19-3675; Rev 1; 8/05
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
The MAX9505 filters and amplifies standard-definition
video signals. Maxim’s DirectDrive™ technology eliminates large output-coupling capacitors and sets the
video black level to ground. An internal reconstruction
filter smoothes the steps and reduces the spikes on the
video signal from the video digital-to-analog converter
(DAC). The input of the MAX9505 can be directly connected to the output of a DAC. The MAX9505 provides
a compact, integrated, and low-power solution.
The reconstruction filter typically has 3dB attenuation at
9MHz and 50dB attenuation at 27MHz, and ±1dB passband flatness to 5.5MHz.
Maxim’s DirectDrive uses an integrated charge pump
and a linear regulator to create a negative power supply
to drive the sync below ground. The charge pump injects
so little noise into the video output that the picture is visibly flawless.
The MAX9505 features an internal 1.7Ω analog switch
that interfaces with a 4-pole multimedia jack. This
switch allows one of the poles to be set as a video
input, a video output, or a microphone input.
The MAX9505 is offered in space-saving 16-pin QSOP
and 16-pin TQFN packages and is specified over the
-40°C to +85°C extended temperature range.
Features
♦ DC-Coupled Output
♦ Direct Connection to Video DAC
♦ Video Output Black Level Set to Ground
♦ Video Reconstruction Filter with 50dB
Attenuation at 27MHz
♦ 6dB Gain
♦ 1.7Ω RON Analog Switch
♦ 10nA Shutdown Supply Current
♦ 2.7V to 3.6V Single-Supply Operation
Ordering Information
PART*
PINPACKAGE
PKG CODE
TOP MARK
MAX9505EEE
16 QSOP
E16-4
—
MAX9505ETE
16 TQFN
T1633-4
ACW
*All devices are specified over the -40°C to +85°C operating
temperature range.
Applications
Mobile Phones/Smartphones
Space-Constrained, Low-Power Audio/Video
Portable Devices
Functional Diagram/Typical Operating Circuit and Pin
Configurations appear at end of data sheet.
Block Diagram
MAX9505
0 TO 50mV
0V
BUFFER
VIDIN
-0.1V TO
+0.1V
SIN
SOUT
0V
6dB
LOWPASS
FILTER
AMP
VIDOUT
LINEAR
REGULATOR
CHARGE
PUMP
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX9505
General Description
MAX9505
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
ABSOLUTE MAXIMUM RATINGS
VDD to SGND............................................................-0.3V to +4V
VIDIN to SGND .........................................................-0.3V to +4V
BIAS to SGND ............................................-0.3V to (VDD + 0.3V)
MODE0, MODE1 to SGND .......................................-0.3V to +4V
(The greater of VSS and -2V)
SIN, SOUT, VIDOUT to SGND
to (VDD + 0.3V)
CPVDD to CPGND ....................................................-0.3V to +4V
C1P, C1N, CPVSS .............................Capacitor Connection Only
CPGND, SGND, GND............................................-0.1V to +0.1V
CPVSS to VSS ..................................................................-0.1V to +0.1V
VIDOUT Short Circuit to VDD, SGND
and the Greater of (VSS and -2V) ...........................Continuous
Continuous Current
VIDIN, BIAS, MODE0, MODE1, SIN, SOUT ...................±20mA
Continuous Power Dissipation (TA = +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)...........667mW
16-Pin TQFN (derate 15.6mW/°C above +70°C) .......1349mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VDD = CPVDD = MODE1 = 3.0V, MODE0 = SGND = GND = CPGND = 0V, C1 = C2 = C3 = C4 = 1µF, RBIAS = 100kΩ, TA = TMIN to
TMAX. RL = 150Ω to SGND, unless otherwise noted. VVIDIN = 286mV, gain = 6dB. Typical values are at VDD = CPVDD = MODE1 = 3.0V,
TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
Supply Voltage Range
SYMBOL
VDD,
CPVDD
Quiescent Supply Current
IDD
Shutdown Supply Current
ISHDN
Bias Voltage
VBIAS
CONDITIONS
Guaranteed by DC voltage gain and
quiescent supply current
MIN
TYP
MAX
UNITS
3.6
V
12
15
mA
0.01
1
µA
2.7
VDD = 3.6V (IDD = IVDD + ICPVDD, RL = ∞)
VDD = 3.6V (ISHDN = IVDD + ICPVDD),
SHDN = SGND
1
V
VIDEO AMPLIFIER
Input Voltage Range
VRANGE
Input Current
IIN
Input Resistance
RIN
DC Voltage Gain (Note 2)
AV
Output Black Level (Note 3)
Output Resistance
Shutdown Output Impedance
VIDOUT Leakage Current
2
-0.10
+1.05
Guaranteed by DC voltage gain, VDD = 3V
-0.10
+1.28
VDD = 2.7V
-2.5
ISC
+2.5
1
VDD = 2.7V to 3.6V
VDD = 2.7V
Output Voltage Swing
Output Short-Circuit Current
Guaranteed by DC voltage gain,
VDD = 2.7V
6
6.5
dB
-0.1
0
+0.1
V
2.162
Guaranteed by DC voltage gain, VDD = 3V
2.594
Sinking or sourcing
MODE1 = MODE0 = SGND
µA
MΩ
5.5
Guaranteed by DC voltage gain, VDD = 2.7V
ROUT
V
VP-P
50
mA
0.01
Ω
4
kΩ
MODE1 = MODE0 = VDD
0.01
MODE1 = SGND and MODE0 = VDD
0.01
_______________________________________________________________________________________
µA
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
(VDD = CPVDD = MODE1 = 3.0V, MODE0 = SGND = GND = CPGND = 0V, C1 = C2 = C3 = C4 = 1µF, RBIAS = 100kΩ, TA = TMIN to
TMAX. RL = 150Ω to SGND, unless otherwise noted. VVIDIN = 286mV, gain = 6dB. Typical values are at VDD = CPVDD = MODE1 = 3.0V,
TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
MODE1 = VDD
1.7
4.4
MODE1 = SGND
1.2
2.5
MODE1 = VDD
0.5
0.9
MODE1 = SGND
0.3
0.5
UNITS
ANALOG SWITCH
On-Resistance
RON
MODE0 = VDD,
ISIN = 10mA
Ω
On-Resistance Flatness (Note 4)
MODE0 = VDD,
ISIN = 10mA, VDD = 3V
SOUT Off-Leakage Current
(Note 5)
MODE0 = SGND, VDD = 3.6V, VSIN = 0.3V,
3.3V, VSOUT = 3.3V, 0.3V
-1
+1
nA
SIN On-Leakage Current (Note 5)
MODE0 = VDD, VDD = 3.6V, VSIN = 0.3V,
3.3V, VSOUT = 3.3V, 0.3V
-1
+1
nA
Turn-On Time
VSIN = 1.5V, RL = 300Ω, CL = 35pF,
Figure 1; VIH = 1.5V, VIL = 0V
35
60
ns
Turn-Off Time
VSIN = 1.5V; RL = 300Ω, CL = 35pF,
Figure 1; VIH = 1.5V, VIL = 0V
50
80
ns
Charge Injection
VGEN = 1.5V, RGEN = 0Ω, CL = 1nF,
Figure 2
20
MODE0 = SGND, f = 10MHz;
VSOUT = 1VP-P, RL = 50Ω, CL = 5pF
30
MODE0 = SGND, f = 1MHz; VSOUT = 1VP-P,
RL = 50Ω, CL = 5pF
50
On-Channel -3dB Bandwidth
MODE0 = VDD, signal = 0dBm, RL = 50Ω,
CL = 5pF
200
MHz
Total Harmonic Distortion
MODE0 = VDD, VSIN = 2VP-P, RL = 600Ω
0.025
%
SOUT Off-Capacitance
MODE0 = SGND, f = 1MHz
18
pF
Switch On-Capacitance
MODE0 = VDD, f = 1MHz
60
pF
VIDIN to SIN
MODE1 = MODE0 = VDD, f = 20kHz,
1VP-P at VIDIN
100
dB
VIDOUT to SIN
MODE1 = VDD, MODE0 = SGND,
f = 20kHz, 2VP-P at VIDOUT
85
dB
Off-Isolation
Ω
pC
dB
CROSSTALK (VIDEO TO AUDIO)
CHARGE PUMP
Switching Frequency
150
250
300
kHz
0.5
V
1
µA
LOGIC SIGNALS (MODE0, MODE1)
Logic-Low Threshold
VIL
VDD = 2.7V to 3.6V
Logic-High Threshold
VIH
VDD = 2.7V to 3.6V
Logic Input Current
IIL
1.5
V
_______________________________________________________________________________________
3
MAX9505
ELECTRICAL CHARACTERISTICS (continued)
MAX9505
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
AC ELECTRICAL CHARACTERISTICS
(VDD = CPVDD = MODE1 = 3.0V, MODE0 = SGND = GND = CPGND = 0V, C1 = C2 = C3 = C4 = 1µF, RBIAS = 100kΩ, TA = TMIN to
TMAX. RL = 150Ω to SGND, unless otherwise noted. VVIDIN = 286mV, gain = 6dB. Typical values are at VDD = CPVDD = MODE1 = 3.0V,
TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
Passband Flatness
VDD = 2.7V, f = 100kHz to 5.5MHz
Attenuation
VDD = 2.7V,
VIDOUT= 2VP-P, attenuation
is referred to 100kHz
MIN
TYP
MAX
UNITS
-1
0
+1
dB
f = 9.1MHz
3
dB
f = 27MHz
35
50
Power-Supply Rejection Ratio
PSRR
f = 100kHz
62
Output Impedance
ZOUT
f = 5MHz
0.5
dB
Ω
Differential Gain Error
DG
NTSC, VIDOUT = 2VP-P
0.1
%
Differential Phase Error
DP
NTSC, VIDOUT = 2VP-P
0.2
degrees
2T Pulse-to-Bar K Rating
2T = 250ns, bar time is 18µs, the beginning
2.5% and the ending 2.5% of the bar time
are ignored
-0.3
K%
2T Pulse Response
2T = 250ns
0.3
K%
2T Bar Response
2T = 250ns, bar time is 18µs, the beginning
2.5% and the ending 2.5% of the bar time
are ignored
0.7
K%
Nonlinearity
5-step staircase
0.2
%
Group Delay Distortion
DDt
100kHz to 5.5MHz
10
ns
VIDOUT Capacitive-Load Stability
CL
VOUT = 2VP-P, no sustained oscillations
20
pF
Peak Signal-to-RMS Noise
SNR
100kHz to 5.5MHz
64
dB
Enable Time
tON
VIDIN = 0.5V, VIDOUT settled to within 1%
of the final voltage
0.2
ms
Disable Time
tOFF
VIDIN = 0.5V, VIDOUT settled to below 1%
of the output voltage
0.1
ms
All devices are 100% production tested at TA = +25°C. Specifications over temperature are guaranteed by design.
Voltage gain (AV) is a two-point measurement in which the output voltage swing is divided by the input voltage swing.
With an output load attached, this offset will directly contribute to quiescent current.
Flatness is defined as the difference between the maximum and minimum value of on-resistance as measured over the
specified analog signal ranges.
Note 5: Guaranteed by design.
Note 1:
Note 2:
Note 3:
Note 4:
4
_______________________________________________________________________________________
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
VDD
VIH
VDD
VNO
SOUT
MODE0
SIN
VIL
VOUT
RL
MODE0
tR < 5ns
tF < 5ns
50%
tOFF
CL
VOUT
SWITCH OUTPUT
0.9 x VOUT
0.9 x VOUT
0V
LOGIC
INPUT
SGND
tON
CL INCLUDES FIXTURE AND STRAY CAPACITANCE.
VOUT = VNO (RL / (RL + RON))
Figure 1. Analog Switch Turn-On/Off Time
VDD
VDD
RGEN
SOUT
∆VOUT
SIN
VGEN
VOUT
VOUT
CL
ON
SGND
MODE0
IN
IN
OFF
OFF
Q = (∆VOUT) (CL)
VIL TO VIH
Figure 2. Charge Injection
_______________________________________________________________________________________
5
MAX9505
Timing Diagrams
Typical Operating Characteristics
(VDD = CPVDD = MODE1 = 3.0V, MODE0 = SGND = GND = CPGND = 0V, no load, C1 = C2 = C3 = C4 = 1µF, RBIAS = 100kΩ, TA =
TMIN to TMAX. RIN = 150Ω to SGND, unless otherwise noted. VVIDIN = 286mV, gain = 6dB. Typical values are at TA = +25°C, unless
otherwise noted.)
SMALL-SIGNAL GAIN FLATNESS
vs. FREQUENCY
VVIDOUT = 100mVP-P
GAIN = 6dB
7
-10
-20
-30
-40
-50
-10
6
5
-30
-40
-60
VVIDOUT = 2VP-P
GAIN = 6dB
-70
-80
3
-80
0.1
-20
-50
VVIDOUT = 100mVP-P
GAIN = 6dB
1
0.1
100
10
1
0.1
10
1
10
100
FREQUENCY (MHz)
FREQUENCY (MHz)
FREQUENCY (MHz)
LARGE-SIGNAL GAIN FLATNESS
vs. FREQUENCY
GROUP DELAY
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
125
GROUP DELAY (ns)
7
VVIDOUT = 2VP-P
6
5
20
0
-20
100
PSRR (dB)
VVIDOUT = 2VP-P
GAIN = 6dB
MAX9505 toc05
150
MAX9505 toc04
8
MAX9505 toc06
-70
75
-40
-60
50
-80
4
25
-100
0
3
0.1
-120
0.1
10
1
1
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE (VIDEO MODE)
10
35
TEMPERATURE (°C)
60
85
2
1
0
5.8
10
3
OUTPUT VOLTAGE (V)
VOLTAGE GAIN (dB)
6.0
5.9
11
4
MAX9505 toc08
6.1
12
10
1
OUTPUT VOLTAGE vs. INPUT VOLTAGE
VOLTAGE GAIN vs. TEMPERATURE
13
-15
0.1
FREQUENCY (MHz)
6.2
MAX9505 toc07
MODE0 = SGND, MODE1 = VDD
-40
0.01
FREQUENCY (MHz)
FREQUENCY (MHz)
14
100
10
MAX9505 toc09
GAIN FLATNESS (dB)
0
4
-60
6
10
GAIN (dB)
GAIN FLATNESS (dB)
0
LARGE-SIGNAL GAIN vs. FREQUENCY
20
MAX9505 toc02
10
GAIN (dB)
8
MAX9505 toc01
20
MAX9505 toc03
SMALL-SIGNAL GAIN vs. FREQUENCY
SUPPLY CURRENT (mA)
MAX9505
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
-1
-40
-15
10
35
TEMPERATURE (°C)
60
85
-0.2
0.3
0.8
1.3
1.8
INPUT VOLTAGE (V)
_______________________________________________________________________________________
2.3
2.8
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
2T RESPONSE
MAX9505 toc11
MAX9505 toc10
DIFFERENTIAL GAIN (%)
DIFFERENTIAL PHASE (deg)
DIFFERENTIAL GAIN AND PHASE
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
1
2
3
4
5
VIDIN
200mV/div
6
VIDOUT
400mV/div
1
2
3
4
5
6
100ns/div
OUT RESPONSE
TO NTC-7 VIDEO TEST SIGNAL
12.5T RESPONSE
MAX9505 toc12
MAX9505 toc13
VIDIN
250mV/div
VIDIN
500mV/div
0V
VIDOUT
500mV/div
VIDOUT
1V/div
0V
400ns/div
10µs/div
ON-RESISTANCE vs. VSOUT
FIELD SQUARE-WAVE RESPONSE
MAX9505 toc14
MAX9505 toc15
5
MODE0 = MODE1 = VDD
0V
VIDOUT
1V/div
0V
4
ON-RESISTANCE (Ω)
VIDIN
500mV/div
VDD = 2.7V
3
2
VDD = 3.0V
VDD = 3.6V
1
0
2ms/div
0
0.6
1.2
1.8
2.4
3.0
3.6
VSOUT (V)
_______________________________________________________________________________________
7
MAX9505
Typical Operating Characteristics (continued)
(VDD = CPVDD = MODE1 = 3.0V, MODE0 = SGND = GND = CPGND = 0V, no load, C1 = C2 = C3 = C4 = 1µF, RBIAS = 100kΩ, TA =
TMIN to TMAX. RIN = 150Ω to SGND, unless otherwise noted. VVIDIN = 286mV, gain = 6dB. Typical values are at TA = +25°C, unless
otherwise noted.)
Typical Operating Characteristics (continued)
(VDD = CPVDD = MODE1 = 3.0V, MODE0 = SGND = GND = CPGND = 0V, no load, C1 = C2 = C3 = C4 = 1µF, RBIAS = 100kΩ, TA =
TMIN to TMAX. RIN = 150Ω to SGND, unless otherwise noted. VVIDIN = 286mV, gain = 6dB. Typical values are at TA = +25°C, unless
otherwise noted.)
SWITCH LEAKAGE CURRENT
ON-RESISTANCE vs. VSOUT
vs. TEMPERATURE
800
LEAKAGE CURRENT (pA)
TA = +85°C
3
2
TA = +25°C
600
400
TA = -40°C
SIN ON-LEAKAGE
200
0
0
30
0.5
1.0
1.5
2.0
2.5
3.0
-40
-15
10
35
60
85
VSOUT (V)
TEMPERATURE (°C)
CHARGE INJECTION vs. VSOUT
SUPPLY CURRENT vs. TEMPERATURE
(NORMAL SWITCH MODE)
150
MAX9505 toc18
0
CL = 1nF
25
20
VDD = 3V
MODE0 = MODE1 = VDD
120
SUPPLY CURRENT (nA)
CHARGE INJECTION (pC)
SOUT OFF-LEAKAGE
15
10
5
0
MAX9505 toc19
ON-RESISTANCE (Ω)
4
MAX9505 toc17
MODE0 = MODE1 = VDD
1
1000
MAX9505 toc16
5
90
60
30
-5
-10
0.5
1.0
1.5
2.0
2.5
0
3.0
-40
-15
10
35
60
TEMPERATURE (°C)
ON-RESPONSE, OFF-ISOLATION,
CROSSTALK vs. FREQUENCY
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
20
ON-RESPONSE
0
10
VSIN = 2VP-P
RL = 600Ω
1
OFF-ISOLATION
THD+N (%)
-20
85
MAX9505 toc21
VSOUT (V)
MAX9505 toc20
0
LOSS (dB)
MAX9505
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
-40
-60
0.1
VIDOUT CROSSTALK
-80
0.01
-100
VIDIN CROSSTALK
-120
0.001
0.01
0.1
1
FREQUENCY (MHz)
8
10
0.01
0.1
1
10
FREQUENCY (kHz)
_______________________________________________________________________________________
100
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
PIN
NAME
QSOP
TQFN
1
15
VSS
2
16
CPVSS
3
1
C1N
4
2
CPGND
5
3
C1P
6
4
CPVDD
7
5
BIAS
8
6
SGND
FUNCTION
Negative Power Supply. Connect to CPVSS.
Charge-Pump Negative Power Supply. Bypass with a 1µF capacitor to CPGND.
Charge-Pump Flying Capacitor Negative Terminal. Connect a 1µF capacitor from C1P to C1N.
Charge-Pump Power Ground
Charge-Pump Flying Capacitor Positive Terminal. Connect a 1µF capacitor from C1P to C1N.
Charge-Pump Positive Power Supply. Bypass with a 1µF capacitor to CPGND.
Common-Mode Voltage. Connect a 100kΩ resistor from BIAS to SGND.
Signal Ground. Connect to GND.
9
7
VIDIN
10
8
MODE0
Mode Logic Input 0. See Table 1.
Video Input
11
9
MODE1
Mode Logic Input 1. See Table 1.
12
10
GND
Ground. Connect to SGND.
13
11
VDD
Positive Power Supply. Bypass with a 1µF capacitor to SGND.
14
12
SOUT
Analog Switch Output
15
13
VIDOUT
16
14
SIN
Analog Switch Input
—
EP
EP
Exposed Paddle. Connect to GND.
Video Output
Detailed Description
The MAX9505 completely eliminates the need for
capacitors in the video output by using Maxim’s
DirectDrive technology that includes an inverting
charge pump and linear regulator. The charge pump
and linear regulator create a clean negative supply
allowing the amplifier output to swing below ground.
The amplifier output can swing both positive and negative so that the video signal black level can be placed
at ground. The MAX9505 features a six-pole,
Butterworth filter to perform reconstruction filtering on
the video input signal from the DAC.
DirectDrive
Background
Integrated video filter/amplifier circuits operating from a
single, positive supply usually create video output signals that are level-shifted above ground to keep the
signal within the linear range of the output amplifier. For
applications in which the positive DC level shift of the
video signal is not acceptable, a series capacitor can
be inserted in the output connection in an attempt to
eliminate the positive DC level shift. The series capacitor cannot truly level shift a video signal because the
average level of the video varies with picture content.
The series capacitor biases the video output signal
around ground, but the actual level of the video signal
can vary significantly depending upon the RC time constant and the picture content.
The series capacitor creates a highpass filter. Since
the lowest frequency in video is the frame rate, which
can be between 24Hz and 30Hz, the pole of the highpass filter should ideally be an order of magnitude
lower in frequency than the frame rate. Therefore, the
series capacitor must be very large, typically from
220µF to 3000µF. For space-constrained equipment,
the series capacitor is unacceptable. Changing from a
single series capacitor to a SAG network that requires
two smaller capacitors can only reduce space and
cost slightly.
The series capacitor in the usual output connection
also prevents damage to the output amplifier if the connector is shorted to a supply or to ground. While the
output connection of the MAX9505 does not have a
series capacitor, the MAX9505 will not be damaged if
the connector is shorted to a supply or to ground (see
the Short-Circuit Protection section).
_______________________________________________________________________________________
9
MAX9505
Pin Description
MAX9505
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
INPUT
500mV/div
0V
0V
OUTPUT
500mV/div
0V
2ms/div
Figure 3. AC-Coupled Output
Video Amplifier
Typically, the black level of the video signal created by
the video DAC is around 300mV. The MAX9505 shifts
the black level to ground at the output. Therefore, the
active video is above ground, and sync is below
ground. The amplifier needs a negative supply for its
output stage to remain in its linear region when driving
sync below ground.
The MAX9505 has an integrated charge pump and linear
regulator to create a low-noise negative supply from the
positive supply voltage. The charge pump inverts the
positive supply to create a raw negative voltage that is
then fed into the linear regulator, which outputs -2V. The
linear regulator filters out the charge-pump noise.
Comparison Between DirectDrive Output
and AC-Coupled Output
The actual level of the video signal varies less with a
DirectDrive output than an AC-coupled output. The
video signal average can change greatly depending
upon the picture content. With an AC-coupled output,
the average will change according to the time constant
formed by the series capacitor and series resistance
(usually 150Ω). For example, Figure 3 shows an ACcoupled video signal alternating between a completely
black screen and a completely white screen. Notice the
excursion of the video signal as the screen changes.
With the DirectDrive amplifier, the black level is held at
ground. The video signal is constrained between
-0.3V to +0.7V. Figure 4 shows the video signal from a
DirectDrive amplifier with the same input signal as the
AC-coupled system.
10
INPUT
500mV/div
0V
OUTPUT
500mV/div
2ms/div
Figure 4. DirectDrive Output
Analog Switch
The MAX9505 features an internal 4.4Ω (max) analog
normally open switch that interfaces with a 4-pole multimedia jack in which one of the poles can be set to a
video input, a video output, or a microphone input. The
switch has three modes of operation: open, normal
switch, and extended range switch. In normal switch
mode, the analog range is from 0V to VDD. In extendedrange switch mode, the analog range is from -2V to
VDD. Logic inputs MODE1 and MODE0 control the analog switch operating modes (Table 1).
Video Reconstruction Filter
Before the video signal from the DAC can be amplified,
it must be lowpass filtered to smooth the steps and to
reduce the spikes created whenever the DAC output
changes value. In the frequency domain, the steps and
spikes cause images of the video signal to appear at
multiples of the sampling clock. The MAX9505 contains
a six-pole Butterworth lowpass filter. The passband
extends to 5.5MHz, and the minimum attenuation is
35dB at 27MHz.
Operating Modes
The MAX9505 uses two logic inputs to set the device
into one of the following modes: 1) shutdown mode, 2)
extended-range switch mode, 3) video output mode,
and 4) normal switch mode.
In video output mode, the video circuitry is on, the
charge pump is on, and the analog switch is open. In
normal switch mode, the analog switch is closed, and
the video circuitry and charge pump are off. In the
extended-range switch mode, the charge pump is on
and the analog switch is closed. Shutdown mode
reduces the supply current to 10nA typically (see Table
1 and Typical Application Circuits).
______________________________________________________________________________________
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
MAX9505
Table 1. Operating Modes
MODE1
MODE0
VIDEO
CIRCUIT
CHARGE
PUMP
ANALOG
SWITCH
Shutdown Mode
0
0
Off
Off
Open
Video output is 4kΩ and analog
switch is open
Extended Range Switch
Mode
0
1
Off
On
Closed
Video output is high impedance.
Analog switch range is from -2V
to VDD.
Video Output Mode
1
0
On
On
Open
Video output is in normal operation.
Analog switch is open.
Normal Switch Mode
1
1
Off
Off
Closed
Video output is high impedance.
Analog switch range is from SGND
to VDD.
OPERATING MODE
Short-Circuit Protection
The MAX9505 typical operating circuit includes a 75Ω
back-termination resistor that limits short-circuit current if
an external short is applied to the video output. The
MAX9505 features internal output, short-circuit protection
to prevent device damage in prototyping and applications where the amplifier output can be directly shorted.
Shutdown
The MAX9505 features a low-power shutdown mode for
battery-powered/portable applications. Shutdown
reduces the quiescent current to less than 10nA. Setting
MODE1 and MODE0 low disables the outputs and
places the MAX9505 into a low-power shutdown mode.
In shutdown mode the amplifier, charge pump, and linear regulator are turned off and the video output resistance is 4kΩ.
COMMENTS
Applications Information
Power-Supply Bypassing and Ground
Management
The MAX9505 operates from a 2.7V to 3.6V single supply and requires proper layout and bypassing. For the
best performance, place the components as close to
the device as possible.
Proper grounding improves performance and prevents
any switching noise from coupling into the video signal.
Connect GND and SGND together at a single point on
the PC board. Route all traces that carry switching transients away from SGND. Return SGND to the lowest
impedance ground available. Route CPGND and all
traces carrying switching transients away from SGND,
GND, and other traces and components in the video
signal path. Bypass the analog supply (VDD) with a 1µF
capacitor to SGND, placed as close to the device as
possible. Bypass the charge-pump supply (CPV DD)
with a 1µF capacitor to CPGND, placed as close to the
device as possible. Connect CPVSS to VSS and bypass
with a 1µF capacitor to CPGND as close to the device
as possible.
______________________________________________________________________________________
11
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
VDD
GND
MODE1
TOP VIEW
SOUT
MAX9505
Pin Configurations
12
11
10
9
VSS 1
VIDOUT
13
8
MODE0
SIN
14
7
VIDIN
16 SIN
CPVSS 2
15 VIDOUT
C1N 3
MAX9505
13 VDD
C1P 5
12 GND
MAX9505
VSS
15
6
SGND
CPVSS
16
5
BIAS
CPVDD 6
11 MODE1
BIAS 7
10 MODE0
SGND 8
4
9
VIDIN
QSOP
CPVDD
3
C1P
2
CPGND
C1N
1
14 SOUT
CPGND 4
3mm x 3mm TQFN
Functional Diagram/Typical Operating Circuits
BIAS
1V
100kΩ
MAX9505
VDD
MODE1
LOGIC
CONTROL
MODE0
VIDEO
ASIC
6dB
BUFFER
VIDIN
DAC
SGND
150Ω
C4
1µF
VIDEO
AMP
RECONSTRUCTION
FILTER
GND
DC
LEVEL SHIFT
VDD
VIDOUT
75Ω
1
2
3
AUDIO OUT RIGHT
4
GROUND
LINEAR
REGULATOR
CPVDD
CHARGE PUMP
C3
1µF
CPGND C1P
C1N
CPVSS
VSS
C1
1µF
C2
1µF
VIDEO OUTPUT MODE
12
VIDEO OUT
AUDIO OUT LEFT
______________________________________________________________________________________
4-POLE MULTIMEDIA JACK
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
2.8V FROM LDO
BASEBAND
IC
2kΩ
1µF
SIN
SOUT
MIC
AMP
2kΩ
BIAS
1V
100kΩ
VIDOUT
MAX9505
1
2
VDD
MODE1
MODE0
75Ω
LOGIC
CONTROL
MIC INPUT
AUDIO OUT LEFT
3
AUDIO OUT RIGHT
4
GROUND
4-POLE MULTIMEDIA JACK
SGND
C4
1µF
GND
VDD
CPVDD
C3
1µF
CPGND C1P
C1N
CPVSS
VSS
C1
1µF
NORMAL SWITCH MODE
POLE 1 USED AS A MICROPHONE INPUT
C2
1µF
______________________________________________________________________________________
13
MAX9505
Functional Diagram/Typical Operating Circuits (continued)
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
MAX9505
Functional Diagram/Typical Operating Circuits (continued)
VIDEO
DECODER
SIN
SOUT
75Ω
BIAS
1V
100kΩ
VIDOUT
MAX9505
1
VIDEO INPUT
2
VDD
MODE1
MODE0
75Ω
LOGIC
CONTROL
AUDIO OUT LEFT
3
AUDIO OUT RIGHT
4
GROUND
4-POLE MULTIMEDIA JACK
SGND
C4
1µF
LINEAR
REGULATOR
GND
VDD
CPVDD
CHARGE PUMP
C3
1µF
CPGND C1P
C1N
CPVSS
VSS
C1
1µF
NORMAL SWITCH MODE
POLE 1 USED AS A VIDEO INPUT
C2
1µF
Chip Information
PROCESS: BICMOS
14
______________________________________________________________________________________
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
QSOP.EPS
PACKAGE OUTLINE, QSOP .150", .025" LEAD PITCH
21-0055
E
1
1
______________________________________________________________________________________
15
MAX9505
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
(NE - 1) X e
E
MARKING
12x16L QFN THIN.EPS
MAX9505
DirectDrive Video Amplifier with
Reconstruction Filter and Analog Switch
E/2
D2/2
(ND - 1) X e
AAAA
D/2
e
CL
D
D2
k
b
CL
0.10 M C A B
E2/2
L
E2
CL
0.10 C
CL
0.08 C
A
A2
L
A1
L
e
e
PACKAGE OUTLINE
12, 16L THIN QFN, 3x3x0.8mm
F
21-0136
PKG
12L 3x3
MIN.
NOM.
MAX.
MIN.
NOM.
MAX.
A
0.70
0.75
0.80
0.70
0.75
0.80
b
0.20
0.25
0.30
0.20
0.25
0.30
D
2.90
3.00
3.10
2.90
3.00
3.10
E
e
2.90
3.00
3.10
2.90
3.00
3.10
L
0.45
0.50 BSC.
0.50 BSC.
0.65
0.30
0.40
0.50
EXPOSED PAD VARIATIONS
PKG.
CODES
T1233-1
E2
D2
DOWN
BONDS
ALLOWED
PIN ID
JEDEC
1.25
0.35 x 45°
WEED-1
NO
MIN.
NOM.
MAX.
MIN.
NOM. MAX.
0.95
1.10
1.25
0.95
1.10
T1233-3
0.95
1.10
1.25
0.95
1.10
1.25
0.35 x 45°
WEED-1
YES
T1233-4
0.95
1.10
1.25
0.95
1.10
1.25
0.35 x 45°
WEED-1
YES
T1633-1
0.95
1.10
1.25
0.95
1.10
1.25
0.35 x 45°
WEED-2
NO
N
12
16
T1633-2
0.95
1.10
1.25
0.95
1.10
1.25
0.35 x 45°
WEED-2
YES
ND
3
4
T1633F-3
0.65
0.80
0.95
0.65
0.80
0.95
0.225 x 45°
WEED-2
N/A
T1633FH-3
0.65
0.80
0.95
0.65
0.80
0.95
0.225 x 45°
WEED-2
N/A
T1633-4
0.95
1.10
1.25
0.95
1.10
1.25
0.35 x 45°
WEED-2
NO
NE
A1
A2
k
3
0
0.02
0.20 REF
0.25
2
16L 3x3
REF.
0.55
1
4
0.05
-
0
0.02
0.05
0.25
0.20 REF
-
-
NOTES:
1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994.
2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES.
3. N IS THE TOTAL NUMBER OF TERMINALS.
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO
JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED
WITHIN THE ZONE INDICATED. THE TERMINAL #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE.
5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.20 mm AND 0.25 mm
FROM TERMINAL TIP.
6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY.
7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION.
8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS.
9. DRAWING CONFORMS TO JEDEC MO220 REVISION C.
10. MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY
11. NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY
PACKAGE OUTLINE
12, 16L THIN QFN, 3x3x0.8
21-0136
F
2
2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2005 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products. Inc.
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