Application Note 1352 ISL28194EVAL1Z, ISL28195EVAL1Z Evaluation Board User’s Guide Introduction • ISL28194EVAL1Z Reference Documents C4 • ISL28194, ISL28195 Data Sheet, FN6236 J1 R21 R1 C1 + 4.7µF 0 0 + 4.7µF D2 D1 V+ C3 0.1µF 0.1µF Evaluation Board Key Features VM The ISL28194EVAL1Z, ISL28195EVAL1Z is designed to enable the IC to operate from a single supply, +1.8VDC to +5.5VDC or from split supplies, ±0.9VDC to ±2.75V. The board is configured for a single op amp connected for differential input with a closed loop gain of 10. It also contains a single external reference voltage (VREF) pin and provisions for a user-selectable voltage divider (filter are included). Power Supplies R20 • ISL28195EVAL1Z C2 0 V- R24 Ordering Information J2 The ISL28194 and ISL28195 micro-power operational amplifiers feature ultra-low power consumption, rail-to-rail input and output drive capability, and are designed to operate with two 1.5V Alkaline batteries. 0 The ISL28194EVAL1Z, ISL28195EVAL1Z evaluation board is a design platform containing all the circuitry needed to characterize critical performance parameters of the ISL28194 and ISL28195 operational amplifiers, using a variety of user defined test circuits. J3 supplies V+ and V- terminals connect to their respective power supply terminals. De-coupling capacitors C1 and C2 connect to ground through R1 and R21 0Ω resistors. Resistors R20 and R24 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. Two additional capacitors, C3 and C4 are connected close to the part to filter out high frequency noise. Anti-reverse diodes D1 and D2 protect the circuit in the case of accidental polarity reversal. VP FIGURE 1. POWER SUPPLY CIRCUIT Amplifier Configuration (Figure 2) The schematic of the op amp with the components supplied is shown in Figure 2. (Figure 1) External power connections are made through the V+, Vand Ground connections on the evaluation board. For single supply operation, the V- and Ground pins are tied together to the power supply negative terminal. For split RF 10MΩ IN RIN- IN- IN- IN+ V+ IN+ VCM 0Ω VOUT V+ VM 1MΩ IN+ VP - 1MΩ RIN+ ISL28194, ISL28195 RREF+ VREF VREF GND 0Ω 10MΩ 10kΩ FIGURE 2. BASIC AMPLIFIER CONFIGURATION May 26, 2010 AN1352.1 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, 2010. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Application Note 1352 User-Selectable Options 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. (Figures 3 and 4) Component pads are included to enable a variety of user-selectable circuits to be added to the amplifier inputs, the VREF input, outputs and the amplifier feedback loops. The output (Figure 4) has additional resistor and capacitor placements for loading. J4 A voltage divider and filter option (Figure 3) can be added to establish a power supply-tracking common J5 OUT DNP R27 DNP R25 0 DNP 0 OPEN R26 R23 C8 TO IN+ OPEN R22 C9 + 4.7µF TO OUT TO IN- C10 DNP DNP RINA2+ 100M R13 0 6 DNP DNP R3 RINA+ R11 10M OPEN R IN2+ J8 RREFA+ R14 R9 C7 RREF OPEN RINA1+ R7 IN1+ J7 0 DNP 10k C5 OPEN DNP RREFAR15 R12 DNP DNP R2 1M RINA2- R8 R5 IN- J6 0 C6 R17 RINAR10 R18 REF1 RGA+ FIGURE 4. OUTPUT STAGE FIGURE 3. INPUT STAGE ISL28194EVAL1Z, ISL28195EVAL1Z Components Parts List DEVICE NUMBER C1, C2, C5 C3, C4 C6 to C10 D1, D2 DESCRIPTION CAP-TANTALUM, SMD, D, 4.7µF, 50V, 10%, LOW ESR, ROHS Power supply decoupling CAP, SMD, 0603, 0.1µF, 25V, 10%, X7R, ROHS Power supply decoupling CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS User-selectable capacitors - not populated DIODE-RECTIFIER, SMD, SOD-123, 2P, 40V, 0.5A, ROHS Reverse power protection U1 (ISL28194EVAL1Z) ISL28194FHZ-T7, IC-RAIL-TO-RAIL OP AMP, SOT-23, ROHS U1 (ISL28195EVAL1Z) ISL28195FHZ-T7, IC-RAIL-TO-RAIL OP AMP, SOT-23, ROHS R2, R3, R6, R8, R9, R12, RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER R13, R15, R23, R25, R27 R1, R5, R11, R17, R20, R21, R22, R24, R26 R4, R18 R16 R7, R10 R14, R19 COMMENTS User-selectable resistors - not populated RES, SMD, 0603, 0Ω, 1/10W, TF, ROHS 0Ω user-selectable resistors RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS Gain and other user-selectable resistors RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS Gain resistors RES, SMD, 0603, 1M, 1/10W, 1%, TF, ROHS Gain and other user-selectable resistors RES, SMD, 0603, 10M, 1/10W, 1%, TF, ROHS Gain resistors 2 AN1352.1 May 26, 2010 Application Note 1352 ISL28194EVAL1Z, ISL28195EVAL1Z Top View 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 3 AN1352.1 May 26, 2010 C2 R1 0 0 C1 + D1 4.7µF RREFA+ R14 EN DNP 100k J9 R4 10k 2 S1 3ENABLE 1 DISABLE VP R16 VM 2 3 3 4 SOT23_6 VP 5 4 DNP 6 0 J5 R27 1 6 GENERIC 2 PACK 5 0 DNP 1 R26 R25 U1 R22 DNP R13 RGA+ OPEN 10M R23 OPEN C9 R19 DNP R9 R3 DNP RINA2+ C10 OPEN 0 R6 DNP IN2+ C8 OPEN J8 10M RINA+ R11 DNP 1M C7 0 R24 R20 0 VP OUT Application Note 1352 RINA1+ R7 J7 CLOSE TO PART 0.1µF VM IN1+ C3 0.1µF + 4.7µF R12 CLOSE TO PART 10k C5 DNP 0 R17 OPEN V+ RREF C4 R18 RREFAR15 DNP R8 R2 DNP 0 RINA2- 1M C6 DNP 4 IN- R5 J6 R21 + 4.7µF D2 RINAR10 J1 J2 V- REF1 J3 J4 ISL28194EVAL1Z, ISL28195EVAL1Z Schematic Diagram AN1352.1 May 26, 2010