Application Note 1542 ISL28213/14MSOPEVAL2Z Evaluation Board User’s Guide RF 100k IN - GND ISL28213, ISL28214 (1/2) VP V+ 10k VREF (Figure 2) The schematic of 1/2 of the op-amp 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 supply or from dual supplies. The VREF pin must be connected to ground to establish a ground referenced input for dual supply operation, or can be externally set to any reference level for single supply operation. VREF should not be left floating. (Figure 1) IN+ + 0Ω VOUT VVM 10k RREF+ 0Ω 0 Amplifier Configuration External power connections are made through the +V, -V, VREF and 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 supplies, +V and -V terminals connect to their VREF R31 0 R16 The ISL28213/14MSOPEVAL2Z is designed to enable the IC to operate from a single supply, +2.4VDC to +5.5VDC or from split supplies, ±1.2VDC to ±2.75V. The board is configured for a dual op amp 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 are included. IN + J14 Evaluation Board Key Features IN+ J13 • ISL28214 Data Sheet, FN6800 RIN+ 0.01µF respective power supply terminals. De-coupling capacitors C2 and C4 connect to their respective supplies through R16 and R31 0Ω resistors. These resistors are 0Ω, but can be changed by the user to provide additional power supply filtering. Two additional capacitors, C3 and C5, are connected close to the DUT to filter out high frequency noise. Anti-reverse diode D1 protects the circuit in the case of accidental polarity reversal. • ISL28213 Data Sheet, FN6728 IN- TO DUT C5 FIGURE 1. POWER SUPPLY CIRCUIT • ISL28213/14MSOPEVAL2Z Evaluation Board User’s Guide IN- VREF D1 0.01µF RIN- C4 1µF CLOSE C3 Reference Documents Power Supplies C2 1µF J12 The ISL28213 and ISL28214 CMOS operational amplifiers feature low power consumption, low input bias current, and rail-to-rail input and output drive capability. They are designed to operate with a single lithium cell or two Ni_Cd batteries. V+ J8 V- The ISL28213/14MSOPEVAL2Z evaluation board is a design platform containing all the circuitry needed to characterize critical performance parameters of the ISL28213 and ISL28214 operational amplifiers, using a variety of user defined test circuits. VCM J11 J6 Introduction 100k RL 10k 10k FIGURE 2. BASIC AMPLIFIER CONFIGURATION February 18, 2010 AN1542.0 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. 2010. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Application Note 1542 User-Selectable Options (Figures 3 and 4) Component pads are included to enable a variety of user-selectable circuits to be added to the amplifier VREF, inputs, outputs, and the amplifier feedback loops. The inputs (see Figure 3) have additional resistor, capacitor, and jumper placements for loading and/or measurement of frequency sensitive parameters. J2 R2 R5 R3 DNP OUT R11 R13 10k 100k C1 OPEN R14 10k DNP FROM OUTPUT VREF R15 R18 DNP 100k C6 OPEN R26 0 10k DNP DNP R12 DNP R17 R10 OPEN R28 0 NODE 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 with the output. C8 R1 DNP DNP R4 J1 DNP IN+ R6 IN- The outputs (see Figure 4) have a 10kΩ load resistor to ground and have additional resistor and capacitor placements for loading. TO OUTPUT TO INTO IN+ FIGURE 3. INPUT STAGE (1/2) FIGURE 4. OUTPUT STAGE (1/2) ISL28213/14MSOPEVAL2Z Components Parts List DEVICE # DESCRIPTION COMMENTS C2, C4 CAP-TANTALUM, SMD, 1.0µF, 50V, 10%, LOW ESR, ROHS Power Supply Decoupling C3, C5 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-SCHOTTKY BARRIER, SMD, SOT-23, 3P, 40V, ROHS Reverse Power Protection C1, C6-C10 D1 U1 (ISL28213FUZ) ISL28213FUZ-T7, IC-RAIL-TO-RAIL OP AMP, MSOP, ROHS U1 (ISL28214FUZ) ISL28214FUZ-T7, IC-RAIL-TO-RAIL OP AMP, MSOP, ROHS R30, R32, R34-R36 RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER 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 R4, R16, R25-R27, R31 R11, R14, R21, R24, R28, R29 R13, R18, R19, R23 2 AN1542.0 February 18, 2010 Application Note 1542 ISL28213/14MSOPEVAL2Z FIGURE 5. ISL28213/14MSOPEVAL2Z EVALUATION BOARD 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 AN1542.0 February 18, 2010 ISL28213/14MSOPEVAL2Z Schematic Diagram J11 R31 0 R16 IN+ IN- J14 C4 1µF J13 4 C2 1µF VREF J12 J8 V+ 0 J6 V- D1 R30 4 5 R21 10k 0 VREF R15 R18 R19 R22 DNP 100k 100k DNP R7 DNP J4 J24 C7 OPEN R27 R8 DNP AN1542.0 February 18, 2010 FIGURE 6. DNP C8 OPEN R28 J16 DNP 10k OPEN C9 OPEN R14 U1 8 2 MSOP8 7 GENERIC 3 PACK. 6 1 J15 0 DNP 10k 100k C1 DNP R36 R24 R13 10k R35 R23 100k C10 R11 OPEN R26 DNP DNP 0 R20 R34 DNP DNP R32 DNP DNP R12 DNP R17 R10 DNP J3 J23 NODE J21 J20 J19 OUT R25 R5 C6 OUT OPEN R29 R2 DNP R6 J2 R3 DNP 0 DNP R4 R1 DNP J1 NODE J18 IN+ J17 IN- 0.01µF J22 0.01µF Application Note 1542 CLOSE TO DUT C3 C5