 OUTPUT CURRENT (mA) 350 VIN = 12V 0.209 MAX16800 toc02 ILOAD = 350mA (VCS+ - VCS-) (V) OUTPUT CURRENT (mA) 400 0.210 MAX16800 toc01 450 OUTPUT CURRENT vs. INPUT VOLTAGE (VCS+ - VCS-) vs. OUTPUT CURRENT 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 20 50 80 110 140 170 200 230 260 290 320 350 TEMPERATURE (°C) OUTPUT CURRENT (mA) 0 5 10 15 20 25 30 35 40 INPUT VOLTAGE (V) _______________________________________________________________________________________ 3 MAX16800 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (VIN = VEN = +12V, TA = +25°C, unless otherwise noted.) SHUTDOWN CURRENT vs. TEMPERATURE 0.7 0.6 ILOAD = 350mA 0.5 0.4 0.3 25 20 VIN = 20V 15 VIN = 12V 10 0.2 0 ILOAD = 1mA NO LOAD 5.3 5.2 ILOAD = 5mA 5.0 0 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 -40 -25 -10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) +5V REGULATOR OUTPUT vs. VIN 200Hz DIMMED OPERATION (VCS+ - VCS-) vs. IV5 0.208 0.207 0.206 0.205 0.204 0.203 ILOAD = 410mA 0.202 0.201 MAX16800 toc09 5.30 NO LOAD 5V REGULATOR OUTPUT (V) MAX16800 toc07 0.210 0.209 VIN 5V/div 5.25 0V ILOAD = 350mA, VIN = VEN, VIN PULSED AT 200Hz (50% DUTY CYCLE) 5.20 ILOAD 200mA/div LOAD = 1mA 5.15 LOAD = 5mA 0.200 0.199 0.198 5.10 0 1 2 3 4 5 6 7 5 8 10 15 20 25 30 35 40 200Hz DIMMED OPERATION EXPANDED 200Hz DIMMED OPERATION EXPANDED MAX16800 toc10 MAX16800 toc11 ILOAD = 350mA, VIN = VEN, VIN PULSED AT 200Hz (50% DUTY CYCLE) 0 20μs/div MAX16800 toc12 EN 10V/div 0V 0V ILOAD 100mA/div 200Hz DIMMED OPERATION VIN 5V/div VIN 5V/div ILOAD = 350mA, VIN = VEN, VIN PULSED AT 200Hz (50% DUTY CYCLE) 1ms/div VIN (V) IV5 (mA) 4 5.4 5.1 VIN = 6.5V 5 0.1 MAX16800 toc06 VIN = 40V 30 5.5 MAX16800 toc08 DROPOUT VOLTAGE (V) 0.8 35 MAX16800 toc05 0.9 SHUTDOWN CURRENT (μA) MAX16800 toc04 1.0 +5V REGULATOR OUTPUT vs. TEMPERATURE 5V REGULATOR OUTPUT (V) DROPOUT VOLTAGE vs. TEMPERATURE (VCS+ - VCS-) (V) MAX16800 High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver ILED 100mA/div 0V ILOAD = 350mA, VIN = 12V, EN PULSED AT 200Hz (50% DUTY CYCLE) ILED 100mA/div 0 4μs/div 0 1ms/div _______________________________________________________________________________________ High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver PIN NAME FUNCTION 1, 16 OUT 2, 3 IN 4–8, 13, 14 N.C. Not Internally Connected 9 CS+ Positive Input of the Internal Differential Amplifier. Connect the current-sense resistor between CS+ and CS- to program the output current level. 10 CS- Negative Input of the Internal Differential Amplifier. Connect the current-sense resistor between CS- and CS+ to program the output current level. 11 V5 +5V Regulated Output. Connect a 0.1µF capacitor from V5 to GND. 12 GND 15 EN Enable Input. Drive EN high to enable the output. — EP Exposed Pad. Connect to the ground plane for effective power dissipation. Do not use as the only ground connection. Current-Regulated Output. Connect pin 1 to pin 16. Positive Input Supply. Bypass IN with a 0.1µF (min) capacitor to GND. Connect pin 2 to pin 3. Ground Functional Diagram V5 IN REGULATOR IN EN ENABLE REFERENCE GENERATOR I_REQ OUT DIFFERENTIAL SENSE AMPLIFIER MAX16800 CS+ CS- THERMAL SHUTDOWN Detailed Description The MAX16800 is a high-current regulator capable of providing up to a total of 350mA of current to one or more strings of high-brightness LEDs. A wide operating input voltage range of +6.5V to +40V makes the MAX16800 ideal for automotive applications. A +5V regulated output provides up to 4mA of current to power external circuitry. In addition, the MAX16800 fea- tures thermal and output short-circuit protection. The wide operating voltage range helps protect the MAX16800 against large transients such as those found in load-dump situations up to 40V. The MAX16800 uses a feedback loop to control the output current. The differential voltage across the sense resistor is compared to a fixed reference voltage, and the error is amplified to serve as the drive to the internal _______________________________________________________________________________________ 5 MAX16800 Pin Description MAX16800 High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver power series pass device (see the Functional Diagram). The regulation point is factory set at (VCS+ VCS-) = 204mV ±3.5%. The regulated current is user defined by the value of RSENSE. The MAX16800 is a current controller internally optimized for driving the impedance range expected from one or more HB LEDs. +5V Regulator The MAX16800 includes a fixed +5V output regulator that delivers up to 4mA of load current for low-power applications throughout the +6.5V to +40V input voltage range. Connect a 0.1µF compensation capacitor from V5 to ground. Shorting V5 to ground disables the thermal shutdown. Thermal Protection The MAX16800 enters a thermal-shutdown mode in the event of overheating. This typically occurs in overload or output short-circuit conditions. When the junction temperature exceeds TJ = +155°C (typ), the internal thermal-protection circuitry turns off the series pass device. The MAX16800 recovers from thermal-shutdown mode once the junction temperature drops by 23°C (typ). The part will therefore protect itself by thermally cycling in the event of a short-circuit or overload condition. Applications Information Programming the LED Current The MAX16800 uses a sense resistor across CS+ and CS- to set the LED current. The differential sense ampli- fier connected across RSENSE provides ground-loop immunity and low-frequency noise rejection. The LED current is given by the equation below: ILED = VSENSE / RSENSE Input Voltage Considerations For proper operation, the minimum input voltage must always be +1.2V (+1.5V for VIN