QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1444A 2 1-CHANNEL/2-CHANNEL, 12-BIT, SAR ADCS WITH I C INTERFACE LTC2301/LTC2305 DESCRIPTION Demonstration circuit 1444A features the connecting the DC1444A into a customer LTC2301/LTC2305, low noise, low power, 1- application the performance of the Channel/2-Channel, 12-Bit, successive LTC2301/LTC2305 can be evaluated directly 2 approximation ADCs with an I C compatible in that circuit. DC1444A-A uses serial interface. The LTC2301/LTC2305 are LTC2301CMS. available in a 12-pin MSOP package. DC1444A-B uses LTC2305CMS. DC1444A demonstrates the DC performance of the LTC2301/LTC2305 ADCs in Design files for this circuit board are available. conjunction with the DC590B Quick Eval Call the LTC factory. LTC is a trademark of Linear Technology Corporation data collection board. Alternatively, by FIGURE 1. DC1444A CONNECTION DIAGRAM 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 1444A 2 1-CHANNEL/2-CHANNEL, 12-BIT, SAR ADCS WITH I C INTERFACE DC590B QUICK START PROCEDURE Connect DC1444A to a DC590B USB serial contains information on Data Logging the ADC controller using the supplied 14-conductor ribbon results. The Tools menu has the Data Logging cable. Make sure the VCCIO jumper of the option as well as options for changing the number DC590B is in the 5V position. Connect DC590B of points displayed, the number of points in an to a host PC with a standard USB A/B cable. average and whether the data is displayed in LSBs Apply analog input voltage to IN+ and IN- (CH0 or Volts. The View menu can be used to access and CH1 for LTC2301) on connector JP1. Run the the LTC2301/LTC2305 product page. evaluation software supplied with DC590B or If the Quick Eval program is started without the download it from www.linear.com. The correct demo board attached to DC590B, the Tools menu control panel will be loaded automatically. Click can be used to check for updates and automatically the COLLECT/PAUSE (Figure 2) button to begin install them. DC1444A requires at least version reading the ADC. Pressing COLLECT/PAUSE K76 of the Quick Eval software. again stops data collection. The Help menu HARDWARE SET UP SIGNAL CONNECTIONS See Figure 1 for locations. EXT BIAS External Bias connection. This can be used to drive the BIAS/2 line through a 2:1 JP1 Connector for IN+/IN- LTC2301 (CH0- divider. To use this pin put jumper JP5 in the EXT CH1 LTC2305), COM and BIAS/2. Limit input position and apply desired bias voltage. voltage swings to GND-VDD. For optimum 5V Five volt supply line for DC1444A. Power is performance, the input should be bandlimited to normally provided to this line by DC590B. Apply the frequencies of interest. power to this line only if DC590B is not used. JP2 DC590 interface connector. Provides power GND Ground line for DC1444A and I2C interface to DC1444A. 2 SDA I C bidirectional data line. Controlled by 2 JP3 AD1 I C address line. Set to GND for DC590B if connected. operation with supplied software. 2 SCL I C clock line. Controlled by DC590B if 2 connected. JP4 AD0 I C address line. Set to GND for operation with supplied software. VREF Connected to ADC Vref pin through 50 ohm resistor. JP5 BIAS Selects between Refcomp and an external bias voltage to drive the Bias/2 line. REFCOMP Connected to ADC Refcomp pin. Bias/2 is designed to set a center point for the BIAS/2 Bias voltage/2 (Refcomp or Ext) minus input during bipolar operation. 2