ISL282x6EVAL1Z Evaluation Board User’s Guide ® Application Note August 28, 2008 AN1420.0 Introduction J11 J6 V- R31 C2 C4 4.7µF C3 4.7µF C5 0.01µF • ISL28256 Data Sheet • ISL28266 Data Sheet Evaluation Board Key Features The ISL282x6EVAL1Z 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. Amplifier Configuration (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 Power Supplies (Figure 1) External power connections are made through the +V, -V, VREF and Ground connections on the evaluation board. RF VP RIN- IN- IN- V+ 10kΩ RIN+ VREF ISL282x6 (1/2) 100kΩ IN - VREF 0.01µF User selectable SMA edge connectors are also provided for +V and -V. 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 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, or to reduce the voltage rate-of-rise to less than ±1V/µs. Two additional capacitors, C3 and C5 are connected close to the part to filter out high frequency noise. Anti-reverse diode D1 protects the circuit in the case of accidental polarity reversal. • ISL28246 Data Sheet VCM J14 FIGURE 1. POWER SUPPLY CIRCUIT • ISL28236 Data Sheet IN + J13 D1 Reference Documents IN+ J12 0 R16 The ISL28236 and ISL28246 high-speed operational amplifiers feature low power consumption, while ISL28256 and ISL28266 operational amplifiers feature ultra-low power consumption. All op amps have rail-to-rail output drive capability and are designed to operate with a single lithium cell or two Ni_Cd batteries. VREF V+ J8 0 The ISL282x6EVAL1Z evaluation board is a design platform containing all the circuitry needed to characterize critical performance parameters of the ISL282x6 operational amplifiers in both MSOP-8 and SOIC-8 packages, using a variety of user defined test circuits. IN+ 0Ω VOUT V- + VM 10kΩ RREF+ RL 100kΩ 10kΩ GND 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. 2008. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Application Note 1420 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. The outputs (see Figure 4) have a 10kΩ load resistor to ground and have additional resistor and capacitor placements for loading. User-selectable Options (Figures 3 and 4) 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. 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 (Figure 3) have additional resistor and capacitor, and jumper placements for loading and/or measurement of frequency sensitive parameters. OUT R13 10k 100k C1 OPEN R14 R2 10k DNP R15 R18 DNP 100k C6 OPEN R26 TO OUTPUT TO INTO IN+ 0 VREF FIGURE 3. INPUT STAGE (1/2) 2 FROM OUTPUT 10k R11 OPEN R28 R12 DNP R17 R10 DNP DNP NODE C8 DNP R6 J2 R3 DNP 0 R5 R1 DNP J1 R4 DNP IN+ IN- FIGURE 4. OUTPUT STAGE (1/2) AN1420.0 August 28, 2008 Application Note 1420 ISL282x6EVAL1Z Components Parts List DEVICE # DESCRIPTION COMMENTS C2, C4 CAP-TANTALUM, SMD, D, 4.7µF, 50V, 10%, LOW ESR, ROHS Power supply decoupling C3, C5 CAP, SMD, 0603, 0.1µF, 25V, 10%, X7R, ROHS Power supply decoupling C1, C6 thru C10 CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS User-selectable capacitors - not populated D1 DIODE-SCHOTTKY BARRIER, SMD, SOT-23, 3P, 40V, ROHS Reverse power protection U1 (ISL28236FUZ) IC-5 MHz RRIO OP AMP, 8P, MSOP, ROHS U1 (ISL28236FBZ) IC-5 MHz RRIO OP AMP, 8P, SOIC, ROHS U1 (ISL28246FUZ) IC-5 MHz RRIO OP AMP, 8P, MSOP, ROHS U1 (ISL28246FBZ) IC-5 MHz RRIO OP AMP, 8P, SOIC, ROHS U1 (ISL28256FUZ) IC-39µA RRIO OP AMP, 8P, MSOP, ROHS U1 (ISL28256FBZ) IC-39µA RRIO OP AMP, 8P, SOIC, ROHS U1 (ISL28266FUZ) IC-39µA RRIO OP AMP, 8P, MSOP, ROHS U1 (ISL28266FBZ) IC-39µA RRIO OP AMP, 8P, SOIC, ROHS R30, R32, R34 thru R36 RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER User selectable resistors - not populated R4, R16, R25 thru R27, R31 RES, SMD, 0603, 0Ω, 1/10W,TF, ROHS 0Ω user selectable resistors R11, R14, R21, R24, R28, R29 RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS Gain and other user selectable resistors R13, R18, R19, R23 Gain resistors RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS 3 AN1420.0 August 28, 2008 Application Note 1420 FIGURE 5. ISL282x6EVAL1Z TOP VIEW (SOIC SHOWN) 4 AN1420.0 August 28, 2008 Application Note 1420 J16 J15 ISL282x6EVAL1Z Schematic Diagram 10k C7 0 OPEN R27 0 C8 C9 OPEN R26 OPEN R28 OPEN R29 C6 10k DNP DNP R22 DNP R19 R18 100k R15 R13 100K C1 1 OPEN 2 R14 3 10K 4 R11 10k R4 0 VREF 1 8 U1 2 7 SOIC8 6 3 MSOP8 5 4 DNP 100k 8 7 OPEN 6 5 R21 10k R24 10K R23 100k C10 R34 DNP OUTB NODEB IN+B IN-B 0.01µF C4 4.7µF C5 V+ R32 DNP R12 R10 DNP 0.01µF DNP R6 R5 IN-A IN+A NODEA OUTA DNP DNP C2 D1 R17 4.7µF C3 2 1 DNP 0 R16 V- R30 J6 DNP 0 R31 J8 R35 3 DNP J11 R25 J12 0 R20 J13 DNP R36 VREF J14 DNP R8 J4 R7 DNP J3 DNP DNP R2 J2 J1 R1 R3 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 5 AN1420.0 August 28, 2008