《Application Note》.pdfVIP

No. AN9331.1 January 1994 Application Note Using the HI1175 Evaluation Board Author: Phil Louzon Description The HI1175 evaluation board can be used to evaluate the per- by individual clean linear regulated supplies. They can be formance of the HI1175 8-bit 20MSPS analog-to-digital con- hooked up with external 16 gauge wires to the holes marked verter (ADC). The board includes clock driver circuitry a +5V, +12V, -12V, and GND on the prototype area. Do not tie reference voltage generator, and a choice of input drive cir- the supply grounds together back at the supplies as this will cuitry. create a ground loop and create additional noise. Table 1 lists the operating conditions for the power supplies. HI1175 Theory of Operation TABLE 1. POWER SUPPLIES As illustrated in the functional block diagram of the HI1175, the part is a 2-step ADC converter featuring a 4-bit upper POWER TYP SUPPLY MIN TYP MAX CURRENT comparator group and two lower comparator groups of 4-bits each. The reference voltage can be obtained from the +5V +4.75V +5.0V +5.25V 60mA onboard bias generator or be supplied externally. This IC uses an offset canceling type CMOS comparator that operates syn- +12V