ISL284xxEVAL1Z Evaluation Board User’s Guide Application Note July 23, 2007 Introduction AN1339.0 2 • ISL28476 Data Sheet, FN6301 R37 • ISL28478 Data Sheet, FN6339 • ISL28486 Data Sheet, FN6312 2 C4 D2 0 1 J1 R1 0 2 C3 1 VM Evaluation Board Key Features The schematic of each of the 4 op amps with the components supplied is shown in Figure 2. The circuit implements a differential input-amp with a closed loop gain of 10. The circuit can operate from a single 2.4VDC to +5VDC supply, or from dual supplies from ±1.2VDC to ±2.5VDC. The VREF pin can be connected to ground to establish a ground referenced input for split supply operation, or can be externally set to any reference level for single supply operation. External power connections are made through the V+, Vand GND connections on the evaluation board. For single RF + IN(A,B,C,D)RIN- IN- INRIN+ IN+ 1/4 ISL284xx 100kΩ VP 0Ω V+ 10kΩ IN+ VOUT(x) V- + VM 10kΩ 10kΩ RREF(A,B,C,D)+ VREF 0Ω VP Amplifier Configuration (Figure 2) Power Supplies (Figure 1) VCM 2 0.1UF FIGURE 1. POWER SUPPLY CIRCUIT The ISL284xxEVAL1Z is designed to enable the IC to operate from a single supply (+2.4VDC to +5VDC), or from split supplies (±1.2VDC to ±2/5V). The board is configured for 4 independent op amps connected for differential input with a closed loop gain of 10. A single external reference voltage (VREF) pin and provisions for a user-selectable voltage divider (filter is included). IN(A,B,C,D)+ 1 4.7UF 1 D1 1 • ISL28488 Data Sheet, FN6339 C1 2 R48 4.7UF 2 R44 1 1 C2 1 Reference Documents V+ 0 V- 1 The ISL284xx are quad operational amplifiers featuring low noise, low distortion, and rail-to-rail output drive capability. They are designed to operate with single and dual supplies from +5VDC (±2.5VDC) down to +2.4VDC (±1.2VDC). J3 The ISL284xxEVAL1Z evaluation board is a design platform containing all the circuitry needed to characterize critical performance parameters of the ISL28470 quad instrumentation amplifier using a variety of user defined test circuits. J2 supply operation, the V- and GND pins are tied together to the power supply negative terminal. For split supplies +V and V- terminals connect to their respective power supply terminals. De-coupling capacitors C1 and C2, connect to GND through R1 and R2, 0Ω resistors. Resistors R3 and R4 are 0Ω but can be changed by the user to provide additional power supply filtering, or to reduce the voltage rate-of-rise to less than ±1V/µs. Anti-reverse diodes D1 and D2 protect the circuit in the case of accidental polarity reversal. 0 ® 100kΩ 0Ω TO OTHER CHANNELS VREF GND 10kΩ FIGURE 2. BASIC AMPLIFIER CONFIGURATION 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2007. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Application Note 1339 User-selectable Options (Figure 3) J4 . Component pads are included to enable a variety of user-selectable circuits to be added to the amplifier inputs, the VREF input, and the amplifier feedback loops. A voltage divider and filter option can be added to establish a power supply-tracking common mode reference at the VREF input. The inverting and non-inverting inputs have additional resistor placements for adding input attenuation, or to establish input DC offsets through the VREF pin. RREF C5 4.7UF 2 R33 10K 1 0 R32 1 REF1 R14 IN(A,B,C,D)R6 R28 2 DNP DNP RINA2- RINA1+ RREFA+ R24 R5 C7 OPEN 100K RINA+ 2 R15 IN+A 0 DNP 4 3 10K 1 R21 1 2 5 C6 OPEN R11 R2 DNP 4 3 IN(A,B,C,D)+ J6 1 0 R20 1 2 5 IN-A RREFA- DNP J5 RINA- 10K RGA+ FIGURE 3. COMPONENT-SELECTABLE OPTIONS ISL284xxEVAL1Z Components Parts List DEVICE NUMBER DESCRIPTION C1, C2, C5 COMMENTS CAP-TANTALUM, SMD, D, 4.7µF, 50V, 10% LOW ESR, ROHS Power Supply Decoupling C3, C4 CAP, SMD, 0603, 0.1µF, 25V, 10%, X7R, ROHS Power Supply Decoupling C6-C25 CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS User selectable capacitors - not populated D1, D2 DIODE-RECTIFIER, SMD, SOD-123, 2P, 40V, 0.5A, ROHS Reverse Power Protection U1 (ISL28476EVAL1Z) ISL28476FAZ, IC-RAIL-TO-RAIL PRECISION OP AMP, 16P, QSOP, ROHS U1 (ISL28478EVAL1Z) ISL28478FAZ, IC-RAIL-TO-RAIL PRECISION OP AMP, 16P, QSOP, ROHS U1 (ISL28486EVAL1Z) ISL28486FAZ, IC-RAIL-TO-RAIL PRECISION OP AMP, 16P, QSOP, ROHS U1 (ISL28488EVAL1Z) ISL28488FAZ, IC-RAIL-TO-RAIL PRECISION OP AMP, 16P, QSOP, ROHS R2-R4, R11-R13, R20-R23, R25, RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER R26, R28, R30, R31, R34, R38, R42, R43, R46, R55-R58, R59-R62 User selectable resistors - not populated R6, R8, R10, R15, R17, R19, R36, RES, SMD, 0603, 0Ω, 1/16W,TF, ROHS R41, R51-R54, R63-R66 0Ω user selectable resistors R5, R7, R9, R14, R16, R18, R33, RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS R35, R40, R67-R70 RG gain resistors R24, R27, R29, R39, R45, R47, R49, R50 R1, R32, R37, R44, R48 2 RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS RF gain resistors RES, SMD, 0805, 0Ω, 1/8W, TF, ROHS 0Ω user selectable resistors AN1339.0 July 23, 2007 Application Note 1339 ISL28xxEVAL1Z Top View 3 AN1339.0 July 23, 2007 5 5 IN1+J10 C 5 IN- J9 IN1+ J8 B 5 J7 5 J6 IN- IN1+ A 5 4 4 1 2 1 2 1 R2 2 1 2 1 1 1 2 1 2 1 10K C7 R5 1 1 10K C9 R7 1 1 OPEN 10K C11 2 2 10K C8 2 2 1 2 2 0 R19 RINA+ OPEN 10K C10 2 1 IN+B 2 1 IN+C RGA+ 100K R29 RREFA+ DNP R31 RREFA- IN-C RGA+ 100K R27 RREFA+ DNP R30 IN-B RREFA- R18 RINA- 0 R17 RINA+ IN+A RGA+ 100K R16 RINA- OPEN 1 RINA1+ R9 1 1 0 R15 1 RREFA+ DNP R28 R24 2 2 RINA+ OPEN 2 RINA2- 0 R10 2 2 RINA1+ OPEN 1 2 RINA2- 0 R8 2 2 RINA1+ OPEN 1 1 2 RINA2- 0 R6 RREFAR20 J4 RREF REF1 D 5 5 IN-J11 IN1+J12 1 R32 R33 IN- J5 3 4 3 3 3 4 4 3 3 4 DNP DNP DNP 0 10K 10K C6 R13 R3 R4 R11 DNP DNP DNP DNP DNP R12 DNP R21 R22 R23 R25 R26 1 C5 2 IN-A 4 4 4.7UF 3 3 2 1 2 1 2 1 1 2 C4 V- 1 1 OPEN 10K C13 2 2 RINA1+ R35 C2 1 D2 1 0 R44 100K OPEN R39 C23 1 8 7 6 5 4 3 2 1 2 2 2 0 R41 RINA+ OPEN 10K C12 R40 RINA- OUTA IN-A IN+A VP IN+B IN-B OUTB 1 VM J2 2 IN+D 1 RGA+ 100K R45 RREFA+ DNP R46 D1 2 1 4.7UF C1 15 16 1 9 10 11 12 C3 2 0.1UF 9 10 OUTC 11 IN-C 12 IN+C 13 VM 14 IN+D 15 IN-D 16 OUTD 100K R47 OPEN C22 1 2 CLOSE TO PART 0 2 R1 U1 QSOP16 14 Generic 13 Pack. 1 IN-D RREFA- 8 7 6 5 4 3 2 1 CLOSE TO PART 2 4.7UF 1 2 J3 1 2 RINA2- 0 R36 0.1UF DNP 0 R38 R37 DNP DNP DNP DNP DNP DNP 1 0 VP V+ 1 1 2 100K R50 OPEN C25 100K R49 OPEN C24 2 0 R54 0 R53 0 R52 0 R51 OPEN R14 RINA- R42 R43 J1 1 R48 2 C14 1 2 C16 1 2 C18 1 2 C20 1 OPEN OPEN OPEN R55 1 C15 2 R56 1 C17 2 R57 1 C19 OPEN OPEN OPEN OPEN 2 R58 1 C21 2 2 DNP R59 1 2 DNP R60 1 0 R66 0 R65 0 R64 0 R63 R68 R69 DNP DNP DNP DNP 2 DNP R61 1 2 DNP R62 1 2 R67 1 2 R70 1 2 2 1 10K 2 1 10K 2 1 10K 1 2 1 2 1 3 3 4 3 3 4 4 4 4 10K 1 5 J16 5 J15 5 J14 5 J13 OUT OUT OUT OUT Application Note 1339 ISL284XXEVAL1Z Schematic Diagram Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com AN1339.0 July 23, 2007 R34