Datasheet

AD9984A
Rev. 0 | Page 41 of 44
DIGITAL INPUTS
Digital inputs on the AD9984A (HSYNC0, HSYNC1, VSYNC0,
VSYNC1, SOGIN0, SOGIN1, SDA, SCL, and CLAMP) are
designed to work with 3.3 V signals, but are tolerant of 5 V
signals. Therefore, no extra components need to be added if
using 5 V logic.
Any noise that gets onto the Hsync input trace adds jitter to the
system. Therefore, minimize the trace length and do not run
any digital or other high frequency traces near it.
Reference Bypass
The AD9984A has two reference voltages that must be bypassed
for proper operation of the ADC. REFLO and REFHI are
connected to each other through a 10 μF capacitor. These
references are used by the ADC circuitry to assure the greatest
stability. Place them as close to the AD9984A pin as possible.