Application Note 1761 Author: Dan Goodhew ISL21080XXEV1Z User’s Guide Introduction TABLE 1. ORDERING INFORMATION (Continued) The ISL21080XXEV1Z evaluation board is designed to measure the performance of the nano power ISL21080 voltage reference. The reference comes in a wide selection of output voltages ranging from 0.9V to 5.0V, and an initial accuracy as low as 0.2% (3.0V to 5.0V options). With a typical supply current of 500nA or less, the ISL21080 is ideal for extending battery life while reducing cost for general purpose portable applications. The evaluation board includes voltage input test points (VIN and GND) for a power supply input, as well as a pair of test points for the output (VOUT and GND). Additionally, a jumperable R-C damper network can connect to VOUT (J1), and R2 accepts surface mount or through-hole style resistors for output load testing. Reference Documents BOARD NUMBER OUTPUT VOLTAGE (V) TYPE ISL2108030EV1Z 3.0 Evaluation Board ISL2108033EV1Z 3.3 Evaluation Board ISL2108040EV1Z 4.096 Evaluation Board ISL2108050EV1Z 5.0 Evaluation Board ISL21080XXEV1Z Board The schematic of the evaluation board is shown in Figure 5. The ISL21080XXEV1Z contains the ISL21080 voltage reference (U1), input decoupling capacitors (C1, C2), and a load capacitor (C3). The power supply leads attach to TP1 and TP2 (VIN, GND). The output is measured at test points TP3 and TP4 (VOUT, GND). The R-C damper network is populated and can be connected to the reference output by adding a shunt to the R-C jumper (J1). The damper network improves stability by reducing transient load ringing with high value (>0.47µF) capacitors. • ISL21080 Datasheet, FN6934 TABLE 1. ORDERING INFORMATION TABLE 2. COMPONENTS PARTS LIST BOARD NUMBER OUTPUT VOLTAGE (V) TYPE ISL2108009EV1Z 0.9 Evaluation Board ISL2108010EV1Z 1.024 Evaluation Board ISL2108012EV1Z 1.25 Evaluation Board ISL2108015EV1Z 1.5 Evaluation Board ISL2108020EV1Z 2.048 Evaluation Board ISL2108025EV1Z 2.5 Evaluation Board DEVICE # VALUE DESCRIPTION C1 10µF Bypass Capacitor C2 0.01µF Bypass Capacitor C3 0.01µF Load Capacitor C4 10µF Damper Capacitor R1 2.21kΩ Damper Resistor R2 DNP Optional Load Resistor U1 ISL21080 SOT-23 3-Pin Package FIGURE 1. VOLTAGE REFERENCE EVALUATION BOARD June 8, 2012 AN1761.0 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Copyright Intersil Americas Inc. 2012. All Rights Reserved. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. Application Note 1761 Voltage Reference Evaluation Board Layout FIGURE 2. TOP COMPONENTS FIGURE 3. BOTTOM LAYER FIGURE 4. ASSEMBLY DRAWING 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 2 AN1761.0 June 8, 2012 ISL21080XXEV1Z Schematic *1' 9287 9,1 *1' & & 73 5 5& & 3 3 FIGURE 5. SCHEMATIC 8) & '13 /2$' % 5 % . 8 8) & - Application Note 1761 & 8) 73 8) 3 73 73 AN1761.0 June 8, 2012