FMS6151_10 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 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 that 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 decrease of the large 220μF
output coupling capacitor. A 22μF is used for SAG correc-
tion and a 47μF is used for the output coupling
capacitor; much smaller and cheaper than 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
FMS6151 Application Note, AN-8005.
© 2006 Fairchild Semiconductor Corporation
FMS6151 • Rev. 1.0.6
7
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