MAX9532AUB+T Maxim Integrated Products, MAX9532AUB+T Datasheet - Page 9

• Manufacturer Part Number: MAX9532AUB+T
• Description: IC AMP VID DIRECTDRIVE 10-MSOP
• Manufacturer: Maxim Integrated Products
• Series: DirectDrive™r

Specifications of MAX9532AUB+T

• Applications: Automotive Systems
• Number Of Circuits: 1
• Current - Supply: 15mA
• Current - Output / Channel: 90mA
• Voltage - Supply, Single/dual (±): 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• For Use With: MAX9532EVKIT+ - EVALUATION KIT FOR MAX9532
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Devices designed to generate 1V
the output of the video DAC can work with the
MAX9532. Most video DACs source current into a
ground-referenced resistor, which converts the current
into a voltage. Figure 3 shows a video DAC that creates
a video signal from 0V to 1V across a 150Ω resistor.
With a gain of 2V/V, the following video filter produces a
2V
The MAX9532 accepts input signals that are 0.5V
nominally. The video DAC in Figure 3 can be made to
work with the MAX9532 by scaling down the 150Ω
resistor to a 75Ω resistor, as shown in Figure 4. The
75Ω resistor is one-half the size of the 150Ω resistor,
resulting in a video signal that is one-half the amplitude.
In some applications, the video source generates a sig-
nal with a positive DC voltage bias, i.e., the sync tip of
the signal is well above ground. Figure 5 shows an
example in which the outputs of the luma (Y) DAC and
the chroma (C) DAC are connected together. Since the
Figure 3. Typically, a Video DAC Generates a 1V
Across a 150 Ω Resistor Connected to Ground
Table 1. Power Consumption of the MAX9532 with Different Video Signals
Note: The supply voltage is 3.3V.
All Black Screen
All White Screen
75% Color Bars
50% Flat Field
PROCESSOR
P-P
VIDEO SIGNAL
IMAGE
ASIC
DAC
Interfacing to Video DACs that Produce
output.
Video Source with a Positive DC Bias
0V TO 1V
Video Signals Higher than 0.5V
150Ω
_______________________________________________________________________________________
GENERIC 2V/V CONFIGURATION
LPF
MAX9532 POWER CONSUMPTION (mW)
2V/V
P-P
WITH 150Ω LOAD
DirectDrive Video Amplifier with
video signals at
51.236
57.077
53.074
49.513
P-P
2V
Signal
P-P
Short-to-Battery Protection
P-P
P-P
DACs are current-mode, the output currents sum
together into the resistor, which converts the resulting
current into a voltage representing a composite video
signal.
When the chroma DAC is connected to an independent
output resistor to ground, the chroma signal, which is a
carrier at 3.58MHz for NTSC or at 4.43MHz for PAL,
generates a positive DC bias to keep the signal above
ground at all times. When the luma DAC is connected
to an independent output resistor to ground, the luma
signal usually does not have a positive DC bias, and
the sync tip is at approximately ground. When the chro-
ma and luma signals are added together, the resulting
composite video signal generates a positive DC bias.
Therefore, the signal must be AC-coupled into the
MAX9532 because the composite video signal is above
the nominal 0V to 0.7V DC-coupled input range.
Minimize the length of the PCB trace between the out-
put of the video DAC and the input of the MAX9532 to
reduce coupling of external noise into the video signal.
If possible, shield the PCB trace.
Figure 4. Video DAC Generates a 0.5V
Resistor Connected to Ground
PROCESSOR
IMAGE
ASIC
DAC
0V TO 0.5V
MAX9532 POWER CONSUMPTION (mW)
75Ω
WITH 100Ω LOAD
LPF
MAX9532
Video Signal Routing
53.978
65.399
57.486
51.596
P-P
4V/V
Signal Across a 75 Ω
2V
P-P
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