MAX4090EXT+T Maxim Integrated Products, MAX4090EXT+T Datasheet - Page 8

• Manufacturer Part Number: MAX4090EXT+T
• Description: IC VIDEO BUFFER 6DB SC70-6
• Manufacturer: Maxim Integrated Products

Specifications of MAX4090EXT+T

• Applications: Buffer
• Number Of Circuits: 1
• -3db Bandwidth: 55MHz
• Slew Rate: 275 V/µs
• Current - Supply: 6.5mA
• Current - Output / Channel: 85mA
• Voltage - Supply, Single/dual (±): 2.7 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 6-TSSOP, SC-88, SOT-363
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3V/5V, 6dB Video Buffer with Sync-Tip Clamp
and 150nA Shutdown Current
between 20Ω to 100Ω is needed to isolate the input
capacitor (C4) to the filter to prevent the oscillation
problem.
Figure 2 shows the frequency response for R1 = R2 =
150Ω. At 6MHz, the attenuation is about 1.4dB. The
attenuation at 27MHz is about 20dB. Figure 3 shows
the multiburst response for R1 = R2 = 150Ω.
Figure 1. 2nd-Order Butterworth LPF with MAX4090
Figure 2. Frequency Response
8
_______________________________________________________________________________________
CURRENT
VIDEO
DAC
-10
-20
-30
-40
-50
-60
0
0.1
C
150Ω
=
R1
FREQUENCY RESPONSE
2
π
C
f R
FREQUENCY (MHz)
C L
1
n
2-POLE RECONSTRUCTION LPF
L
=
C1
150pF
L R
2
10
n L
π
3.9μH
f
C
L1
100
R2
150Ω
49.9Ω
R
V
IS
CC
If more flat passband and more stopband attenuation
are needed, a 3rd-order LPF can be used. The design
procedures are similar to the 2nd-order butterworth
LPF.
Table 3 shows the normalized 3rd-order butterworth
lowpass filter with the cutoff frequency at 1 rad/s and
the stopband frequency at 3 rad/s. Table 4 shows the
appropriated L and C values for different source/load
impedance and the bench measurement values for
-3dB BW and attenuation at 27MHz. The attenuation is
over 40dB at 27MHz. At 6MHz, the attenuation is
approximately 0.6dB for R1 = R2 = 150Ω (Figure 5).
Figure 3. Multiburst Response
3rd-Order Butterworth Lowpass Filter Realization
0.1μF
C4
SHDN
IN
MAX4090
GND
V
CC
10μs/div
OUT
FB
C7
1μF
V
500mV/div
V
500mV/div
75Ω
IN
OUT
R3
V
CC
V
OUT