LT1764S/TR

LT1764 3A Fast-Response LDO Regulator General Description Features The LT1764 is a high-current, low-cost, low-dropout voltage regulator which uses Micrel's proprietary Super ȕeta PNP® process with a PNP pass element. The 3A LDO regulator features 450mV (full load) dropout voltage and very low ground current. Designed for high-current loads, these devices also find applications in lower current, low dropout-critical systems, where their dropout voltage and ground current values are important attributes. Along with a total accuracy of ±2% (over temperature, line and load regulation) the regulator features very-fast transient recovery from input voltage surges and output load current changes. The LT1764 has an adjustable output which can be set by two external resistors to a voltage between 1.24V to 15V. In addition, the device is fully protected against over current faults, reversed input polarity, reversed lead insertion, and overtemperature operation. A TTL logic enable (EN) pin is available in the LT1764 to shutdown the regulator. When not used, the device can be set to continuous operation by connecting EN to the input (IN). The LT1764 is available in the standard and 5-pin TO-263 and TO-252 packages with an operating junction temperature range of 40qC to +85°C. x High-current capability  3A over full temperature range x Low-dropout voltage of 450mV at full load x Low ground current x Accurate 1% guaranteed tolerance x Extremely-fast transient response x Zero-current shutdown mode x Error flag signals output out-of-regulation x Adjustable output voltage x Packages: TO-263-5L.TO-220-5L and TO-252-5L Applications x x x x x x x Processor peripheral and I/O supplies High-efficiency “Green” computer systems Automotive electronics High-efficiency linear lower supplies Battery-powered equipment PC add-in cards High-efficiency lost-regulator for switching supply Typical Application Dropout Voltage vs. Output Current VOUT DROPOUT VOLTAGE (mV) 500 § R1 · 1.242 u ¨  1¸ © R2 ¹ VIN = 3.3V 400 TA = 25ºC VADJ = 0V 300 200 100 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 OUTPUT CURRENT (A) LT1764 Adjustable Output Regulator http://www.hgsemi.com.cn 1 2018 JUN LT1764 ORDERING INFORMATION DEVICE Package Type MARKING Packing Packing Qty LT1764T TO220-5L LT1764 TUBE 1000pcs/box LT1764S/TR TO263-5L LT1764 REEL 500pcs/reel LT1764DT/TR TO252-5L LT1764 REEL 2000pcs/reel TAB Pin Configuration 5 4 3 2 1 ADJ OUT GND IN EN TO-220-5 5-Pin TO-263/TO-252 Pin Description Pin Number TO-263/TO-252 Pin Number TO-220 Pin Name 1 1 EN Enable (Input): Active-high CMOS compatible control input. Do not float. 2 2 IN INPUT: Unregulated input, +2.8V to +16V maximum 3, TAB 3, TAB GND GND: TAB is also connected internally to the IC’s ground on both packages. 4 4 OUT OUTPUT: The regulator output voltage 5 5 ADJ Feedback Voltage: 1.24V feedback from external resistor divider. http://www.hgsemi.com.cn Pin Name 2 2018 JUN LT1764 Absolute Maximum Ratings(1) Operating Ratings(2) Input Supply Voltage (VIN)(1) ........................... –20V to +20V Enable Input Voltage (VEN)................................ –0.3V to VIN Lead Temperature (soldering, 5sec.)......................... 260°C Power Dissipation .....................................Internally Limited Storage Temperature Range ....................–65°C to +150°C ESD Rating all pins(3) Operating Junction Temperature .............. 40°C to +125°C Operating Input Voltage ....................................... 3V to 16V Electrical Characteristics(4) VIN = 4.2V; IOUT = 100mA; TA = 25qC, bold values indicate 40°C” TJ ” +125°C, unless noted. Parameter Condition Min. Typ. Max. Units 2 % Output Voltage 2 Output Voltage Accuracy 100mA d IOUT d3A, (VOUT  1V) d VIN d 16V Line Regulation IOUT = 100mA, (VOUT + 1V) d VIN d 16V 0.1 0.5 % Load Regulation VIN = VOUT + 1V, 100mA d IOUT d 3A 0.2 1 % IOUT = 100mA 80 200 IOUT = 750mA 220 IOUT = 1.5A 275 IOUT = 3A 450 800 IOUT = 750mA, VIN = VOUT + 1V 5 20 IOUT = 1.5A 15 IOUT = 3A 60 IGRNDDO Ground Pin Current @ Dropout VIN = 0.5V less than specified VOUT u IOUT = 10mA 2 Current Limit VOUT = 0V(7) en, Output Noise Voltage (10Hz to 100kHz (6) 'VOUT = 1% Dropout Voltage mV Ground Current Ground Current 4 A CL = 10µF 400 µV IL = 100mA CL = 33 µF 260 Ground Pin Current in Shutdown Input Voltage VIN = 16V 32 http://www.hgsemi.com.cn 3 mA 150 3 (rms) µA 2018 JUN LT1764 Electrical Characteristics(4) (Continued) VIN = 4.2V; IOUT = 10mA; TA = 25qC, bold values indicate 40°C” TJ ” +125°C, unless noted. Reference Reference Voltage (8) 1.215 1.267 40 Adjust Pin Bias Current 120 V nA ENABLE Input Input Logic Voltage 0.8 Low (OFF) 15 VEN = 8V 30 75 Enable Pin Input Current 2 VEN = 0.8V Regulator Output Current in Shutdown V 2.4 High (ON) µA 4 10 (10) 20 µA Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. 4. Specification for packaged product only 5. Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature change. 6. Dropout voltage is defined as the input-to-output differential when output voltage drops to 99% of its normal value with VOUT + 1V applied to VIN. 7. VIN =VOUT (nominal) + 1V. For example, use VIN = 4.3V for a 3.3Vregulator or use 6V for a 5V regulator. Employ pulse testing procedure for current limit. 8. VREF d VOUT d VIN -1, 3V d VOUT d 16V, 10mA d IL d IFL, TJ d TJmax. 9. Thermal regulation is defined as the change in the output voltage at a time T after a change in power dissipation is applied, excluding load or line regulation effects. Specifications are for a 250mA load pulse at VIN =16V (a 4W pulse) for T= 10ms. 10. VEN d 0.8V, VIN d 16V and VOUT = 0V. http://www.hgsemi.com.cn 4 2018 JUN LT1764 Typical Characteristics GND Pin Current vs. Input Voltage Dropout Voltage vs. Input Voltage 70.0 400 IOUT = 3A 300 200 IOUT = 1.0A 100 1.250 IOUT = 3A 60.0 ADJ PIN VOLTAGE (V) GROUND CURRENT (mA) 50.0 40.0 30.0 20.0 V OUT = 1.8V IOUT = 3A 1.245 1.240 1.235 10.0 0 1.230 0.0 0 4 8 12 16 0 4 8 12 INPUT VOLTAGE (V) INPUT VOLTAGE (V) Adjust Pin Current vs. Input Voltage Load Regulation vs. Input Voltage 46 0 16 LOAD REGULATION (%) 42 40 4 8 12 12 V OUT = 1.8V IOUT = 10mA to 3A 0.200 0.100 V OUT = 0V 8 6 4 2 16 0 0 INPUT VOLTAGE (V) 4 8 12 16 INPUT VOLTAGE (V) Enable Pin Current vs. Input Voltage 0 4 8 12 INPUT VOLTAGE (V) Output Voltage vs. Input Voltage 20.00 1.243 OUTPUT VOLTAGE (V) ENABLE PIN CURRENT (µA) VOUT = 1.24V IOUT = 10mA 15.00 10.00 VOUT = 1.8V IOUT = 10mA 5.00 VEN = VIN 1.242 1.241 1.240 0.00 0 4 8 12 INPUT VOLTAGE (V) http://www.hgsemi.com.cn 16 16 10 0.000 0 8 Short-Circuit Current vs. Input Voltage 0.300 ILOAD = 10mA 44 4 INPUT VOLTAGE (V) CURRENT LIMIT (A) DROPOUT VOLTAGE (mV) 500 ADJ PIN CURRENT (nA) Adjust Pin Voltage vs. Input Voltage 0 4 8 12 16 INPUT VOLTAGE (V) 5 2018 JUN 16 LT1764 Typical Characteristics (Continued) Enable Bias Current vs. Temperature (B06) GND Pin Current vs. Temperature 600 VOUT = 1.8V 8.00 EN PIN CURRENT (nA) IOUT = 750mA 6.00 4.00 2.00 VIN = VEN = 8V 25 VOUT = 2.5V IOUT = 10mA 20 15 10 5 0.00 -25 0 25 50 75 100 125 IOUT = 3A 500 400 300 IOUT = 1.5A 200 VIN = 4.2V 100 0 0 -50 -50 -25 0 25 50 75 100 -50 125 -25 0 25 50 75 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) Dropout Voltage vs. Temperature Short-Circuit Current vs. Temperature Adjust Pin Voltage vs. Temperature 400 VIN = 4.2V CURRENT LIMIT (A) IOUT = 750mA 300 200 100 100 125 100 125 1.243 4.250 ADJ PIN VOLTAGE (V) GROUND CURRENT (mA) VIN =4.2V DROPOUT VOLTAGE (mV) 30 10.00 DROPOUT VOLTAGE (mV) Dropout Voltage vs. Temperature 4.000 3.750 VIN = 4.2V 1.240 VIN =4.2V 1.238 VOUT = 1.8V IOUT = 10mA VOUT = 0V IOUT = 100mA 0 3.500 -50 -25 0 25 50 75 100 125 1.235 -50 -25 0 25 50 75 TEMPERATURE (°C) TEMPERATURE (°C) Adjust Pin Current vs. Temperature Line Regulation vs. Temperature 100 125 -50 -25 0 25 50 75 TEMPERATURE (°C) 0.5 80 LINE REGULATION (%/V) ADJ PIN CURRENT (nA) VIN = 3V to 16V 60 40 VIN = 4.2V 20 ILOAD = 10mA 0 VOUT = 1.8V 0.4 IOUT = 10mA 0.3 0.2 0.1 0.0 -50 -25 0 25 50 75 TEMPERATURE (°C) http://www.hgsemi.com.cn 100 125 -50 -25 0 25 50 75 100 125 TEMPERATURE (°C) 6 2018 JUN LT1764 Typical Characteristics (Continued) 500 V IN = 3V DROPOUT VOLTAGE (mV) V ADJ = 0V ADJUSTABLE OPTION 400 300 200 100 VIN = 4.2V 400 VADJ = 0V 300 200 100 0.5 1.0 1.5 2.0 2.5 0.0 3.0 0.5 1.0 Line Regulation vs. Output Current GROUND CURRENT (mA) LINE REGULATION (%) 0.1 0.0 V IN = 4.2V to 16V V OUT = 1.8V -0.2 0.5 1.0 1.5 2.0 2.5 2.0 60 40 40 V IN =3.3V V OUT = 1.8V IOUT = 10mA COUT = 22µF 0 0.01 0.1 1 10 100 FREQUENCY (kHz) http://www.hgsemi.com.cn 1000 2.0 2.5 3.0 30 20 1 1.0 1.5 2.0 2.5 3.0 VIN =3.3V 0.1 VOUT = 1.8V IOUT = 3A 0.01 10 0.5 Noise Spectral Density 10 COUT = 47µF 0.001 0.01 0.1 80 Gain (dB) 60 50 30 20 VIN =3.3V VOUT = 1.8V IOUT = 1.5A COUT = 22µF 10 0 0.01 0.1 1 10 FREQUENCY (kHz) 7 100 10 100 1000 Ripple Rejection (IOUT = 3A) vs. Frequency 70 40 1 FREQUENCY (kHz) Ripple Rejection (IOUT = 1.5A) vs. Frequency 50 1.5 100 OUTPUT CURRENT (A) 60 10 1.0 Output Noise vs. Frequency 50 80 20 0.5 OUTPUT CURRENT (A) V IN = 4.2V Gain (dB) 30 0.0 3.0 V OUT = 1.8V Ripple Rejection (IOUT = 10mA) vs. Frequency 70 2.5 1000 0.0 RIPPLE REJECTION (dB) RIPPLE REJECTION (dB) 1.5 0 3.0 OUTPUT CURRENT (A) 80 1.238 GND Pin Current vs. Output Current 70 0.2 0.0 1.240 OUTPUT CURRENT (A) OUTPUT CURRENT (A) -0.1 V OUT = 1.8V 1.242 OUTPUT NOISE (µV/¥Hz) 0.0 V IN = 4.2V 1.244 1.236 0 0 Adjust Pin Voltage vs. Output Current 1.246 RIPPLE REJECTION (dB) DROPOUT VOLTAGE (mV) 500 Dropout Voltage vs. Output Current ADJ PIN VOLTAGE (V) Dropout Voltage vs. Output Current 1000 Gain (dB) 70 60 50 40 VIN =3.3V 30 IOUT = 3A 20 VOUT = 1.8V COUT = 22µF 10 0 0.01 0.1 1 10 100 FREQUENCY (kHz) 2018 JUN 1000 LT1764 Functional Characteristics Figure 2. LT1764 Load Transient Response Test Circuit http://www.hgsemi.com.cn 8 2018 JUN LT1764 Functional Diagram http://www.hgsemi.com.cn 9 2018 JUN LT1764 First, we calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet: Application Information The LT1764 is a high-performance, low-dropout voltage regulator suitable for all moderate to high-current voltage regulation applications. Its 450mV typical dropout voltage at full load makes it especially valuable in battery-powered systems and as high efficiency noise filters in “post-regulator” applications. Unlike older NPNpass transistor designs, where the minimum dropout voltage is limited by the base-emitter voltage drop and collector-emitter saturation voltage, dropout performance of the PNP output is limited merely by the low VCE saturation voltage. A trade-off for the low-dropout voltage is a varying base driver requirement. But Micrel’s Super ßeta PNP® process reduces this drive requirement to merely 1% of the load current. The LT1764 regulator is fully protected from damage due to fault conditions. Current limiting is linear; output current under overload conditions is constant. Thermal shutdown disables the device when the die temperature exceeds the 125qC maximum safe operating temperature. The output structure of the regulators allows voltages in excess of the desired output voltage to be applied without reverse current flow. The LT1764 offer a logic level ON/OFF control: when disabled, the devices draw nearly zero current. PD Where the ground current is approximated by 2% of IOUT. Then the heat sink thermal resistance is determined with this formula: ș SA The heat sink may be significantly reduced in applications where the minimum input voltage is known and is large compared to the dropout voltage. A series input resistor can be used to drop excessive voltage and distribute the heat between this resistor and the regulator. The low-dropout properties of Micrel Super ȕeta PNP® regulators allow very significant reductions in regulator power dissipation and the associated heat sink without compromising performance. When this technique is employed, a capacitor of at least 0.1µF is needed directly between the input and regulator ground. With no heat sink in the application, calculate the junction temperature to determine the maximum power dissipation that will be allowed before exceeding the maximum junction temperature of the LT1764. The maximum power allowed can be calculated using the thermal resistance (șJA) of the D-Pak (TO252) adhering to the following criteria for the PCB design: 2 oz. copper and 100mm2 copper area for the LT1764. For example, given an expected maximum ambient temperature (TA) of 75qC with VIN = 3.3V, VOUT = 2.5V, and IOUT = 1.5A, first calculate the expected PD using: Thermal Design Linear regulators are simple to use. The most complicated set of design parameters to consider are thermal characteristics. Thermal design requires the following application-specific parameters: Maximum ambient temperature, TA x Output Current, IOUT x Output Voltage, VOUT x Input Voltage, VIN http://www.hgsemi.com.cn TJMAX  TA  ș JC  ș CS  PD where: TJMAX ” 125°C and șCS is between 0 and 2°C/W. Figure 3. Linear Regulators Require Only Two Capacitors for Operation x IOUT 1.02VIN  VOUT  PD 10 3.3V  2.5V  u 3A  3.3V  u 0.016A  2.3472W 2018 JUN LT1764 Next, calcualte the junction temperature for the expected power dissipation: For best performance the total resistance (R1+R2) should be small enough to pass the minimum regulator load current of 10mA. TJ = (șJA×PD) + TA = (35qC/W × 2.3472W) + 75qC = 157.15qC Adjustable Regulator Design The output voltage can be programmed anywhere between 1.25V and the 15V. Two resistors are used. The resistor values are calculated by: Now determine the maximum power dissipation allowed that would not exceed the IC’s maximum junction temperature (125qC) without the use of a heat sink by: R1 PD(MAX) = (TJ(MAX) – TA) / șJA = (125qC – 75qC) / (35qC/W) = 1.428W where VOUT is the desired output voltage. Capacitor Requirements For stability and minimum output noise, a capacitor on the regulator output is necessary. The value of this capacitor is dependent upon the output current; lower currents allow smaller capacitors. The LT1764 is stable with a 10ȝF capacitor at full load. This capacitor need not be an expensive low-ESR type; aluminum electrolytics are adequate. In fact, extremely low-ESR capacitors may contribute to instability. Tantalum capacitors are recommended for systems where fast load transient response is important. When the regulator is powered from a source with high AC impedance, a 0.1µF capacitor connected between input and GND is recommended. Figure 4 shows component definition. Applications with widely varying load currents may scale the resistors to draw the minimum load current required for proper operation (see “Minimum Load Current” section). Transient Response and 5V to 3.3V Conversion The LT1764 has excellent response to variations in input voltage and load current. By virtue of its low dropout voltage, the device does not saturate into dropout as readily as similar NPN-based designs. A 3.3V output Micrel LDO will maintain full speed and performance with an input supply as low as 4.2V, and will still provide some regulation with supplies down to 3.8V, unlike NPN devices that require 5.1V or more for good performance and become nothing more than a resistor under 4.6V of input. Micrel’s PNP regulators provide superior performance in “5V to 3.3V” conversion applications than NPN regulators, especially when all tolerances are considered. Figure 4. Adjustable Regulator with Resistors Enable Input LT1764 features an enable (EN) input that allows ON/OFF control of the device. Special design allows “zero” current drain when the device is disabled—only microamperes of leakage current flows. The EN input has TTL/CMOS compatible thresholds for simple interfacing with logic, or may be directly tied to VIN. Enabling the regulator requires approximately 20µA of current into the EN pin. Minimum Load Current The LT1764 regulator operates within a specified load range. If the output current is too small, leakage currents dominate and the output voltage rises. A minimum load current of 10mA is necessary for proper regulation and to swamp any expected leakage current across the operating temperature range. http://www.hgsemi.com.cn §V · R 2 u ¨¨ OUT  1¸¸ © 1.240 ¹ 11 2018 JUN LT1764      
  
    



 


 

          
        

       
 
      
   
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  2018 JUN LT1764    ＴＯ２２０－５－Ａ２ A D1 D B  Dimensions In Millimeters Symbol
http://www.hgsemi.com.cn 13 Min
Max
Symbol
Min
Max
A 4.400 4.600 A1 1.250 1.300 B 9.850 10.41 F 7.80 TYP D 28.60 28.85 G 12.62 TYP D1 22.45 22.75 q 3.84 TYP  8.500 9.100 0.330 0.430 2018 JUN LT1764 Important statement: Huaguan Semiconductor Co,Ltd. reserves the right to change the products and services provided without notice. Customers should obtain the latest relevant information before ordering, and verify the timeliness and accuracy of this information. Customers are responsible for complying with safety standards and taking safety measures when using our products for system design and machine manufacturing to avoid potential risks that may result in personal injury or property damage. Our products are not licensed for applications in life support, military, aerospace, etc., so we do not bear the consequences of the application of these products in these fields. Huaguan Semiconductor Co,Ltd. the performance of the semi conductor products produced by the company can reach the performance indicators that can be applied at the time of sales. the use of testing and other quality control technologies is limited to the quality assurance scope of Huaguan semicondu ctor. Not all parameters of each device need to be tested. The above documents are for reference only, and all are subject to the physical parameters. Our documentation is only permitted to be copied without any tampering with the content, so we do not accept any responsibility or liability for the altered documents. http://www.hgsemi.com.cn 14 2018 JUN