EV-129 AAT1230 EVAL: 18V/10V 100mA Boost Converter Introduction The AAT1230 evaluation board provides a platform for test and evaluation of the AAT1230 switching boost regulator. The evaluation board demonstrates the suggested size and placement of external components to achieve output voltages from 10V to 18V and up to 100mA output load. The external components are selected for small size to suit portable applications, while the layout has been optimized to achieve high efficiency and low output noise with the TSOPJW-12 package. The AAT1230 operates across an input voltage range from 2.7V to 5.5V. The AAT1230 evaluation board provides a single 18V output or 10V output at 100mA maximum output current. The desired output is determined by the logic level of the SEL pin, which is set by the JP2 jumper setting. Connecting SEL (JP2) to logic high (VIN) sets the output voltage to 18V while logic low (GND) sets the output voltage to 10V. This document provides details on the operation and testing of the AAT1230 evaluation board. Modification of the resistor divider network (R1, R2, R3) allows outputs from 10V to 18V and up to 100mA. Operating Specifications, Schematic, and BOM R4 VIN 10K JP1 3 U1 AAT1230 TSOPJW-12 1 2 2 3 1 4 Enable 5 6 JP2 3 C1 2.2µF VP LIN EN/SET FB1 SEL FB2 VIN GND N/C PGND SW SW L1 2.2µH D1 MBR0530 VOUT 12 11 R1 78.7K 10 9 8 7 R2 562 C2 2.2µF 25V R3 4.99K 2 1 Select C1 10V 0603 2.2µF C2 25V 0805 2.2µF D1 30V 0.5A MBR0530T1 SOD-123 L1 2.2µH SD3814-2R2 R1 78.7k 0603 R2 562 0603 R3 4.99k 0603 R4 10k 0603 Figure 1: AAT1230 Evaluation Board Schematic (AAT1230-DB2). Specification Test Conditions Input Voltage Output Error Voltage Output Voltage Output Current VOUT = 10V to 18V; 1% Tolerance R1, R2, R3 EN = VIN (JP1), SEL = VIN (JP2) EN = VIN (JP1); SEL = GND (JP2) EN = S2CWire™1; SEL = GND (JP2) VIN = 2.7V to 5.5V Min Typ 2.7 -4.0 Max Units 5.5 4.0 V % 18.0 10.0 10.0 0 V 18.0 100 2 mA Table 1: AAT1230 Evaluation Board Operating Specifications. 1 Contact an AnalogicTech sales representative for information on Simple Serial Control™ (S2Cwire) programming options. 2 Maximum nominal output voltage should be limited to 18V to avoid damaging the AAT1230 device. EV-129.2006.05.1.2 1 EV-129 AAT1230 EVAL: 18V/10V 100mA Boost Converter Test Equipment 1. Unit under test (UUT) is the AAT1230 Evaluation Board. 2. 6.0V (minimum) 2.0A laboratory input power supply: HP33401A or equivalent. 3. DC 0A to 0.5A electronic load capable of operation up to 20V: Keithley 2400 or equivalent. When using the Keithley 2400, set the meter to operate in voltage source mode and set the load current by varying the current compliance (maximum current) of the meter. 4. Two (2) DC voltmeters: Fluke 189 or equivalent; set to DCV setting. 5. Oscilloscope: Tektronix TS744A or equivalent; Tektronix P6139 oscilloscope probes or equivalent. 6. Miscellaneous test leads (banana plug to clip lead type is recommended). Conductor thickness is not important for low current levels of UUT. 7. Aluminum electrolytic or tantalum input decoupling capacitor: 10µF to 120µF, ≥ 10V. 8. Optional S2Cwire interface for 16-level dynamic voltage programmability. Contact an AnalogicTech sales representative for information on S2Cwire programming options. Set-Up 1. Configure the specified test equipment, as shown in Figure 2. JP1, JP2, and S2Cwire options are shown. 2. An additional 10µF to 120µF input capacitor may be required to decouple the input power supply and maintain stable operation. Solder to input pins. 3. Input power supply with remote sense is optional (not shown in Figure 2). This simplifies the test procedure and maintains high accuracy of the input voltage across the load range. Connect remote sense from input power source remote sense terminals to VIN and GND terminals on the UUT. 3.600V 3.600V Voltmeter Voltmeter Load 0-400mA Power Supply 3.650V Oscilliscope 0.147A Output Ripple Probe Location (see Figure 3 for probe ground detail ) CADD Jumper 1 EN = High to Enable PS Jumper 1 EN = High to Enable PS Jumper 1 Removed: Input Connection S2Cwire Jumper 1 Jumper 1 S2CWire Conn. Jumper 2 Jumper 2 Jumper 2 Jumper 2 SEL = High for 18V Output Jumper 2 SEL = Low for 10V Output Jumper 2 SEL = Low for S2Cwire Programmable Output Figure 2: AAT1230 Evaluation Board Connection Diagram and JP1, JP2 Settings. 2 EV-129.2006.05.1.2 EV-129 AAT1230 EVAL: 18V/10V 100mA Boost Converter Test Load and Line Regulation 1. Enable the UUT jumper JP1 to the ON position. Select JP2 position based on desired DC output voltage (10V or 18V), as shown in Figure 2. 2. Turn on the input power supply and set to desired input voltage based on the DC voltmeter. 3. Vary the output load from 0A to 100mA and vary the input voltage from 2.7V to 5.5V while monitoring the output voltage. Enable Turn-On and Turn-Off 1. With input voltage applied, remove JP1 and reinsert in the OFF position. 2. The output voltage should decay to zero. 3. Remove JP1 and reinsert in the ON position. The output voltage should recover to its initial DC value. Output Ripple Measurement 1. Configure oscilloscope CH1 for output ripple measurement. Plug probe into CH1, as shown in Figure 2. a. AC coupling, 100mV/div. b. BW < 100MHz to limit high frequency probe pick-up. 2. Configure oscilloscope to trigger on CH1 rising or falling edge. 3. Turn on input power supply. Set input voltage between 2.7V and 5.5V and adjust output load from 0mA to 100mA, as desired. It should be noted that light load measurements (<20mA) may be affected by electronic load characteristics. As an alternative, parallel arrangement of 1/4W carbon film resistor(s) can be used. 4. To minimize high frequency noise pick-up due to PCB parasitics and guarantee consistent results, CH1 output ripple should be measured directly across output capacitor C2, as shown in Figure 2. Probe tip contacting capacitor positive terminal. Probe ground consisting of a small bus wire wrapped around probe ground (see Figure 3). Probe GND contacting capacitor C2 return conductor for best results. Probe Tip Bus wire wrapped around probe ground, with probe spring tip removed Probe GND Output Voltage (V) Figure 3: Oscilloscope Probe Set-Up for Output Ripple Measurement. 18.4 18.2 18.0 17.8 17.6 Time (500ns/div) Figure 4: Typical Output Ripple: 18V @ 100mA; VIN = 2.7V. EV-129.2006.05.1.2 3 EV-129 AAT1230 EVAL: 18V/10V 100mA Boost Converter Output Voltage Setting SEL Logic Pin Voltage Programming The output voltage can be set to any voltage between 10V and 18V. Table 2 provides resistor combinations for common output voltages. For specific output voltages not shown in Table 2, the following calculations can be utilized. Nearest 1% resistor value is recommended for optimum output voltage tolerance. R3 = 4.99kΩ, 1% VOUT(1) > VOUT(2) Select nearest 1% R1, R2 value(s) from calculation: X(2) = VOUT(2) -1 0.6 X(1) = VOUT(1) -1 1.2 R1 = R3 · X(2) · ⎛ 1 + X(2) ⎞ X(2) X + ⎝ (2) X(1)⎠ R2 = R1 · X(2) · ⎛ X(2) ⎞ -1 X(1) ⎝ 1 + X(2) ⎠ ⎜ ⎜ Ω R3 = 4.99kΩ VOUT(1) VOUT(2) Ω) R2 (kΩ Ω) (SEL = High) (SEL = Low) R1 (kΩ 10.0V 12.0V 15.0V 16.0V 18.0V – – – – – 12.0V 15.0V 16.0V 18.0V 15.0V 16.0V 18.0V 18.0V – – – – – 10.0V 12.0V 15.0V 16.0V 18.0V 10.0V 10.0V 10.0V 10.0V 12.0V 12.0V 12.0V 15.0V 36.5 44.2 57.6 61.9 69.8 78.7 95.3 121 127 143 75 76.8 76.8 78.7 90.9 93.1 93.1 115 0 0 0 0 0 0 0 0 0 0 3.32 1.65 1.24 0.562 3.01 2.49 1.65 3.32 Table 2: SEL Pin Voltage Control Resistor Values. ⎟ ⎟ Verify VOUT(1), VOUT(2) VOUT(1) = 1.2 · ⎛ R1 ⎞ +1 ⎝ R2 + R3 ⎠ VOUT(2) = 0.6 · ⎛ R1 + R2 ⎞ +1 ⎝ ⎠ R3 4 EV-129.2006.05.1.2 EV-129 AAT1230 EVAL: 18V/10V 100mA Boost Converter Printed Circuit Board Figure 4: AAT1230 Evaluation Board Top Layer (not to scale). Figure 5: AAT1230 Evaluation Board Bottom Layer (not to scale) EV-129.2006.05.1.2 5 EV-129 AAT1230 EVAL: 18V/10V 100mA Boost Converter © Advanced Analogic Technologies, Inc. AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. AnalogicTech warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with AnalogicTech’s standard warranty. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders. Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737-4600 Fax (408) 737-4611 6 EV-129.2006.05.1.2