LT1676

FEATURES n n n n n n n n n n n LT3010/LT3010-5 50mA, 3V to 80V Low Dropout Micropower Linear Regulator DESCRIPTION The LT®3010 is a high voltage, micropower low dropout linear regulator. The device is capable of supplying 50mA output current with a dropout voltage of 300mV. Designed for use in battery-powered or high voltage systems, the low quiescent current (30µA operating and 1µA in shutdown) makes the LT3010 an ideal choice. Quiescent current is also well controlled in dropout. Other features of the LT3010 include the ability to operate with very small output capacitors. The regulators are stable with only 1µF on the output while most older devices require between 10µF and 100µF for stability. Small ceramic capacitors can be used without the necessary addition of ESR as is common with other regulators. Internal protection circuitry includes reverse-battery protection, current limiting, thermal limiting and reverse current protection. The device is available in a fixed output voltage of 5V and as an adjustable device with a 1.275V reference voltage. The LT3010 regulator is available in the 8-lead MSOP package with an exposed pad for enhanced thermal handling capability. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n n n Wide Input Voltage Range: 3V to 80V Low Quiescent Current: 30µA Low Dropout Voltage: 300mV Output Current: 50mA Thermally Enhanced 8-Lead MSOP Package No Protection Diodes Needed Fixed Output Voltage: 5V (LT3010-5) Adjustable Output from 1.275V to 60V (LT3010) 1µA Quiescent Current in Shutdown Stable with 1µF Output Capacitor Stable with Aluminum, Tantalum or Ceramic Capacitors Reverse-Battery Protection No Reverse Current Flow from Output Thermal Limiting APPLICATIONS n n n n Low Current High Voltage Regulators Regulator for Battery-Powered Systems Telecom Applications Automotive Applications TYPICAL APPLICATION Dropout Voltage 350 5V Supply with Shutdown IN VIN 5.4V TO 80V 1µF OUT LT3010-5 SHDN SENSE GND 30105 TA01 300 VOUT 5V 50mA 1µF DROPOUT VOLTAGE (mV) 250 200 150 100 50 0 0 10 40 20 30 OUTPUT CURRENT (mA) 50 30105 TA02 VSHDN (PIN 5) OUTPUT 2.0V ON 30105fe 1 LT3010/LT3010-5 ABSOLUTE MAXIMUM RATINGS (Note 1) PIN CONFIGURATION TOP VIEW OUT SENSE/ADJ* NC GND 1 2 3 4 9 GND 8 7 6 5 IN NC NC SHDN IN Pin Voltage ........................................................ ±80V OUT Pin Voltage ..................................................... ±60V IN to OUT Differential Voltage ................................ ±80V ADJ Pin Voltage ....................................................... ±7V SHDN Pin Input Voltage ......................................... ±80V Output Short-Circuit Duration ......................... Indefinite Storage Temperature Range.................. –65°C to 150°C Operating Junction Temperature Range (Notes 3, 10, 11) LT3010E ............................................. –40°C to 125°C LT3010H ............................................ –40°C to 140°C LT3010MP.......................................... –55°C to 125°C Lead Temperature (Soldering, 10 sec) ................. 300°C MS8E PACKAGE 8-LEAD PLASTIC MSOP *SENSE FOR LT3010-5, ADJ FOR LT3010 TJMAX = 125°C (LT3010E/LT3010MP), θJA = 40°C/W, θJC = 16°C/W† TJMAX = 140°C (LT3010H), θJA = 40°C/W, θJC = 16°C/W† SEE APPLICATIONS INFORMATION SECTION. EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB †MEASURED AT BOTTOM PAD ORDER INFORMATION LEAD FREE FINISH LT3010EMS8E#PBF LT3010EMS8E-5#PBF LT3010HMS8E#PBF LT3010HMS8E-5#PBF LT3010MPMS8E#PBF LT3010MPMS8E-5#PBF LEAD BASED FINISH LT3010EMS8E LT3010EMS8E-5 LT3010HMS8E LT3010HMS8E-5 LT3010MPMS8E LT3010MPMS8E-5 TAPE AND REEL LT3010EMS8E#TRPBF LT3010EMS8E-5#TRPBF LT3010HMS8E#TRPBF LT3010HMS8E-5#TRPBF LT3010MPMS8E#TRPBF LT3010MPMS8E-5#TRPBF TAPE AND REEL LT3010EMS8E#TR LT3010EMS8E-5#TR LT3010HMS8E #TR LT3010HMS8E-5 #TR LT3010MPMS8E#TR LT3010MPMS8E-5#TR PART MARKING* LTZF LTAEF LTCLP LTCLQ LTZF LTAEF PART MARKING* LTZF LTAEF LTCLP LTCLQ LTZF LTAEF PACKAGE DESCRIPTION 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP PACKAGE DESCRIPTION 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP TEMPERATURE RANGE –40°C to 125°C –40°C to 125°C –40°C to 140°C –40°C to 140°C –55°C to 125°C –55°C to 125°C TEMPERATURE RANGE –40°C to 125°C –40°C to 125°C –40°C to 140°C –40°C to 140°C –55°C to 125°C –55°C to 125°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ (LT3010E, LT3010MP) The l denotes the specifications which apply over the –40°C to 125°C (LT3010E) or –55°C to 125°C (LT3010MP) operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER Minimum Input Voltage Regulated Output Voltage (Note 3) ADJ Pin Voltage (Notes 2, 3) CONDITIONS LT3010 LT3010-5 LT3010 ILOAD = 50mA VIN = 5.5V, ILOAD = 1mA 6V < VIN < 80V, 1mA < ILOAD < 50mA VIN = 3V, ILOAD = 1mA 4V < VIN < 80V, 1mA < ILOAD < 50mA l ELECTRICAL CHARACTERISTICS MIN 4.925 l 4.850 l TYP 3 5.000 5.000 1.275 1.275 MAX 4 5.075 5.150 1.292 1.313 UNITS V V V V V 30105fe 1.258 1.237 2 LT3010/LT3010-5 ELECTRICAL CHARACTERISTICS PARAMETER Line Regulation Load Regulation CONDITIONS LT3010-5 ΔVIN = 5.5V to 80V, ILOAD = 1mA LT3010 (Note 2) ΔVIN = 3V to 80V, ILOAD = 1mA LT3010-5 VIN = 6V, ΔILOAD = 1mA to 50mA VIN = 6V, ΔILOAD = 1mA to 50mA l (LT3010E, LT3010MP) The l denotes the specifications which apply over the –40°C to 125°C (LT3010E) or –55°C to 125°C (LT3010MP) operating temperature range, otherwise specifications are at TA = 25°C. MIN TYP 3 3 25 l MAX 15 13 50 90 20 32 150 190 260 350 370 550 60 180 700 3.3 100 2 2 0.5 5 UNITS mV mV mV mV mV mV mV mV mV mV mV mV µA µA µA mA µVRMS nA V V µA µA µA dB dB mA mA mA LT3010 (Note 2) VIN = 4V, ΔILOAD = 1mA to 50mA VIN = 4V, ΔILOAD = 1mA to 50mA Dropout Voltage VIN = VOUT(NOMINAL) (Notes 4, 5) ILOAD = 1mA ILOAD = 1mA ILOAD = 10mA ILOAD = 10mA ILOAD = 50mA ILOAD = 50mA GND Pin Current VIN = VOUT(NOMINAL) (Notes 4, 6) Output Voltage Noise ADJ Pin Bias Current Shutdown Threshold SHDN Pin Current (Note 8) Ripple Rejection Current Limit ILOAD = 0mA ILOAD = 1mA ILOAD = 10mA ILOAD = 50mA COUT = 10µF ILOAD = 50mA, BW = 10Hz to 100kHz , (Note 7) VOUT = Off to On VOUT = On to Off VSHDN = 0V VSHDN = 6V LT3010 LT3010-5 VIN = 7V(Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 50mA VIN = 7V(Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 50mA 10 l 100 l 200 l 300 l l l l l 30 100 400 1.8 100 50 l l 0.3 1.3 1.1 0.5 0.1 1 Quiescent Current in Shutdown VIN = 6V, VSHDN = 0V 65 60 l l l 75 68 140 VIN = 7V, VOUT = 0V LT3010-5 VIN = 6V, ΔVOUT = – 0.1V LT3010 (Note 2) VIN = 4V, ΔVOUT = – 0.1V 60 60 Input Reverse Leakage Current VIN = –80V, VOUT = 0V LT3010-5 VOUT = 5V, VIN < 5V Reverse Output Current LT3010 (Note 2) VOUT = 1.275V, VIN < 1.275V (Note 9) 6 10 8 20 15 mA µA µA (LT3010H) The l denotes the specifications which apply over the –40°C to 140°C operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER Minimum Input Voltage Regulated Output Voltage (Note 3) ADJ Pin Voltage (Notes 2, 3) Line Regulation Load Regulation CONDITIONS LT3010 LT3010-5 LT3010 ILOAD = 50mA VIN = 5.5V, ILOAD = 1mA 6V < VIN < 80V, 1mA < ILOAD < 50mA VIN = 3V, ILOAD = 1mA 4.25V < VIN < 80V, 1mA < ILOAD < 50mA l l l l l l MIN 4.925 4.825 1.258 1.230 TYP 3 5.000 5.000 1.275 1.275 3 3 25 10 MAX 4.25 5.075 5.15 1.292 1.313 20 15 50 100 20 45 UNITS V V V V V mV mV mV mV mV mV LT3010-5 ΔVIN = 5.5V to 80V, ILOAD = 1mA LT3010 (Note 2) ΔVIN = 3V to 80V, ILOAD = 1mA LT3010-5 VIN = 6V, ΔILOAD = 1mA to 50mA VIN = 6V, ΔILOAD = 1mA to 50mA LT3010 (Note 2) VIN = 4V, ΔILOAD = 1mA to 50mA VIN = 4.25V, ΔILOAD = 1mA to 50mA l 30105fe 3 LT3010/LT3010-5 ELECTRICAL CHARACTERISTICS PARAMETER Dropout Voltage VIN = VOUT(NOMINAL) (Notes 4, 5) CONDITIONS ILOAD = 1mA ILOAD = 1mA ILOAD = 10mA ILOAD = 10mA ILOAD = 50mA ILOAD = 50mA GND Pin Current VIN = VOUT(NOMINAL) (Notes 4, 6) Output Voltage Noise ADJ Pin Bias Current Shutdown Threshold SHDN Pin Current (Note 8) Ripple Rejection Current Limit ILOAD = 0mA ILOAD = 1mA ILOAD = 10mA ILOAD = 50mA COUT = 10µF ILOAD = 250mA, BW = 10Hz to 100kHz , (Note 7) VOUT = Off to On VOUT = On to Off VSHDN = 0V VSHDN = 6V LT3010 LT3010-5 VIN = 7V(Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 50mA VIN = 7V(Avg), VRIPPLE = 0.5VP-P, fRIPPLE = 120Hz, ILOAD = 50mA l l l l l l l (LT3010H) The l denotes the specifications which apply over the –40°C to 140°C operating temperature range, otherwise specifications are at TA = 25°C. MIN TYP 100 200 l MAX 150 220 260 380 370 600 80 200 750 3.5 100 2 2 0.5 5 UNITS mV mV mV mV mV mV µA µA µA mA µVRMS nA V V µA µA µA dB dB mA mA mA 300 l l l l l 30 100 400 1.8 100 50 0.3 1.3 0.8 0.5 0.1 1 65 60 55 55 75 68 140 Quiescent Current in Shutdown VIN = 6V, VSHDN = 0V VIN = 7V, VOUT = 0V LT3010-5 VIN = 6V, ΔVOUT = – 0.1V LT3010 (Note 2) VIN = 4.25V, ΔVOUT = – 0.1V Input Reverse Leakage Current VIN = – 80V, VOUT = 0V LT3010-5 VOUT = 5V, VIN < 5V Reverse Output Current LT3010 (Note 2) VOUT = 1.275V, VIN < 1.275V (Note 9) 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 LT3010 (adjustable version) is tested and specified for these conditions with the ADJ pin connected to the OUT pin. Note 3: Operating conditions are limited by maximum junction temperature. The regulated output voltage specification will not apply for all possible combinations of input voltage and output current. When operating at maximum input voltage, the output current range must be limited. When operating at maximum output current, the input voltage range must be limited. Note 4: To satisfy requirements for minimum input voltage, the LT3010 (adjustable version) is tested and specified for these conditions with an external resistor divider (249k bottom, 392k top) for an output voltage of 3.3V. The external resistor divider will add a 5µA DC load on the output. Note 5: Dropout voltage is the minimum input to output voltage differential needed to maintain regulation at a specified output current. In dropout, the output voltage will be equal to (VIN – VDROPOUT). Note 6: GND pin current is tested with VIN = VOUT (nominal) and a current source load. This means the device is tested while operating in its dropout region. This is the worst-case GND pin current. The GND pin current will decrease slightly at higher input voltages. 6 10 8 20 15 mA µA µA Note 7: ADJ pin bias current flows into the ADJ pin. Note 8: SHDN pin current flows out of the SHDN pin. Note 9: Reverse output current is tested with the IN pin grounded and the OUT pin forced to the rated output voltage. This current flows into the OUT pin and out the GND pin. Note 10: The LT3010E is guaranteed to meet performance specifications from 0°C to 125°C operating junction temperature. Specifications over the –40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The LT3010H is tested to the LT3010H Electrical Characteristics table at 140°C operating junction temperature. The LT3010MP is 100% tested and guaranteed over the –55°C to 125°C operating junction temperature range. High junction temperatures degrade operating lifetimes. Operating lifetime is derated at junction temperatures greater than 125°C. Note 11: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125°C (LT3010E and LT3010MP) or 140°C (LT3010H) when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. 30105fe 4 LT3010/LT3010-5 TYPICAL PERFORMANCE CHARACTERISTICS Typical Dropout Voltage 500 450 DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV) 400 350 300 250 200 150 100 50 0 0 5 10 15 20 25 30 35 40 45 50 OUTPUT CURRENT (mA) 30105 G01 Guaranteed Dropout Voltage 600 500 DROPOUT VOLTAGE (mV) = TEST POINTS 500 450 400 350 300 250 200 150 100 50 0 5 10 15 20 25 30 35 40 45 50 OUTPUT CURRENT (mA) 30105 G02 Dropout Voltage TJ = 125°C 400 300 IL = 50mA TJ ≤ 125°C TJ ≤ 25°C IL = 10mA TJ = 25°C 200 100 0 IL = 1mA 0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G03 Quiescent Current 40 35 QUIESCENT CURRENT (µA) ADJ PIN VOLTAGE (V) 30 25 20 15 10 5 0 –50 –25 0 VSHDN = 0V 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G04 LT3010 ADJ Pin Voltage 1.295 1.290 OUTPUT VOLTAGE (V) IL = 1mA 5.08 5.06 5.04 5.02 5.00 4.98 4.96 4.94 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G05 LT3010-5 Output Voltage IL = 1mA VSHDN = VIN VIN > 6V RL = ∞, IL = 0 (LT3010-5) RL = 250k, IL = 5µA (LT3010) 1.285 1.280 1.275 1.270 1.265 1.260 1.255 –50 –25 4.92 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G06 LT3010 Quiescent Current 50 45 QUIESCENT CURRENT (µA) 40 35 30 25 20 15 10 5 0 0 1 2 VSHDN = 0V 34567 INPUT VOLTAGE (V) 8 9 10 TJ = 25°C RL = ∞ VSHDN = VIN QUIESCENT CURRENT (µA) 200 LT3010-5 Quiescent Current TJ = 25°C 180 RL = ∞ 140 120 100 80 60 40 20 0 0 1 2 VSHDN = VIN VSHDN = 0V 34567 INPUT VOLTAGE (V) 8 9 10 GND PIN CURRENT (mA) 160 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 LT3010 GND Pin Current TJ = 25°C *FOR VOUT = 1.275V RL = 25.5Ω IL = 50mA* RL = 51Ω IL = 25mA* RL = 127Ω IL = 10mA* RL = 1.27k IL = 1mA* 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10 30105 G07 30105 G08 30105 G09 30105fe 5 LT3010/LT3010-5 TYPICAL PERFORMANCE CHARACTERISTICS LT3010-5 GND Pin Current 2.0 TJ = 25°C 1.8 *FOR VOUT = 5V GND PIN CURRENT (mA) GND PIN CURRENT (mA) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 0 1 2 RL = 100Ω IL = 50mA* RL = 200Ω IL = 25mA* RL = 500Ω IL = 10mA* RL = 5k, IL = 1mA* 34567 INPUT VOLTAGE (V) 8 9 10 2.0 GND Pin Current vs ILOAD VIN = VOUT(NOMINAL) + 1V 1.8 TJ = 25°C SHDN PIN THRESHOLD (V) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 0 5 10 15 20 25 30 35 40 45 50 OUTPUT CURRENT (mA) 30105 G11 SHDN Pin Threshold 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G12 OFF-TO-ON ON-TO-OFF 30105 G10 SHDN Pin Current 0.6 0.5 SHDN PIN CURRENT (µA) 0.4 0.3 0.2 0.1 0 TJ = 25°C CURRENT FLOWS OUT OF SHDN PIN SHDN PIN CURRENT (µA) 0.8 SHDN Pin Current VSHDN = 0V 0.7 CURRENT FLOWS OUT OF SHDN PIN 0.6 0.5 0.4 0.3 0.2 0.1 200 180 ADJ PIN BIAS CURRENT (nA) 160 140 120 100 80 60 40 20 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G14 ADJ Pin Bias Current 0 0.5 1 1.5 2 2.5 3 3.5 4 SHDN PIN VOLTAGE (V) 4.5 5 0 –50 –25 0 –50 –25 0 30105 G13 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G15 Current Limit 200 VOUT = 0V 180 TJ = 25°C 160 CURRENT LIMIT (mA) CURRENT LIMIT (mA) 140 120 100 80 60 40 20 0 0 1 2 34567 INPUT VOLTAGE (V) 8 9 10 200 180 160 140 120 100 80 60 40 20 Current Limit REVERSE OUTPUT CURRENT (µA) VIN = 7V VOUT = 0V 100 90 80 70 60 50 40 30 20 10 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G17 Reverse Output Current TJ = 25°C VIN = 0V CURRENT FLOWS INTO OUTPUT PIN VOUT = VADJ (LT3010) VOUT = VSENSE (LT3010-5) ADJ PIN CLAMP (SEE APPLICATIONS INFORMATION) LT3010 LT3010-5 0 –50 –25 0 0 1 2 345678 OUTPUT VOLTAGE (V) 9 10 30105 G18 30105 G16 30105fe 6 LT3010/LT3010-5 TYPICAL PERFORMANCE CHARACTERISTICS Reverse Output Current 80 REVERSE OUTPUT CURRENT (µA) 70 60 50 40 30 20 10 0 –50 –25 0 LT3010-5 LT3010 25 50 75 100 125 150 TEMPERATURE (°C) 3010 G19 Input Ripple Rejection 80 78 76 RIPPLE REJECTION (dB) RIPPLE REJECTION (dB) 74 72 70 68 66 64 62 VIN = 7V + 0.5VP-P RIPPLE AT f = 120Hz IL = 50mA VOUT = 1.275V 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G20 Input Ripple Rejection 100 90 80 70 60 50 40 30 20 10 0 10 100 1k 10k FREQUENCY (Hz) 100k 1M 30105 G21 VIN = 0V VOUT = VADJ = 1.275V (LT3010) VOUT = VSENSE = 5V (LT3010-5) VIN = 7V + 50mVRMS RIPPLE IL = 50mA COUT = 10µF COUT = 1µF 60 –50 –25 LT3010 Minimum Input Voltage 4.0 3.5 MINIMUM INPUT VOLTAGE (V) LOAD REGULATION (mV) 3.0 2.5 2.0 1.5 1.0 0.5 0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G22 Load Regulation –5 –10 –15 –20 –25 –30 –35 –40 –45 –50 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 30105 G23 Output Noise Spectral Density LT3010 OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) 10 COUT = 1µF IL = 50mA ILOAD = 50mA 0 ΔIL = 1mA TO 50mA 1 LT3010-5 0.1 0.01 10 100 1k 10k FREQUENCY (Hz) 100k 30105 G24 LT3010-5 10Hz to 100kHz Output Noise OUTPUT VOLTAGE DEVIATION (V) 0.2 0.1 0 –0.1 –0.2 LT3010-5 Transient Response VOUT 100µV/DIV LOAD CURRENT (mA) 50 25 0 0 200 VIN = 6V CIN = 1µF CERAMIC COUT = 1µF CERAMIC ΔILOAD = 1mA TO 50mA 1ms/DIV COUT = 1µF IL = 50mA 30105 G25 400 600 TIME (µs) 800 1000 30105 G26 30105fe 7 LT3010/LT3010-5 PIN FUNCTIONS OUT (Pin 1): Output. The output supplies power to the load. A minimum output capacitor of 1µF is required to prevent oscillations. Larger output capacitors will be required for applications with large transient loads to limit peak voltage transients. See the Applications Information section for more information on output capacitance and reverse output characteristics. SENSE (Pin 2): Sense. For the LT3010-5, the SENSE pin is the input to the error amplifier. Optimum regulation will be obtained at the point where the SENSE pin is connected to the OUT pin of the regulator. In critical applications, small voltage drops are caused by the resistance (RP) of PC traces between the regulator and the load. These may be eliminated by connecting the SENSE pin to the output at the load as shown in Figure 1 (Kelvin Sense Connection). Note that the voltage drop across the external PC traces will add to the dropout voltage of the regulator. The SENSE pin bias current is 10µA at the nominal rated output voltage. ADJ (Pin 2): Adjust. For the adjustable LT3010, this is the input to the error amplifier. This pin is internally clamped to ±7V. It has a bias current of 50nA which flows into the pin (see curve of ADJ Pin Bias Current vs Temperature 8 IN OUT LT3010 SHDN SENSE GND 4, 9 30105 F01 in the Typical Performance Characteristics). The ADJ pin voltage is 1.275V referenced to ground, and the output voltage range is 1.275V to 60V. NC (Pins 3, 6, 7): No Connection. May be floated, tied to IN or tied to GND. GND (Pin 4, Pin 9): Ground. The exposed backside (pin 9) of the package is an electrical connection for GND. As such, to ensure optimum device operation, pin 9 must be connected directly to pin 4 on the PC board. SHDN (Pin 5): Shutdown. The SHDN pin is used to put the LT3010 into a low power shutdown state. The output will be off when the SHDN pin is pulled low. The SHDN pin can be driven either by 5V logic or open-collector logic with a pull-up resistor. The pull-up resistor is only required to supply the pull-up current of the open-collector gate, normally several microamperes. If unused, the SHDN pin must be tied to a logic high or VIN. IN (Pin 8): Input. Power is supplied to the device through the IN pin. A bypass capacitor is required on this pin if the device is more than six inches away from the main input filter capacitor. In general, the output impedance of a battery rises with frequency, so it is advisable to include a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of 1µF to 10µF is sufficient. The LT3010 is designed to withstand reverse voltages on the IN pin with respect to ground and the OUT pin. In the case of a reversed input, which can happen if a battery is plugged in backwards, the LT3010 will act as if there is a diode in series with its input. There will be no reverse current flow into the LT3010 and no reverse voltage will appear at the load. The device will protect both itself and the load. 1 2 RP VIN + 5 + LOAD Figure 1. Kelvin Sense Connection 30105fe 8 LT3010/LT3010-5 APPLICATIONS INFORMATION The LT3010 is a 50mA high voltage low dropout regulator with micropower quiescent current and shutdown. The device is capable of supplying 50mA at a dropout voltage of 300mV. The low operating quiescent current (30µA) drops to 1µA in shutdown. In addition to the low quiescent current, the LT3010 incorporates several protection features which make it ideal for use in battery-powered systems. The device is protected against both reverse input and reverse output voltages. In battery backup applications where the output can be held up by a backup battery when the input is pulled to ground, the LT3010 acts like it has a diode in series with its output and prevents reverse current flow. Adjustable Operation The adjustable version of the LT3010 has an output voltage range of 1.275V to 60V. The output voltage is set by the ratio of two external resistors as shown in Figure 2. The device servos the output to maintain the voltage at the adjust pin at 1.275V referenced to ground. The current in R1 is then equal to 1.275V/R1 and the current in R2 is the current in R1 plus the ADJ pin bias current. The ADJ pin bias current, 50nA at 25°C, flows through R2 into the ADJ pin. The output voltage can be calculated using the formula in Figure 2. The value of R1 should be less than 250k to minimize errors in the output voltage caused by the ADJ pin bias current. Note that in shutdown the output is turned off and the divider current will be zero. A small capacitor (C1) placed in parallel with the top resistor (R2) of the output divider is necessary for stability and transient performance of the adjustable LT3010. The impedance of C1 at 10kHz should be less than the value of R1. IN VIN OUT LT3010 ADJ GND R1 30105 F02 The adjustable device is tested and specified with the ADJ pin tied to the OUT pin and a 5µA DC load (unless otherwise specified) for an output voltage of 1.275V. Specifications for output voltages greater than 1.275V will be proportional to the ratio of the desired output voltage to 1.275V; (VOUT/1.275V). For example, load regulation for an output current change of 1mA to 50mA is –10mV typical at VOUT = 1.275V. At VOUT = 12V, load regulation is: (12V/1.275V) • (–10mV) = –94mV Output Capacitance and Transient Response The LT3010 is designed to be stable with a wide range of output capacitors. The ESR of the output capacitor affects stability, most notably with small capacitors. A minimum output capacitor of 1µF with an ESR of 3Ω or less is recommended to prevent oscillations. The LT3010 is a micropower device and output transient response will be a function of output capacitance. Larger values of output capacitance decrease the peak deviations and provide improved transient response for larger load current changes. Bypass capacitors, used to decouple individual components powered by the LT3010, will increase the effective output capacitor value. Extra consideration must be given to the use of ceramic capacitors. Ceramic capacitors are manufactured with a variety of dielectrics, each with different behavior across temperature and applied voltage. The most common dielectrics used are specified with EIA temperature characteristic codes of Z5U, Y5V, X5R and X7R. The Z5U and Y5V dielectrics are good for providing high capacitances in a small package, but they tend to have strong voltage and temperature coefficients as shown in Figures 3 and 4. When used with a 5V regulator, a 16V 10µF Y5V capacitor can exhibit an effective value as low as 1µF to 2µF for the DC bias voltage applied and over the operating temperature range. The X5R and X7R dielectrics result in more stable characteristics and are more suitable for use as the output capacitor. The X7R type has better stability across temperature, while the X5R is less expensive and is available in higher values. Care still must be exercised when using X5R and X7R capacitors; the X5R and X7R codes only specify operating temperature range and maximum 30105fe R2 C1 + VOUT VOUT = 1.275V 1 + R2 + (IADJ)(R2) R1 VADJ = 1.275V IADJ = 50nA AT 25°C OUTPUT RANGE = 1.275V TO 60V () Figure 2. Adjustable Operation 9 LT3010/LT3010-5 APPLICATIONS INFORMATION 20 0 CHANGE IN VALUE (%) –20 –40 –60 –80 –100 BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10µF X5R Thermal Considerations The power handling capability of the device will be limited by the maximum rated junction temperature (125°C, LT3010E/LT3010MP or 140°C, LT3010H). The power dissipated by the device will be made up of two components: 1. Output current multiplied by the input/output voltage differential: IOUT • (VIN – VOUT) and, Y5V 0 2 4 6 8 10 12 DC BIAS VOLTAGE (V) 14 16 2. GND pin current multiplied by the input voltage: IGND • VIN The GND pin current can be found by examining the GND Pin Current curves in the Typical Performance Characteristics. Power dissipation will be equal to the sum of the two components listed above. The LT3010 series regulators have internal thermal limiting designed to protect the device during overload conditions. For continuous normal conditions the maximum junction temperature rating of 125°C (LT3010E/LT3010MP) or 140°C (LT3010H) must not be exceeded. It is important to give careful consideration to all sources of thermal resistance from junction to ambient. Additional heat sources mounted nearby must also be considered. 30105 F03 Figure 3. Ceramic Capacitor DC Bias Characteristics 40 20 CHANGE IN VALUE (%) 0 –20 –40 –60 –80 Y5V X5R BOTH CAPACITORS ARE 16V, 1210 CASE SIZE, 10µF –100 25 75 –50 –25 0 50 TEMPERATURE (°C) 100 125 30105 F04 Figure 4. Ceramic Capacitor Temperature Characteristics capacitance change over temperature. Capacitance change due to DC bias with X5R and X7R capacitors is better than Y5V and Z5U capacitors, but can still be significant enough to drop capacitor values below appropriate levels. Capacitor DC bias characteristics tend to improve as component case size increases, but expected capacitance at operating voltage should be verified. Voltage and temperature coefficients are not the only sources of problems. Some ceramic capacitors have a piezoelectric response. A piezoelectric device generates voltage across its terminals due to mechanical stress, similar to the way a piezoelectric accelerometer or microphone works. For a ceramic capacitor the stress can be induced by vibrations in the system or thermal transients. For surface mount devices, heat sinking is accomplished by using the heat spreading capabilities of the PC board and its copper traces. Copper board stiffeners and plated through-holes can also be used to spread the heat generated by power devices. The following table lists thermal resistance for several different board sizes and copper areas. All measurements were taken in still air on 3/32" FR-4 board with one ounce copper. Table 1. Measured Thermal Resistance COPPER AREA TOPSIDE BACKSIDE 2500 sq mm 2500 sq mm 1000 sq mm 2500 sq mm 225 sq mm 100 sq mm 2500 sq mm 2500 sq mm THERMAL RESISTANCE BOARD AREA (JUNCTION-TO-AMBIENT) 2500 sq mm 2500 sq mm 2500 sq mm 2500 sq mm 40°C/W 45°C/W 50°C/W 62°C/W 30105fe 10 LT3010/LT3010-5 APPLICATIONS INFORMATION The thermal resistance junction-to-case (θJC), measured at the exposed pad on the back of the die, is 16°C/W. Continuous operation at large input/output voltage differentials and maximum load current is not practical due to thermal limitations. Transient operation at high input/output differentials is possible. The approximate thermal time constant for a 2500sq mm 3/32" FR-4 board with maximum topside and backside area for one ounce copper is 3 seconds. This time constant will increase as more thermal mass is added (i.e. vias, larger board, and other components). For an application with transient high power peaks, average power dissipation can be used for junction temperature calculations as long as the pulse period is significantly less than the thermal time constant of the device and board. Calculating Junction Temperature Example 1: Given an output voltage of 5V, an input voltage range of 24V to 30V, an output current range of 0mA to 50mA, and a maximum ambient temperature of 50°C, what will the maximum junction temperature be? The power dissipated by the device will be equal to: IOUT(MAX) • (VIN(MAX) – VOUT) + (IGND • VIN(MAX)) where: IOUT(MAX) = 50mA VIN(MAX) = 30V IGND at (IOUT = 50mA, VIN = 30V) = 1mA So: P = 50mA • (30V – 5V) + (1mA • 30V) = 1.28W The thermal resistance will be in the range of 40°C/W to 62°C/W depending on the copper area. So the junction temperature rise above ambient will be approximately equal to: 1.31W • 50°C/W = 65.5°C The maximum junction temperature will then be equal to the maximum junction temperature rise above ambient plus the maximum ambient temperature or: TJMAX = 50°C + 65.5°C = 115.5°C Example 2: Given an output voltage of 5V, an input voltage of 48V that rises to 72V for 5ms(max) out of every 100ms, and a 5mA load that steps to 50mA for 50ms out of every 250ms, what is the junction temperature rise above ambient? Using a 500ms period (well under the time constant of the board), power dissipation is as follows: P1(48V in, 5mA load) = 5mA • (48V – 5V) + (200µA • 48V) = 0.23W P2(48V in, 50mA load) = 50mA • (48V – 5V) + (1mA • 48V) = 2.20W P3(72V in, 5mA load) = 5mA • (72V – 5V) + (200µA • 72V) = 0.35W P4(72V in, 50mA load) = 50mA • (72V – 5V) + (1mA • 72V) = 3.42W Operation at the different power levels is as follows: 76% operation at P1, 19% for P2, 4% for P3, and 1% for P4. PEFF = 76%(0.23W) + 19%(2.20W) + 4%(0.35W) + 1%(3.42W) = 0.64W With a thermal resistance in the range of 40°C/W to 62°C/W, this translates to a junction temperature rise above ambient of 26°C to 38°C. High Temperature Operation Care must be taken when designing LT3010H applications to operate at high ambient temperatures. The LT3010H works at elevated temperatures but erratic operation can occur due to unforeseen variations in external components. Some tantalum capacitors are available for high temperature operation, but ESR is often several ohms; capacitor ESR 30105fe 11 LT3010/LT3010-5 APPLICATIONS INFORMATION above 3Ω is unsuitable for use with the LT3010H. Ceramic capacitor manufacturers (Murata, AVX, TDK, and Vishay Vitramon at this writing) now offer ceramic capacitors that are rated to 150°C using an X8R dielectric. Device instability will occur if output capacitor value and ESR are outside design limits at elevated temperature and operating DC voltage bias (see information on capacitor characteristics under Output Capacitance and Transient Response). Check each passive component for absolute value and voltage ratings over the operating temperature range. Leakages in capacitors or from solder flux left after insufficient board cleaning adversely affects low quiescent current operation. Consider junction temperature increase due to power dissipation in both the junction and nearby components to ensure maximum specifications are not violated for the LT3010H or external components. Protection Features The LT3010 incorporates several protection features which make it ideal for use in battery-powered circuits. In addition to the normal protection features associated with monolithic regulators, such as current limiting and thermal limiting, the device is protected against reverse-input voltages, and reverse voltages from output to input. Current limit protection and thermal overload protection are intended to protect the device against current overload conditions at the output of the device. For normal operation, the junction temperature should not exceed 125°C (LT3010E/LT3010MP) or 140°C (LT3010H). The input of the device will withstand reverse voltages of 80V. Current flow into the device will be limited to less than 6mA (typically less than 100µA) and no negative voltage will appear at the output. The device will protect both itself and the load. This provides protection against batteries which can be plugged in backward. The ADJ pin of the adjustable device can be pulled above or below ground by as much as 7V without damaging the device. If the input is left open circuit or grounded, the ADJ pin will act like an open circuit when pulled below ground, and like a large resistor (typically 100k) in series with a diode when pulled above ground. If the input is powered by a voltage source, pulling the ADJ pin below the reference voltage will cause the device to try and force the current limit current out of the output. This will cause the output to go to a unregulated high voltage. Pulling the ADJ pin above the reference voltage will turn off all output current. In situations where the ADJ pin is connected to a resistor divider that would pull the ADJ pin above its 7V clamp voltage if the output is pulled high, the ADJ pin input current must be limited to less than 5mA. For example, a resistor divider is used to provide a regulated 1.5V output from the 1.22V reference when the output is forced to 60V. The top resistor of the resistor divider must be chosen to limit the current into the ADJ pin to less than 5mA when the ADJ pin is at 7V. The 53V difference between the OUT and ADJ pins divided by the 5mA maximum current into the ADJ pin yields a minimum top resistor value of 10.6k. 30105fe 12 LT3010/LT3010-5 APPLICATIONS INFORMATION In circuits where a backup battery is required, several different input/output conditions can occur. The output voltage may be held up while the input is either pulled to ground, pulled to some intermediate voltage, or is left open circuit. Current flow back into the output will follow the curve shown in Figure 5. The rise in reverse output current above 7V occurs from the breakdown of the 7V clamp on the ADJ pin. With a resistor divider on the regulator output, this current will be reduced depending on the size of the resistor divider. 100 REVERSE OUTPUT CURRENT (µA) When the IN pin of the LT3010 is forced below the OUT pin or the OUT pin is pulled above the IN pin, input current will typically drop to less than 2µA. This can happen if the input of the LT3010 is connected to a discharged (low voltage) battery and the output is held up by either a backup battery or a second regulator circuit. The state of the SHDN pin will have no effect on the reverse output current when the output is pulled above the input. TA = 25°C 90 VIN = 0V CURRENT FLOWS 80 INTO OUTPUT PIN 70 VOUT = VADJ (LT3010) VOUT = VSENSE 60 (LT3010-5) 50 40 30 20 10 0 0 1 2 LT3010 LT3010-5 ADJ PIN CLAMP (SEE ABOVE) 345678 OUTPUT VOLTAGE (V) 9 10 30105 F05 Figure 5. Reverse Output Current 30105fe 13 LT3010/LT3010-5 TYPICAL APPLICATIONS 5V Buck Converter with Low Current Keep Alive Backup D2 D1N914 6 VIN 5.5V* TO 60V 4 C3 4.7µF 100V CERAMIC VIN BOOST LT1766 15 14 SHDN SYNC GND BIAS FB VC CC 1nF 1 2 * FOR INPUT VOLTAGES BELOW 7.5V, SOME RESTRICTIONS MAY APPLY † INCREASE L1 TO 30µH FOR LOAD CURRENTS ABOVE 0.6A AND TO 60μH ABOVE 1A 30105 TA03 SW 2 C2 0.33µF L1† 15µH D1 10MQ060N 10 12 R1 15.4k R2 4.99k VOUT 5V 1A/50mA + C1 100µF 10V SOLID TANTALUM 1, 8, 9, 16 11 8 OPERATING CURRENT LOW HIGH 5 IN LT3010-5 GND 4 OUT SHDN SENSE Buck Converter Efficiency vs Load Current 100 VOUT = 5V L = 68µH VIN = 10V VIN = 42V 80 90 EFFICIENCY (%) 70 60 50 0 0.25 1.00 0.50 0.75 LOAD CURRENT (A) 1.25 30105 TA04 30105fe 14 LT3010/LT3010-5 TYPICAL APPLICATIONS LT3010 Telecom Application VIN 48V (72V TRANSIENT) IN 1µF LT3010-5 SHDN OUT NO PROTECTION DIODE NEEDED! 1µF LOAD: SYSTEM MONITOR ETC + – SENSE GND BACKUP BATTERY OFF ON 30105 TA05b Constant Brightness for Indicator LED over Wide Input Voltage Range RETURN 1µF OFF ON –48V IN OUT LT3010 SHDN GND ILED = 1.275V/RSET –48V CAN VARY FROM –4V TO –80V ADJ RSET 30105 TA06 1µF 30105fe 15 LT3010/LT3010-5 PACKAGE DESCRIPTION MS8E Package 8-Lead Plastic MSOP Exposed Die Pad , (Reference LTC DWG # 05-08-1662 Rev I) BOTTOM VIEW OF EXPOSED PAD OPTION 1 1.88 (.074) 1.68 (.066) 0.05 REF 0.29 REF 1.88 ± 0.102 (.074 ± .004) 0.889 ± 0.127 (.035 ± .005) 5.23 (.206) MIN 1.68 ± 0.102 3.20 – 3.45 (.066 ± .004) (.126 – .136) 8 0.42 ± 0.038 (.0165 ± .0015) TYP 0.65 (.0256) BSC 3.00 ± 0.102 (.118 ± .004) (NOTE 3) DETAIL “B” CORNER TAIL IS PART OF DETAIL “B” THE LEADFRAME FEATURE. FOR REFERENCE ONLY NO MEASUREMENT PURPOSE 0.52 (.0205) REF 8 7 65 RECOMMENDED SOLDER PAD LAYOUT DETAIL “A” 0° – 6° TYP 0.254 (.010) GAUGE PLANE 4.90 ± 0.152 (.193 ± .006) 3.00 ± 0.102 (.118 ± .004) (NOTE 4) 0.53 ± 0.152 (.021 ± .006) DETAIL “A” 1 1.10 (.043) MAX 23 4 0.86 (.034) REF 0.18 (.007) SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 6. EXPOSED PAD DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH ON E-PAD SHALL NOT EXCEED 0.254mm (.010") PER SIDE. 0.65 (.0256) BSC 0.1016 ± 0.0508 (.004 ± .002) MSOP (MS8E) 0910 REV I 30105fe 16 LT3010/LT3010-5 REVISION HISTORY REV D E DATE 5/10 4/11 DESCRIPTION Added MP-Grade to All Sections Updated Related Parts List Update MSOP Package Drawing (Revision history begins at Rev D) PAGE NUMBER 2 to 4, 10, 12 18 16 30105fe Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 17 LT3010/LT3010-5 TYPICAL APPLICATION LT3010 Automotive Application VIN 12V (LATER 42V) + 1µF NO PROTECTION DIODE NEEDED! IN LT3010-5 SHDN OUT 1µF LOAD: CLOCK, SECURITY SYSTEM ETC SENSE GND OFF ON 30105 TA05a RELATED PARTS PART NUMBER DESCRIPTION LT1676 LT1761 LT1762 LT1763 LT1766 LT1776 LT1956 LT1962 LT3011 LT3012 LT3013 LT3014 LT3050 60V, 440mA (IOUT), 100kHz, High Efficiency Step-Down DC/DC Converter 100mA, Low Noise Micropower, LDO 150mA, Low Noise Micropower, LDO 500mA, Low Noise Micropower, LDO 60V, 1.2A (IOUT), 200kHz, High Efficiency Step-Down DC/DC Converter 40V, 550mA (IOUT), 200kHz, High Efficiency Step-Down DC/DC Converter 60V, 1.2A (IOUT), 500kHz, High Efficiency Step-Down DC/DC Converter 300mA, Low Noise Micropower, LDO 50mA, High Voltage, Micropower LDO with PWRGD COMMENTS VIN: 7.4V to 60V, VOUT = 1.24V, IQ = 3.2mA, ISD = 2.5µA, S8 Package VIN: 1.8V to 20V, VOUT = 1.22V, VDO = 0.3V, IQ = 20µA, ISD =