DATASHEET

EL8302
®
Data Sheet
May 6, 2005
500MHz Rail-to-Rail Amplifier
Features
The EL8302 represents a triple rail-to-rail amplifier with a 3dB bandwidth of 500MHz and slew rate of 600V/µs.
Running off a very low supply current of 5.6mA per channel,
the EL8302 also features inputs that go to 0.15V below the
VS- rail.
• 500MHz -3dB bandwidth
The EL8302 includes a fast-acting disable/power-down
circuit. With a 25ns disable and a 200ns enable, the EL8302
is ideal for multiplexing applications.
• Rail-to-rail output
The EL8302 is designed for a number of general purpose
video, communication, instrumentation, and industrial
applications. The EL8302 is available in an 16-pin SO and
16-pin QSOP packages and is specified for operation over
the -40°C to +85°C temperature range.
Pinout
FN7348.2
• 600V/µs slew rate
• Low supply current = 5.6mA per amplifier
• Supplies from 3V to 5.5V
• Input to 0.15V below VS• Fast 25ns disable
• Low cost
• Pb-Free available (RoHS compliant)
Applications
• Video amplifiers
EL8302
(16-PIN SO, QSOP)
TOP VIEW
INA+ 1
CEA 2
16 INA+
VS- 3
CEB 4
14 VS+
+
-
INB+ 5
NC 6
CEC 7
15 OUTA
+
-
INC+ 8
• Portable/hand-held products
• Communications devices
Ordering Information
PART
NUMBER
PACKAGE
TAPE & REEL PKG. DWG. #
EL8302IS
16-Pin SO
-
MDP0027
13 OUTB
EL8302IS-T7
16-Pin SO
7”
MDP0027
12 INB-
EL8302IS-T13
16-Pin SO
13”
MDP0027
11 NC
EL8302ISZ
(See Note)
16-Pin SO
(Pb-free)
-
MDP0027
EL8302ISZ-T7
(See Note)
16-Pin SO
(Pb-free)
7”
MDP0027
EL8302ISZ-T13
(See Note)
16-Pin SO
(Pb-free)
13”
MDP0027
EL8302IU
16-Pin QSOP
-
MDP0040
EL8302IU-T7
16-Pin QSOP
7”
MDP0040
EL8302IU-T13
16-Pin QSOP
13”
MDP0040
EL8302IUZ
(See Note)
16-Pin QSOP
(Pb-free)
-
MDP0040
EL8302IUZ-T7
(See Note)
16-Pin QSOP
(Pb-free)
7”
MDP0040
EL8302IUZ-T13
(See Note)
16-Pin QSOP
(Pb-free)
13”
MDP0040
10 OUTC
9 INC-
NOTE: Intersil Pb-free products employ special Pb-free material sets;
molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible with
both SnPb and Pb-free soldering operations. Intersil Pb-free products
are MSL classified at Pb-free peak reflow temperatures that meet or
exceed the Pb-free requirements of IPC/JEDEC J STD-020.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-352-6832 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2003, 2005. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
EL8302
Absolute Maximum Ratings (TA = 25°C)
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +125°C
Ambient Operating Temperature . . . . . . . . . . . . . . . .-40°C to +85°C
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . +125°C
Supply Voltage from VS+ to VS- . . . . . . . . . . . . . . . . . . . . . . . . . 5.5V
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . VS+ + 0.3V to VS- -0.3V
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2V
Continuous Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . 40mA
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. Typ values are for information purposes only. Unless otherwise noted, all tests are
at the specified temperature and are pulsed tests, therefore: TJ = TC = TA
Electrical Specifications
PARAMETER
VS+ = 5V, VS- = GND, TA = 25°C, VCM = 2.5V, RL to 2.5V, AV = 1, Unless Otherwise Specified
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
-7
-0.8
+7
mV
INPUT CHARACTERISTICS
VOS
Offset Voltage
TCVOS
Offset Voltage Temperature Coefficient Measured from TMIN to TMAX
IB
Input Bias Current
VIN = 0V
IOS
Input Offset Current
VIN = 0V
TCIOS
Input Bias Current Temperature
Coefficient
Measured from TMIN to TMAX
CMRR
Common Mode Rejection Ratio
VCM = -0.15V to +3.5V
CMIR
Common Mode Input Range
RIN
Input Resistance
CIN
Input Capacitance
AVOL
Open Loop Gain
-10
3
µV/°C
-6
µA
0.1
70
µA
2
nA/°C
95
dB
VS- -0.15
Common Mode
0.6
VS+ - 1.5
V
7
MΩ
0.5
pF
100
dB
VOUT = +1.5V to +3.5V, RL = 150Ω to
GND
80
dB
30
mΩ
VOUT = +1.5V to +3.5V, RL = 1kΩ to GND
75
OUTPUT CHARACTERISTICS
ROUT
Output Resistance
AV = +1
VOP
Positive Output Voltage Swing
RL = 1kΩ
4.85
4.9
V
RL = 150Ω
4.65
4.7
V
VON
Negative Output Voltage Swing
RL = 150Ω
150
200
mV
RL = 1kΩ
50
70
mV
IOUT
Linear Output Current
ISC (source)
Short Circuit Current
RL = 10Ω
ISC (sink)
Short Circuit Current
65
mA
50
80
mA
RL = 10Ω
90
150
mA
VS+ = 4.5V to 5.5V
70
95
dB
POWER SUPPLY
PSRR
Power Supply Rejection Ratio
IS-ON
Supply Current - Enabled per Amplifier
5.6
6.2
mA
IS-OFF
Supply Current - Disabled per Amplifier
40
90
µA
tEN
Enable Time
200
ns
tDS
Disable Time
25
ns
VIH-ENB
ENABLE Pin Voltage for Power-up
0.8
V
VIL-ENB
ENABLE Pin Voltage for Shut-down
2
V
ENABLE
2
EL8302
Electrical Specifications
PARAMETER
VS+ = 5V, VS- = GND, TA = 25°C, VCM = 2.5V, RL to 2.5V, AV = 1, Unless Otherwise Specified
DESCRIPTION
CONDITIONS
MIN
TYP
MAX
UNIT
IIH-ENB
ENABLE Pin Input Current High
8.6
µA
IIL-ENB
ENABLE Pin Input for Current Low
0.01
µA
AV = +1, RF = 0Ω, CL = 1.5pF
500
MHz
AV = -1, RF = 1kΩ, CL = 1.5pF
140
MHz
AV = +2, RF = 1kΩ, CL = 1.5pF
165
MHz
AV = +10, RF = 1kΩ, CL = 1.5pF
18
MHz
AC PERFORMANCE
BW
-3dB Bandwidth
BW
±0.1dB Bandwidth
AV = +1, RF = 0Ω, CL = 1.5pF
36
MHz
Peak
Peaking
AV = +1, RL = 1kΩ, CL = 1.5pF
1
dB
GBWP
Gain Bandwidth Product
200
MHz
PM
Phase Margin
RL = 1kΩ, CL = 1.5pF
55
°
SR
Slew Rate
AV = 2, RL = 100Ω, VOUT = 0.5V to 4.5V
600
V/µs
tR
Rise Time
2.5VSTEP, 20% - 80%
4
ns
tF
Fall Time
2.5VSTEP, 20% - 80%
2
ns
OS
Overshoot
200mV step
10
%
tPD
Propagation Delay
200mV step
1
ns
tS
0.1% Settling Time
200mV step
15
ns
dG
Differential Gain
AV = +2, RF = 1kΩ, RL = 150Ω
0.01
%
dP
Differential Phase
AV = +2, RF = 1kΩ, RL = 150Ω
0.01
°
eN
Input Noise Voltage
f = 10kHz
12
nV/√Hz
iN+
Positive Input Noise Current
f = 10kHz
1.7
pA/√Hz
iN-
Negative Input Noise Current
f = 10kHz
1.3
pA/√Hz
eS
Channel Separation
f = 100kHz
95
dB
500
Pin Descriptions
PIN
NAME
1, 5, 8
INA+, INB+, INC+
Non-inverting input for each channel
2, 4, 7
CEA, CEB, CEC
Enable and disable input for each channel
3
VS-
Negative power supply
6, 11
NC
Not connected
9, 12, 16
INC-, INB-, INA-
10, 13, 15
OUTC, OUTB, OUTA
14
VS+
3
FUNCTION
Inverting input for each channel
Amplifier output for each channel
Positive power supply
EL8302
Typical Performance Curves
3
2
GAIN (dB)
5
VS=5V
AV=1
RL=1kΩ
CL=1.5pF
NORMALIZED GAIN (dB)
5
4
VOP-P=200mV
1
0
-1
VOP-P=1V
-2
-3
VOP-P=2V
-4
-5
1M
10M
RF=RG=1kΩ
-1
-3
RF=RG=500Ω
VS=5V
AV=2
RL=1kΩ
CL=1.5pF
1M
FREQUENCY (Hz)
5
NORMALIZED GAIN (dB)
NORMALIZED GAIN (dB)
2
AV=2
1
AV=1
0
-1
AV=5
-2
-3
AV=10
-4
-5
1M
10M
100M
2
VS=5V
CL=1.5pF
RL=1kΩ
RF=1kΩ
AV=-1
AV=-5
-2
-4
AV=-10
-6
100K
1G
1M
GAIN (dB)
9
RL=100Ω
RL=1kΩ
GAIN (dB)
3
2
1
0
1G
-1
VS=5V
AV=2
CL=1.5pF
RF=RG=1kΩ
RL=500Ω
7
5
RL=1kΩ,
150Ω
-2
3
-3
-4
-5
1M
100M
FIGURE 4. SMALL SIGNAL FREQUENCY RESPONSE FOR
VARIOUS INVERTING GAINS
11
VS=5V
AV=1
CL=1.5pF
VOP-P=200mV
10M
FREQUENCY (Hz)
FIGURE 3. SMALL SIGNAL FREQUENCY RESPONSE FOR
VARIOUS NON-INVERTING GAINS
5
1G
0
FREQUENCY (Hz)
4
100M
FIGURE 2. SMALL SIGNAL FREQUENCY RESPONSE
vs RF AND RG
4
VS=5V
CL=1.5pF
RL=1kΩ
3
10M
FREQUENCY (Hz)
FIGURE 1. FREQUENCY RESPONSE FOR VARIOUS OUTPUT
VOLTAGE LEVELS
4
RF=RG=2kΩ
1
-5
100K
1G
100M
3
RL=500Ω
10M
100M
1G
FREQUENCY (Hz)
FIGURE 5. SMALL SIGNAL FREQUENCY RESPONSE FOR
VARIOUS RLOAD
4
1
100K
1M
10M
100M
1G
FREQUENCY (Hz)
FIGURE 6. SMALL SIGNAL FREQUENCY RESPONSE vs
VARIOUS RLOAD
EL8302
Typical Performance Curves (Continued)
16
VS=5V
AV=1
RL=1kΩ
VOP-P=200mV
4
3
GAIN (dB)
2
12
CL=3.7pF
10
1
0
-1
CL=1.5pF
-2
4
-3
-2
CL=10pF
CL=1.5pF
-4
1M
1G
FIGURE 7. SMALL SIGNAL FREQUENCY RESPONSE vs CL
70 R =150Ω
L
315
-30
30
225
RL=150Ω
-10
135
RL=1kΩ
-90
1K
10K
GAIN (dB)
-10
RL=1kΩ
PHASE (°)
GAIN (dB)
FIGURE 8. SMALL SIGNAL FREQUENCY RESPONSE FOR
VARIOUS CL
405
-50
1M
10M
100M
VS=5V
AV=1
RL=1kΩ
-50
-70
-90
45
100K
1G
100M
10M
FREQUENCY (Hz)
FREQUENCY (Hz)
110
CL=13.5pF
2
100M
CL=28.5pF
6
-4
10M
CL=20pF
8
0
-5
1M
VS=5V
AV=2
RL=1kΩ
RF=RG=1kΩ
14
CL=4.8pF
GAIN (dB)
5
-110
1K
-45
1G
10K
1M
100K
10M
100M
1G
FREQUENCY (Hz)
FREQUENCY (Hz)
FIGURE 9. OPEN LOOP GAIN AND PHASE vs FREQUENCY
FIGURE 10. DISABLED OUTPUT ISOLATION FREQUENCY
RESPONSE
-10
550
-30
450
BANDWIDTH (MHz)
PSRR (dB)
500
PSRR-
-50
-70
PSRR+
-90
RL=1kΩ
CL=1.5pF
400
AV=1
350
300
250
200
AV=2
150
-110
1K
100
10K
100K
1M
FREQUENCY (Hz)
FIGURE 11. POWER SUPPLY REJECTION
RATIO vs FREQUENCY
5
10M
100M
3
3.5
4.5
4
5
5.5
VS (V)
FIGURE 12. SMALL SIGNAL BANDWIDTH vs
SUPPLY VOLTAGE
EL8302
Typical Performance Curves (Continued)
2.5
100
RL=1kΩ
CL=1.5pF
PEAKING (dB)
IMPEDANCE (Ω)
2
10
1
0.1
AV=1
1.5
1
0.5
0
0.01
10K
100K
1M
10M
100M
AV=2
3
4
3.5
4.5
FREQUENCY (Hz)
10
-35
8
-55
6
IS (mA)
CMRR (dB)
-15
-75
4
2
-95
-115
100K
1M
10M
0
100M
0.5
0
1
1.5
2
2.5
3
3.5
4.5
4
5
5.5
VS (V)
FREQUENCY (Hz)
FIGURE 15. COMMON-MODE REJECTION RATIO vs
FREQUENCY
FIGURE 16. SUPPLY CURRENT vs SUPPLY VOLTAGE (PER
AMPLIFIER)
-70
V
VS
=5V
S=5V
R
=1kΩ
RLL=1kΩ
C
=1.5pF
CLL=1.5p
F
AV=2
-70
-80
[email protected]
H
@1M
HD2
-90
HD
1
-75
[email protected]
DISTORTION (dBc)
-60
DISTORTION (dBc)
5.5
FIGURE 14. SMALL SIGNAL PEAKING vs SUPPLY VOLTAGE
FIGURE 13. OUPUT IMPEDANCE vs FREQUENCY
-100
5
VS (V)
z
Hz
[email protected]
z
[email protected] H
2
3
4
5
VOP-P (V)
FIGURE 17. HARMONIC DISTORTION vs OUTPUT VOLTAGE
6
-80
H D 2@
AV =2
AV =1
-85
VS=5V
f=5MHz
-90
-95
[email protected]
HD2@
HD3 @
VO=1VP-P for AV=1
VO=2VP-P for AV=2
-100
100
HD3 @
AV =2
AV =1
1K
2K
RLOAD (Ω)
FIGURE 18. HARMONIC DISTORTION vs LOAD RESISTANCE
EL8302
Typical Performance Curves (Continued)
1K
-50
DISTORTION (dBc)
-60
-70
HD2 @
-80
-90
-100
AV=2
VOLTAGE NOISE (nV/√Hz)
CURRENT NOISE (pA/√Hz),
VS=5V
RL=1kΩ
CL=1.5pF
VO=1VP-P for AV=1
VO=2VP-P for AV=2
[email protected]=1
[email protected]=2
HD3
=1
@A V
10
1
100
eN
10
IN+
1
10
40
100
IN-
1K
10K
100K
1M
10M
FREQUENCY (Hz)
FREQUENCY (MHz)
FIGURE 19. HARMONIC DISTORTION vs FREQUENCY
FIGURE 20. VOLTAGE AND CURRENT NOISE vs FREQUENCY
VS=5V, AV=1, RL=1kΩ TO 2.5V, CL=1.5pF
CHANNEL SEPARATION (dB)
0
-10
-20
-30
3.5
-40
-50
-60
-70
2.5
CH2-->CH1
CH2-->CH1
CH2-->CH3
-80
-90
-100
1.00E+05 1.00E+06
1.00E+07
CH3-->CH2
CH1-->CH2
CH1<=>CH3
1.00E+08
1.5
1.00E+09
2ns/DIV
FREQUENCY (Hz)
FIGURE 21. CHANNEL SEPARATION vs FREQUENCY
FIGURE 22. LARGE SIGNAL TRANSIENT
RESPONSE - RISING
VS=5V, AV=1, RL=1kΩ to 2.5V, CL=1.5pF
VS=5V, AV=1, RL=1kΩ TO 2.5V, CL= 1.5pF
2.6
VIN
2.5
3.5
2.4
2.5
2.6
VOUT
2.5
1.5
2.4
2ns/DIV
FIGURE 23. LARGE SIGNAL TRANSIENT
RESPONSE - FALLING
7
10ns/DIV
FIGURE 24. SMALL SIGNAL TRANSIENT REPONSE
EL8302
Typical Performance Curves (Continued)
VS=5V, AV=5, RL=1kΩ TO 2.5V
VS=5V, AV=5, RL=1kΩ TO 2.5V
5
5
2.5
2.5
0
0
2µs/DIV
2µs/DIV
FIGURE 26. OUTPUT SWING
FIGURE 25. OUTPUT SWING
CH1
ENABLE
INPUT
ENABLE
INPUT
CH1
CH2
CH2
VOUT
VOUT
CH1, CH2, 1V/DIV, M=100ns
CH1, CH2, 0.5V/DIV, M=20ns
FIGURE 28. DISABLED RESPONSE
FIGURE 27. ENABLED RESPONSES
1
0.6
633mW
0.4
θJ
0.2
0
SO
1
θ
JA 6 ( 0
=1
.
10 150
°C ”)
/W
909mW
0.8
1.4
POWER DISSIPATION (W)
POWER DISSIPATION (W)
1.2
JEDEC JESD51-3 LOW EFFECTIVE THERMAL
CONDUCTIVITY TEST BOARD
QS
A=
OP
15
8°
C
16
/W
1.2
25
50
75 85 100
125
150
AMBIENT TEMPERATURE (°C)
FIGURE 29. PACKAGE POWER DISSIPATION vs AMBIENT
TEMPERATURE
8
1.250W
θ
SO
JA
1
0.8
893mW
0.6
θJ
A=
0.4
QS
11
OP
2°
16
=8
(0
.1
0° 50”
)
C/
W
16
C/
W
0.2
0
0
JEDEC JESD51-7 HIGH EFFECTIVE THERMAL
CONDUCTIVITY TEST BOARD
0
25
50
75 85 100
125
150
AMBIENT TEMPERATURE (°C)
FIGURE 30. PACKAGE POWER DISSIPATION vs AMBIENT
TEMPERATURE
EL8302
Simplified Schematic Diagram
VS+
I1
I2
Q5
IN+
Q1
R8
VBIAS1
Q6
R3
R1
R7
R6
Q7
R2
Q2
DIFFERENTIAL TO
SINGLE ENDED
DRIVE
GENERATOR
IN-
VBIAS2
Q3
OUT
Q4
Q8
R4
R5
R9
VS-
Description of Operation and Application
Information
Product Description
The EL8302 is wide bandwidth, single supply, low power and
rail-to-rail output voltage feedback operational amplifiers.
The amplifiers are internally compensated for closed loop
gain of +1 of greater. Connected in voltage follower mode
and driving a 1kΩ load, the EL8302 has a -3dB bandwidth of
500MHz. Driving a 150Ω load, the bandwidth is about
350MHz while maintaining a 600V/us slew rate. The EL8302
is available with a power down pin for each channel to
reduce power to 30µA typically while the amplifier is
disabled.
Input, Output and Supply Voltage Range
The EL8302 has been designed to operate with a single
supply voltage from 3V to 5.0V. Split supplies can also be
used as long as their total voltage is within 3V to 5.0V. The
amplifiers have an input common mode voltage range from
0.15V below the negative supply (VS- pin) to within 1.5V of
the positive supply (VS+ pin). If the input signal is outside the
above specified range, it will cause the output signal to be
distorted.
The output of the EL8302 can swing rail to rail. As the load
resistance becomes lower, the ability to drive close to each
rail is reduced. For the load resistor 1kΩ, the output swing is
about 4.9V at a 5V supply. For the load resistor 150Ω, the
output swing is about 4.6V.
Choice of Feedback Resistor and Gain Bandwidth
Product
For applications that require a gain of +1, no feedback
resistor is required. Just short the output pin to the inverting
input pin. For gains greater than +1, the feedback resistor
forms a pole with the parasitic capacitance at the inverting
9
input. As this pole becomes smaller, the amplifier’s phase
margin is reduced. This causes ringing in the time domain
and peaking in the frequency domain. Therefore, RF has
some maximum value that should not be exceeded for
optimum performance. If a large value of RF must be used, a
small capacitor in the few pF range in parallel with RF can
help to reduce the ringing and peaking at the expense of
reducing the bandwidth.
As far as the output stage of the amplifier is concerned, the
output stage is also a gain stage with the load. RF and RG
appear in parallel with RL for gains other than +1. As this
combination gets smaller, the bandwidth falls off.
Consequently, RF also has a minimum value that should not
be exceeded for optimum performance. For gain of +1, RF=0
is optimum. For the gains other than +1, optimum response
is obtained with RF between 300Ω to 1kΩ.
The EL8302 has a gain bandwidth product of 200MHz. For
gains ≥5, its bandwidth can be predicted by the following
equation:
Gain × BW = 200MHz
Video Performance
For good video performance, an amplifier is required to
maintain the same output impedance and the same
frequency response as DC levels are changed at the output.
This is especially difficult when driving a standard video load
of 150Ω, because the change in output current with DC level.
Special circuitry has been incorporated in the EL8302 to
reduce the variation of the output impedance with the current
output. This results in dG and dP specifications of 0.01%
and 0.01°, while driving 150Ω at a gain of 2. Driving high
impedance loads would give a similar or better dG and dP
performance.
EL8302
Driving Capacitive Loads and Cables
The EL8302 can drive 5pF loads in parallel with 1kΩ with
less than 5dB of peaking at gain of +1. If less peaking is
desired in applications, a small series resistor (usually
between 5Ω to 50Ω) can be placed in series with the output
to eliminate most peaking. However, this will reduce the gain
slightly. If the gain setting is greater than 1, the gain resistor
RG can then be chosen to make up for any gain loss which
may be created by the additional series resistor at the
output.
When used as a cable driver, double termination is always
recommended for reflection-free performance. For those
applications, a back-termination series resistor at the
amplifier’s output will isolate the amplifier from the cable and
allow extensive capacitive drive. However, other applications
may have high capacitive loads without a back-termination
resistor. Again, a small series resistor at the output can help
to reduce peaking.
The maximum power dissipation allowed in a package is
determined according to:
T JMAX – T AMAX
PD MAX = -------------------------------------------θ JA
Where:
TJMAX = Maximum junction temperature
TAMAX = Maximum ambient temperature
θJA = Thermal resistance of the package
The maximum power dissipation actually produced by an IC
is the total quiescent supply current times the total power
supply voltage, plus the power in the IC due to the load, or:
For sourcing:
3
PD MAX = V S × I SMAX +
V OUTi
∑ ( VS – VOUTi ) × ---------------R Li
i=1
Disable/Power-Down
The EL8302 can be disabled and placed its output in a high
impedance state. The turn off time is about 25ns and the turn
on time is about 200ns. When disabled, the amplifier’s
supply current is reduced to 30µA typically, thereby
effectively eliminating the power consumption. The
amplifier’s power down can be controlled by standard TTL or
CMOS signal levels at the ENABLE pin. The applied logic
signal is relative to VS- pin. Letting the ENABLE pin float or
applying a signal that is less than 0.8V above VS- will enable
the amplifier. The amplifier will be disabled when the signal
at ENABLE pin is 2V above VS-.
Output Drive Capability
The EL8302 does not have internal short circuit protection
circuitry. They have a typical short circuit current of 80mA
sourcing and 150mA sinking for the output is connected to
half way between the rails with a 10Ω resistor. If the output is
shorted indefinitely, the power dissipation could easily
increase such that the part will be destroyed. Maximum
reliability is maintained if the output current never exceeds
±40mA. This limit is set by the design of the internal metal
interconnections.
Power Dissipation
With the high output drive capability of the EL8302, It is
possible to exceed the 125°C absolute maximum junction
temperature under certain load current conditions.
Therefore, it is important to calculate the maximum junction
temperature for the application to determine if the load
conditions or package types need to be modified for the
amplifier to remain in the safe operating area.
For sinking:
3
PD MAX = V S × I SMAX +
∑ ( VOUTi – VS - ) × ILOADi
i=1
Where:
VS = Total supply voltage
ISMAX = Maximum quiescent supply current
VOUTi = Maximum output voltage of the application for
each channel
RLOADi = Load resistance tied to ground for each
channel
ILOADi = Load current for eachh channel
By setting the two PDMAX equations equal to each other, we
can solve the output current and RLOAD to avoid the device
overheat.
Power Supply Bypassing and Printed Circuit
Board Layout
As with any high frequency device, a good printed circuit
board layout is necessary for optimum performance. Lead
lengths should be as short as possible. The power supply
pin must be well bypassed to reduce the risk of oscillation.
For normal single supply operation, where the VS- pin is
connected to the ground plane, a single 4.7µF tantalum
capacitor in parallel with a 0.1µF ceramic capacitor from VS+
to GND will suffice. This same capacitor combination should
be placed at each supply pin to ground if split supplies are to
be used. In this case, the VS- pin becomes the negative
supply rail.
For good AC performance, parasitic capacitance should be
kept to a minimum. Use of wire wound resistors should be
10
EL8302
avoided because of their additional series inductance. Use
of sockets should also be avoided if possible. Sockets add
parasitic inductance and capacitance that can result in
compromised performance. Minimizing parasitic capacitance
at the amplifier’s inverting input pin is very important. The
feedback resistor should be placed very close to the
inverting input pin. Strip line design techniques are
recommended for the signal traces.
VIN1 is passed through to the output when the ENABLE
signal is low and turns off in about 25ns when the ENABLE
signal is high. About 200ns later, Amp B turns on and VIN2 is
passed through to the output. The break-before-make
operation ensures that more than one amplifier isn’t trying to
drive the bus at the same time.
+2.5V
B 2MHz
1VP-P
Typical Applications
VIDEO SYNC PULSE REMOVER
Many CMOS analog to digital converters have a parasitic
latch up problem when subjected to negative input voltage
levels. Since the sync tip contains no useful video
information and it is a negative going pulse, we can chop it
off. Figure 31 shows a gain of 2 connections for EL8302.
Figure 32 shows the complete input video signal applied at
the input, as well as the output signal with the negative going
sync pulse removed.
+
75Ω
-2.5V
1K
1K
75Ω
VOUT
+2.5V
A 2MHz
2VP-P
75Ω
+
-
75Ω
-2.5V
1K
1K
5V
VIN
-
VOUT
VS-
75Ω
ENABLE
75Ω
VS+
+
75Ω
1K
FIGURE 33. TWO TO ONE MULTIPLEXER
1K
0V
-0.5V
FIGURE 31. SYNC PULSE REMOVER
ENABLE
-1.5V
-2.5V
1V
1V
0V
0.5V
VIN
0V
B
A
-1V
1V
0.5V
VOUT
0V
M = 50ns/DIV
FIGURE 34.
SINGLE SUPPLY VIDEO LINE DRIVER
M = 10µs/DIV
FIGURE 32. VIDEO SIGNAL
MULTIPLEXER
Besides the normal power down usage, the ENABLE pin of
the EL8302 can be used for multiplexing applications. Figure
33 shows two channels with the outputs tied together, driving
a back terminated 75Ω video load. A 2VP-P 2MHz sine wave
is applied to Amp A and a 1VP-P 2MHz sine wave is applied
to Amp B. Figure 34 shows the ENABLE signal and the
resulting output waveform at VOUT. Observe the breakbefore-make operation of the multiplexing. Amp A is on and
11
The EL8302 is wideband rail-to-rail output op amplifiers with
large output current, excellent dG, dP, and low distortion that
allow them to drive video signals in low supply applications.
Figure 35 is the single supply non-inverting video line driver
configuration and Figure 36 is the inverting video ling driver
configuration. The signal is AC coupled by C1. R1 and R2
are used to level shift the input and output to provide the
largest output swing. RF and RG set the AC gain. C2 isolates
the virtual ground potential. RT and R3 are the termination
resistors for the line. C1, C2 and C3 are selected big enough
to minimize the droop of the luminance signal.
EL8302
5V
RF
1kΩ
VIN
C1
47µF
R1
10K
+
RT
75Ω
R2
10K
R3
C3
470µF 75Ω
VOUT
C1
RG
47µF 500Ω
-
75Ω
RG
1kΩ
VIN
RT
75Ω
5V
5V
-
R3
C3
470µF 75Ω
VOUT
+
R1
10K
75Ω
RF
1kΩ
R2
10K
C2
220µF
NORMALIZED GAIN (dB)
FIGURE 35. 5V SINGLE SUPPLY NON INVERTING
VIDEO LINE DRIVER
C2
220µF
FIGURE 36. SINGLE SUPPLY INVERTING VIDEO LINE DRIVER
4
3
2
1
AV = 2
0
-1
-2
AV = -2
-3
-4
-5
-6
100K
1M
10M
100M 500M
FREQUENCY (Hz)
FIGURE 37. VIDEO LINE DRIVER FREQUENCY RESPONSE
12
EL8302
SO Package Outline Drawing
13
EL8302
QSOP Package Outline Drawing
NOTE: The package drawing shown here may not be the latest version. To check the latest revision, please refer to the Intersil website at
http://www.intersil.com/design/packages/index.asp
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
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