QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1074 LTC2630 FAMILY OF SINGLE SPI DACS LTC2630 DESCRIPTION Demonstration circuit 1074 features the LTC2630 family of 12 bit DACs. This device establishes a new benchmark for size and integration of 12 bit DACs and onboard reference. Four DACs are included: LTC2630HZ (4.096V reference, reset to zero) LTC2630HM (4.096V reference, reset to midscale) LTC2630LZ (2.5V reference, reset to zero) LTC2630LM (2.5V reference, reset to midscale) DC1074 may be connected directly to the target application’s analog signals while using the DC590 USB Serial Controller board and supplied software to measure performance. After evaluating with Linear Technology’s software, the digital signals can be connected to the end application’s processor / controller for development of the serial interface. Design files for this circuit board are available. Call the LTC factory. , LTC and LT are registered trademarks of Linear Technology Corporation. Figure 1. Proper Measurement Equipment Setup Ribbon cable To DC590 Controller DAC outputs Table 1. LTC2630 Performance Summary, AHM / AHZ versions (Vfs = 4.096V) PARAMETER CONDITION Resolution VALUE 12 BITS Monotonicity Vcc = 5V, Vref = internal 12 BITS Differential Nonlinearity Vcc = 5V, Vref = internal +/-1 LSB Integral Nonlinearity Vcc = 5V, Vref = internal +/-0.5 LSB Typical Load Regulation Vout = Midscale, Iout = +/- 5 mA 0.1 LSB/mA 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1074 LTC2630 FAMILY OF SINGLE SPI DACS QUICK START PROCEDURE Connect DC1074 to a DC590 USB serial controller using the supplied 14 conductor ribbon cable. Connect DC590 to a host PC with a standard USB A/B cable. Run the evaluation software supplied with DC590 or download it from www.linear.com. The correct control panel will be loaded automatically. Options are available to display the DAC output in Voltage, hex code, or decimal count. Additionally, the supply or internal reference voltage may be changed to reflect an actual measured value such that the output voltage matches the theoretical output voltage. The reference mode may be changed from internal reference to supply as reference. Figure 2. Software Screenshot 2 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1074 LTC2630 FAMILY OF SINGLE SPI DACS HARDWARE SET-UP JUMPERS 4.096V DAC VCC – Select the supply for the H DACs, either 5V (default) or supplied externally to the turret post. 2.5V DAC VCC – Select the supply for the L DACs, either 5V, 3.3V (default) or supplied externally to the turret post. (remove jumper.) ANALOG CONNECTIONS DAC outputs are provided on the row of turret posts at the edge of the board. GROUNDING AND POWER CONNECTIONS Power (Vcc) – Normally DC1074 is powered by the DC590 controller. Vcc can be supplied to the 5V turret, however the power supply on DC590 must be disabled! Refer to DC590 Quick Start Guide for more details on this mode of operation. Grounding – Four ground posts are provided. Exposed ground planes at the edges of the board are also provided for optimum grounding to other circuits. 3 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC1074 LTC2630 FAMILY OF SINGLE SPI DACS 4