DAC8541EVM User’s Guide August 2002 Data Acquisition SLAU085A
IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.
EVM IMPORTANT NOTICE Texas Instruments (TI) provides the enclosed product(s) under the following conditions: This evaluation kit being sold by TI is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not considered by TI to be fit for commercial use.
EVM WARNINGS AND RESTRICTIONS It is important to operate this EVM within the specified input and output ranges described in the EVM User’s Guide. Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM. If there are questions concerning the input range, please contact a TI field representative prior to connecting the input power.
Information About Cautions and Warnings Preface Read This First About This Manual This user’s guide describes the characteristics, operation, and the use of the DAC8541 evaluation module. It covers all pertinent areas involved to properly use this EVM board along with the devices that it supports. The physical PCB layout, schematic diagram and circuit descriptions are included.
Trademarks The information in a caution or a warning is provided for your protection. Please read each caution and warning carefully. Related Documentation From Texas Instruments To obtain a copy of any of the following TI documents, call the Texas Instruments Literature Response Center at (800) 477- 8924 or the Product Information Center (PIC) at (972) 644 - 5580. When ordering, identify this manual by its title and literature number. Updated documents can also be obtained through our website at www.ti.
Contents Contents 1 EVM Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2.1 Supply Voltage . . . . . . . . . . . . . . . . . . . . .
Contents Figures 1 - 1. 2 - 1. 2 - 2. 2 - 3. 3 - 1. 3 - 2. EVM Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Layer One (Top Silkscreen) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Layer Two (Bottom Layer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Drill Drawing . . . . . . . . . . . . . . . . . .
Chapter 1 EVM Overview This chapter gives a general overview of the DAC8541EVM and describes some of the factors that must be considered in using this module. Topic Page 1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 1.2 Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 1.3 EVM Basic Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features 1.1 Features This EVM features the DAC8541 digital-to-analog converter. The DAC8541EVM is a simple evaluation module designed for a quick and easy way to evaluate the functionality of the high resolution, single-channel, parallel input DAC. This EVM features a parallel interface to communicate to any host processor base system. 1.2 Power Requirements The following sections describe the power requirements of this EVM. 1.2.
EVM Basic Functions Caution When applying an external voltage reference through TP2 or J4-20, make sure that it does not exceed 5 V maximum. Otherwise, this damages U1 part, DUT. 1.3 EVM Basic Functions The DAC8541EVM is a functional evaluation platform to test certain functional characteristics of the DAC8541 digital-to-analog converter. Functional evaluation of the DAC device can be accomplished with the use of any microprocessor, DSP, or some sort of a waveform generator.
EVM Basic Functions Figure 1 - 1. DAC8541EVM Block Diagram 15 V - 15 V VCC DAC Out (J1) W5 (J6) (J7) DVCC W6 Output Buffer Module 15 V GND - 15 V GND VCC DVDD Reference Module TP2 W6 VREF Ext. Ref. Input (J6) (J7) DAC Module PD0 PD1 LDAC RST RSTSEL BTC/USB CS R/W DB15 (MSB) W1 (J1) DB1 (LSB) TP1 - VREF Ext. Ref.
Chapter 2 Physical Description This chapter describes the physical characteristics and PCB layout of the EVM and lists the components used on the module. Topic Page 2.1 PCB Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 2.2 Bill of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PCB Layout 2.1 PCB Layout The DAC8541EVM is constructed on two-layer printed-circuit board using a copper-clad FR-4 laminate material. The printed-circuit board has a dimension of 99,06 mm (3.90 inch) × 104, 14 mm (4.10 inch), and the board thickness is 1,57 mm (0.062 inch). Figures 2 - 2 through 2 - 4 show the individual artwork layers. Figure 2 - 1.
PCB Layout Figure 2 - 2.
PCB Layout Figure 2 - 3.
Bill of Materials 2.2 Bill of Materials Table 2 - 1. Parts Lists Item # Qty Designator Manufacturer Part Number Description 1 2 1 R2 Panasonic ERJ-8GEY0R00V 0 Ω, 1/4 W, 1206 chip resistor 2 C8, C9 Panasonic ECUV1H103KBM 0.01 µF, 1206 multilayer ceramic capacitor 3 4 C4, C5, C6, C7 Panasonic ECJ3VB1C104K 0.01 µF, 1206 multilayer ceramic capacitor 4 1 C11 Panasonic ECUV1H102JCH 1 nF, 1206 multilayer ceramic capacitor 5 3 W6, W7, W8 Samtec TSW-102-07-L-S 2 position jumper_0.
2-6
Chapter 3 EVM Operation This chapter covers the operation of the DAC8541EVM and provides guidance to the user in evaluating the onboard DAC and interfacing the EVM to a specific host processor. For information about its parallel interface and other related topics, refer to the DAC8541 data sheet, TI literature number SLAS353. The EVM board is factory-tested and configured to operate in the bipolar output mode. Topic Page 3.1 Factory Default Setting . . . . . . . . . . . . . . . . . . . . . . . . . . .
Factory Default Setting 3.1 Factory Default Setting The EVM board is set as default from the factory to the configuration below to operate in bipolar mode through U2. Table 3 - 1. Factory Default Jumper Setting Reference Jumper Position Function W1 1-2 VREF(L) tied to AGND W2 1-2 Adjustable onboard VREF(H) is supplied by U3. W3 1-2 Negative supply rail of U2 is tied to - 15 V. W4 1-2 Positive supply rail of U2 is tied to 15 V.
Host Processor Operation Table 3 - 2. Unity Gain Output Jumper Settings Reference Jumper Position Function W3 2-3 Negative rail of the op amp tied to analog GND W4 Don’t care Positive rail of the op amp can be supplied by 15 V or VCC W5 3-4 Buffered output of DAC is channeled to the output terminals W6 Open Disconnect VREF(H) from negative input of op amp W7 Open Disconnect negative input of op amp from GND 3.2.
Host Processor Operation Table 3 - 4. Capacitive Load Drive Output Jumper Settings Reference Jumper Position Function W3 2-3 Negative rail of the op amp tied to analog GND W4 1-2 Positive rail supply of the op amp tied to 15 V W5 3-4 Capacitive load drive output of DAC is channeled to the output terminals W6 Open Disconnect VREF(H) from negative input of op amp Open Disconnect R8 (see Note) W7 Note: 3.2.
Host Processor Operation 0000h corresponding to a - 5 V output and FFFFh corresponding to a 5 V output when BTC/USB = 0. If BTC/USB = 1, 8000h corresponds to - 5 V output and 7FFFh corresponds to 5 V output. Bipolar zero is given by the code 0000h applied to the DAC. Figure 3 - 2. DAC8541 Bipolar Output of Operation DAC8541 Output Bipolar Output Similarly, adjusting the VREF(H) voltage to any desired value less than 5 V produces a voltage output range of ±VREF(H).
Jumper Setting Reference 3.3 Jumper Setting Reference The illustrations in Table 3 - 6 shows the function of each jumper on the DAC8541EVM. Table 3 - 6.
Schematic Diagram 3.4 Schematic Diagram This section contains the schematic diagram for the DAC8541EVM.
1 2 3 4 5 6 Revision History REV J1 D 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 J2 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 31 29 27 25 23 21 19 17 15 13 11 9 7 5 3 1 PD0 PD1 LDAC RST RSTSEL BTC/USB U1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Male Header (TSM Series) DVdd DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 18 RST RSTSEL BTC/USB PWRDWN0 PWRDWN1 VOUT VOUT_S AVdd DVdd 21 C1 10µF CS R/W LD
