ADP7112CB-EVALZ

ADP7112CB-EVALZ User Guide UG-777 One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.com Evaluating the ADP7112 Low Noise, CMOS LDO Linear Regulator FEATURES GENERAL DESCRIPTION Input voltage range: 2.7 V to 20 V Output current range: 0 mA to 200 mA Output voltage initial accuracy: ±0.8% Operating temperature range: −40°C to +125°C Adjustable output voltage via two external resistors from any fixed output voltage option The ADP7112CB-EVALZ is an evaluation board used to demonstrate the functionality of the ADP7112 linear regulator. Simple device measurements, such as line and load regulation, dropout voltage, and ground current, can be demonstrated with just a single voltage source, load resistors, and a voltmeter or an ammeter. For more details about the linear regulators, visit www.analog.com. Complete specifications for the ADP7112 are available in the ADP7112 data sheet available from Analog Devices, Inc., and should be consulted in conjunction with this user guide when using the evaluation board. 12796-001 EVALUATION BOARD Figure 1. ADP7112CB-EVALZ Printed Circuit Board (PCB) Layout PLEASE SEE THE LAST PAGE FOR AN IMPORTANT WARNING AND LEGAL TERMS AND CONDITIONS. Rev. 0 | Page 1 of 7 UG-777 ADP7112CB-EVALZ User Guide TABLE OF CONTENTS Features .............................................................................................. 1 Line Regulation..............................................................................5 General Description ......................................................................... 1 Load Regulation ............................................................................5 Evaluation Board .............................................................................. 1 Dropout Voltage ............................................................................5 Revision History ............................................................................... 2 Ground Current Measurements ......................................................6 Evaluation Board Hardware and Schematic ................................. 3 Ground Current Consumption ...................................................6 Evaluation Board Configurations .............................................. 3 Ordering Information .......................................................................7 Output Voltage Measurements ....................................................... 4 Bill of Materials ..............................................................................7 REVISION HISTORY 12/14—Revision 0: Initial Version Rev. 0 | Page 2 of 7 ADP7112CB-EVALZ User Guide UG-777 EVALUATION BOARD HARDWARE AND SCHEMATIC The output voltage is set by EVALUATION BOARD CONFIGURATIONS VOUT = VOUT (FIXED) × (1 + R1/R2) The evaluation board comes supplied with different components depending on which version is ordered. Components common to all versions are C1, C2, C3, JP1, and JP2. Resistors R1 and R2 adjust the output voltage above any fixed voltage option. C3 and R3 are not installed. C3 and R3 are optional components for the noise reduction network. Figure 2 shows the schematic of this evaluation board configuration. J9 J10 J2 1 CON2 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 CON4 TP1 J1 1 CON4 A1 2 C1 3 2.2µF 4 2 JP1 1 1-WAY LINK C1 ADP7112 VIN VOUT SENSE/ADJ EN SS GND C2 5 6 TP3 7 CON4 CON4 TP2 U1 VIN J12 1 1 A2 J3 VOUT B2 VOUT 1 2 C2 B1 2.2µF C4 R1 280kΩ R3 C3 1000pF 2 1 JP2 1-WAY LINK 3 4 5 6 1 R2 160kΩ 8 7 8 CON8 CON8 12796-002 2 J11 1 Figure 2. Evaluation Board Schematic Table 1. Evaluation Board Hardware Components Component U1 C1 C2 C3 Function Linear regulator Input capacitor Output capacitor Noise reduction capacitor C4 R1 R2 R3 Soft start capacitor Output resistor divider Output resistor divider Noise reduction resistor JP1 JP2 Jumper Jumper Description ADP7112 linear regulator. The adjustable (1.2 V) model option is used on the evaluation board. 2.2 μF input bypass capacitor. 2.2 μF output capacitor. Required for stability and transient performance. Not installed. Noise reduction network with R3. See the ADP7112 data sheet for the value of C3 and R3 noise reduction components. 1000 pF soft start capacitor. Sets the soft start time to limit inrush current. 280 kΩ output resistor divider. Sets the output voltage to 3.3 V with R2. 160 kΩ output resistor divider. Sets the output voltage to 3.3 V with R1. Not installed. Noise reduction network with C3. See the ADP7112 data sheet for the value of C3 and R3 noise reduction components. Connects the EN pin to the VIN pin for automatic startup. Connects the SENSE pin to the output for fixed output options. Rev. 0 | Page 3 of 7 UG-777 ADP7112CB-EVALZ User Guide OUTPUT VOLTAGE MEASUREMENTS Figure 3 shows how the evaluation board can be connected to a voltage source and a voltmeter for basic output voltage accuracy measurements. A resistor can be used as the load for the regulator. Ensure that the resistor has a power rating that is adequate to handle the power expected to be dissipated across it. An electronic load can also be used as an alternative. Ensure that the voltage source can supply enough current for the expected load levels. The voltage source can be turned on after these steps are complete. If JP1 is inserted (connecting the EN pin to the VIN pin for automatic startup), the regulator powers up. If the load current is large, connect the voltmeter as close as possible to the output capacitor to reduce the effects of voltage drops along the PCB traces. Use the following steps to connect to a voltage source and voltmeter: 2. 3. 4. 5. Connect the negative terminal (−) of the voltage source to one of the GND pads on the evaluation board. Connect the positive terminal (+) of the voltage source to the VIN pad of the evaluation board. Connect a load between the VOUT pad and one of the GND pads. Connect the negative terminal (−) of the voltmeter to one of the GND pads. Connect the positive terminal (+) of the voltmeter to the VOUT pad. VOLTAGE SOURCE VOLMETER 5.00001V 3.2998V LOAD 12796-003 1. Figure 3. Output Voltage Measurement Rev. 0 | Page 4 of 7 ADP7112CB-EVALZ User Guide UG-777 LINE REGULATION DROPOUT VOLTAGE For line regulation measurements, the output of the regulator is monitored while its input is varied. For good line regulation, the output must change as little as possible with varying input levels. To ensure that the device is not in dropout during this measurement, VIN must be varied between VOUT_NOM + 1 V (or 2.7 V, whichever is greater) and VIN_MAX. For example, for an ADP7112 with a 3.3 V output, VIN must be varied between 4.3 V and 20 V. This measurement can be repeated under different load conditions. Figure 4 shows the typical line regulation performance of an ADP7112 with a 3.3 V output. Dropout voltage can be measured using the configuration shown in Figure 3. Dropout voltage is the input to output voltage differential when the input voltage is set to the nominal output voltage, VOUT_NOM. This definition applies only for output voltages greater than 2.3 V. Dropout voltage increases with larger loads. For more accurate measurements, use a second voltmeter to monitor the input voltage across the input capacitor. The input supply voltage may need to be adjusted to account for voltage drops, especially if large load currents are used. Figure 6 shows a typical curve of dropout voltage measurements over the load currents. 3.35 200 DROPOUT VOLTAGE (mV) 3.33 3.31 3.29 3.27 100 50 0 5 10 VIN (V) 15 20 0 12796-004 3.25 1 For load regulation measurements, the output of the regulator is monitored while the load is varied. For good load regulation, the output must change as little as possible with a varying load. The input voltage must be held constant during this measurement. The load current can be varied from 0 mA to 200 mA. Figure 5 shows the typical load regulation performance of an ADP7112 with a 3.3 V output for an input voltage of 4.3 V. 3.35 3.33 3.31 3.29 10 100 ILOAD (mA) 1000 12796-005 3.27 1 100 Figure 6. Dropout Voltage vs. Load Current (ILOAD) LOAD REGULATION 3.25 0.1 10 ILOAD (mA) Figure 4. Output Voltage (VOUT) vs. Input Voltage (VIN) VOUT (V) 150 Figure 5. Output Voltage (VOUT) vs. Load Current (ILOAD) Rev. 0 | Page 5 of 7 1000 12796-006 VOUT (V) 250 LOAD = 100µA LOAD = 1mA LOAD = 10mA LOAD = 50mA LOAD = 100mA LOAD = 200mA UG-777 ADP7112CB-EVALZ User Guide GROUND CURRENT MEASUREMENTS Use the following steps to connect to a voltage source and ammeter: 2. 3. 4. Ground current measurements can determine how much current the internal circuits of the regulator are consuming while the circuits perform the regulation function. To be efficient, the regulator must consume as little current as possible. Typically, the regulator uses the maximum current when supplying its largest load level (200 mA). Figure 7 shows the typical ground current consumption over load level at an input voltage of 4.3 V for an output voltage of 3.3 V. 200 Connect the positive terminal (+) of the voltage source to the VIN pad on the evaluation board. Connect the positive terminal (+) of the ammeter to one of the GND pads of the evaluation board. Connect the negative terminal (−) of the ammeter to the negative (−) terminal of the voltage source. Connect a load between the negative (−) terminal of the voltage source and the VOUT pad of the evaluation board. 180 160 GROUND CURRENT (µA) 1. GROUND CURRENT CONSUMPTION The voltage source can be turned on after these steps are completed. If JP1 is inserted (connecting the EN pin to the VIN pin for automatic startup), the regulator powers up. 140 120 100 80 60 40 20 0 0.1 1 10 100 ILOAD (mA) 1000 12796-008 Figure 8 shows how the evaluation board can be connected to a voltage source and an ammeter for ground current measurements. A resistor can be used as the load for the regulator. Ensure that the resistor has a power rating that is adequate to handle the power expected to be dissipated across it. An electronic load can be used as an alternative. Ensure that the voltage source used can supply enough current for the expected load levels. Figure 7. Ground Current vs. Load Current (ILOAD) When the device is disabled (EN = GND), the ground current drops to less than 3 μA. VOLTAGE SOURCE 5.00001V AMMETER 12796-007 LOAD Figure 8. Ground Current Measurement Rev. 0 | Page 6 of 7 ADP7112CB-EVALZ User Guide UG-777 ORDERING INFORMATION BILL OF MATERIALS Table 2. Quantity 1 2 1 1 2 1 1 1 Reference Designator U1 C1, C2 C3 C4 JP1, JP2 R1 R2 R3 Description ADP7112 linear regulator Capacitor, MLCC, 2.2 μF, 16 V, 1206, X7R Capacitor, MLCC, 0603 case Capacitor, MLCC, 1 μF, 16 V, 0603 case Header, single, STR, two pins Resistor, 280 kΩ, 1%, 0603 case Resistor, 160 kΩ, 1%, 0603 case Resistor, 3.01 kΩ, 1%, 0603 case Manufacturer/Vendor Analog Devices, Inc. Murata (or equivalent) Not installed Murata (or equivalent) M20-9990246 Panasonic (or equivalent) Panasonic (or equivalent) Not installed Vendor Part Number ADP7112ACBZ-1.2-R7 GRM31CR71H225KA88L GRM1885C1H102JA01D M20-9990246 ERJ-3EKF2803V ERJ-3EKF1603V 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. Legal Terms and Conditions By using the evaluation board discussed herein (together with any tools, components documentation or support materials, the “Evaluation Board”), you are agreeing to be bound by the terms and conditions set forth below (“Agreement”) unless you have purchased the Evaluation Board, in which case the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not use the Evaluation Board until you have read and agreed to the Agreement. Your use of the Evaluation Board shall signify your acceptance of the Agreement. This Agreement is made by and between you (“Customer”) and Analog Devices, Inc. (“ADI”), with its principal place of business at One Technology Way, Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement, ADI hereby grants to Customer a free, limited, personal, temporary, non-exclusive, non-sublicensable, non-transferable license to use the Evaluation Board FOR EVALUATION PURPOSES ONLY. Customer understands and agrees that the Evaluation Board is provided for the sole and exclusive purpose referenced above, and agrees not to use the Evaluation Board for any other purpose. Furthermore, the license granted is expressly made subject to the following additional limitations: Customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the Evaluation Board; and (ii) permit any Third Party to access the Evaluation Board. As used herein, the term “Third Party” includes any entity other than ADI, Customer, their employees, affiliates and in-house consultants. The Evaluation Board is NOT sold to Customer; all rights not expressly granted herein, including ownership of the Evaluation Board, are reserved by ADI. CONFIDENTIALITY. This Agreement and the Evaluation Board shall all be considered the confidential and proprietary information of ADI. Customer may not disclose or transfer any portion of the Evaluation Board to any other party for any reason. Upon discontinuation of use of the Evaluation Board or termination of this Agreement, Customer agrees to promptly return the Evaluation Board to ADI. ADDITIONAL RESTRICTIONS. Customer may not disassemble, decompile or reverse engineer chips on the Evaluation Board. Customer shall inform ADI of any occurred damages or any modifications or alterations it makes to the Evaluation Board, including but not limited to soldering or any other activity that affects the material content of the Evaluation Board. Modifications to the Evaluation Board must comply with applicable law, including but not limited to the RoHS Directive. TERMINATION. ADI may terminate this Agreement at any time upon giving written notice to Customer. Customer agrees to return to ADI the Evaluation Board at that time. LIMITATION OF LIABILITY. THE EVALUATION BOARD PROVIDED HEREUNDER IS PROVIDED “AS IS” AND ADI MAKES NO WARRANTIES OR REPRESENTATIONS OF ANY KIND WITH RESPECT TO IT. ADI SPECIFICALLY DISCLAIMS ANY REPRESENTATIONS, ENDORSEMENTS, GUARANTEES, OR WARRANTIES, EXPRESS OR IMPLIED, RELATED TO THE EVALUATION BOARD INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, TITLE, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS. IN NO EVENT WILL ADI AND ITS LICENSORS BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES RESULTING FROM CUSTOMER’S POSSESSION OR USE OF THE EVALUATION BOARD, INCLUDING BUT NOT LIMITED TO LOST PROFITS, DELAY COSTS, LABOR COSTS OR LOSS OF GOODWILL. ADI’S TOTAL LIABILITY FROM ANY AND ALL CAUSES SHALL BE LIMITED TO THE AMOUNT OF ONE HUNDRED US DOLLARS ($100.00). EXPORT. Customer agrees that it will not directly or indirectly export the Evaluation Board to another country, and that it will comply with all applicable United States federal laws and regulations relating to exports. GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the substantive laws of the Commonwealth of Massachusetts (excluding conflict of law rules). Any legal action regarding this Agreement will be heard in the state or federal courts having jurisdiction in Suffolk County, Massachusetts, and Customer hereby submits to the personal jurisdiction and venue of such courts. The United Nations Convention on Contracts for the International Sale of Goods shall not apply to this Agreement and is expressly disclaimed. ©2014 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. UG12796-0-12/14(0) Rev. 0 | Page 7 of 7