FMS6151 Datasheet, PDF (5/7 Pages) Fairchild Semiconductor – Ultra Portable Video Filter Driver

Typical Performance Characteristics
T_c = 25˚C, V_cc = 2.7V, R_s = 37.5Ω, AC coupled output into 150Ω load, SAG pin connected to V_OUT pin;
unless otherwise noted.
Figure 7. Supply Current vs. Temp.
4.0
3.9
3.8
3.7
3.6
3.5
-40 -20 0 20 40 60 80
Temperature (°C)
Figure 8. Shutdown Current vs. Temp.
60
50
40
30
20
10
0
-40 -20 0 20 40 60 80
Temperature (°C)
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 cou-
pling 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 syn-
chronization 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 out-
put 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.
FMS6151 Rev. 1B
5
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