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FEATURES 60 MHz Pulse Rate 8-Bit Resolution Center, Left or Right Justify Low Power: 700 mW typical Minimum Pulse Width: <5 ns Maximum PW: 100 % Full-scale
APPLICATIONS Laser Printers Digital Copiers Color Copiers
Pulse Width Modulator AD9561
FUNCTIONAL BLOCK DIAGRAM
AD9561
CLOCK
RSET CAL IN
INTERNAL TIMING
RAMP
CAL OUT
RAMP REF
CAL DAC
8-BIT DATA
SEM/DEM LEM/TEM RETRACE
LL AA TT CC HH
DAC
OUTPUT LOGIC
PWM OUT
CAL OUT
GENERAL DESCRIPTION The AD9561 is a second generation high speed, digitally programmable pulse width modulator (PWM). Output pulse width is proportional to an 8-bit DATA input value. Two additional control inputs determine if the pulse is placed at the beginning, middle or end of the clock period. Pulse width and placement can be changed every clock cycle up to 60 MHz.
Pulse width modulation is a well proven method for controlling gray scale and resolution enhancement in scanning laser print engines. Modulating pulse width provides the most cost effective m.