STEVAL-CCA057V1

AN4495 Application note STEVAL-CCA057V1 evaluation board user guidelines for dual operational amplifiers in an SO8 package By Nicolas Aupetit Introduction The STEVAL-CCA057V1 evaluation board from STMicroelectronics is designed to help customers quickly prototype new dual op amp circuits in an SO8 package and reduce design time. The evaluation board can be used with almost any STMicroelectronics dual op amp in various configurations and applications. The evaluation board is a bare board (that is, there are no components or amplifier soldered to the board; these must be ordered separately). This document provides:  A description of the evaluation board  A layout of the top and bottom layers  Some examples of classic configurations that can be tested with the board Figure 1. SO8 pinout Figure 2. STEVAL-CCA057V1 evaluation board September 2014 DocID026366 Rev 1 1/18 www.st.com Contents AN4495 Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 Different possible configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1 Low-pass Sallen-key configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.2 High-pass Sallen-key configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.3 Instrumentation amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.4 Transimpedance configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 3.5 AC coupled circuit configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4 Associated products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 2/18 DocID026366 Rev 1 AN4495 1 Description Description This board is designed with versatility in mind, and allows many circuits to be constructed easily and quickly. A few possible circuits are as follows:  Voltage follower  Non-inverting amplifier  Inverting amplifier  Sallen-key filter  Instrument amplifier  AC-coupled circuit  Out-of-loop compensation circuit Circuit The circuit schematic in Figure 3 shows the connections for all possible components. Each configuration uses only some of the components. The board is designed for surface-mounted components and can be used to perform onboard characterization prior to the integration of STMicroelectronics products in your designs. Resistor and capacitor footprints are implemented for the 1206 series. DocID026366 Rev 1 3/18 18 4/18 DocID026366 Rev 1 PP 9,1% *1' B&,1 PP 9,1%B'& B&,1 &,1% 95()% 9,1%B'& B&,1 &,1% 95()% 9,1$B'& PP 9,1% PP &,1$ 95()$ 9,1%21 9,1%21 9,1$21 9,1$21 *1' *1' *1' *1' 9,1%2)) 5B 9,1%2)) 5B 9,1$2)) 5B 9,1$2)) 5B 5B 5% 5B 5% 5B 5$ 5B 5$ *1' *1' *1' 5B% 5 5B%  5 5B$ 5B$   9%  9% 9 9 5)LOWHU% $233,16 ,&% 5B &)%B23(1 5% &)%% 5)LOWHU$  9RXW%  9RXW$ ,&$ $233,16 9&&1 9&&3 &$39&&3  *1' 9$ 9$   *1' *1' 9,1$B'& B&,1 &,1$ 95()$ &$39&&1 5B &)%B23(1 5$  9,1$ 9,1$ *1' *1' *1' &)%$ B 5B% 5)%% B 5B$ 5)%$ B&287B5,62 &287B% B&287B5,62 &287B$ *1' 5/B% 5/B23(1 *1' 5/B$ 5/B23(1 &/B% &/B23(1 &/B$ &/B23(1 *1' 9287%60% 9287B% PP 37B9287B% *1' 9287$60% 9287B$ PP 37B9287B$ PP 9&&1 PP *1' & &,1B9&&1B21 9&&1B5 *1' B23(1 9&&1B60% *1' PP 9&&3B5()B60% *1' & &,1B9&&SB21 B&287B5,62 9&&3B60% 9&&3 & *1' & 9&&1 ()B60% *1' 9&&3 Description AN4495 Figure 3. Evaluation board schematics *63*', Power requirements A 0  resistance must be connecting on CIN_VCCN_ON and CIN_VCCP_ON in order to supply power to the dual amplifier. A set of two decoupling capacitors (C1, C2 and C3, C4) have been implemented on both power supply pins, so as to benefit from the maximum performance of ST products. In order to reject low frequencies, 1 µF and 10 µF are good values for these. AN4495 Description Others decoupling capacitors (CAPVCCN, CAPVCCP) as close as possible to the SO8 package, might also be used to obtain excellent power supply decoupling. 100 pF values can be used in order to reject high frequencies. When using single-supply circuits, the negative supply is shorted to ground by bridging C3 or C4 capacitances. Power is therefore between VCCP and GND. Output options The outputs have additional resistor (RL_A, RL_B) and capacitor (CL_A, CL_B) placements for loading. Or it might be used as an anti-alias filter, or to limit amplifier output noise by reducing its output bandwidth. Note: Operational amplifiers are sensitive to output capacitance and may oscillate. In the event of oscillation, reduce output capacitance by using shorter cables, or add a resistor in series on COUT_A, COUT_B placement with a suitable value in order to improve amplifier phase margin. Measurement tips In the datasheet, some measurements, such as settling time and peaking, have been performed with 50  output equipment. In order to keep the integrity of the square input signal, the input tracks from VINA+, VINB+, VINA-, VINB+, have an impedance of 50 . And in order to adapt input impedance, 50  resistances can be added on the R50_1A, R50_2A and R50_1B, R50_2B. DocID026366 Rev 1 5/18 18 Layout 2 AN4495 Layout The board has the following physical characteristics: – Board dimensions: 3526 x 3300 mils (89.6 x 83.8 mm) – 2-layer PCB – Both sides have a ground plane. – For Vout_A, Vout_B, VinA+, VinA-, VinB+ and VinB- female SMB or female 2 mm connectors can be implanted. You can also implant test points on these voltages. They will facilitate the visualization of your signals. Top and bottom layers are shown on Figure 4 and Figure 5: Figure 4. Top layer 6/18 Figure 5. Bottom layer DocID026366 Rev 1 AN4495 3 Different possible configurations Different possible configurations The following provides some instructions on how to set up the board in order to perform several classical configurations.  Figure 6: Low-pass Sallen-key filter order 4  Figure 7: High-pass Sallen-key filter order 4  Figure 8: Instrumentation amplifier  Figure 9: Transimpedance configuration  Figure 10: AC coupled configuration You can also put several boards in cascade which allows you to obtain a more complex configurations. 3.1 Low-pass Sallen-key configuration The following low-pass Sallen-key configuration is a fourth order filter configuration. This circuit has 80 dB roll-off per decade. The transfer function is: Equation 1 The low frequency gain is: Equation 2 DocID026366 Rev 1 7/18 18 Different possible configurations AN4495 Figure 6. Low-pass Sallen-key 4th order configuration *1' 5)$ &$39&&1 *1' 37B9287B$ 9&&1 95()$ *1' 5*$ 9$  ,&$ $233,16  9,1$ PP 9 9$  9,1$B'&  RKPV  9287B$ 9287$60%  RKP 9&&3 5 *1' 95()$ *1'  9RXW$ 9 PP *1' & &$39&&3 9,1$ PP *1'  RKP 5 *1' *1' 9,1$B'& *1' & 5)% *1' 37B9287B% 95()% *1' PP ,&% 5*% 9287B% 9,1% PP 9%   9RXW% 9%  9,1%B'&  RKP 9287%60%  RKP $233,16 5 *1' 95()% *1' *1' 9,1% PP &  RKP 5 *1' *1' 9,1%B'& & *1' 3.2 *63*60' High-pass Sallen-key configuration Like the low-pass Sallen-key configuration above, this one is also a fourth order. It has a slope of +80 dB per decade. The transfer function is: Equation 3 The high frequency gain is: Equation 4 8/18 DocID026366 Rev 1 AN4495 Different possible configurations Figure 7. High-pass Sallen-key configuration *1' 5)$ &$39&&1 *1' 37B9287B$ 9&&1 95()$ *1' 5*$  PP 9$  9,1$ 9$ ,&$ $233,16 9   9RXW$ 9 9,1$B'&  PP  RKPV 9287B$ 9287$60%  RKP 9&&3 & 95()$ *1' *1' 5 *1' &$39&&3 9,1$ PP *1'  RKP & *1' *1' 9,1$B'& *1' 5 5)% *1' 37B9287B% 95()% *1' PP ,&% 5*% 9287B% 9,1% PP 9%  9%  9RXW%  9,1%B'&  RKP 9287%60%  RKP $233,16 & 95()% *1' *1' 5 *1' PP *1' 9,1%  RKP & *1' 9,1%B'& 5 *63*60' *1' The upper limit of the frequency range is determined by the GBP of the op amp 3.3 Instrumentation amplifier The instrumentation amplifiers are generally used for precise measurement in a differential way. The architecture of the instrumentation amplifier with dual op amps is the simplest one. The input impedance is high as the non-inverting of the both op amps are used as input. By considering R1.R2 = RFA.RFB And Vout = Vreference for Vdiff = 0 V The gain can be expressed as follows: Equation 5 DocID026366 Rev 1 9/18 18 Different possible configurations AN4495 10/18 1RQLQYHUWLQJ LQSXW ,QYHUWLQJLQSXW 5HIHUHQFH 2XWSXW Figure 8. Instrumentation amplifier DocID026366 Rev 1 AN4495 Different possible configurations 3.4 Transimpedance configuration The Figure 9 shows how to configure op amp IC1A as a transimpedance amplifier (TIA). The output voltage of the TIA is the input current multiplied by the feedback resistor RFA: Equation 6 where Iin is defined as the input current source applied at the VINA- pad, IBIAS is the input bias current, and VOS is the input offset voltage of the op amp. For the type of usage, the feedback resistor RFA is generally high and the impedance seen on the VA- node is pretty capacitive (ex: photodiode). In order to stabilize the op amp it is recommended to connect a feedback capacitance CF. Figure 9. Transimpedance configuration &I *1' 5)$ &$39&&1 *1' 37B9287B$ 9&&1 95()$ *1' 9,1$ PP 9$   RKPV  RKPV ,&$ $233,16   9RXW$ 9  RKPV 9$  9,1$B'& 9  PP  RKP 9287B$ 9287$60%  RKP 9&&3 95()$ *1' *1' *1'  RKP &$39&&3 *1' *1' PP 9,1$ *1' 9,1$B'& *1'  RKP *1' 37B9287B% 95()% *1' PP 9287B% ,&% 9,1% PP 9%  9%   9RXW% 9,1%B'&  RKP 9287%60%  RKP $233,16 95()% *1' *1' *1'  RKP *1' *1' PP 9,1% 9,1%B'& *1' *63*60' Note: If only IC1A op amp is used as transimpedance amplifier, the second one, IC1B, should be configured in follower mode in order to avoid any undesired oscillation on its output. DocID026366 Rev 1 11/18 18 Different possible configurations 3.5 AN4495 AC coupled circuit configuration This typical configuration allows you to amplify the AC part of the input signal only; for example, a typical stereo audio amplifier. Figure 10. AC coupled circuit configuration *1' 5)$ &$39&&1 *1' 37B9287B$ 9&&1 95()$ *1' 9$   ,&$ $233,16 9,1$ PP 9  RKPV 5*$ &LQ$ 9$  9,1$B'&  5 *1'  RKP 9287B$ 9287$60% 5RXW 9&&3 5*$ 95()$ *1'  9RXW$ 9 PP &RXW$ *1' &$39&&3 9,1$ PP *1'  RKPV &LQ$ *1' *1' 9,1$B'& *1' 5)% *1' 37B9287B% 95()% *1' PP 9287B% ,&% 9,1% PP 9%   RKPV  5*% &LQ% 9%  9,1%B'& 9RXW%  RKP 9287%60% 5RXW% $233,16 &RXW% 5*% 95()% *1' *1' *1' 5 PP *1' 9,1%  RKPV &LQ% *1' 9,1%B'& *1' *63*60' 12/18 DocID026366 Rev 1 AN4495 4 Associated products Associated products Table 1. Associated products Part number General description LF351DT JFET inputs, low input bias & offset current, (15nV/√Hz & 0.01%) LF353DT JFET inputs, low input bias & offset current, (15nV/√Hz & 0.01%) LM301ADT Input & output overload protection, low input offset current LM358DT Low-power dual op amps with low input bias current TL072ADT JFET inputs, low input bias current TS461DT Output rail-to-rail op amps TS462DT Output rail-to-rail op amps TSH62DT Wide band, low power operational amplifier with standby function TSH71DT Rail-to-rail video op amp with standby TSH72DT Rail-to-rail video op amp TS613IDT ADSL line driver TS931IDT Micropower amplifier with CMOS inputs TS932IDT Micropower amplifier with CMOS inputs TS941IDT Ultra-micropower amplifier with CMOS inputs TS942IDT Ultra-micropower amplifier with CMOS inputs TS942AIDT Ultra-micropower amplifier with CMOS inputs TSH80IDT Rail-to-rail video op amp with standby TSH82IDT Rail-to-rail video op amp TSV612IDT Rail to rail input/output CMOS op amp TSV612AIDT Rail to rail input/output CMOS op amp TSV6192IDT Rail to rail input/output CMOS op amp TSV6192AIDT Rail to rail input/output CMOS op amp LF253IDT JFET inputs, low input bias & offset current, (15nV/√Hz & 0.01%) LM201AIDT Input & output overload protection, low input offset current LM258IDT Low-power dual op amps with low input bias current LM258WIDT Low power dual operational amplifiers LS204IDT Low-noise bipolar op amps MC1458IDT High performance dual op amps with wide input common-mode voltage range MC33078IDT Low-noise op amps MC33171IDT Low consumption versus speed MC4558IDT Wide bandwidth dual bipolar op amps DocID026366 Rev 1 13/18 18 Associated products AN4495 Table 1. Associated products (continued) 14/18 Part number General description TL061IDT JFET inputs, low input bias current TL062IDT JFET inputs, low input bias current TL062AIDT JFET inputs, low input bias current TL062BIDT JFET inputs, low input bias current TL071IDT JFET inputs, low input bias current TL072IDT JFET inputs, low input bias current TL072BIDT JFET inputs, low input bias current TL081IDT JFET inputs, low input bias current TL082IDT JFET inputs, low input bias current UA741IDT Wide applications range UA748IDT Wide applications range LM158IDT Low power dual op amps with low input bias current LM158WIDT Low power dual operational amplifiers LM2904IDT Low power, bipolar op amp LM2904AIDT Low power, bipolar op amp LM2904WIDT Low power dual operational amplifier LM833IDT Low-noise dual op amps amplifier LMV358IDT Low cost low power rail-to-rail input/output op amp LMV358LIDT Low-power, general-purpose operational amplifier op amp LMV822IDT Low power, high accuracy, general purpose operational amplifier LMV822AIDT Low power, high accuracy, general purpose operational amplifier LMX358IDT Low-power, general-purpose operational amplifier MC33172IDT Low consumption versus speed TJM4558IDT Wide bandwidth dual bipolar op amps TS1851IDT 1.8V min. voltage supply, micropower TS1852IDT 1.8V min. voltage supply, micropower TS1852AIDT 1.8V min. voltage supply, micropower TS1871IDT 1.8V input/output rail-to-rail low power operational amplifiers TS1872IDT 1.8V min. voltage supply, micropower TS1872AIDT 1.8V min. voltage supply, micropower TS271IDT Micropower, programmable op amp TS272IDT Micropower, wide range of input offset voltage TS27L2IDT Micropower, high voltage CMOS op amp TS27M2IDT Micropower, high voltage CMOS op amp TS27M2AIDT Micropower, high voltage CMOS op amp DocID026366 Rev 1 AN4495 Associated products Table 1. Associated products (continued) Part number General description TS27M2BIDT Micropower, high voltage CMOS op amp TS507IDT High precision single supply rail to rail op amp TS512IDT Precision op amps TS512AIDT Low noise & distortion (8nV/√Hz & 0.03%) TS522IDT Precision low-noise dual op amps TS912IDT Low power with CMOS inputs TS912AIDT Low power with CMOS inputs TS912BIDT Low power with CMOS inputs TS921IDT Rail-to-rail high output current op amps TS922IDT Excellent audio performance / low distortion (0.005%) TS9222IDT Precision rail-to-rail high output current op amps TS922AIDT Excellent audio performance / low distortion (0.005%) TS951IDT Real input & output rail to rail / low distortion (0.01%) TS952IDT Real input & output rail to rail / low distortion (0.01%) TS971IDT Output rail-to-rail very low-noise op amps TS972IDT Output rail-to-rail very low-noise op amps TSH22IDT High gain bandwidth product bipolar op amp TSV358IDT General purpose low voltage rail to rail input/output op amp TSV622IDT Micro-power CMOS op amp TSV622AIDT Micro-power CMOS op amp TSV6292IDT Micro-power CMOS op amp TSV6292AIDT Micro-power CMOS op amp TSV632IDT Micro-power CMOS op amp TSV632AIDT Micro-power CMOS op amp TSV6392IDT Micro-power CMOS op amp TSV6392AIDT Micro-power CMOS op amp TSV852IDT Low-power, high accuracy, general-purpose operational amplifier TSV852AIDT Low-power, high accuracy, general-purpose operational amplifier TSV911IDT Rail to rail input/output wide bandwidth op amps TSV911AIDT Rail to rail input/output wide bandwidth op amps TSV912IDT Rail to rail input/output wide bandwidth op amps TSV912AIDT Rail to rail input/output wide bandwidth op amps TSV991IDT Rail to rail input/output high merit factor op amps TSV991AIDT Rail to rail input/output high merit factor op amps TSV992IDT Rail to rail input/output high merit factor op amps DocID026366 Rev 1 15/18 18 Associated products AN4495 Table 1. Associated products (continued) 16/18 Part number General description TSV992AIDT Rail to rail input/output high merit factor op amps TSX562IDT Micropower, wide bandwidth 16V CMOS op amps TSX562AIDT Micropower, wide bandwidth 16V CMOS op amps TSX922IDT 10MHz, rail-to-rail 16V CMOS op amps TSX9292IDT 16MHz, rail-to-rail 16V CMOS op amps TSZ122IDT Very high accuracy (5 µV) zero drift micropower 5 V LM2904WHIDT Dual general purpose operational amplifier TSV912HIDT High temperature rail to rail input/output wide bandwidth op amps DocID026366 Rev 1 AN4495 5 Revision history Revision history Table 2. Document revision history Date Revision 03-Sep-2014 1 Changes Initial release. DocID026366 Rev 1 17/18 18 AN4495 IMPORTANT NOTICE – PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgement. Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers’ products. No license, express or implied, to any intellectual property right is granted by ST herein. Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners. Information in this document supersedes and replaces information previously supplied in any prior versions of this document. © 2014 STMicroelectronics – All rights reserved 18/18 DocID026366 Rev 1