Application Note 1835 Author: Dan Goodhew ISL21060EVAL1Z User’s Guide Introduction ISL21060EVAL1Z Board The ISL21060EVAL1Z evaluation board is designed to measure the performance of the low power, high precision ISL21060 voltage reference. The reference comes in output voltages ranging from 2.048V to 4.096V, and an initial accuracy of ±1mV to ±2.5mV. With a maximum temperature coefficient of 10ppm/°C (grade B) and 10µVP-P noise from 0.1Hz to 10Hz, the ISL21060 is ideal for high end equipment, but is also good for low power applications thanks to a typical supply current of 14µA and a shutdown current of 0.4µA typical. The schematic of the evaluation board is shown in Figure 5. The ISL21060EVAL1Z contains the ISL21060 voltage reference (U1), input decoupling capacitors (C1, C2), and a load capacitor on each output line (C3,C4). The enable pin is pulled high by R1 and can be controlled with the EN test point. The evaluation board includes voltage input test points (VIN and GND) for a power supply input, as well as three test points for the output (VOUTF, VOUTS, 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 • ISL21060 Datasheet, FN6706 TABLE 1. ORDERING INFORMATION When measuring the output voltage, VOUTF and VOUTS must connect in order to provide the correct voltage. Connect these two lines as close to the load as possible for the most accurate results. The R-C damper network can be populated by adding a 10µF ceramic capacitor to C5 and a 2.21kΩ resistor to R3. Connect the network 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. TABLE 2. COMPONENTS PARTS LIST DEVICE # VALUE DESCRIPTION C1 10µF Bypass Capacitor C2 0.1µF Bypass Capacitor BOARD NUMBER OUTPUT VOLTAGE (V) TYPE C3 1000pF Load Capacitor ISL2106020EVAL1Z 2.048 Evaluation Board C4 1000pF Load Capacitor ISL2106025EVAL1Z 2.5 Evaluation Board C5 10µF Damper Capacitor ISL2106030EVAL1Z 3.0 Evaluation Board R1 10kΩ Enable Pull-up Resistor ISL2106033EVAL1Z 3.3 Evaluation Board R2 DNP Optional Load Resistor ISL2106041EVAL1Z 4.096 Evaluation Board R3 2.21kΩ U1 ISL21060 J1 Shunt Damper Resistor SOT-23 6-Pin Package Damper Jumper FIGURE 1. VOLTAGE REFERENCE EVALUATION BOARD April 4, 2013 AN1835.0 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas LLC 2013. All Rights Reserved 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 1835 Voltage Reference Evaluation Board Layout FIGURE 2. TOP COMPONENTS FIGURE 3. BOTTOM LAYER 1 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 AN1835.0 April 4, 2013 ISL21060EVAL1Z Schematic 3 RC 2.21kΩ C5 J1 U1 EN 1000pF 1 VOUTF 6 NC 2 5 GND VOUTS 4 3 EN VIN R1 10kΩ ISL21060 10µF VOUTF C4 VOUTS C2 0.1µF VIN C1 10µF GND1 GND FIGURE 5. ISL21060 SCHEMATIC C3 1000pF Application Note 1835 LOAD R2 R3 AN1835.0 April 4, 2013