Evaluation Board for the ADP1712/ADP1713/ADP1714 EVAL-ADP1712/ADP1713/ADP1714 FEATURES GENERAL DESCRIPTION Input voltage range: 2.5 V to 5.5 V Output current range: 0 mA to 300 mA Output voltage accuracy: ±1% Operating temperature range: −40°C to +125°C External soft start (ADP1712 fixed) Adjustable output voltages (ADP1712 adjustable) Reference bypass to reduce noise (ADP1713) Track mode (ADP1714) The ADP1712/ADP1713/ADP1714 evaluation boards are used to demonstrate the functionality of the ADP1712, ADP1713, and ADP1714 series of linear regulators. Depending on what component combinations are used, the evaluation board can be used for ADP1712 fixed output voltage devices with soft start, ADP1712 adjustable output voltage devices, ADP1713 fixed output voltage devices with a bypass capacitor, and ADP1714 fixed output voltage devices with tracking. Simple device measurements such as line and load regulation, dropout, and ground current can be demonstrated with just a single voltage supply, a voltage meter, a current meter, and load resistors. For more details about the ADP1712/ADP1713/ADP1714 linear regulators, visit www.analog.com. EVALUATION BOARD EVAL-ADP1712/ADP1713/ADP1714 GND GND C1 C2 U1 C3 R1 GND J1 R2 EN SS/ADJ/BYP/TRK VOUT GND 06491-001 VIN Figure 1. Rev. 0 Evaluation boards are only intended for device evaluation and not for production purposes. Evaluation boards as supplied “as is” and without warranties of any kind, express, implied, or statutory including, but not limited to, any implied warranty of merchantability or fitness for a particular purpose. No license is granted by implication or otherwise under any patents or other intellectual property by application or use of evaluation boards. Information furnished by Analog Devices is believed to be accurate and reliable. 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. Analog Devices reserves the right to change devices or specifications at any time without notice. Trademarks and registered trademarks are the property of their respective owners. Evaluation boards are not authorized to be used in life support devices or systems. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2007 Analog Devices, Inc. All rights reserved. EVAL-ADP1712/ADP1713/ADP1714 TABLE OF CONTENTS Features .............................................................................................. 1 Line Regulation..............................................................................5 General Description ......................................................................... 1 Load Regulation ............................................................................6 Evaluation Board .............................................................................. 1 Dropout Voltage ............................................................................6 Revision History ............................................................................... 2 Ground Current Measurements ......................................................7 Evaluation Board Hardware and Schematic ................................. 3 Ground Current Consumption ...................................................7 Evaluation Board Configurations................................................... 4 Ordering Information.......................................................................8 ADP1712 Fixed Output with Soft Start..................................... 4 Bill of Materials..............................................................................8 ADP1712 Adjustable Output ...................................................... 4 Ordering Guide .............................................................................8 ADP1713 Fixed Output with Bypass ......................................... 4 ESD Caution...................................................................................8 ADP1714 Fixed Output with Tracking...................................... 4 Output Voltage Measurements ....................................................... 5 REVISION HISTORY 3/07—Revision 0: Initial Version Rev. 0 | Page 2 of 8 EVAL-ADP1712/ADP1713/ADP1714 EVALUATION BOARD HARDWARE AND SCHEMATIC U1 VIN VOUT 1 IN 2 GND 3 EN OUT 5 C2 J1 SS/ADJ/ BYP/TRK R1 4 C3 R2 06491-002 C1 Figure 2. Evaluation Board Schematic Table 1. Evaluation Board Hardware Components Component Function Description U1 1 C1 C2 C3 2 Linear regulator Input capacitor Output capacitor Soft start/bypass capacitor R1, R2 3 J1 Output voltage adjust resistors Jumper ADP1712/ADP1713/ADP1714 Low Dropout Linear Regulator. 2.2 μF Input Bypass Capacitor. 2.2 μF Output Capacitor. Required for stability and transient performance. 10 nF Soft Start Capacitor (ADP1712 Fixed Version) or 10 nF Bypass Capacitor (ADP1713). Soft start capacitor determines VOUT ramp-up time during startup. Bypass capacitor reduces output noise and improves PSRR. External Resistors. Used to set VOUT with the ADP1712 adjustable version. Jumper. Connects EN to IN for automatic startup. 1 2 3 Component varies depending on the evaluation board type ordered. Present only on boards with ADP1712 fixed output devices and ADP1713. Present only on boards with ADP1712 adjustable output devices. Rev. 0 | Page 3 of 8 EVAL-ADP1712/ADP1713/ADP1714 EVALUATION BOARD CONFIGURATIONS ADP1713 FIXED OUTPUT WITH BYPASS The ADP1712/ADP1713/ADP1714 evaluation boards come supplied with different components depending on which version is ordered. Components common to all versions are C1, C2, and J1. Evaluation boards that come supplied with ADP1713 fixed output voltage option devices has the additional C3 bypass capacitor to reduce the output noise and improve PSRR. Figure 5 shows the schematic of this evaluation board configuration. ADP1712 FIXED OUTPUT WITH SOFT START ADP1713 Evaluation boards that come supplied with the ADP1712 fixed output voltage option devices has the additional C3 soft start capacitor. This capacitor controls the rise time when the output voltage starts up. Figure 3 shows the schematic of this evaluation board configuration. VIN C1 VOUT J1 OUT 1 IN 2 GND 3 EN J1 2 GND 3 EN 5 Figure 5. ADP1713 Fixed Output with Bypass ADP1714 FIXED OUTPUT WITH TRACKING C2 SS 4 06491-003 C3 U1 Figure 3. ADP1712 Fixed Output with Soft Start ADP1712 ADJUSTABLE OUTPUT Evaluation boards that come supplied with ADP1712 adjustable output voltage option devices have the additional R1 and R2 resistors to set the output voltage. Figure 4 shows the schematic of this evaluation board configuration. Evaluation boards that come supplied with ADP1714 fixed output voltage option devices with tracking do not have C3, R1, or R2 populated. The user can instead connect an external voltage to the SS/ADJ/BYP/TRK pad of the evaluation board to use the track function. Figure 6 shows the schematic of this evaluation board configuration. ADP1712 ADJUSTABLE VIN VOUT 1 IN 2 GND 3 EN OUT J1 IN 2 GND 3 EN OUT 5 C2 C1 J1 TRK 4 U1 Figure 6. ADP1714 Fixed Output with Tracking R1 4 R2 06491-004 ADJ U1 Figure 4. ADP1712 Adjustable Output The output voltage is set based on the following equation: VOUT = 0.8 V (1 + VOUT 1 5 C2 C1 ADP1714 VIN R1 ) R2 For example, if R1 = 10 kΩ and R2 = 4.99 kΩ, then VOUT is 2.403 V. Rev. 0 | Page 4 of 8 VTRK 06491-006 C1 4 U1 VOUT OUT BYP 06491-005 VIN IN C2 C3 ADP1712 1 5 EVAL-ADP1712/ADP1713/ADP1714 OUTPUT VOLTAGE MEASUREMENTS VOLTMETER VOLTAGE SOURCE + V EVAL-ADP1712/ ADP1713/ADP1714 _ _ GND GND C1 + C2 U1 C3 R1 VIN J1 R2 VOUT GND EN SS/ADJ/BYP/TRK 06491-007 LOAD GND Figure 7. Output Voltage Measurement 1. 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 voltage meter to one of the GND pads, and the positive terminal (+) of the voltage meter to the VOUT pad. The voltage source can now be turned on. If J1 is inserted (this connects EN to VIN for automatic startup), then the regulator powers up. For line regulation measurements, the regulator’s output 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 the device is not in dropout during this measurement, VIN must be varied between VOUTNOM + 0.5 V (or 2.5 V, whichever is greater) and VINMAX. For example, for an ADP1712 with fixed 3.3 V output, VIN needs to be varied between 3.8 V and 5.5 V. This measurement can be repeated under different load conditions. Figure 8 shows the typical line regulation performance of an ADP1712 with fixed 3.3 V output. If the load current is large, the user needs to connect the voltage meter as close as possible to the output capacitor to reduce the effects of IR drops. 3.305 3.300 3.295 3.290 3.285 3.280 3.3 ILOAD ILOAD ILOAD ILOAD ILOAD ILOAD = 100µA = 1mA = 10mA = 100mA = 200mA = 300mA 3.8 06491-008 Follow these steps to connect to a voltage source and voltage meter: LINE REGULATION VOUT (V) Figure 7 shows how the evaluation board can be connected to a voltage source and a voltage meter 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 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. 4.3 4.8 VIN (V) Figure 8. Output Voltage vs. Input Voltage Rev. 0 | Page 5 of 8 5.3 EVAL-ADP1712/ADP1713/ADP1714 LOAD REGULATION DROPOUT VOLTAGE For load regulation measurements, the regulator’s output is monitored while the load is varied. For good load regulation, the output must change as little as possible with varying load. The input voltage must be held constant during this measurement. The load current can be varied from 0 mA to 300 mA. Figure 9 shows the typical load regulation performance of an ADP1712 with fixed 3.3 V output for an input voltage of 3.8 V. Dropout voltage can be measured using the configuration shown in Figure 7. Dropout voltage is defined as the input-tooutput voltage differential when the input voltage is set to the nominal output voltage. This applies only for output voltages above 2.5 V. Dropout voltage increases with larger loads. For more accurate measurements, a second voltage meter can be used to monitor the input voltage across the input capacitor. The input supply voltage may need to be adjusted to account for IR drops, especially if large load currents are used. Figure 10 shows a typical curve of dropout voltage measurements with different load currents. 3.304 3.302 3.300 3.296 140 VDROPOUT (mV) 160 3.294 3.290 0.1 1 10 100 1000 120 100 80 60 40 ILOAD (mA) Figure 9. Output Voltage vs. Load Current 20 0 0.1 06491-010 3.292 06491-009 VOUT (V) 180 3.298 1 10 100 ILOAD (mA) Figure 10. Dropout Voltage vs. Load Current Rev. 0 | Page 6 of 8 1000 EVAL-ADP1712/ADP1713/ADP1714 GROUND CURRENT MEASUREMENTS VOLTAGE SOURCE + AMMETER _ _ μA + LOAD GND EVAL-ADP1712/ ADP1713/ADP1714 C1 C2 U1 GND C3 GND R1 J1 R2 VOUT EN SS/ADJ/BYP/TRK 06491-011 VIN GND Figure 11. Ground Current Measurement supplying its largest load level (300 mA). Figure 12 shows the typical ground current consumption for various load levels. 400 350 300 250 IGND (µA) Follow these steps to connect to a voltage source and ammeter: 1. 2. 3. 4. 5. 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 VOUT pad of the evaluation board and the negative (−) terminal of the voltage source. The voltage source can now be turned on. If J1 is inserted (this connects EN to VIN for automatic startup), then the regulator powers up. GROUND CURRENT CONSUMPTION Ground current measurements are a way of determining how much current the regulator’s internal circuits are consuming while performing the regulation function. To be efficient, the regulator needs to consume as little current as possible. Typically, the regulator uses the maximum current when 200 150 100 50 0 0.1 06491-012 Figure 11 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 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. 1 10 100 1000 ILOAD (mA) Figure 12. Ground Current vs. Load Current When the device is disabled (EN = GND), ground current drops to less than 1 μA. Note: Larger ground current levels occur when using an evaluation board with R1 and R2 present. Rev. 0 | Page 7 of 8 EVAL-ADP1712/ADP1713/ADP1714 ORDERING INFORMATION BILL OF MATERIALS Table 2. Qty 2 1 2 1 4 Reference Designator C1, C2 C3 R1, R2 J1 U1 Description Capacitor, MLCC, 2.2 μF, 16 V, 0805, X5R Capacitor, MLCC, 10 nF, 16 V, 0805, X5R Resistor, 10 kΩ, 1%, 0805 Header, single, STR, 2 pins IC, LDO regulator Manufacturer/Vendor Murata or equivalent Murata or equivalent Vishay Dale or equivalent Digi-Key, Corp. Analog Devices, Inc. Vendor Part No. GRM21BR61C225KA88 GRM21BR72A103KA01 CRCW080510K0FKEA S1012E-36-ND ADP1712AUJZ-3.3-R7 ADP1712AUJZ-R7 ADP1713AUJZ-3.3-R7 ADP1714AUJZ-3.3-R7 ORDERING GUIDE Model ADP1712-3.3-EVALZ 1 ADP1712-EVALZ1 ADP1713-3.3-EVALZ1 ADP1714-3.3-EVALZ1 1 Output Voltage 3.3 V Adjustable, but set to 1.6 V 3.3 V 3.3 V Description ADP1712 Fixed 3.3 V Output with Soft Start Evaluation Board ADP1712 Adjustable Output Evaluation Board ADP1713 Fixed 3.3 V Output with Bypass Evaluation Board ADP1714 Fixed 3.3 V Output with Track Mode Evaluation Board Z = RoHS Compliant Part. ESD CAUTION ©2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. EB06491-0-3/07(0) Rev. 0 | Page 8 of 8