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ADP7142AUJZ-5.0

ADP7142AUJZ-5.0

  • 厂商:

    AD(亚德诺)

  • 封装:

    -

  • 描述:

  • 数据手册
  • 价格&库存
ADP7142AUJZ-5.0 数据手册
Data Sheet ADP7142 40 V, 200 mA, Low Noise, CMOS LDO Linear Regulator FEATURES ► ► ► ► ► ► ► ► ► ► ► ► ► ► ► ► TYPICAL APPLICATION CIRCUITS Low noise: 11 µV rms independent of fixed output voltage PSRR of 88 dB at 10 kHz, 68 dB at 100 kHz, 50 dB at 1 MHz, VOUT ≤ 5 V, VIN = 7 V Input voltage range: 2.7 V to 40 V Maximum output current: 200 mA Initial accuracy: ±0.8% Accuracy over line, load, and temperature ► −1.2% to +1.5%, TJ = −40°C to +85°C ► ±1.8%, TJ = −40°C to +125°C Low dropout voltage: 200 mV (typical) at a 200 mA load, VOUT = 5V User programmable soft start (LFCSP and SOIC only) Low quiescent current, IGND = 50 μA (typical) with no load Low shutdown current: 1.8 μA at VIN = 6 V, 3.0 μA at VIN = 40 V Stable with a small 2.2 µF ceramic output capacitor Fixed output voltage options: 1.8 V, 2.5 V, 3.3 V, 3.8 V, and 5.0 V ► 15 standard voltages between 1.2 V and 5.0 V are available Adjustable output from 1.2 V to VIN – VDO, output can be adjusted above initial set point Precision enable 2 mm × 2 mm, 6-lead LFCSP, 8-Lead SOIC, 5-Lead TSOT AEC-Q100 qualified for automotive applications APPLICATIONS ► Regulation to noise sensitive applications ADC, DAC circuits, precision amplifiers, power for VCO VTUNE control Communications and infrastructure Medical and healthcare Industrial and instrumentation Automotive ► ► ► ► ► Figure 1. ADP7142 with Fixed Output Voltage, 5 V Figure 2. ADP7142 with 5 V Output Adjusted to 6 V GENERAL DESCRIPTION The ADP7142 is a CMOS, low dropout (LDO) linear regulator that operates from 2.7 V to 40 V and provides up to 200 mA of output current. This high input voltage LDO is ideal for the regulation of high performance analog and mixed signal circuits operating from 39 V down to 1.2 V rails. Using an advanced proprietary architecture, the device provides high power supply rejection, low noise, and achieves excellent line and load transient response with a small 2.2 µF ceramic output capacitor. The ADP7142 regulator output noise is 11 μV rms independent of the output voltage for the fixed options of 5 V or less. The ADP7142 is available in 15 fixed output voltage options. The following voltages are available from stock: 1.2 V (adjustable), 1.8 V, 2.5 V, 3.3 V, 3.8 V, and 5.0 V. Additional voltages available by special order are 1.5 V, 1.85 V, 2.0 V, 2.2 V, 2.75 V, 2.8 V, 2.85 V, 3.0 V, 4.2 V, and 4.6 V. Each fixed output voltage can be adjusted above the initial set point with an external feedback divider. This allows the ADP7142 to provide an output voltage from 1.2 V to VIN − VDO with high PSRR and low noise. User programmable soft start with an external capacitor is available in the LFCSP and SOIC packages. The ADP7142 is available in a 6-lead, 2 mm × 2 mm LFCSP making it not only a very compact solution, but it also provides excellent thermal performance for applications requiring up to 200 mA of output current in a small, low profile footprint. The ADP7142 is also available in a 5-lead TSOT and an 8-lead SOIC. Rev. I DOCUMENT FEEDBACK TECHNICAL SUPPORT Information furnished by Analog Devices is believed to be accurate and reliable "as is". However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Data Sheet ADP7142 TABLE OF CONTENTS Features................................................................ 1 Applications........................................................... 1 Typical Application Circuits....................................1 General Description...............................................1 Specifications........................................................ 3 Input and Output Capacitance, Recommended Specifications..........................4 Absolute Maximum Ratings...................................5 Thermal Data......................................................5 Thermal Resistance........................................... 5 ESD Caution.......................................................5 Pin Configurations and Function Descriptions.......6 Typical Performance Characteristics..................... 7 Theory of Operation.............................................13 Applications Information...................................... 14 Design Tools.....................................................14 Capacitor Selection.......................................... 14 Programmable Precision Enable......................14 Soft Start.......................................................... 15 Noise Reduction of the ADP7142 in Adjustable Mode.............................................15 Effect of Noise Reduction on Start-Up Time.....16 Current-Limit and Thermal Overload Protection....................................................... 16 Thermal Considerations................................... 17 Printed Circuit Board Layout Considerations.......20 Outline Dimensions............................................. 22 Ordering Guide.................................................23 Output Voltage Options ................................... 24 Evaluation Boards............................................ 24 Automotive Products........................................ 24 REVISION HISTORY 3/2022—Rev. H to Rev. I Changes to Features Section.......................................................................................................................... 1 Change to Applications Section....................................................................................................................... 1 Change to General Description Section...........................................................................................................1 Change to Specifications Section.................................................................................................................... 3 Changes to Table 3.......................................................................................................................................... 5 Changes to Figure 6 Caption, Figure 9 Caption, Figure 10 Caption, and Figure 11 Caption.......................... 7 Changes to Figure 12 Caption, Figure 13 Caption, Figure 15 Caption, and Figure 16 Caption...................... 8 Changes to Figure 19 Caption to Figure 22 Caption....................................................................................... 9 Changes to Figure 24 Caption and Figure 25 Caption.................................................................................. 10 Changed ADISIMPower Design Tool Section to Design Tools Section......................................................... 14 Changes to Design Tools Section.................................................................................................................. 14 Changes to Input and Output Capacitor Properties Section ......................................................................... 14 Changes to Soft Start Section........................................................................................................................15 Changes to Figure 48.................................................................................................................................... 15 Change to Effect of Noise Reduction on Start-Up Time Section....................................................................16 Changes to Thermal Considerations Section................................................................................................ 17 Changes to Ordering Guide........................................................................................................................... 23 Added Voltage Output Options Section......................................................................................................... 24 Added Automotive Products Section............................................................................................................. 24 analog.com Rev. I | 2 of 24 Data Sheet ADP7142 SPECIFICATIONS VIN = VOUT +1 V or 2.7 V, whichever is greater, VOUT = 5 V, VEN = VIN, IOUT = 10 mA, CIN = COUT = 2.2 µF, CSS = 0 pF, TA = 25°C for typical specifications, TJ = −40°C to +125°C for minimum/maximum specifications, unless otherwise noted. Table 1. Parameter Symbol INPUT VOLTAGE RANGE OPERATING SUPPLY CURRENT VIN IGND SHUTDOWN CURRENT IGND-SD OUTPUT VOLTAGE ACCURACY Output Voltage Accuracy VOUT LINE REGULATION LOAD REGULATION1 SENSE INPUT BIAS CURRENT DROPOUT VOLTAGE2 ∆VOUT/∆VIN ∆VOUT/∆IOUT SENSEI-BIAS VDROPOUT START-UP TIME3 SOFT START SOURCE CURRENT CURRENT-LIMIT THRESHOLD4 THERMAL SHUTDOWN Thermal Shutdown Threshold Thermal Shutdown Hysteresis UNDERVOLTAGE THRESHOLDS Input Voltage Rising Input Voltage Falling Hysteresis PRECISION EN INPUT Logic High Logic Low Logic Hysteresis Leakage Current Delay Time OUTPUT NOISE POWER SUPPLY REJECTION RATIO tSTART-UP SSI-SOURCE ILIMIT TSSD TSSD-HYS Test Conditions/Comments Min Typ Max Unit 40 140 190 320 10 V µA µA µA µA µA –0.8 –1.2 +0.8 +1.5 % % –1.8 –0.01 +1.8 +0.01 0.004 1000 60 420 % %/V %/mA nA mV mV µs µA mA 2.7 IOUT = 0 µA IOUT = 10 mA IOUT = 200 mA EN = GND EN = GND, VIN = 40 V IOUT = 10 mA, TJ = 25°C 100 μA < IOUT < 200 mA, VIN = (VOUT + 1 V) to 40 V, TJ = −40°C to +85°C 100 μA < IOUT < 200 mA, VIN = (VOUT + 1 V) to 40 V VIN = (VOUT + 1 V) to 40 V IOUT = 100 μA to 200 mA 100 μA < IOUT < 200 mA VIN = (VOUT + 1 V) to 40 V IOUT = 10 mA IOUT = 200 mA VOUT = 5 V SS = GND 50 80 180 1.8 3.0 250 TJ rising UVLORISE UVLOFALL UVLOHYS 0.002 10 30 200 380 1.15 360 460 150 15 °C °C 2.69 V V mV 1.30 1.18 V V mV µA μs µV rms dB dB dB 2.2 230 2.7 V ≤ VIN ≤ 40 V ENHIGH ENLOW ENHYS IEN-LKG tEN-DLY OUTNOISE PSRR 1.15 1.06 EN = VIN or GND From EN rising from 0 V to VIN to 0.1 × VOUT 10 Hz to 100 kHz, all output voltage options 1 MHz, VIN = 7 V, VOUT = 5 V 100 kHz, VIN = 7 V, VOUT = 5 V 10 kHz, VIN = 7 V, VOUT = 5 V 1.22 1.12 100 0.04 80 11 50 68 88 1 1 Based on an endpoint calculation using 100 μA and 200 mA loads. See Figure 7 for typical load regulation performance for loads less than 1 mA. 2 Dropout voltage is defined as the input-to-output voltage differential when the input voltage is set to the nominal output voltage. Dropout applies only for output voltages above 2.7 V. 3 Start-up time is defined as the time between the rising edge of EN to OUT being at 90% of its nominal value. 4 Current-limit threshold is defined as the current at which the output voltage drops to 90% of the specified typical value. For example, the current limit for a 5.0 V output voltage is defined as the current that causes the output voltage to drop to 90% of 5.0 V or 4.5 V. analog.com Rev. I | 3 of 24 Data Sheet ADP7142 SPECIFICATIONS INPUT AND OUTPUT CAPACITANCE, RECOMMENDED SPECIFICATIONS Table 2. Parameter Symbol Test Conditions/Comments Min INPUT AND OUTPUT CAPACITANCE Minimum Capacitance1 Capacitor Effective Series Resistance (ESR) CMIN RESR TA = −40°C to +125°C TA = −40°C to +125°C 1.5 0.001 1 Typ Max Unit 0.3 µF Ω The minimum input and output capacitance must be greater than 1.5 μF over the full range of operating conditions. The full range of operating conditions in the application must be considered during device selection to ensure that the minimum capacitance specification is met. X7R and X5R type capacitors are recommended, while Y5V and Z5U capacitors are not recommended for use with any LDO. analog.com Rev. I | 4 of 24 Data Sheet ADP7142 ABSOLUTE MAXIMUM RATINGS Table 3. Parameter Rating VIN to GND VOUT to GND EN to GND SENSE/ADJ to GND SS to GND –0.3 V to +44 V –0.3 V to VIN –0.3 V to +44 V –0.3 V to +6 V –0.3 V to VIN or +6 V (whichever is less) –65°C to +150°C 150°C –40°C to +125°C Storage Temperature Range Junction Temperature (TJ) Operating Ambient Temperature (TA) Range Soldering Conditions ESD 6-Lead LFCSP, 8-Lead SOIC Human Body Model (HBM) Field Induced Charged Device Model (FICDM) 5-Lead TSOT HBM FICDM 5-Lead TSOT (W Grade) HBM1 HBM2 FICDM JEDEC J-STD-020 ±1000 V ±1000 V ±1000 V ±1250 V ±1000 V ±2000 V ±1250 V 1 All pins passing. 2 All pins passing with elevated output noise. No physical damage to circuitry. Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability. THERMAL DATA Absolute maximum ratings apply individually only, not in combination. The ADP7142 can be damaged when the junction temperature limits are exceeded. Monitoring ambient temperature does not guarantee that TJ is within the specified temperature limits. In applications with high power dissipation and poor thermal resistance, the maximum ambient temperature may have to be derated. In applications with moderate power dissipation and low printed circuit board (PCB) thermal resistance, the maximum ambient temperature can exceed the maximum limit as long as the junction temperature is within specification limits. The junction temperature of the device is dependent on the ambient temperature, the power dissipation (PD) of the device, and the junction-to-ambient thermal resistance of the package (θJA). T J = TA + PD × θ JA (1) θJA of the package is based on modeling and calculation using a 4-layer board. The θJA is highly dependent on the application and board layout. In applications where high maximum power dissipation exists, close attention to thermal board design is required. The value of θJA may vary, depending on PCB material, layout, and environmental conditions. The specified values of θJA are based on a 4-layer, 4 inches × 3 inches circuit board. See JESD51-7 and JESD51-9 for detailed information on the board construction. ΨJB is the junction-to-board thermal characterization parameter with units of °C/W. The ΨJB of the package is based on modeling and calculation using a 4-layer board. The JESD51-12, Guidelines for Reporting and Using Electronic Package Thermal Information, states that thermal characterization parameters are not the same as thermal resistances. ΨJB measures the component power flowing through multiple thermal paths rather than a single path as in thermal resistance (θJB). Therefore, ΨJB thermal paths include convection from the top of the package as well as radiation from the package, factors that make ΨJB more useful in real-world applications. Maximum TJ is calculated from the board temperature (TB) and PD using the formula T J = TB  + PD × Ψ JB (2) See JESD51-8 and JESD51-12 for more detailed information about ΨJB. THERMAL RESISTANCE θJA, θJC, and ΨJB are specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. Table 4. Thermal Resistance Package Type θJA θJC ΨJB Unit 6-Lead LFCSP 8-Lead SOIC 5-Lead TSOT 72.1 52.7 170 42.3 41.5 N/A1 47.1 32.7 43 °C/W °C/W °C/W 1 N/A means not applicable. ESD CAUTION ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality. Maximum TJ is calculated from the TA and PD using the formula analog.com Rev. I | 5 of 24 Data Sheet ADP7142 PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS Figure 5. 8-Lead SOIC Pin Configuration Figure 3. 6-Lead LFCSP Pin Configuration Figure 4. 5-Lead TSOT Pin Configuration Table 5. Pin Function Descriptions Pin No. 6-Lead LFCSP 8-Lead SOIC 5-Lead TSOT Mnemonic Description 1 2 1, 2 3 5 4 VOUT SENSE/ADJ 3 4 4 5 2 3 GND EN 5 6 Not applicable SS 6 7, 8 1 VIN EP Regulated Output Voltage. Bypass VOUT to GND with a 2.2 µF or greater capacitor. Sense Input (SENSE). Connect to load. An external resistor divider may also be used to set the output voltage higher than the fixed output voltage (ADJ). Ground. The Enable Pin Controls the Operation of the LDO. Drive EN high to turn on the regulator. Drive EN low to turn off the regulator. For automatic startup, connect EN to VIN. Soft Start. An external capacitor connected to this pin determines the soft-start time. Leave this pin open for a typical 380 μs start-up time. Do not ground this pin. Regulator Input Supply. Bypass VIN to GND with a 2.2 µF or greater capacitor. Exposed Pad. The exposed pad on the bottom of the package enhances thermal performance and is electrically connected to GND inside the package. It is recommended that the exposed pad connect to the ground plane on the board. analog.com Rev. I | 6 of 24 Data Sheet ADP7142 TYPICAL PERFORMANCE CHARACTERISTICS VIN = VOUT + 1 V or 2.7 V, whichever is greater, VOUT = 5 V, IOUT = 10 mA, CIN = COUT = 2.2 µF, TA = 25°C, unless otherwise noted. Figure 6. Output Voltage (VOUT) vs. Junction Temperature (TJ) Figure 9. Ground Current (IGND) vs. Junction Temperature (TJ) Figure 7. Output Voltage (VOUT) vs. Load Current (ILOAD) Figure 10. Ground Current (IGND) vs. Load Current (ILOAD) Figure 8. Output Voltage (VOUT) vs. Input Voltage (VIN) Figure 11. Ground Current (IGND) vs. Input Voltage (VIN) analog.com Rev. I | 7 of 24 Data Sheet ADP7142 TYPICAL PERFORMANCE CHARACTERISTICS Figure 12. Shutdown Current (IGND-SD) vs. Temperature at Various Input Voltages (VIN) Figure 15. Ground Current (IGND) vs. Input Voltage (VIN) in Dropout, VOUT = 5 V Figure 13. Dropout Voltage (VDROPOUT) vs. Load Current (ILOAD), VOUT = 5 V Figure 16. Output Voltage (VOUT) vs. Junction Temperature (TJ), VOUT = 3.3 V Figure 14. Output Voltage (VOUT) vs. Input Voltage (VIN) in Dropout, VOUT = 5 V Figure 17. Output Voltage (VOUT) vs. Load Current (ILOAD), VOUT = 3.3 V analog.com Rev. I | 8 of 24 Data Sheet ADP7142 TYPICAL PERFORMANCE CHARACTERISTICS Figure 18. Output Voltage (VOUT) vs. Input Voltage (VIN), VOUT = 3.3 V Figure 21. Ground Current (IGND) vs. Input Voltage (VIN), VOUT = 3.3 V Figure 19. Ground Current (IGND) vs. Junction Temperature (TJ), VOUT = 3.3 V Figure 22. Dropout Voltage (VDROPOUT) vs. Load Current (ILOAD), VOUT = 3.3 V Figure 20. Ground Current (IGND) vs. Load Current (ILOAD), VOUT = 3.3 V Figure 23. Output Voltage (VOUT) vs. Input Voltage (VIN) in Dropout, VOUT = 3.3 V analog.com Rev. I | 9 of 24 Data Sheet ADP7142 TYPICAL PERFORMANCE CHARACTERISTICS Figure 24. Ground Current (IGND) vs. Input Voltage (VIN) in Dropout, VOUT = 3.3 V Figure 27. Power Supply Rejection Ratio (PSRR) vs. Headroom Voltage, VOUT = 1.8 V, for Different Frequencies Figure 25. Soft Start (SS) Current vs. Temperature (TJ), Multiple Input Voltages (VIN), VOUT = 5 V Figure 28. Power Supply Rejection Ratio (PSRR) vs. Frequency, VOUT = 3.3 V, for Various Headroom Voltages Figure 26. Power Supply Rejection Ratio (PSRR) vs. Frequency, VOUT = 1.8 V, for Various Headroom Voltages Figure 29. Power Supply Rejection Ratio (PSRR) vs. Headroom Voltage, VOUT = 3.3 V, for Different Frequencies analog.com Rev. I | 10 of 24 Data Sheet ADP7142 TYPICAL PERFORMANCE CHARACTERISTICS Figure 30. Power Supply Rejection Ratio (PSRR) vs. Frequency, VOUT = 5 V, for Various Headroom Voltages Figure 31. Power Supply Rejection Ratio (PSRR) vs. Headroom Voltage, VOUT = 5 V, for Different Frequencies Figure 32. RMS Output Noise vs. Load Current (ILOAD) analog.com Figure 33. Output Noise Spectral Density vs. Frequency, ILOAD = 10 mA Figure 34. Output Noise Spectral Density vs. Frequency, for Different Loads Figure 35. Output Noise Spectral Density vs. Frequency, for Different Output Voltages (VOUT) Rev. I | 11 of 24 Data Sheet ADP7142 TYPICAL PERFORMANCE CHARACTERISTICS Figure 36. Load Transient Response, ILOAD = 1 mA to 200 mA, VOUT = 5 V, VIN = 7 V, CH1 Load Current (ILOAD), CH2 VOUT Figure 39. Line Transient Response, ILOAD = 200 mA,VOUT = 3.3 V, CH1 VIN, CH2 VOUT Figure 37. Line Transient Response, ILOAD = 200 mA, VOUT = 5 V, CH1 VIN, CH2 VOUT Figure 40. Load Transient Response, ILOAD = 1 mA to 200 mA, VOUT = 1.8 V, VIN = 3 V, CH1 Load Current (ILOAD), CH2 VOUT Figure 38. Load Transient Response, ILOAD = 1 mA to 200 mA, VOUT = 3.3 V, VIN = 5 V, CH1 Load Current (ILOAD), CH2 VOUT Figure 41. Line Transient Response, ILOAD = 200 mA, VOUT = 1.8 V, CH1 VIN, CH2 VOUT analog.com Rev. I | 12 of 24 Data Sheet ADP7142 THEORY OF OPERATION The ADP7142 is a low quiescent current, LDO linear regulator that operates from 2.7 V to 40 V and provides up to 200 mA of output current. Drawing a low 180 μA of quiescent current (typical) at full load makes the ADP7142 ideal for portable equipment. Typical shutdown current consumption is less than 3 μA at room temperature. Optimized for use with small 2.2 µF ceramic capacitors, the ADP7142 provides excellent transient performance. output voltage to be set to a higher voltage with an external voltage divider. For example, a fixed 5 V output can be set to a 6 V output according to the following equation: VOUT = 5 V 1 + R1/R2   (3) where R1 and R2 are the resistors in the output voltage divider shown in Figure 43. To set the output voltage of the adjustable ADP7142, replace 5 V in Equation 3 with 1.2 V. Figure 42. Internal Block Diagram Internally, the ADP7142 consists of a reference, an error amplifier, and a PMOS pass transistor. Output current is delivered via the PMOS pass device, which is controlled by the error amplifier. The error amplifier compares the reference voltage with the feedback voltage from the output and amplifies the difference. If the feedback voltage is lower than the reference voltage, the gate of the PMOS device is pulled lower, allowing more current to pass and increasing the output voltage. If the feedback voltage is higher than the reference voltage, the gate of the PMOS device is pulled higher, allowing less current to pass and decreasing the output voltage. The ADP7142 is available in 15 fixed output voltage options, ranging from 1.2 V to 5.0 V. The ADP7142 architecture allows any fixed analog.com Figure 43. Typical Adjustable Output Voltage Application Schematic It is recommended that the R2 value be less than 200 kΩ to minimize errors in the output voltage caused by the SENSE/ADJ pin input current. For example, when R1 and R2 each equal 200 kΩ and the default output voltage is 1.2 V, the adjusted output voltage is 2.4 V. The output voltage error introduced by the SENSE/ADJ pin input current is 1 mV or 0.04%, assuming a typical SENSE/ ADJ pin input current of 10 nA at 25°C. The ADP7142 uses the EN pin to enable and disable the VOUT pin under normal operating conditions. When EN is high, VOUT turns on, and when EN is low, VOUT turns off. For automatic startup, EN can be tied to VIN. Rev. I | 13 of 24 Data Sheet ADP7142 APPLICATIONS INFORMATION DESIGN TOOLS ® The ADP7142 is supported by the ADIsimPower™, LTpowerCAD , ® and LTspice design tools to produce complete power designs and simulations. For more information on design tools, visit the ADP7142 product page, www.analog.com/adp7142. CAPACITOR SELECTION Figure 45 depicts the capacitance vs. voltage bias characteristic of an 0805, 2.2 µF, 10 V, X5R capacitor. The voltage stability of a capacitor is strongly influenced by the capacitor size and voltage rating. In general, a capacitor in a larger package or higher voltage rating exhibits better stability. The temperature variation of the X5R dielectric is ~±15% over the −40°C to +85°C temperature range and is not a function of package or voltage rating. Output Capacitor The ADP7142 is designed for operation with small, space-saving ceramic capacitors, but functions with general-purpose capacitors as long as care is taken with regard to the effective series resistance (ESR) value. The ESR of the output capacitor affects the stability of the LDO control loop. A minimum of 2.2 µF capacitance with an ESR of 0.3 Ω or less is recommended to ensure the stability of the ADP7142. Transient response to changes in load current is also affected by output capacitance. Using a larger value of output capacitance improves the transient response of the ADP7142 to large changes in load current. Figure 44 shows the transient responses for an output capacitance value of 2.2 µF. Figure 45. Capacitance vs. Voltage Characteristic Use Equation 4 to determine the worst-case capacitance accounting for capacitor variation over temperature, component tolerance, and voltage. CEFF = CBIAS 1 − TEMPCO × 1 − TOL   (4) where: CBIAS is the effective capacitance at the operating voltage. TEMPCO is the worst-case capacitor temperature coefficient. TOL is the worst-case component tolerance. Figure 44. Output Transient Response, VOUT = 5 V, COUT = 2.2 µF, CH1 Load Current, CH2 VOUT Input Bypass Capacitor Connecting a 2.2 µF capacitor from VIN to GND reduces the circuit sensitivity to the PCB layout, especially when long input traces or high source impedance is encountered. If greater than 2.2 µF of output capacitance is required, increase the input capacitor to match it. Input and Output Capacitor Properties Any good quality ceramic capacitors can be used with the ADP7142, as long as they meet the minimum capacitance and maximum ESR requirements. Ceramic capacitors are manufactured with a variety of dielectrics, each with different behavior over temperature and applied voltage. Capacitors must have a dielectric adequate to ensure the minimum capacitance over the necessary temperature range and dc bias conditions. X5R or X7R dielectrics with a voltage rating of 6.3 V to 100 V are recommended. Y5V and Z5U dielectrics are not recommended, due to their poor temperature and dc bias characteristics. analog.com In this example, the worst-case temperature coefficient (TEMPCO) over −40°C to +85°C is assumed to be 15% for an X5R dielectric. The tolerance of the capacitor (TOL) is assumed to be 10%, and CBIAS is 2.09 μF at 5 V, as shown in Figure 45. These values in Equation 4 yield CEFF = 2 . 09 μF× 1 − 0 . 15 × 1 − 0 . 1 = 1 . 59 μF   (5) Therefore, the capacitor chosen in this example meets the minimum capacitance requirement of the LDO over temperature and tolerance at the chosen output voltage. To guarantee the performance of the ADP7142, it is imperative that the effects of dc bias, temperature, and tolerances on the behavior of the capacitors be evaluated for each application. PROGRAMMABLE PRECISION ENABLE The ADP7142 uses the EN pin to enable and disable the VOUT pin under normal operating conditions. As shown in Figure 46, when a rising voltage on EN crosses the upper threshold, nominally 1.2 V, VOUT turns on. When a falling voltage on EN crosses the lower threshold, nominally 1.1 V, VOUT turns off. The hysteresis of the EN threshold is approximately 100 mV. Rev. I | 14 of 24 Data Sheet ADP7142 APPLICATIONS INFORMATION Figure 48. Typical Start-Up Behavior Figure 46. Typical VOUT Response to EN Pin Operation The upper and lower thresholds are user programmable and can be set higher than the nominal 1.2 V threshold by using two resistors. The resistance values, REN1 and REN2, can be determined from REN2 = nominally 10 kΩ to 100 kΩ REN1 = REN2 × VIN − 1 . 2 V /1 . 2 V (6) (7) where VIN is the desired turn-on voltage. The hysteresis voltage increases by the factor (REN1 + REN2)/ REN2. For the example shown in Figure 47, the enable threshold is 3.6 V with a hysteresis of 300 mV. An external capacitor connected to the SS pin determines the soft start time. The SS pin can be left open for a typical 380 μs start-up time. Do not ground this pin. When an external soft start capacitor (CSS) is used, the soft start time is determined by the following equation: SSTIME sec = tSTARTUP 0 pF + 0 . 6 × CSS /ISS (8) where: tSTARTUP (at 0 pF) is the start-up time at CSS = 0 pF (typically 380 µs). CSS is the soft start capacitor (F). ISS is the soft start current (typically 1.15 µA). Figure 47. Typical EN Pin Voltage Divider Figure 46 shows the typical hysteresis of the EN pin. This prevents on/off oscillations that can occur due to noise on the EN pin as it passes through the threshold points. SOFT START The ADP7142 uses an internal soft start (when the SS pin is left open) to limit the inrush current when the output is enabled. The start-up time for the 3.3 V option is approximately 380 μs from the time the EN active threshold is crossed to when the output reaches 90% of its final value. As shown in Figure 48, the start-up time is independent of the output voltage setting. Figure 49. Typical Soft Start Behavior, Different CSS NOISE REDUCTION OF THE ADP7142 IN ADJUSTABLE MODE The ultralow output noise of the ADP7142 is achieved by keeping the LDO error amplifier in unity gain and setting the reference voltage equal to the output voltage. This architecture does not work for an adjustable output voltage LDO in the conventional sense. However, the ADP7142 architecture allows any fixed output voltage to be set to a higher voltage with an external voltage divider. For example, a fixed 5 V output can be set to a 10 V output according to Equation 3 (see Figure 50): VOUT = 5 V 1 + R1/R2 The disadvantage in using the ADP7142 in this manner is that the output voltage noise is proportional to the output voltage. Therefore, analog.com Rev. I | 15 of 24 Data Sheet ADP7142 APPLICATIONS INFORMATION it is best to choose a fixed output voltage that is close to the target voltage to minimize the increase in output noise. The adjustable LDO circuit can be modified to reduce the output voltage noise to levels close to that of the fixed output ADP7142. The circuit shown in Figure 50 adds two additional components to the output voltage setting resistor divider. CNR and RNR are added in parallel with R1 to reduce the ac gain of the error amplifier. RNR is chosen to be small with respect to R2. If RNR is 1% to 10% of the value of R2, the minimum ac gain of the error amplifier is approximately 0.1 dB to 0.8 dB. The actual gain is determined by the parallel combination of RNR and R1. This gain ensures that the error amplifier always operates at slightly greater than unity gain. CNR is chosen by setting the reactance of CNR equal to R1 − RNR at a frequency between 1 Hz and 50 Hz. This setting places the frequency where the ac gain of the error amplifier is 3 dB down from its dc gain. is limited by its open loop gain characteristic. Therefore, the noise contribution from 20 kHz to 100 kHz is less than what it would be if the error amplifier had infinite bandwidth. This is also the reason why the noise is less than what might be expected simply based on the dc gain, that is, 70 µV rms vs. 110 µV rms. Figure 51. 6 V and 12 V Output Voltage with and Without Noise Reduction Network EFFECT OF NOISE REDUCTION ON START-UP TIME The start-up time of the ADP7142 is affected by the noise reduction network and must be considered in applications where power supply sequencing is critical. Figure 50. Noise Reduction Modification The noise of the adjustable LDO is found by using the following formula, assuming the noise of a fixed output LDO is approximately 11 μV. Noise = 11 μV × RPAR + R2 /R2 (9) where RPAR is a parallel combination of R1 and RNR. Based on the component values shown in Figure 50, the ADP7142 has the following characteristics: ► ► ► ► ► ► ► DC gain of 10 (20 dB) 3 dB roll-off frequency of 1.75 Hz High frequency ac gain of 1.099 (0.82 dB) Theoretical noise reduction factor of 9.1 (19.2 dB) Measured rms noise of the adjustable LDO without noise reduction is 70 µV rms Measured rms noise of the adjustable LDO with noise reduction is 12 µV rms Measured noise reduction of approximately 15.3 dB Note that the measured noise reduction is less than the theoretical noise reduction. Figure 51 shows the noise spectral density of an adjustable ADP7142 set to 6 V and 12 V with and without the noise reduction network. The output noise with the noise reduction network is approximately the same for both voltages, especially beyond 100 Hz. The noise of the 6 V and 12 V outputs without the noise reduction network differs by a factor of 2 up to approximately 20 kHz. Above 40 kHz, the closed loop gain of the error amplifier analog.com The noise reduction circuit adds a pole in the feedback loop, slowing down the start-up time. The start-up time for an adjustable model with a noise reduction network can be approximated using the following equation: SSNRTIME sec = 5 . 5 × CNR × RNR + R1   (10) For a CNR, RNR, and R1 combination of 1 µF, 1 kΩ, and 91 kΩ as shown in Figure 50, the start-up time is approximately 0.5 sec. When SSNRTIME is greater than SSTIME, SSNRTIME dictates the length of the start-up time instead of the soft start capacitor. CURRENT-LIMIT AND THERMAL OVERLOAD PROTECTION The ADP7142 is protected against damage due to excessive power dissipation by current and thermal overload protection circuits. The ADP7142 is designed to current limit when the output load reaches 360 mA (typical). When the output load exceeds 360 mA, the output voltage is reduced to maintain a constant current limit. Thermal overload protection is included, which limits the junction temperature to a maximum of 150°C (typical). Under extreme conditions (that is, high ambient temperature and/or high power dissipation) when the junction temperature starts to rise above 150°C, the output is turned off, reducing the output current to zero. When the junction temperature drops below 135°C, the output is turned on again, and output current is restored to its operating value. Rev. I | 16 of 24 Data Sheet ADP7142 APPLICATIONS INFORMATION Consider the case where a hard short from VOUT to ground occurs. At first, the ADP7142 current limits, so that only 360 mA is conducted into the short. If self heating of the junction is great enough to cause its temperature to rise above 150°C, thermal shutdown activates, turning off the output and reducing the output current to zero. As the junction temperature cools and drops below 135°C, the output turns on and conducts 360 mA into the short, again causing the junction temperature to rise above 150°C. This thermal oscillation between 135°C and 150°C causes a current oscillation between 360 mA and 0 mA that continues as long as the short remains at the output. Table 6. Typical θJA Values θJA (°C/W) Copper Size (mm1) LFCSP SOIC TSOT 500 1000 6400 83.9 71.7 57.4 89.3 77.5 63.2 131 N/A1 N/A1 1 N/A means not applicable. 2 Device soldered to minimum size pin traces. Table 7. Typical ΨJB Values Current and thermal limit protections protect the device against accidental overload conditions. For reliable operation, device power dissipation must be externally limited so that the junction temperature does not exceed 125°C. Model ΨJB (°C/W) 6-Lead LFCSP 8-Lead SOIC 5-Lead TSOT 24 38.8 43 THERMAL CONSIDERATIONS To calculate the junction temperature of the ADP7142, use Equation 1: In applications with a low input-to-output voltage differential, the ADP7142 does not dissipate much heat. However, in applications with high ambient temperature and/or high input voltage, the heat dissipated in the package may become large enough to cause the junction temperature of the die to exceed the maximum junction temperature of 125°C. When the junction temperature exceeds 150°C, the converter enters thermal shutdown. It recovers only after the junction temperature has decreased below 135°C to prevent any permanent damage. Therefore, thermal analysis for the chosen application is very important to guarantee reliable performance over all conditions. The junction temperature of the die is the sum of the ambient temperature of the environment and the temperature rise of the package due to the power dissipation, as shown in Equation 2. To guarantee reliable operation, the junction temperature of the ADP7142 must not exceed 125°C. To ensure that the junction temperature stays below this maximum value, the user must be aware of the parameters that contribute to junction temperature changes. These parameters include ambient temperature, power dissipation in the power device, and thermal resistances between the junction and ambient air (θJA). The θJA number is dependent on the package assembly compounds that are used and the amount of copper used to solder the package GND pins to the PCB. T J = TA + PD × θ JA where: TA is the ambient temperature. PD is the power dissipation in the die, given by PD = VIN − VOUT × ILOAD + VIN × IGND (11) where: VIN and VOUT are input and output voltages, respectively. ILOAD is the load current. IGND is the ground current. Power dissipation due to ground current is quite small and can be ignored. Therefore, the junction temperature equation simplifies to the following: T J = TA + VIN − VOUT × ILOAD × θ JA (12) As shown in Equation 12, for a given ambient temperature, inputto-output voltage differential, and continuous load current, there exists a minimum copper size requirement for the PCB to ensure that the junction temperature does not rise above 125°C. Figure 52 to Figure 60 show junction temperature calculations for different ambient temperatures, power dissipation, and areas of PCB copper. Table 6 shows typical θJA values of the 8-lead SOIC, 6-lead LFCSP, and 5-Lead TSOT packages for various PCB copper sizes. Table 7 shows the typical ΨJB values of the 8-lead SOIC, 6-lead LFCSP, and 5-lead TSOT. Table 6. Typical θJA Values θJA (°C/W) Copper Size (mm1) 252 50 100 analog.com LFCSP SOIC TSOT 182.8 N/A1 142.6 N/A1 N/A1 152 146 181.4 145.4 Figure 52. LFCSP, TA = 25°C Rev. I | 17 of 24 Data Sheet ADP7142 APPLICATIONS INFORMATION Figure 53. LFCSP, TA = 50°C Figure 57. SOIC, TA = 85°C Figure 54. LFCSP, TA = 85°C Figure 58. TSOT, TA = 25°C Figure 55. SOIC, TA = 25°C Figure 59. TSOT, TA = 50°C Figure 56. SOIC, TA = 50°C Figure 60. TSOT, TA = 85°C In the case where the board temperature is known, use the thermal characterization parameter, ΨJB, to estimate the junction temperaanalog.com Rev. I | 18 of 24 Data Sheet ADP7142 APPLICATIONS INFORMATION ture rise (see Figure 61, Figure 62, and Figure 63). Calculate the maximum junction temperature by using Equation 2. T J = TB + PD × Ψ JB The typical value of ΨJB is 24°C/W for the 8-lead LFCSP package, 38.8°C/W for the 8-lead SOIC package, and 43°C/W for the 5-lead TSOT package. Figure 61. LFCSP Junction Temperature Rise, Different Board Temperatures Figure 62. SOIC Junction Temperature Rise, Different Board Temperatures Figure 63. TSOT Junction Temperature Rise, Different Board Temperatures analog.com Rev. I | 19 of 24 Data Sheet ADP7142 PRINTED CIRCUIT BOARD LAYOUT CONSIDERATIONS Heat dissipation from the package can be improved by increasing the amount of copper attached to the pins of the ADP7142. However, as listed in Table 6, a point of diminishing returns is eventually reached, beyond which an increase in the copper size does not yield significant heat dissipation benefits. Place the input capacitor as close as possible to the VIN pin and GND pin. Place the output capacitor as close as possible to the VOUT and GND pins. Use of 0805 or 1206 size capacitors and resistors achieves the smallest possible footprint solution on boards where area is limited. Figure 64. Example LFCSP PCB Layout Figure 65. Example SOIC PCB Layout Figure 66. Example TSOT PCB Layout analog.com Rev. I | 20 of 24 Data Sheet ADP7142 PRINTED CIRCUIT BOARD LAYOUT CONSIDERATIONS Table 8. Recommended LDOs for Very Low Noise Operation Device Number VIN Range (V) VOUT Fixed (V) VOUT Adjust (V) IOUT (mA) IQ at IOUT (µA) IGND-SD Max (µA) Soft Start PGOOD Noise (Fixed) 10 Hz to 100 kHz (µV rms) ADP7102 3.3 to 20 1.5 to 9 1.22 to 19 300 750 75 No Yes 15 60 40 dB ADP7104 3.3 to 20 1.5 to 9 1.22 to 19 500 900 75 No Yes 15 60 40 dB ADP7105 3.3 to 20 1.8, 3.3, 5 1.22 to 19 500 900 75 Yes Yes 15 60 40 dB ADP7112 2.7 to 20 1.2 to 5 1.2 to 19 200 180 10 Yes No 11 68 50 dB ADP7118 2.7 to 20 1.2 to 5 1.2 to 19 200 180 10 Yes No 11 68 50 dB ADP7142 2.7 to 40 1.2 to 5 1.2 to 39 200 180 10 Yes No 11 68 50 dB ADP7182 −2.7 to −28 −1.8 to −5 −1.22 to −27 −200 −650 −8 No No 18 45 45 dB PSRR 100 PSRR 1 kHz (dB) MHz Package 3 mm × 3 mm 8lead LFCSP, 8lead SOIC 3 mm × 3 mm 8lead LFCSP, 8lead SOIC 3 mm × 3 mm 8lead LFCSP, 8lead SOIC 1 mm × 1.2 mm 6ball WLCSP 2 mm × 2 mm 6lead LFCSP, 8lead SOIC, 5-lead TSOT 2 mm × 2 mm 6lead LFCSP, 8lead SOIC, 5-lead TSOT 2 mm × 2 mm 6lead LFCSP, 3 mm × 3 mm 8-lead LFCSP, 5-lead TSOT Table 9. Related Devices Model Input Voltage (V) Output Current (mA) Package ADP7118CP ADP7118RD ADP7118UJ ADP7112CB 2.7 to 20 2.7 to 20 2.7 to 20 2.7 to 20 200 200 200 200 6-lead LFCSP 8-lead SOIC 5-lead TSOT 6-ball WLCSP analog.com Rev. I | 21 of 24 Data Sheet ADP7142 OUTLINE DIMENSIONS Figure 67. 6-Lead Lead Frame Chip Scale Package [LFCSP] 2.00 mm × 2.00 mm Body and 0.55 mm Package Height (CP-6-3) Dimensions shown in millimeters Figure 68. 8-Lead Standard Small Outline Package, with Exposed Pad [SOIC_N_EP] Narrow Body (RD-8-1) Dimensions shown in millimeters Figure 69. 5-Lead Thin Small Outline Transistor Package [TSOT] (UJ-5) Dimensions shown in millimeters analog.com Rev. I | 22 of 24 Data Sheet ADP7142 OUTLINE DIMENSIONS Updated: October 18, 2021 ORDERING GUIDE Model1, 2 Temperature Range Package Description Packing Quantity Package Option ADP7142ACPZN1.8-R7 ADP7142ACPZN2.5-R7 ADP7142ACPZN3.3-R7 ADP7142ACPZN3.8-R7 ADP7142ACPZN5.0-R7 ADP7142ACPZN-R7 ADP7142ARDZ ADP7142ARDZ-1.8 ADP7142ARDZ-1.8-R7 ADP7142ARDZ-2.5 ADP7142ARDZ-2.5-R7 ADP7142ARDZ-3.3 ADP7142ARDZ-3.3-R7 ADP7142ARDZ-5.0 ADP7142ARDZ-5.0-R7 ADP7142ARDZ-R7 ADP7142AUJZ-1.8-R7 ADP7142AUJZ-2.5-R7 ADP7142AUJZ-3.3-R7 ADP7142AUJZ-5.0-R7 ADP7142AUJZ-R2 ADP7142AUJZ-R7 ADP7142WAUJZ-1.8-R7 ADP7142WAUJZ-2.5-R7 ADP7142WAUJZ-3.3-R7 ADP7142WAUJZ-5.0-R7 ADP7142WAUJZ-R7 -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C -40°C to +125°C 6-Lead LFCSP (2mm x 2mm w/ EP) 6-Lead LFCSP (2mm x 2mm w/ EP) 6-Lead LFCSP (2mm x 2mm w/ EP) 6-Lead LFCSP (2mm x 2mm w/ EP) 6-Lead LFCSP (2mm x 2mm w/ EP) 6-Lead LFCSP (2mm x 2mm w/ EP) 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 8-Lead SOIC w/ EP 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT Reel, 3000 Reel, 3000 Reel, 3000 Reel, 3000 Reel, 3000 Reel, 3000 Tube, 98 Tube, 98 Reel, 1000 Tube, 98 Reel, 1000 Tube, 98 Reel, 1000 Tube, 98 Reel, 1000 Reel, 1000 Reel, 3000 Reel, 3000 Reel, 3000 Reel, 3000 Reel, 250 Reel, 3000 Reel, 3000 Reel, 3000 Reel, 3000 Reel, 3000 Reel, 3000 CP-6-3 CP-6-3 CP-6-3 CP-6-3 CP-6-3 CP-6-3 RD-8-1 RD-8-1 RD-8-1 RD-8-1 RD-8-1 RD-8-1 RD-8-1 RD-8-1 RD-8-1 RD-8-1 UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 1 Z = RoHS Compliant Part. 2 W = Qualified for Automotive Applications. analog.com Marking Code LP5 LP7 LP6 LVK LP8 LP4 LP5 LP7 LP6 LP8 LP4 LP4 LVQ LVR LVT LVS LVU Rev. I | 23 of 24 Data Sheet ADP7142 OUTLINE DIMENSIONS OUTPUT VOLTAGE OPTIONS Model Output Voltage (V)1 ADP7142ACPZN1.8-R7 ADP7142ACPZN2.5-R7 ADP7142ACPZN3.3-R7 ADP7142ACPZN3.8-R7 ADP7142ACPZN5.0-R7 ADP7142ACPZN-R7 ADP7142ARDZ ADP7142ARDZ-1.8 ADP7142ARDZ-1.8-R7 ADP7142ARDZ-2.5 ADP7142ARDZ-2.5-R7 ADP7142ARDZ-3.3 ADP7142ARDZ-3.3-R7 ADP7142ARDZ-5.0 ADP7142ARDZ-5.0-R7 ADP7142ARDZ-R7 ADP7142AUJZ-1.8-R7 ADP7142AUJZ-2.5-R7 ADP7142AUJZ-3.3-R7 ADP7142AUJZ-5.0-R7 ADP7142AUJZ-R2 ADP7142AUJZ-R7 ADP7142WAUJZ-1.8-R7 ADP7142WAUJZ-2.5-R7 ADP7142WAUJZ-3.3-R7 ADP7142WAUJZ-5.0-R7 ADP7142WAUJZ-R7 1.8 2.5 3.3 3.8 5 Adjustable (1.2 V) Adjustable (1.2 V) 1.8 1.8 2.5 2.5 3.3 3.3 5 5 Adjustable (1.2 V) 1.8 2.5 3.3 5 Adjustable (1.2 V) Adjustable (1.2 V) 1.8 2.5 3.3 5 Adjustable (1.2 V) 1 For additional voltage options, contact a local Analog Devices, Inc., sales or distribution representative. EVALUATION BOARDS Model1, 2 Package Description ADP7142UJ-EVALZ ADP7142CP-EVALZ ADP7142RD-EVALZ TSOT Evaluation Board LFCSP Evaluation Board SOIC Evaluation Board 1 Z = RoHS Compliant Part. 2 The evaluation boards are preconfigured with an adjustable ADP7142. AUTOMOTIVE PRODUCTS The ADP7142W models are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for these models. ©2014-2022 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. One Analog Way, Wilmington, MA 01887-2356, U.S.A. Rev. I | 24 of 24
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