1
FN7023
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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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.
EL2008
55MHz 1 Amp Buffer Amplifier
The EL2008 is a patented high speed
bipolar monolithic buffer amplifier
designed to provide currents over 1
amp at high frequencies, while drawing only 13mA of
quiescent supply current. The EL2008's 1500V/s slew rate
and 55MHz bandwidth driving a 10
load is second only to
the EL2009 and insures stability in fast op amp feedback
loops. Elantec has applied for patents on unique circuitry
within the EL2008.
Used as an open loop buffer, the EL2008's low output
impedance (1
) gives a gain of 0.99 when driving a 100
load and 0.9 driving a 10
load. The EL2008 has output
short circuit current limiting which will protect the device
under both a DC fault condition and AC operation with
reactive loads.
The EL2008 is constructed using Elantec's proprietary
Complementary Bipolar process that produces PNP and
NPN transistors with essentially identical AC and DC
characteristics. In the EL2008, the Complementary Bipolar
process also insulates the package's metal heat sink tab
from all supply voltages. Therefore the tab may be mounted
to an external heat sink or the chassis without an insulator.
Pinout
EL2008
(5-PIN TO-220)
TOP VIEW
Features
High slew rate 2500V/s
Wide bandwidth 100MHz @ R
L
= 50
and 55MHz
@ R
L
= 10
Output current 1A continuous
Output impedance 1
Quiescent current 13mA
Short circuit protected
Power package with isolated metal tab
Applications
Video distribution amplifier
Fast op amp booster
Flash converter driver
Motor driver
Pulse transformer driver
A.T.E. pin driver
Simplified Schematic
Ordering Information
PART NUMBER
TEMP. RANGE
PACKAGE
PKG. NO.
EL2008CT
0C to +75C
5-Pin TO-220
MDP0028
Manufactured under U.S. Patent No. 4,833,424 and 4,827,223 and U.K.
Patent No. 2217134.
Data Sheet
December 23, 1999
OBS
OLE
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NO R
ECO
MME
NDE
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PLAC
EME
NT
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ur Te
chnic
al Su
ppor
t Cen
ter a
t
1-888
-INTE
RSIL
or w
ww.i
nters
il.com
/tsc
2
NOTES:
1. Force the input to +12V and the output to +10V and measure the output current. Repeat with -12V and -10V on the output.
2. V
S
= 4.5V then V
S
is changed to 18V.
3. V
S
+ = +15V, V
S
- = -4.5V then V
S
- is changed to -18V and V
S
- = -15V, V
S
+ = +4.5V then V
S
+ is changed to +18V.
4. Slew Rate is measured between V
OUT
= +5V and -5V.
5. 7:Slew Rate is measured between V
OUT
= +2.5V and -2.5V.
Absolute Maximum Ratings
(T
A
= 25
C)
V
S
Supply Voltage (V+ - V-) . . . . . . . . . . . . . . . . . . . . 18V or 36V
V
IN
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15V or V
S
If the input exceeds the ratings shown (or the supplies) or if the input to output
voltage exceeds 7.5V then the input current must be limited to 50mA. See
the applications section for more information.
I
IN
Input Current (See above note) . . . . . . . . . . . . . . . . . . . 50mA
P
D
Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . See Curves
The maximum power dissipation depends on package type, ambient
temperature and heat sinking. See the characteristic curves for more details.
T
A
Operating Temperature Range . . . . . . . . . . . . . . 0
C to +75
C
T
J
Operating Junction Temp . . . . . . . . . . . . . . . . . . . . . . . . . 175
C
T
ST
Storage Temp Range . . . . . . . . . . . . . . . . . . . -65
C to +150
C
T
LD
Lead Solder Temp <10 seconds . . . . . . . . . . . . . . . . . . . 300
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: T
J
= T
C
= T
A
Electrical Specifications
V
S
= 15V, R
S
= 50
, unless otherwise specified.
PARAMETER
DESCRIPTION
TEST CONDITIONS
LIMITS
UNITS
V
IN
LOAD
TEMP
MIN
TYP
MAX
V
OS
Output Offset Voltage
0
25C
-40
10
+40
mV
T
MIN
, T
MAX
-50
+50
mV
I
IN
Input Current
0
25C
-35
-5
+35
A
T
MIN
, T
MAX
-50
+50
A
R
IN
Input Impedance
12V
100
25C
0.5
2
M
A
V1
A
V2
A
V3
Voltage Gain
Voltage Gain
Voltage Gain, V
S
= 15V
10V
10V
3V
10
10
25C
25C
25C
0.985
0.88
0.87
0.9995
0.91
0.89
V/V
V/V
V/V
V
01
Output Voltage Swing
14V
100
25C
13
V
V
02
Output Voltage Swing
12V
10
25C
10.5
11
V
R
01
Output Impedance
10V
10mA
25C
1.8
2.5
R
02
Output Impedance
10V
1A
25C
0.8
1.15
I
O
Output Current
12V
(Note 1)
25C
1.25
1.8
A
T
MIN
, T
MAX
1
A
I
S
Supply Current
0
25C
12
17
26
mA
PSRR
Supply Rejection (Note 2)
0
25C
60
dB
V
S
+, V
S
-
Supply Sensitivity (Note 3)
25C
2
mV/V
SR
1
Slew Rate (Note 4)
10V
10V
50
10
25C
25C
2500
1500
V/s
V/s
SR
2
Slew Rate (Note 5)
5V
10
25C
800
V/s
t
R
, t
F
Rise/Fall Time
100mV
10
25C
7
ns
BW
-3dB Bandwidth
100mV
10
25C
55
MHz
C
IN
Input Capacitance
25C
25
pF
THD
25C
1
%
EL2008
3
Typical Performance Curves
Slew Rate
vs Capacitance Load
Slew Rate
vs Supply Voltage
Rise Time
vs Temperature
Output Impedance
vs Frequency
Output Resistance
vs Supply Voltage
Small Signal Output
Resistance
vs DC Output Current
-3dB Bandwidth
vs Supply Voltage
Quiescent Supply Current
vs Supply Voltage
Input Current
vs Input Voltage
EL2008
4
Typical Performance Curves
(Continued)
Voltage Gain
vs Frequency at
Various Resistive Loads
Voltage Gain
vs Frequency at
Various Capacitive Loads
Voltage Gain
vs Frequency at
Various Capacitive Loads
Phase Shift
vs Frequency at
Various Resistive Loads
Reverse Isolation
vs Frequency
Power Supply
Rejection Ratio
vs Frequency
Active Operating Area
Active Operating Area
EL2008
5
Burn-In Circuit
Applications Information
The EL2008 is a monolithic buffer amplifier built on Elantec's
proprietary dielectric isolation process that produces NPN
and PNP transistors with essentially identical DC and AC
characteristics. The EL2008 takes full advantage of the
complementary process with a unique circuit topology.
Elantec has applied for two patents based on the EL2008's
topology. The patents relate to the base drive and feedback
mechanism in the buffer. This feedback makes 3000V/s
slew rates with 10
load possible with modest supply
current.
Power Supplies
The EL2008 may be operated with single or split supplies
with total voltage difference between 10V (5V) and 36V
(18V). However, bandwidth, slew rate and output
impedance are affected by total supply voltages below 20V
(10V) as shown by the characteristic curves. It is not
necessary to use equal split value supplies. For example -5V
and +12V would be excellent for signals from -2V to +9V.
Bypass capacitors from each supply pin to ground are highly
recommended to reduce supply ringing and the interference
it can cause. At a minimum a 10F tantalum capacitor in
parallel with a 0.1F capacitor with short leads should be
used for both supplies.
Input Characteristics
The input to the EL2008 looks like a resistance in parallel
with about 25pF in addition to a DC bias current. The DC
bias current is due to the mismatch in beta and collector
current between the NPN and PNP transistors connected to
the input pin. The bias current can be either positive or
negative. The change in input current with input voltage
(R
IN
) is affected by the output load, beta and the internal
boost. R
IN
can actually appear negative over portions of the
input range in some units. A few typical input current (I
IN
)
curves are shown in the characteristic curves.
Internal clamp diodes from the input to the output are
provided. These diodes protect the transistor base emitter
junctions and limit the boost current during slew to avoid
saturation of internal transistors. The diodes begin
conduction at about 2.5V input to output differential. When
that happens the input resistance drops dramatically. The
diodes are rated at 50mA. When conducting they have a
series resistance of about 20
. If the output of the EL2008 is
accidentally shorted it is possible that some devices driving
the EL2008's input could be damaged or destroyed driving
the EL2008's load through the diodes while the EL2008 is
unaffected. In such cases a resistor in series with the input of
the EL2008 can limit the current.
Source Impedance
The EL2008 has good input to output isolation. Open loop,
capacitive and resistive sources up to 100k
present no
oscillation problem driving resistive loads as long as care is
used in board layout to minimize output to input coupling and
the supplies are properly bypassed. When driving capacitive
loads in the 100pF to 1000pF region source resistances
above 25
can cause peaking and oscillation. Such
problems can be eliminated by placing a capacitor from the
EL2008s input to ground. The value should be about 1/4 the
load capacitance. In a feedback loop there is a speed
penalty and a possibility of oscillation when the EL2008 is
driven with a source impedance of 200
or more. Significant
phase shift can occur due to the EL2008's 25pF input
capacitance. Inductive sources can cause oscillations. A
series resistor of a few hundred ohms to 1k
will usually
solve the problem.
Current Limit
The EL2008 has internal current limiting to protect the output
transistors. The current limit is about 1.5A at room
temperature and decreases with junction temperature. At
150C junction temperature it is above 1A.
Heat Sinking
A suitable heat sink will be required for most applications.
The thermal resistance junction to case for the TO-220
package is 4C per watt. No voltage appears at the heat sink
tab so no precautions need to be taken to avoid shorting the
tab to a supply voltage or ground. As there is a small
parasitic capacitance between the tab and the buffer
circuitry, it is recommended that the tab be connected to AC
ground (either supply voltage or DC ground). The center
lead is internally connected to the tab so the connection can
be made at the tab or the center lead.
Parallel Operation
If more than 1A is required or if heat management is a
problem, several EL2008s may be paralleled together. The
result is as through each device was driving only part of the
load. For example, if two units are paralleled then a 5
load
looks like 10
to each EL2008. Of course, parallel operation
reduces both the input and output impedance and increases
EL2008
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