EL4453 Datasheet

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January 1995, Rev A
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8-INT
1-88
EL4453
®
FN7171
Video Fader
Features
The EL4453 is a complete fader
subsystem. It variably blends two
inputs together for such applications
as video picture-in-picture effects.
• Complete two-input fader with output amplifier—uses no
extra components
The EL4453 operates on ±5V to ±15V supplies and has an
analog differential input range of ±2V. AC characteristics do
not change appreciably over the supply range.
The circuit has an operational temperature of -40°C to +85°C
and is packaged in 14-pin PDIP and SO-14.
The EL4453 is fabricated with Elantec’s proprietary
complementary bipolar process which gives excellent signal
symmetry and is free from latch up.
Pinout
• 80MHz bandwidth
• Fast fade control speed
• Operates on ±5V to ±15V supplies
• > 60dB attenuation @ 5MHz
Applications
• Mixing two inputs
• Picture-in-picture
• Text overlay onto video
• General gain control
EL4453
(14-PIN PDIP, SO)
TOP VIEW
1
Ordering Information
PART
NUMBER
TEMP. RANGE
PACKAGE
PKG. NO.
EL4453CN
-40°C to +85°C
14-Pin PDIP
MDP0031
EL4453CS
-40°C to +85°C
14-Pin SOIC
MDP0027
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2003. All Rights Reserved. Elantec is a registered trademark of Elantec Semiconductor, Inc.
All other trademarks mentioned are the property of their respective owners.
EL4453
Absolute Maximum Ratings (TA = 25°C)
V+
VS
VIN
VIN
IIN
Positive Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . 16.5V
V+ to V- Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . .33V
Voltage at any Input or Feedback . . . . . . . . . . . . . . . V+ to VDifference between Pairs of Inputs or Feedback . . . . . . . .6V
Current into any Input, or Feedback Pin . . . . . . . . . . . . . 4mA
IOUT
PD
TA
TS
Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30mA
Maximum Power Dissipation. . . . . . . . . . . . . . . . See Curves
Operating Temperature Range . . . . . . . . . . . .-40°C to +85°C
Storage Temperature Range- . . . . . . . . . . . . 60°C to +150°C
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests
are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA
Open-Loop DC Electrical Specifications
PARAMETER
VDIFF
Power Supplies at ±5V, Sum+ = Sum- = 0, TA = 25°C
DESCRIPTION
VINA, VINB, or Sum Differential Input Voltage
Clipping
MIN
TYP
1.8
2.0
V
0.7
V
0.2% Nonlinearity
VCM
Common-Mode Range (All Inputs; VDIFF = 0)
MAX
UNITS
VS = ±5V
±2.5
±2.8
V
VS = ±15V
±12.5
±12.8
V
VOS
A or B Input Offset Voltage
VFADE, 100%
Extrapolated Voltage for 100% Gain for VINA
0.9
VFADE, 0%
Extrapolated Voltage for 0% Gain for VINA
-1.2
IB
Input Bias Current (All Inputs) with all VIN = 0
IOS
Input Offset Current between VINA+ and VINA-, VINB+ and VINB-, Fade+ and
Fade-, and Sum+ and Sum-
FT
VINA Signal Feedthrough, VFADE = -1.5V
NL
A or B Input Nonlinearity, VIN between +1V and -1V
25
mV
1.05
1.2
V
-1.15
-0.9
V
9
20
µA
0.2
4
µA
-100
-60
dB
VINA or VINB
0.2
0.5
%
Sum Input
0.5
%
RIN, Signal
Input Resistance, A, B, or Sum Input
230
k
RIN, Fade
Input Resistance, Fade Input
120
k
CMRR
Common-Mode Rejection Ratio, VINA or VINB
70
80
dB
PSRR
Power Supply Rejection Ratio
50
70
dB
EG
Gain Error, VFADE = 1.5V
VO
Output Voltage Swing (VIN = 0, VREF Varied)
ISC
Output Short-Circuit Current
IS
Supply Current, VS = ±15V
2
VINA or VINB
-2
+2
%
Sum Input
-4
+4
%
VS = ±5V
±2.5
±2.8
V
VS = ±15V
±12.5
±12.8
V
40
85
mA
17
21
mA
EL4453
Open-Loop DC Electrical Specifications
Power supplies at ±12V, TA = 25°C, RL = 500, CL = 15pF, VFADE = 1.5V, Sum+ =
Sum- = 0
PARAMETER
DESCRIPTION
MIN
TYP
MAX
UNITS
BW, -3dB
-3dB Small-Signal Bandwidth, VINA or VINB
80
MHz
BW, ±0.1dB
0.1dB Flatness Bandwidth, VINA or VINB
9
MHz
Peaking
Frequency Response Peaking
1.0
dB
BW, Fade
-3dB Small-Signal Bandwidth, Fade Input
80
MHz
SR
Slew Rate, VOUT between -2V and +2V
380
V/µs
VN
Input-Referred Noise Voltage Density
160
nV/Hz
FT
Feedthrough of Faded-Out Channel, F = 3.58MHz
-63
dB
dG
Differential Gain Error, VOFFSET from 0 to ±0.714V,
Fade at 100%
VINA or VINB
0.05
%
Sum Input
0.35
%
Differential Phase Error, VOFFSET from 0 to ±0.71V,
Fade at 100%
VINA or VINB
0.05
(°)
Sum Input
0.1
(°)
d
TBD
Test Circuit
Note: For typical performance curves Sum+ = Sum- = 0, RF = 0W, RG = ,
VFADE = +1.5V, and CL = 15pF, unless otherwise noted.
3
EL4453
Typical Performance Curves
Frequency Response
Frequency Response vs Gain
Frequency Response for
Various Loads, VS = ±5V
Frequency Response for
Various Loads, VS = ±15V
-3dB Bandwidth and Peaking
vs Supply Voltage
4
-3dB Bandwidth and Peaking
vs Die Temperature
EL4453
Typical Performance Curves
(Continued)
Frequency Response for
Different Gains, VS = ±5V
VIN Differential Gain
and Phase Error vs Gain
VIN Differential Phase Error
vs Input Offset Voltage for Gain =
100%, 75%, 50% and 25%. VS = ±5V
5
Input Common-Mode Rejection
Ratio vs Frequency
Input Voltage and Current
Noise vs Frequency
VIN Differential Gain Error
vs Input Offset Voltage
for Gain = 100%, 75%, 50% and 25%
VIN Differential Phase Error
vs Input Offset Voltage for Gain =
100%, 75%, 50% and 25%. VS = ±12V
EL4453
Typical Performance Curves
(Continued)
Nonlinearity vs VIN Signal Span
Slew Rate vs Supply Voltage
VINA Gain vs VFADE
6
Nonlinearity vs Sum Signal Span
Slew Rate vs Die Temperature
Frequency Response of Fade Input
EL4453
Typical Performance Curves
(Continued)
Transient Response of Fade Input
Constant Signal into VINA
VINA Transient Response for Various Gains
Supply Current vs Supply Voltage
7
Overdrive Recovery Glitch from
VFADE, No Input Signal
Cross-Fade Balance with VINA = VINB = 0
Supply Current vs Die Temperature
EL4453
FIGURE 1.
Applications Information
The EL4453 is a complete two-quadrant fader/gain control
with 80MHz bandwidth. It has four sets of inputs; a
differential signal input VINA, a differential signal input VINB,
a differential fade-controlling input VFADE, and another
differential input Sum which can be used to add in a third
input at full gain. This is the general connection of the
EL4453 (Figure 1).
The gain of the feedback dividers are HA and HB, and
0  H  1. The transfer function of the part is:
VOUT = AO [((VINA+) – HA VOUT) (1 + (VFADE+)
- (VFADE-)) / 2 + ((VINB+) – HB VOUT) (1 - (VFADE+)
+ (VFADE-)) / 2 + (Sum+) – (Sum-))],
with -1  (VFADE+)–(VFADE-)  +1 numerically.
AO is the open-loop gain of the amplifier, and is about 600.
The large value of AO drives:
((VINA+) – HA VOUT) (1 + (VFADE+) – (VFADE-)) / 2
+ ((VINB+) – HB VOUT) (1- (VFADE+) + (VFADE-)) / 2
+ (Sum+) – (Sum-))0.
Rearranging and substituting:
F  V IN A + F  V IN B + Sum
V OUT = -------------------------------------------------------------------------F  HA + F  HB
F =  1 +  V FADE+  –  V FADE-    2
F =  1 –  V FADE+  +  V FADE-    2
and Sum =  Sum+  –  Sum- 
Where
In the above equations, F represents the fade amount, with
F = 1 giving 100% gain on VINA but 0% for VINB; F = 0
giving 0% gain for VINA but 100% to VINB. F is 1 - F, the
complement of the fade gain. When F = 1,
V IN A + Sum
V OUT = ---------------------------------HA
8
and the amplifier passes VINA and Sum with a gain of 1/HA.
Similarly, for F = 0,
V IN B + Sum
V OUT = ---------------------------------HA
and the gains vary linearly between fade extremes.
The EL4453 is stable for a direct connection between VOUT
and VINA- or VINB-, yielding a gain of +1. The feedback
divider may be used for higher output gain, although with the
traditional loss of bandwidth. It is important to keep the
feedback divider’s impedances low so that stray capacitance
does not diminish the feedback loop’s phase margin. The
pole caused by the parallel impedance of the feedback
resistors and stray capacitance should be at least 150MHz;
typical strays of 3pF thus require a feedback impedance of
360 or less. Alternatively, a small capacitor across RF can
be used to create more of a frequency-compensated divider.
The value of the capacitor should scale with the parasitic
capacitance at the FB input. It is also practical to place small
capacitors across both the feedback resistors (whose values
maintain the desired gain) to swamp out parasitics. For
instance, two 10pF capacitors across equal divider resistors
for a gain of two will dominate parasitic effects and allow a
higher divider resistance. Either input channel can be set up
for inverting gain using traditional feedback resistor
connections.
At 100% gain, an input stage operates just like an op-amp’s
input, and the gain error is very low, around -0.2%.
Furthermore, nonlinearities are vastly improved since the
gain core sees only small error signals, not full inputs.
Unfortunately, distortions increase at lower fade gains for a
given input channel.
The Sum pins can be used to inject an additional input
signal, but it is not as linear as the VIN paths. The gain error
is also not as good as the main inputs, being about 1%. Both
sum pins should be grounded if they are not to be used.
EL4453
Fade-Control Characteristics
The quantity VFADE in the above equations is bounded as
-1  VFADE  1, even though the externally applied voltages
often exceed this range. Actually, the gain transfer function
around -1V and +1V is “soft”, that is, the gain does not clip
abruptly below the 0%-VFADE voltage or above the 100%–
VFADE level. An overdrive of 0.3V must be applied to VFADE
to obtain truly 0% or 100%. Because the 0% = or 100%VFADE levels cannot be precisely determined, they are
extrapolated from two points measured inside the slope of
the gain transfer curve. Generally, an applied VFADE range
of -1.5V to +1.5V will assure the full span of numerical
-1  VFADE  1 and 0  F 1.
The fade control has a small-signal bandwidth equal to the
VIN channel bandwidth, and overload recovery resolves in
about 20ns.
tantalum capacitors are very good, and no smaller bypasses
need be placed in parallel. Capacitors as small as 0.01µF
can be used if small load currents flow.
Singe-polarity supplies, such as +12V with +5V can be used,
where the ground pin is connected to +5V and V- to ground.
The inputs and outputs will have to have their levels shifted
above ground to accommodate the lack of negative supply.
The dissipation of the fader increases with power supply
voltage, and this must be compatible with the package
chosen. This is a close estimate for the dissipation of a
circuit:
PD = 2VS, maxVS+(VS-VO)VO/RPAR
where
IS, max is the maximum supply current
Input Connections
VS is the ± supply voltage (assumed equal)
The input transistors can be driven from resistive and
capacitive sources, but are capable of oscillation when
presented with an inductive input. It takes about 80nH of
series inductance to make the inputs actually oscillate,
equivalent to four inches of unshielded wiring or about six
inches of unterminated input transmission line. The
oscillation has a characteristic frequency of 500MHz. Often
placing one’s finger (via a metal probe) or an oscilloscope
probe on the input will kill the oscillation. Normal high
frequency construction obviates any such problems, where
the input source is reasonably close to the fader input. If this
is not possible, one can insert series resistors of around 51
to de-Q the inputs.
VO is the output voltage
Signal Amplitudes
Signal input common-mode voltage must be between
(V-) + 2.5V and (V+) - 2.5V to ensure linearity. Additionally,
the differential voltage on any input stage must be limited to
±6V to prevent damage. The differential signal range is ±2V
in the EL4453. The input range is substantially constant with
temperature.
The Ground Pin
The ground pin draws only 6µA maximum DC current, and
may be biased anywhere between (V-) +2.5V and
(V+) - 3.5V. The ground pin is connected to the IC’s
substrate and frequency compensation components. It
serves as a shield within the IC and enhances input stage
CMRR and channel-to-channel isolation over frequency, and
if connected to a potential other than ground, it must be
bypassed.
Power Supplies
The EL4453 works well on any supplies from ±3V to ±15V.
The supplies may be of different voltages as long as the
requirements of the GND pin are observed (see the Ground
Pin section for a discussion). The supplies should be
bypassed close to the device with short leads. 4.7µF
9
RPAR is the parallel of all resistors loading the output
For instance, the EL4453 draws a maximum of 21 mA. With
light loading, RPARand the dissipation with ±5V supplies
is 210mW. The maximum supply voltage that the device can
run on for a given PD and the other parameters is:
VS, max = (PD+VO2/RPAR)/(2IS+VO/RPAR)
The maximum dissipation a package can offer is:
PD, max = (TD, max - TA, max)/JA
where
TD, max is the maximum die temperature, 150°C for
reliability, less to retain optimum electrical performance
TA, max is the ambient temperature, 70°C for commercial
and 85°C for industrial range
JA is the thermal resistance of the mounted package,
obtained from datasheet dissipation curves
The more difficult case is the SO-14 package. With a
maximum die temperature of 150°C and a maximum
ambient temperature of 70°C, the 80°C temperature rise and
package thermal resistance of 110°/W gives a dissipation of
636mW at 85°C.
This allows ±15V operation over the commercial
temperature range, but higher ambient temperature or
output loading may require lower supply voltages.
Output Loading
The output stage of the EL4453 is very powerful. It typically
can source 80mA and sink 120mA. Of course, this is too
much current to sustain and the part will eventually be
destroyed by excessive dissipation or by metal traces on the
die opening. The metal traces are completely reliable while
delivering the 30mA continuous output given in the Absolute
EL4453
Maximum Ratings table in this data sheet, or higher purely
transient currents.
Gain changes only 0.2% from no load to 100 load. Heavy
resistive loading will degrade frequency response and video
distortion for loads < 100.
Capacitive loads will cause peaking in the frequency
response. If capacitive loads must be driven, a small-valued
series resistor can be used to isolate it. 12 to 51 should
suffice. A 22 series resistor will limit peaking to 2.5dB with
even a 220pF load.
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