Evaluation Board for the ADP170/ADP171 EVAL-ADP170/ADP171 FEATURES GENERAL DESCRIPTION Input voltage range: 1.6 V to 3.6 V Output current range: 0 mA to 300 mA Output voltage accuracy: ±1% Operating temperature range: −40°C to +125°C The ADP170/ADP171 evaluation board is used to demonstrate the functionality of the ADP170/ADP171 linear regulators. Simple device measurements such as line and load regulation, dropout, and ground current can be demonstrated with just a single voltage supply, a voltmeter, a current meter, and load resistors. For more details about the ADP170/ADP171 linear regulators, visit www.analog.com. 07723-001 EVALUATION BOARD Figure 1. 5-Lead TSOT Layout Rev. 0 Evaluation boards are only intended for device evaluation and not for production purposes. Evaluation boards are 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. www.analog.com Tel: 781.329.4700 Fax: 781.461.3113 ©2009 Analog Devices, Inc. All rights reserved. EVAL-ADP170/ADP171 TABLE OF CONTENTS Features .............................................................................................. 1 Load Regulation ............................................................................5 General Description ......................................................................... 1 Dropout Voltage ............................................................................5 Evaluation Board .............................................................................. 1 Ground Current Measurements ......................................................6 Revision History ............................................................................... 2 Ground Current Consumption ...................................................7 Evaluation Board Hardware and Schematics ................................ 3 Ordering Information .......................................................................8 Evaluation Board Configurations .............................................. 3 Bill of Materials ..............................................................................8 Output Voltage Measurements ....................................................... 4 Ordering Guide .............................................................................8 Line Regulation ............................................................................. 5 ESD Caution...................................................................................8 REVISION HISTORY 1/09—Revision 0: Initial Version Rev. 0 | Page 2 of 8 EVAL-ADP170/ADP171 EVALUATION BOARD HARDWARE AND SCHEMATICS VIN = 2.3V VIN 2 GND 3 EN VOUT U1 5 ADP170 C1 C3 C4 J1 C2 C5 C6 NC 4 07723-002 The ADP170/ADP171 evaluation boards come supplied with different components, depending on which version is ordered. Components common to all versions are C1 through C6 and J1. The J2, R1, and R2 components are populated on the adjustable ADP171 version only; these components are not populated on the ADP170. C1, C3, and C4 are input capacitors, and C2, C5, and C6 are output capacitors. These capacitors have different size footprints to facilitate evaluating the regulator using a wide variety of components. Figure 2 shows the schematic of ADP170 evaluation board configuration. Figure 3 shows the schematic of ADP171 evaluation board configuration. VOUT = 1.8V 1 Figure 2. ADP170 Evaluation Board Schematic VOUT = 0.5V(1 + R1/R2) VIN = 2.3V 1 VIN 2 GND VOUT U1 5 ADP171 C1 C3 C4 J1 J2 C2 C5 C6 R1 3 EN ADJ 4 R2 Figure 3. ADP171 Evaluation Board Schematic Table 1. Evaluation Board Hardware Components Component U1 1 C1 C2 C3 C4 C5 C6 J1 J2 TP1 TP2 1 Function Linear regulator 0805 size input capacitor 0402 size output capacitor 0603 size input capacitor 0402 size input capacitor 0603 size output capacitor 0805 size input capacitor Jumper Jumper Test point Test point Description ADP170/ADP171 low dropout linear regulator. Not populated. Not populated. 1 μF input bypass capacitor. Not populated. 1 μF output capacitor. Required for stability and transient performance. Not populated. Jumper. Connects EN to VIN for automatic startup. Jumper. Connects the VOUT to the resistor feedback network. Test point closest to VIN pin. Test point closest to VOUT pin. Component depends on the evaluation board type ordered. Rev. 0 | Page 3 of 8 07723-003 EVALUATION BOARD CONFIGURATIONS EVAL-ADP170/ADP171 OUTPUT VOLTAGE MEASUREMENTS Figure 4 shows how the evaluation board can be connected to a voltage source and a voltmeter for basic measurements of the output voltage accuracy. A resistor can be used as the load for the regulator. Ensure that the resistor has an adequate power rating for handling 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. Use the following steps to connect to a voltage source and voltmeter: 2. 3. 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. 5. Connect the negative terminal (−) of the voltmeter to one of the GND pads. Connect the positive terminal (+) of the voltmeter to the pad closest to the VOUT pin. The voltage source can then be turned on. If J1 is inserted (which connects EN to VIN for automatic startup), the regulator powers up. For ADP170, Jumper J2 need not be inserted as shown in Figure 4. The current from the external resistor divider network when there is adjustable voltage output (as with the ADP171) should be subtracted from the ground current measured. If the load current is large, the user must connect the voltmeter as close as possible to the output capacitor to reduce the effects of IR drops due to trace resistance. VIN VOUT VOLTAGE SOURCE VOLTMETER 1.800 – + + – LOAD 07723-004 1. 4. Figure 4. Configuration for Output Voltage Measurements Rev. 0 | Page 4 of 8 EVAL-ADP170/ADP171 LINE REGULATION DROPOUT VOLTAGE For line regulation measurements, the output of the regulator is monitored while its input varies. For good line regulation, the output (VOUT) must change as little as possible with varying input (VIN) levels. To ensure that the device is not in dropout during this measurement, VIN must be varied between VOUTNOM + 0.5 V (or 1.6 V, whichever is greater) and VINMAX. For example, for an ADP170 with fixed 1.8 V output, VIN needs to be varied between 2.3 V and 5.5 V. This measurement can be repeated under different load conditions. Figure 5 shows the typical line regulation performance of an ADP170 with fixed 1.8 V output. Dropout voltage can be measured using the configuration shown in Figure 4. 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 greater than 1.6 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 IR drops due to trace resistance, especially if large load currents are used. Figure 7 shows a typical curve of dropout voltage measurements with different load currents. 1.805 70 1.804 TA = 25°C 60 DROPOUT VOLTAGE (mV) 1.802 1.801 1.800 1.799 LOAD = 100µA LOAD = 1mA 2.3 2.5 LOAD = 10mA LOAD = 100mA 2.7 2.9 3.1 LOAD = 200mA LOAD = 300mA 3.3 3.5 VIN (V) 1 10 100 Figure 7. Dropout Voltage vs. Load Current For load regulation measurements, the output of the regulator is monitored while the load varies. For good load regulation, the output must change as little as possible with varying load current. The input voltage must be held constant during this measurement. The load current can be varied from 0 mA to 150 mA. Figure 6 shows the typical load regulation performance of an ADP170 with fixed 1.8 V output for an input voltage of 2.3 V. 1.804 1.803 1.802 1.801 1.800 1.799 07723-006 VOUT (V) 20 LOAD CURRENT (mA) LOAD REGULATION 0.1 30 0 Figure 5. Output Voltage vs. Input Voltage 1.798 0.01 40 10 07723-007 1.798 2.1 50 1 10 100 1k LOAD CURRENT (mA) Figure 6. Output Voltage vs. Load Current Rev. 0 | Page 5 of 8 1k 07723-012 VOUT (V) 1.803 EVAL-ADP170/ADP171 GROUND CURRENT MEASUREMENTS Figure 8 shows how the evaluation board can be connected to a voltage source and an ammeter to measure ground currents. A resistor can be used as the load for the regulator. Ensure that the resistor has an adequate power rating for handling 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. 2. Use the following steps to connect to a voltage source and ammeter: The voltage source can then be turned on. If J1 is inserted (which connects EN to VIN for automatic startup), the regulator powers up. For ADP170, Jumper J2 need not be inserted as shown in Figure 8. Connect the positive terminal (+) of the voltage source to the VIN pad on the evaluation board. 4. VIN GROUND CURRENT VOLTAGE SOURCE AMMETER 0.035 + – – + 07723-008 1. 3. 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 pad closest to the VOUT pin of the evaluation board. Figure 8. Configuration for Ground Current Measurements Rev. 0 | Page 6 of 8 EVAL-ADP170/ADP171 GROUND CURRENT CONSUMPTION 180 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 needs to consume as little current as possible. Typically, the regulator uses the maximum current when supplying its largest load level (300 mA). Figure 9 shows the typical ground current consumption for various load levels at an input voltage of 2.3 V. When the device is disabled (EN = GND), the ground current drops to less than 1 μA. 160 120 100 80 60 40 07723-009 GROUND CURRENT (µA) 140 20 0 0.01 0.1 1 10 100 LOAD CURRENT (mA) Figure 9. Ground Current vs. Load Current Rev. 0 | Page 7 of 8 1000 EVAL-ADP170/ADP171 ORDERING INFORMATION BILL OF MATERIALS Table 2. Qty 2 1 1 1 Reference Designator C1, C2 J1 U1 Description Capacitor, MLCC, 1 μF, 10 V, 0603, X5R Header, single, STR, two pins IC, LDO regulator Component depends on the evaluation board type ordered. ORDERING GUIDE Model ADP170-1.8-EVALZ1 ADP171-EVALZ1 1 Manufacturer/Vendor Murata or equivalent Digi-Key Corp. Analog Devices, Inc. Output Voltage (V) 1.8 1.0 ESD CAUTION Description Evaluation Board Evaluation Board Z = RoHS Compliant Part. ©2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. EB07723-0-1/09(0) Rev. 0 | Page 8 of 8 Vendor Part No. GRM188R61A105KA61 S1012E-36-ND ADP170/ADP171 1