FMS6151_08 Datasheet, PDF (7/9 Pages) Fairchild Semiconductor – Ultra Portable Video Filter Driver

Application Information
Input Voltage
The FMS6151 is intended to be directly driven by a DC
coupled DAC output. The input common mode range of
the FMS6151 is 1.2V_pp, ground referenced.
Enable/Shutdown
The FMS6151 has a shutdown feature that disables the
output and reduces the quiescent current to ~25nA. This
feature is especially useful in portable applications, such
as cellular phones, hand held gaming devices, and video
cameras requiring video filtering and drive capability.
Internal Level Shift
The FMS6151 has an internal level shift circuit to avoid
sync tip clipping. The output signal is shifted 200mV
toward the V_CC rail to help prevent clipping. This offset
is extremely useful when DC coupled out or using SAG
correction.
SAG Correction
Sag correction provides excellent performance with a
small output coupling capacitor. It eliminates the 220μF -
1000μF output coupling capacitors traditionally used. The
traditional output circuit (220μF into 150Ω load) creates a
single pole (-3dB) at 5Hz. Reducing this capacitor causes
excessive phase shift, resulting in video field tilt which can
prevent proper recovery of the synchronization signals.
The FMS6151 sag correction circuit provides a small
amount of peaking, which provides compensation of the
phase response, significantly reducing video field tilt. The
SAG correction circuit allows you to decrease the large,
220μF, output coupling capacitor. A 22μF is used for sag
correction and a 47μF is used for the output coupling
capacitor, extremely smaller and cheaper than the traditional
circuit requirements.
Output Configuration
The FMS6151 output is a low impedance voltage driver. It
is capable of driving an AC or DC coupled single load.
For more application information, please refer to our
FMS6151 Application Note, AN-8005.
© 2006 Fairchild Semiconductor Corporation
FMS6151 Rev. 1.0.3
7
www.fairchildsemi.com