19-1646; Rev 0; 2/00 MAX1294 Evaluation Kit Features The MAX1294 evaluation kit (EV kit) is assembled with a MAX1294 and the basic components necessary to evaluate the 12-bit analog-to-digital converter (ADC). Connectors for power supplies, analog inputs, and digital signals simplify connections to the device. A 40-pin header allows the user to connect a logic analyzer using a ribbon cable or the conventional miniclips. BNC connectors with 50Ω termination provide easy connection between function generators and the analog inputs. ♦ 12-Bit Analog-to-Digital Conversion The board layout is designed to yield 12-bit accuracy with low noise when sampling at the maximum rate of 420ksps. The MAX1294 EV kit may also be used to evaluate the MAX1295. Request a free sample of the MAX1295BCEI when ordering the MAX1294 EV kit. ♦ Internal Clock ♦ Six Input Channels ♦ 12-Bit-Wide Digital Interface ♦ Internal Track and Hold ♦ 420kHz Sampling Rate ♦ Internal 2.5V Reference ♦ Low-Power Standby Mode ♦ Fully Assembled Surface-Mount Board Ordering Information PART TEMP. RANGE MAX1294EVKIT 0°C to +70°C Component List DESIGNATION QTY DESCRIPTION C1, C3 2 4.7µF, 10V tantalum capacitors AVX TAJB475M010R C2, C6–C12 8 0.1µF ceramic capacitors C4, C5 2 0.01µF ceramic capacitors INT, RD, WR, CLK, CS, COM, CH0-CH5 12 BNC connectors J1 1 40-pin header JU1, JU2 2 2-pin headers R1, R2 2 47kΩ, 9-resistor, 10-pin SIPs R4–R14 11 51Ω ±5% resistors U1 1 MAX1294BCEI None 2 Shunts None 1 MAX1294 printed circuit board None 1 MAX1294 data sheet IC PACKAGE 28 QSOP Quick Start The MAX1294 EV kit comes fully assembled and tested. The following equipment is required: • A +5V linear power supply (switching supplies will induce excess noise on the power input) • A low-distortion function generator • A logic analyzer A logic analyzer or other digital system is needed to provide the clock and control signals and to capture the conversion results of the MAX1294. Connect the logic analyzer using a 40-pin ribbon cable or a combination of BNC cables, ribbon cable, and miniclips. Refer to the MAX1294 data sheet for detailed information on timing requirements. The analog input signals must be delivered by a lowdistortion source to achieve full 12-bit accuracy. All analog channels connect to BNC connectors terminated with 51Ω resistors. For best low-noise performance, maintain separate analog and digital supplies and grounds to the board. The grounds are connected in a star configuration centered on the ground plane of the board. Refer to the MAX1294/MAX1296 data sheet for a detailed discussion of signal grounds. Many of the digital and analog signals on the evaluation kit have 51Ω termination resistors matching typical generator impedance. These should be removed if highimpedance sources are used. ________________________________________________________________ Maxim Integrated Products 1 For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. Evaluates: MAX1294/MAX1295 General Description Evaluates: MAX1294/MAX1295 MAX1294 Evaluation Kit Connections and Setup Connect all supplies and signal lines before turning on any supply or signal source: 1) Connect a +5V power supply to the VDD pad. Connect the ground to the AGND pad. The DGND provides additional access to the digital ground plane. 2) Make sure there is no shunt installed on JU1 (Table 1). This enables the internal 2.5V reference. 3) Connect the analog source (function generators or user signals) to the analog input channels (CH0– CH5). Install a shunt on JU2 to connect the COM pin to GND. 4) Connect a logic analyzer, word generator, or other source for the digital data lines D0–D11. These signals are available on the 40-pin header (Table 2). 5) Connect the digital control signals for CS, RD, and WR. These signals are available on the 40-pin header or on BNC connectors. 6) Connect the clock signal (0.1MHz to 7.6MHz) to the CLK BNC connector or leave the pin open to use the internal clock. 7) Turn on the VDD supply, then enable the digital signal source. 8) Turn on the analog sources, and the system is ready for use. Table 1. Jumper Functions SHUNT LOCATION SHDN PIN Open JU1 Shorted Open JU2 Shorted MAX1294 OUTPUT REFADJ pin open or driven externally REFADJ pin shorted to VDD* COM pin open or driven externally COM pin shorted to AGND *The MAX1294’s 2.5V reference must be disabled before an external reference voltage is connected. Installing a shunt across JU1 connects the REFADJ pin to VDD and disables the on-board reference. Table 2. 40-Pin Header (J1) Signals PIN SIGNAL 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39 GND 2 D0 4 D1 6 D2 Detailed Description 8 D3 10 D4 Analog Input Signals 12 D5 The analog inputs are configured for using a function generator. The inputs have 51Ω loads and 0.1µF capacitors to match the generator’s impedance. It may be necessary to remove these if the board is connected to the user’s system. The system must provide low impedance and any necessary anti-aliasing filtering. 14 D6 16 D7 18 D8 9) Use the logic analyzer for data analysis. 20 D9 22 D10 Grounding 24 D11 The MAX1294 evaluation board uses two separate ground planes to reduce noise. All digital signals connect to the digital ground plane (DGND), and the noise-sensitive analog signals connect to the separate analog ground plane (AGND). The two grounds connect at only one point near the ground pin (pin 23) of the MAX1294. The ground connection (RGND) for the optional external reference supply is connected directly to the same point. This “star” ground configuration is common in low-noise analog systems. 26 INT 2 28 RD 30 WR 32 CLK 34 CS 36, 38, 40 N.C. _______________________________________________________________________________________ _______________________________________________________________________________________ J1–4 J1–6 J1–8 J1–10 J1–12 J1–14 J1–16 J1–18 J1–20 CH5 CS CLK WR RD INT J1–2 R1–I 47k VDD R2–A 47k J1–34 J1–32 J1–30 J1–28 J1–26 R2–I 47k R2–B 47k R1–F 47k R2–C 47k R13 51Ω R2–D 47k R2–E 47k C11 0.1µF R4 51Ω R2–F 47k R5 51Ω R2–G 47k R6 51Ω R2–H 47k CH3 18 11 INT R7 51Ω 14 CLK CS 15 CH4 17 CH2 19 10 D0 CH5 16 CH1 20 9 D1 12 RD CH0 21 8 D2 13 WR GND 23 COM 22 6 D4 7 D3 REF 25 REF ADJ 24 4 D6 VDD 26 3 D7 5 D5 D10 28 D11 27 1 D9 2 D8 MAX1294 DGND AGND JU2 C12 0.1µF C10 0.1µF C9 0.1µF C8 0.1µF C7 0.1µF C6 0.1µF C5 0.01µF C4 0.01µF C2 0.1µF R1–H 47k VDD R14 51Ω R12 51Ω R11 51Ω R10 51Ω R9 51Ω R8 51Ω JU1 C3 4.7µF 10V C1 4.7µF 10V R1–G 47k CH4 CH3 CH2 CH1 CH0 COM RGND REF ADJ REF VDD J1–24 J1–22 VDD J1–40 J1–36 N.C. J1–38 N.C. N.C. J1–39 J1–37 J1–35 J1–33 J1–31 J1–29 J1–27 J1–25 J1–23 J1–21 J1–19 J1–17 J1–15 J1–13 J1–11 J1–9 J1–7 J1–5 J1–3 J1–1 Evaluates: MAX1294/MAX1295 VDD MAX1294 Evaluation Kit Figure 1. MAX1294 EV Kit Schematic 3 Evaluates: MAX1294/MAX1295 MAX1294 Evaluation Kit 1.0" Figure 2. MAX1294 EV Kit Component Placement Guide—Component Side 4 _______________________________________________________________________________________ MAX1294 Evaluation Kit Evaluates: MAX1294/MAX1295 1.0" Figure 3. MAX1294 EV Kit PC Board Layout—Component Side _______________________________________________________________________________________ 5 Evaluates: MAX1294/MAX1295 MAX1294 Evaluation Kit 1.0" Figure 4. MAX1294 EV Kit PC Board Layout—Interior Layer 1 6 _______________________________________________________________________________________ MAX1294 Evaluation Kit Evaluates: MAX1294/MAX1295 1.0" Figure 5. MAX1294 EV Kit PC Board Layout—Interior Layer 2 _______________________________________________________________________________________ 7 Evaluates: MAX1294/MAX1295 MAX1294 Evaluation Kit 1.0" Figure 6. MAX1294 EV Kit PC Board Layout—Solder Side Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.