DC1858A

DEMO MANUAL DC1858A Low Noise, Low Distortion Sine Wave Generator for Testing ADC Demo Boards Description Demonstration circuit 1858A is a low noise, low distortion sine wave generator designed to be used in conjunction with Linear Technology 16-bit and 18-bit ADC demo boards. Functionally, this board uses a Wien bridge oscillator that has been level shifted to match the input range of 0V to 5V 16-bit and 18-bit Linear Technology ADC demo boards. The default oscillator output level is 0.5V to 4.5V. The output frequency is 2kHz. The output level and frequency can be adjusted by changing a few resistors and capacitors. For additional frequencies and output levels see Tables 1 and 2. For a detailed description of this oscillator see AN132. The DC1858A has 5V and ±12V outputs that can be used to provide power for the ADC demo board under test and the DC1216A low jitter clock source if required. The DC1858A combined with the DC1216A, an ADC demo board and a high speed USB controller (DC718 or DC890) form a complete ADC evaluation system when used with LTC’s PScope™ software. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and PScope is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Board Photo Figure 1. DC1858A Typical Connection Diagram dc1858af 1 DEMO MANUAL DC1858A Quick Start Procedure Use the connection diagram of Figure 1. Connect the ADC demo board to a DC718 or DC890 USB high speed data collection board (DC718 or DC890 will be determined by the ADC demo board being tested). Then, connect the DC718 or DC890 to a host PC with a standard USB A/B cable. Apply ±12V from the DC1858A power outputs (see Figure 2) to the plus or ±terminals of the ADC demo board as required. Connect the SINE OUT (see Figure 3) of the DC1858A to the analog input of the ADC demo board. (The SINE OUT output is designed to drive a high impedance input. Do not use this to drive 50Ω inputs.) Connect a low jitter clock to the clock input of the demo board. DC1858A has a 5V output supply available to power the DC1216A low jitter clock source if desired. (See Figure 1 for connection diagram. A twisted pair or shielded cable from the DC1858A to the DC1216A power pins is recommended to minimize interference from the AC adapter.) Plug in the provided AC adapter. is located at the top of the PScope window. Remember that to calculate the true SNR, the F1 amplitude has to be added back to the SNR that PScope displays. IF THE OSCILLATOR DOESN’T START Use the supplied non-conductive screwdriver to adjust the potentiometer through the opening in the box until a steady 2kHz sine wave with an amplitude of approximately 4.5VP-P is observed. The oscillator has three states, normal oscillation, oscillation with modulated amplitude, and no oscillation. It takes only a small change in the potentiometer to go through all three states so adjust the potentiometer slowly. Download and run the PScope software from www.linear. com/designtools/software. Complete software documentation is available from the Help menu. Updates can be downloaded from the Tools menu. Check for updates periodically as new features may be added. The PScope software should recognize the ADC demo board and configure itself automatically. Figure 2. DC1858A Rear Panel Set the sample rate in Msps to what is appropriate for the ADC used. The sample size should be set to 32768 for 16-bit ADCs or 131072 for 18-bit ADCs and above. If synchronous sampling is not used set the window to Blkmn-Harris 92dB, otherwise select None. Sample rate, sample size and window are located in the right hand center section of the PScope window. Click the Collect button to begin acquiring data. The Collect button then changes to Pause, which can be clicked to stop data acquisition. F1 should read approximately 2kHz and F1 amplitude should read approximately –1dBFS. To get the best SNR performance it is recommended to turn on power averaging. The power averaging (MAVG) button Figure 3. DC1858A Front Panel dc1858af 2 DEMO MANUAL DC1858A Quick Start Procedure Table 1. Amplitude and Offset Options for DC1858A (SNR and THD Taken at fOSC = 2kHz) ADC FS Range (V) R22 (kΩ) R18 (kΩ) C11 (µF) Sine Out (VP-P) Offset (V) SNR (dB)* THD (dB)* 0 to 2.5 14 36.5 0.47 2.25 1.25 100 –119 0.5 to 4.5 22.6 12.1 0.47 3.6 2.5 103 –121 0 to 4.096 23.2 17.4 0.47 3.7 2.048 103 –121 0 to 5 28 12.1 0.47 4.5 2.5 104 –118 ±2.5 28 ∞ 0.47 4.5 0 104 –119 ±5 56.2 ∞ 0.47 9 0 107 –117 ±10 118 ∞ 0.1 18 0 100 –107 *SNR and THD measurements made with Stanford Research Model SR1 Audio Analyzer. Table 2. Frequency Options for DC1858A (SNR and THD Taken at SINE OUT = 4.5VP-P, Offset = 2.5V) fOSC (kHz) R1 = R8 (kΩ) C10 (µF) C11 (µF) SNR (dB)* THD (dB)* 2 7.87 0.0068 0.47 104 –118 5 3.16 0.0022 0.22 102 –112 10 1.58 0.0012 0.1 102 –112 20 0.787 0.00068 0.047 101 –117 Use 1% metal film resistors and mylar or silver mica capacitors when making modifications, to maintain the low noise, low distortion performance of this demo board. *SNR and THD measurements made with Stanford Research Model SR1 Audio Analyzer. dc1858af 3 DEMO MANUAL DC1858A Quick Start Procedure Figure 4. DC1858A PC Board dc1858af 4 DEMO MANUAL DC1858A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 1 13 C1 TO C6, C13 TO C18, C20 CAP, OSCON, 10µF 20V 20% SMT SANYO, 20SVPA10M 2 2 C7, C9 CAP, POLYSTYRENE, 0.01µF, 33V 1% AXIAL LEAD CENTRALAB, 14OMFD33V-J 3 1 C8 CAP, MICA CHIP, 5pF, 100V ±0.5PF 0805 CDE, MC08CA050D-F 4 1 C10 CAP, PPS FILM, 0.0068µF, 16V 5% 0805 PANASONIC, ECHU1C682JX5 5 1 C11 CAP, PLASTIC FILM, 0.47µF, 100V 10% 3022 PANASONIC, ECWU1474KCV 6 1 C12 CAP, PLASTIC FILM, 0.1µF, 16V 5% 1210 PANASONIC, ECHU1C104JX5 7 2 C19, C25 CAP, PLASTIC FILM, 1.0µF, 100V 10% 3925 PANASONIC, ECWU1105KCV 8 1 C22 CAP, TANT, 47µF 35V 20% 7343 KEMET, T495X476K035ATE300/AVX, TAJE476M035RNJ 9 1 C23 CAP, TANT, 10µF 25V 10% 6032 AVX, TAJC106K025RNJ 10 1 C24 CAP, TANT, 15µF 25V 10% 7343 AVX, TAJD156K025RNJ 11 1 C26 CAP, TANT, 100µF 20V 20% 7361 AVX, TPSE107M020R0200/TPSV107M020R0085 12 2 D1, D2 DIODE, SMALL SIGNAL, SOD323 DIODES INC, 1N4148WS-7-F 13 2 D3, D4 DIODE, SCHOTTKY, 40V 1A SMA ON SEMI, MBRA140T3G 14 5 E1, E2, E3, E4, E5 TESTPOINT, TURRET, 0.094, PBF MILL MAX, 2501-2-00-80-00-00-07-0 15 2 E6, E7 TEST POINT, TURRET, 0.061 MILL MAX, 2308-2-00-80-00-00-07-0 16 1 J1 CONN RCPT HOUSING 5POS 3.96MM MOLEX, 09-50-1051 17 1 J2 CON, BNC 50Ω, JACK, RIGHT ANGLE PCB MOUNT MOLEX, 731385033 18 1 J3 CONNECTOR, 5-PIN DIN, RIGHT ANGLE PCB, 180 DEG CUI, SDS-50J 19 1 J4 CONN, JACK BANANA INSUL NYLON VIOLET EMERSON NETWORK, 108-0912-001 20 1 J5 CONN, JACK BANANA INSUL NYLON BLACK EMERSON NETWORK, 108-0903-001 21 1 J6 CONN, JACK BANANA INSUL NYLON YELLOW EMERSON NETWORK, 108-0907-001 22 1 J7 CONN, JACK BANANA INSUL NYLON RED EMERSON NETWORK, 108-0902-001 23 1 P1 HEADER, 5 PIN, 0.156, LOCKING MOLEX, 09-65-2058 24 1 Q1 TRANS, GP, 40V, 200mA, SOT-23 ON SEMI, MMBT3904LT1G 25 2 R1, R8 RES, METAL FILM, 7.87k, 1/4W, 0.1% RC55 IRC, RC55LF-D-7K87-B-B 26 1 R2 RES, METAL FILM, 249Ω, 1/8W, 0.1% 0805 VISHAY, TNPW0805249RBEEA 27 1 R3 RES, CHIP, 240Ω, 1W, 5% 2512 PANASONIC, ERJ-1TYJ241U 28 1 R4 TRIMPOT, SEALED, 500Ω, CERMET, SMT BOURNS, 3361P-1-501GLF rl 29 1 R5 RES, METAL FILM, 715Ω, 1/4W, 0.1% RC55 IRC, RC55LF-D-715R-B-B 30 1 R6 RES, METAL FILM, 19.1k, 1/4W, 0.1% RC55 IRC, RC55LF-D-19K1-B-B 31 1 R7 RES, METAL FILM, 40.2k, 1/4W, 0.1% RC55 IRC, RC55LF-D-40K2-B-B 32 1 R9 RES, METAL FILM, 9.09k, 1/4W, 0.1% RC55 IRC, RC55LF-D-9K09-B-B 33 1 R10 RES, METAL FILM, 12.1k, 1/4W, 0.1% RC55 IRC, RC55LF-D-12K1-B-B 34 1 R11 RES, METAL FILM, 130Ω, 1/8W, 0.1% 0805 VISHAY, TNPW0805130RBEEA 35 1 R12 RES, METAL FILM, 1M, 1/8W, 0.1% 0805 VISHAY, TNPW08051M00BEEA 36 4 R13, R15 TO R17 RES, METAL FILM, 10k, 1/8W, 0.1% 0805 VISHAY, TNPW080510K0BEEA 37 1 R14 RES, METAL FILM, 4.99k, 1/8W, 0.1% 0805 VISHAY, TNPW08054K99BEEA 38 2 R18, R19 RES, METAL FILM, 12.1k, 1/8W, 0.1% 0805 VISHAY, TNPW080512K1BEEA dc1858af 5 DEMO MANUAL DC1858A Parts List ITEM QTY 39 1 REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER R20 RES, METAL FILM, 4.3k, 1/8W, 0.1% 0805 PANASONIC, ERA-6AEB432V 40 1 R21 RES, METAL FILM, 100k, 1/8W, 0.1% 0805 VISHAY, TNPW0805100KBEEA 41 1 R22 RES, METAL FILM, 28k, 1/8W, 0.1% 0805 VISHAY, TNPW080528K0BEEA 42 1 R23 RES, METAL FILM, 36k, 1/8W, 0.1% 0805 VISHAY, TNPW080536K0BEEA 43 1 R24 RES, METAL FILM, 100Ω, 1/8W, 0.1% 0805 VISHAY, TNPW0805100RBEEA 44 2 R25, R26 RES, METAL FILM, 470Ω, 1/8W, 0.1% 0805 VISHAY, TNPW0805470RBEEA 45 1 R27 RES, CHIP, 100Ω, 0.5W, 5% 2010 ROHM, MCR50JZHJ101/VISHAY, CRCW2010100RJNEA 46 3 U1, U2, U3 IC, OP-AMP, 90MHz, SO-8 LINEAR TECHNOLOGY, LT1468CS8#PBF 47 1 U4 OPTOCOUPLER, ANALOG, AXIAL VACTEC, VTL5C10 48 3 U5, U6, U7 IC, OP-AMP, JFET, SO-8 LINEAR TECHNOLOGY, LT1122CS8#PBF 49 1 U8 IC, OP-AMP, PRECISION, SO-8 LINEAR TECHNOLOGY, LT1006CS8#PBF 50 1 U9 IC, MICROPOWER REFERENCE, 5V, SOIC LINEAR TECHNOLOGY, LT1634ACS8-5#PBF 51 5 TERMINAL, 18-24 AWG CRIMP FEMALE TIN, BAG MOLEX, 08-70-1030 52 1 BOX, ALUM. 4.72 x 4.06 x 2.09" BL/NAT HAMMOND, 1455N1201 53 2 SCREWS, THREAD-FORMING PHILLIPS PANHEAD, M2 x 0.4mm x 6mm LENGTH GRAINGER, ITEM #1PU17 54 1 ALIGNMENT TOOL PHILMORE, # 63-8608 55 1 AC ADAPTOR POWER SUPPLY W/ PSE MARKING AND 5 PIN 180 DEG DIN CONNECTOR OUTPUT ETA-USA, DTA27-3X-W-5 dc1858af 6 DEMO MANUAL DC1858A Schematic Diagram dc1858af Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 7 DEMO MANUAL DC1858A DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and observe good laboratory practice standards. Common sense is encouraged. This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation dc1858af 8 Linear Technology Corporation LT 0313 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com  LINEAR TECHNOLOGY CORPORATION 2013