USERS MANUAL ISL282X7SOICEVAL2Z AN1509 Rev 0.00 Evaluation Board November 6, 2009 These resistors are 0 but can be changed by the user Introduction to provide additional power supply filtering, or to reduce The ISL282X7SOICEVAL2Z evaluation board is a the voltage rate-of-rise to less than 1V/s. Two design platform containing all the circuitry needed to additional capacitors, C3 and C5 are connected close to characterize critical performance parameters of the the part to filter out high frequency noise. Anti-reverse ISL282X7 operational amplifiers in SOIC-8 package, diode D1 protects the circuit in the case of accidental using a variety of user defined test circuits. polarity reversal. The ISL282X7 operational amplifiers feature low bias J11 J6 V- V+ VREF current, low noise, and low offset and temperature J12 J8 J13 J14 drift. Reference Documents ISL28207 Data Sheet, FN6631 C2 C4 1F 1F ISL28217 Data Sheet, FN6632 ISL28227 Data Sheet, FN6633 D1 Evaluation Board Key Features C3 C5 The ISL282X7SOICEVAL2Z is designed to enable the 0.01F 0.01F IC to operate from a single supply, +4.5VDC to FIGURE 1. POWER SUPPLY CIRCUIT +40VDC or from split supplies, 2.25VDC to 20V. The board is configured for a dual op amp connected for differential input with a closed loop gain of 10. A Amplifier Configuration single external reference voltage (VREF) pin and provisions for a user-selectable voltage divider - filter (Figure 2) are included. The schematic of 1/2 of the op-amp with the components supplied is shown in Figure 2. The circuit implements a Power Supplies (Figure 1) differential input amp with a closed loop gain of 10. The External power connections are made through the +V, - circuit can operate from a single supply or from dual V, VREF and Ground connections on the evaluation supplies. The VREF pin must be connected to ground to board. For single supply operation, the -V and Ground establish a ground referenced input for dual supply pins are tied together to the power supply negative operation, or can be externally set to any reference level terminal. For split supplies, +V and -V terminals connect for single supply operation. VREF should not be left to their respective power supply terminals. De-coupling floating. capacitors C2 and C4 connect to their respective supplies through R16 and R31 zero-ohm resistors. RF ISL282X7 (1/2) 100k IN - VP RIN- IN- - IN- 0 V+ 10k VOUT V- RIN+ IN+ + IN+ 10k VM IN + RL VCM RREF+ VREF 100k DNP VREF GND FIGURE 2. BASIC AMPLIFIER CONFIGURATION AN1509 Rev 0.00 Page 1 of 5 November 6, 2009 R16 0 R31 0ISL282X7SOICEVAL2Z The outputs (Figure 4) have additional resistor and User-selectable Options capacitor placements for loading. (Figures 3 and 4) NOTE: Operational amplifiers are sensitive to output Component pads are included to enable a variety of capacitance and may oscillate. In the event of user-selectable circuits to be added to the amplifier oscillation, reduce output capacitance by using shorter VREF, inputs, outputs, and the amplifier feedback cables, or add a resistor in series with the output. loops. The Inputs (Figure 3) have additional resistor and capacitor, and jumper placements for loading and/or measurement of frequency sensitive parameters. IN- IN+ NODE OUT R10 R12 DNP DNP J1 R4 R11 R13 R1 0 10k 100k C1 DNP To Output C6 From Output OPEN To IN- J2 R14 OPEN To IN+ R2 R26 VREF 10k DNP 0 R15 R18 DNP 100k FIGURE 4. OUTPUT STAGE (1/2) FIGURE 3. INPUT STAGE (1/2) TABLE 1. ISL282X7SOICEVAL2Z COMPONENTS PARTS LIST DEVICE DESCRIPTION COMMENTS C2, C4 CAP, SMD, 0805, 1F, 50V, 10%, X7R, ROHS Power Supply Decoupling C3, C5 CAP, SMD, 0603, 0.01F, 50V, 10%, X7R, ROHS Power Supply Decoupling C1, C6-C10 CAP, SMD, 0603, DNP-PLACE HOLDER, ROHS User selectable capacitors - not populated D1 DIODE-RECTIFIER, SMD, SOD-123, 2P, 40V, 0.5A, ROHS Reverse Power Protection U1 (ISL28207FBZ) OP AMP, SOIC, ROHS U1 (ISL28217FBZ) OP AMP, SOIC, ROHS U1 (ISL28227FBZ) OP AMP, SOIC, ROHS R1-R3, R5-R8, R10, R12, RESISTOR, SMD, 0603, 0.1%, MF, DNP-PLACE HOLDER User selectable resistors - not populated R15, R17, R20,R22, R28-R30, R32, R34-R36 R5, R18 RES, SMD, 0603, 0, 1/10W,TF, ROHS Zero ohm user selectable resistors R11, R14, R21, R24 RES, SMD, 0603, 10k, 1/10W, 1%, TF, ROHS Gain resistors R13, R18, R19, R23 RES, SMD, 0603, 100k, 1/10W, 1%, TF, ROHS Gain resistors AN1509 Rev 0.00 Page 2 of 5 November 6, 2009 R3 DNP R5 R6 DNP DNP R17 DNP C8 OPEN R28 DNP