Evaluation Board for the ADP1715/ADP1716 EVAL-ADP1715/ADP1716 FEATURES GENERAL DESCRIPTION Input voltage range: 2.5 V to 5.5 V Output current range: 0 mA to 500 mA Output voltage accuracy: ±1% Operating temperature range: –40°C to +125°C The ADP1715/ADP1716 evaluation board can be used to demonstrate the functionality of the ADP1715/ADP1716 series of linear regulators. Depending on the component combinations used, the evaluation board can be used for ADP1715 fixed output voltage devices with soft start, ADP1715 adjustable output voltage devices, and ADP1716 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 ADP1715/ADP1716 linear regulators, visit www.analog.com. EVALUATION BOARD EVAL-ADP1715/ADP1716 GND GND U1 C1 C2 C3 J1 R2 R1 GND VOUT EN SS/ADJ/TRK GND 06309-001 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-ADP1715/ADP1716 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 ADP1715 Fixed Output with Soft Start..................................... 4 Bill of Materials..............................................................................8 ADP1715 Adjustable Output ...................................................... 4 Ordering Guide .............................................................................8 ADP1716 Fixed Output with Tracking...................................... 4 ESD Caution...................................................................................8 Output Voltage Measurements ....................................................... 5 REVISION HISTORY 3/07—Revision 0: Initial Version Rev. 0 | Page 2 of 8 EVAL-ADP1715/ADP1716 EVALUATION BOARD HARDWARE AND SCHEMATIC GND GND VIN J1 C1 EN SS/ADJ/TRK 1 EN GND 8 2 IN GND 7 3 OUT GND 6 4 SS/ADJ/TRK GND 5 U1 C2 C3 R1 GND GND 06309-002 R2 VOUT Figure 2. Evaluation Board Schematic Table 1. Components Listing Reference Designator U1 1 C1 C2 C3 2 R1, R2 3 J1 Function Linear regulator Input capacitor Output capacitor Soft start capacitor Output voltage adjust resistors Jumper Description ADP1715/ADP1716 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. Determines VOUT ramp-up time during startup. External Resistors. Used to set VOUT with the ADP1715 adjustable version. Jumper. Connects EN to VIN for automatic startup. 1 Component varies depending on which evaluation board model is ordered. Component present only on boards with ADP1715 fixed output devices. 3 Components present only on boards with ADP1715 adjustable output devices. 2 Rev. 0 | Page 3 of 8 EVAL-ADP1715/ADP1716 EVALUATION BOARD CONFIGURATIONS The output voltage is set based on the equation The ADP1715/ADP1716 evaluation boards come supplied with different components depending on which version is ordered. Components common to all versions are C1, C2, and J1. For example, if R1 = 10 kΩ and R2 = 4.99 kΩ, then VOUT = 2.403 V. ADP1715 FIXED OUTPUT WITH SOFT START ADP1716 FIXED OUTPUT WITH TRACKING Evaluation boards that come supplied with ADP1715 fixed output voltage option devices have the C3 soft start capacitor included. This capacitor controls the rise time when the output voltage starts up. Figure 3 shows the schematic of this evaluation board configuration. Evaluation boards that come supplied with ADP1716 fixed output voltage option with tracking devices do not have C3, R1, or R2 populated. The user can instead connect an external voltage to the TRK pad of the evaluation board to see how the track feature works. Figure 5 shows the schematic of this evaluation board configuration. ADP1715 J1 1 EN GND 8 2 IN GND 7 3 C1 4 OUT ADP1716 J1 GND 6 SS VIN GND 5 C1 06309-003 U1 C2 C3 VOUT VOUT ADP1715 ADJUSTABLE 1 EN GND 8 2 IN GND 7 3 OUT GND 6 4 ADJ GND 5 VOUT C2 R2 U1 06309-004 R1 GND 8 2 IN GND 7 3 OUT GND 6 4 TRK GND 5 U1 Figure 5. ADP1716 Fixed Output with Tracking Evaluation boards that come supplied with ADP1715 adjustable output voltage option devices have the R1 and R2 resistors included. Figure 4 shows the schematic of this evaluation board configuration. C1 EN TRK ADP1715 ADJUSTABLE OUTPUT VIN 1 C2 Figure 3. ADP1715 Fixed Output with Soft Start J1 (1) Figure 4. ADP1715 Adjustable Output Rev. 0 | Page 4 of 8 06309-005 VIN VOUT = 0.8 V (1 + R1/R2) EVAL-ADP1715/ADP1716 OUTPUT VOLTAGE MEASUREMENTS VOLTAGE SOURCE GND EVAL-ADP1715/ADP1716 VOLTAGE METER V GND U1 – C1 + C2 C3 J1 R2 R1 VOUT VIN GND EN SS/ADJ/TRK 06309-006 LOAD GND Figure 6. 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 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 mode during this measurement, VIN must be varied between VOUTNOM + 0.5 V (or 2.5 V, whichever is greater) and VINMAX. For an ADP1715 with a 3.3 V fixed output, this means VIN needs to be varied between 3.8 V and 5.5 V. This measurement can be repeated under different load conditions. Figure 7 shows the typical line regulation performance of an ADP1715 with 3.3 V fixed output. If large load currents are to be used, the user needs to connect the voltage meter as close to the output capacitor as possible, to reduce the effects of IR drops. 3.325 3.315 ILOAD = 100µA 3.305 ILOAD = 10mA 3.295 ILOAD = 100mA ILOAD = 250mA 3.285 3.265 3.3 ILOAD = 360mA ILOAD = 500mA 3.275 06309-007 Follow these steps to connect to a voltage source and voltage meter: LINE REGULATION VOUT (V) Figure 6 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 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 the voltage source used can supply adequate current for the expected load levels. 3.8 4.3 4.8 VIN (V) Figure 7. ADP1715 Line Regulation Rev. 0 | Page 5 of 8 5.3 EVAL-ADP1715/ADP1716 LOAD REGULATION DROPOUT VOLTAGE For load regulation measurements, the regulator output is monitored while the load is varied. For good load regulation, the output needs to change as little as possible with varying loads. The input voltage must be held constant during this meas-urement. The load current can be varied from 0 mA to 500 mA. Figure 8 shows the typical load regulation performance of an ADP1715 with 3.3 V fixed output for an input voltage of 3.8 V. Dropout voltage measurements can also be performed using the configuration shown in Figure 6. Dropout voltage is defined as the input-to-output 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 9 shows a typical curve of dropout voltage measurements with different load currents. 3.325 3.315 350 300 3.295 VDROPOUT (mV) 250 3.285 3.275 1 10 100 200 150 100 1000 50 ILOAD (mA) Figure 8. ADP1715 Load Regulation 0 0.1 06309-009 3.265 0.1 06309-008 VOUT (V) 3.305 1 10 100 ILOAD (mA) Figure 9. Dropout Voltage vs. Load Current Rev. 0 | Page 6 of 8 1000 EVAL-ADP1715/ADP1716 GROUND CURRENT MEASUREMENTS VOLTAGE SOURCE CURRENT METER µA EVAL-ADP1715/ADP1716 U1 GND GND C1 LOAD C2 C3 J1 R2 R1 VOUT GND EN SS/ADJ/TRK 06309-010 VIN GND Figure 10. Figure 10 shows how the evaluation board can be connected to a voltage source and a current meter 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 the voltage source used can supply adequate current for the expected load levels. the regulator consumes maximum current when supplying its largest load level (500 mA). Figure 11 shows typical ground current consumption for various load levels. 500 450 400 350 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 current meter to one of the GND pads of the evaluation board. Connect the negative terminal (–) of the current meter 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 internal circuits are consuming while performing the regulation function. To be efficient, the regulator must consume as little current as possible. Typically, 300 250 200 150 100 06309-011 1. IGND (µA) Follow these steps to connect to a voltage source and current meter: 50 0 0.1 1 10 100 1000 ILOAD (mA) Figure 11. Ground Current vs. Load Current When the device is disabled (EN = 0 V), ground current is reduced to less than 1 μA. Note that larger ground current levels are observed when using an evaluation board with R1 and R2 present. Rev. 0 | Page 7 of 8 EVAL-ADP1715/ADP1716 ORDERING INFORMATION BILL OF MATERIALS Table 2. Qty Reference Designator Description Manufacturer/Vendor Vendor Part Number 2 1 1 C1, C2 C3 R1 Capacitor, MLCC, 2.2 μF, 16 V, 0805, X5R Capacitor, MLCC, 10 nF, 100 V, 0805, X7R Resistor, 10 kΩ, 1%, 0805 Murata or equivalent Murata or equivalent Vishay Dale or equivalent GRM21BR61C225KA88 GRM21BR72A103KA01 CRCW080510K0FKEA 1 1 1 R2 J1 U1 Resistor, 4.99 kΩ, 1%, 0805 Header, single, STR, 2 pins IC, LDO regulator Vishay Dale or equivalent Digi-Key, Corp. Analog Devices, Inc. CRCW08054K990FKEA S1012E-36-ND ADP1715ARMZ-R7 ADP1715ARMZ-3.3-R7 ADP1715ARMZ-1.8-R7 ADP1716ARMZ-2.5-R7 ORDERING GUIDE Model ADP1715-EVALZ1 ADP1715-3.3-EVALZ1 ADP1715-1.8-EVALZ1 ADP1716-2.5-EVALZ1 1 ESD CAUTION Description Evaluation Board with Adjustable Output ADP1715 Evaluation Board with 3.3 V Fixed Output ADP1715 Evaluation Board with 1.8 V Fixed Output ADP1715 Evaluation Board with 2.5 V Fixed Output ADP1716 Z = RoHS Compliant Part. ©2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. EB06309-0-3/07(0) Rev. 0 | Page 8 of 8