Elantec EL5421C Quad 12mhz rail-to-rail input-output buffer Datasheet

Quad 12MHz Rail-to-Rail Input-Output Buffer
Features
General Description
•
•
•
•
The EL5421C is a quad, low power, high voltage rail-to-rail input-output buffer. Operating on supplies ranging from 5V to 15V, while
consuming only 500µA per channel, the EL5421C has a bandwidth of
12MHz (-3dB). The EL5421C also provides rail-to-rail input and output ability, giving the maximum dynamic range at any supply voltage.
12MHz -3dB Bandwidth
Unity gain buffer
Supply voltage = 4.5V to 16.5V
Low supply current (per buffer) =
500µA
• High slew rate = 10V/µs
• Rail to Rail operation
• “Mini” SO Package (MSOP)
Applications
•
•
•
•
•
•
•
•
•
•
TFT-LCD Drive Circuits
Electronics Notebooks
Electronics Games
Personal Communication Devices
Personal Digital Assistants (PDA)
Portable Instrumentation
Wireless LANs
Office Automation
Active Filters
ADC/DAC Buffer
EL5421C
EL5421C
The EL5421C also features fast slewing and settling times, as well as
a high output drive capability of 30mA (sink and source). These features make the EL5421C ideal for use as voltage reference buffers in
Thin Film Transistor Liquid Crystal Displays (TFT-LCD). Other
applications include battery power, portable devices and anywhere
low power consumption is important.
The EL5421C is available in a space saving 10-Pin MSOP package
and operates over a temperature range of -40°C to +85°C.
Connection Diagram
Ordering Information
Part No.
Temp. Range
Package
Outline #
EL5421CY
-40°C to +85°C
10-Pin MSOP
MDP0043
VOUTA
1
10
VOUTD
VINA
2
9
VIND
VS+
3
8
VS-
VINB
4
7
VINC
VOUTB
5
6
VOUTC
EL 5421C (MSOP 10)
October 2, 2000
© 2000 Elantec Semiconductor, Inc.
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
Absolute Maximum Ratings (T
A
= 25°C)
Values beyond absolute maximum ratings can cause the device to be prematurely damaged. Absolute maximum ratings are stress ratings only and
functional device operation is not implied
+18V
Supply Voltage between VS+ and VSInput Voltage
VS- - 0.5V, VS+ +0.5V
Maximum Continuous Output Current
30mA
Maximum Die Temperature
Storage Temperature
Operating Temperature
Power Dissipation
ESD Voltage
+125°C
-65°C to +150°C
-40°C to +85°C
See Curves
2kV
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 Characteristics
VS+ = +5V, VS- = -5V, RL = 10kΩ and CL = 10pF to 0V, TA = 25°C unless otherwise specified.
Parameter
Description
Condition
Min
Typ
Max
12
Unit
Input Characteristics
VOS
Input Offset Voltage
VCM = 0V
2
TCVOS
Average Offset Voltage Drift
[1]
5
VCM = 0V
IB
Input Bias Current
RIN
Input Impedance
CIN
Input Capacitance
AV
Voltage Gain
2
50
1
0.995
nA
GΩ
1.35
-4.5V ≤ VOUT ≤ 4.5V
mV
µV/°C
pF
1.005
V/V
-4.85
V
Output Characteristics
VOL
Output Swing Low
IL = -5mA
VOH
Output Swing High
IL = 5mA
4.85
-4.92
4.92
V
ISC
Short Circuit Current
Short to GND [2]
±80
±120
mA
60
Power Supply Performance
PSRR
Power Supply Rejection Ratio
VS is moved from ±2.25V to ±7.75V
IS
Supply Current (Per Buffer)
No Load
80
500
dB
750
µA
Dynamic Performance
SR
Slew Rate [3]
-4.0V ≤ VOUT ≤ 4.0V, 20% to 80%
tS
Settling to +0.1%
VO = 2V Step
500
ns
BW
-3dB Bandwidth
RL = 10kΩ, CL = 10pF
12
MHz
CS
Channel Separation
f = 5MHz
75
dB
1. Measured over the operating temperature range
2. Parameter is guaranteed (but not test) by design and characterization data
3. Slew rate is measured on rising and falling edges
2
7
10
V/µs
Electrical Characteristics
VS+ = +5V, VS- = 0V, RL = 10kΩ and CL = 10pF to 2.5V, TA = 25°C unless otherwise specified.
Parameter
Description
Condition
Min
Typ
Max
10
Unit
Input Characteristics
VOS
Input Offset Voltage
VCM = 2.5V
2
TCVOS
Average Offset Voltage Drift
[1]
5
VCM = 2.5V
2
IB
Input Bias Current
RIN
Input Impedance
CIN
Input Capacitance
AV
Voltage Gain
50
1
0.995
nA
GΩ
1.35
0.5 ≤ VOUT ≤ 4.5V
mV
µV/°C
pF
1.005
V/V
150
mV
Output Characteristics
VOL
Output Swing Low
IL = -5mA
VOH
Output Swing High
IL = 5mA
4.85
4.92
V
ISC
Short Circuit Current
Short to GND [2]
±80
±120
mA
60
80
Power Supply Performance
PSRR
Power Supply Rejection Ratio
VS is moved from 4.5V to 15.5V
IS
Supply Current (Per Buffer)
No Load
80
500
dB
750
µA
Dynamic Performance
SR
Slew Rate [3]
1V ≤ VOUT ≤ 4V, 20% to 80%
tS
Settling to +0.1%
VO = 2V Step
500
ns
BW
-3dB Bandwidth
RL = 10 kΩ, CL = 10pF
12
MHz
CS
Channel Separation
f = 5MHz
75
dB
1. Measured over the operating temperature range
2. Parameter is guaranteed (but not test) by design and characterization data
3. Slew rate is measured on rising and falling edges
3
7
10
V/µs
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
Electrical Characteristics
VS+ = +15V, VS- = 0V, RL = 10kΩ and CL = 10pF to 7.5V, TA = 25°C unless otherwise specified.
Parameter
Description
Condition
Min
Typ
Max
14
Unit
Input Characteristics
VOS
Input Offset Voltage
VCM = 7.5V
2
TCVOS
Average Offset Voltage Drift
[1]
5
VCM= 7.5V
IB
Input Bias Current
RIN
Input Impedance
CIN
Input Capacitance
AV
Voltage Gain
2
50
1
0.995
nA
GΩ
1.35
0.5 ≤ VOUT ≤ 14.5V
mV
µV/°C
pF
1.005
V/V
150
mV
Output Characteristics
VOL
Output Swing Low
IL = -5mA
VOH
Output Swing High
IL = 5mA
ISC
Short Circuit Current
80
14.85
14.92
V
Short to GND [2]
±80
±120
mA
60
Power Supply Performance
PSRR
Power Supply Rejection Ratio
VS is moved from 4.5V to 15.5V
IS
Supply Current (Per Buffer)
No Load
80
500
dB
750
µA
Dynamic Performance
SR
Slew Rate [3]
1V ≤ VOUT ≤14V, 20% to 80%
tS
Settling to +0.1%
VO = 2V Step
500
ns
BW
-3dB Bandwidth
RL = 10 kΩ, CL = 10pF
12
MHz
CS
Channel Separation
f = 5MHz
75
dB
1. Measured over the operating temperature range
2. Parameter is guaranteed (but not test) by design and characterization data
3. Slew rate is measured on rising and falling edges
4
7
10
V/µs
Typical Performance Curves
Input Offset Voltage Distribution
Input Offset Voltage Drift
70
1800
1600
VS=±5V
TA=25°C
Typical
Production
Distribution
60
1200
Quantity (Buffers)
Quantity (Buffers)
1400
VS=±5V
Typical
Production
Distribution
1000
800
600
50
40
30
20
400
10
200
0
21
19
17
15
13
9
11
7
5
3
1
12
8
10
6
4
2
-0
-2
-4
-6
-8
-10
-12
0
Input Offset Voltage Drift, TCVOS(µ V/°C)
Input Offset Voltage (mV)
Input Bias Current vs Temperature
Input Offset Voltage vs Temperature
10
2.0
VS=±5V
Input Bias Current (nA)
Input Offset Voltage (mV)
VS=±5V
5
0
-5
0.0
-2.0
-50
0
50
100
150
-50
0
Output High Voltage vs Temperature
100
150
Output Low Voltage vs Temperature
-4.91
4.97
-4.92
VS=±5V
IOUT=5mA
4.96
Output Low Voltage (V)
Output High Voltage (V)
50
Temperature (°C)
Temperature (°C)
4.95
4.94
VS=±5V
IOUT=-5mA
-4.93
-4.94
-4.95
-4.96
-4.97
4.93
-50
0
50
100
-50
150
0
50
Temperature (°C)
Temperature (°C)
5
100
150
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
Quad 12MHz Rail-to-Rail Input-Output Buffer
Voltage Gain vs Temperature
Slew Rate vs Temperature
10.40
1.0005
VS=±5V
Slew Rate (V/µ S)
Voltage Gain (V/V)
VS=±5V
1.0000
10.35
10.30
0.9995
10.25
-50
0
50
100
-50
150
50
0
Temperature (°C)
100
150
Temperature (°C)
Supply Current per Channel vs Temperature
Supply Current per Channel vs Supply Voltage
700
0.55
VS=±5V
TA=25°C
Supply Current (µ A)
600
0.5
500
400
0.45
-50
0
50
100
150
300
Temperature (°C)
5
0
20
15
10
Supply Voltage (V)
Frequency Response for Various RL
Frequency Response for Various CL
5
20
0
-5
Magnitude (Normalized) (dB)
10kΩ
Magnitude (Normalized) (dB)
Supply Current (mA)
EL5421C
EL5421C
1kΩ
560Ω
CL=10pF
VS=±5V
150Ω
-10
10
RL=10kΩ
VS=±5V
12pF
0
50pF
-10
100pF
-20
1000pF
-15
100k
1M
10M
-30
100k
100M
Frequency (Hz)
1M
10M
Frequency (Hz)
6
100M
Output Impedance vs Frequency
Maximum Output Swing vs Frequency
200
12
VS=±5V
TA=25°C
Maximum Output Swing (VP-P)
Output Impedance (Ω)
160
120
80
40
10
8
VS=±5V
TA=25°C
RL=10kΩ
CL=12pF
Distortion <1%
6
4
2
0
10k
100k
1M
10M
0
10k
Frequency (Hz)
100k
1M
10M
Frequency (Hz)
PSRR vs Frequency
80
600
PSRR+
Voltage Noise (nV√Hz)
PSRR-
60
PSRR (dB)
Input Voltage Noise Spectral Density vs
Frequency
40
VS=±
5V
20
0
100
1k
10k
100k
1M
100
10
1
100
10M
Frequency (Hz)
10k
100k
1M
10M
100M
Frequency (Hz)
Channel Separation vs Frequency Response
Total Harmonic Distortion + Noise vs Frequency
-60
0.010
Dual measured Channel A to B
Quad measured Channel A to D or B to C
Other combinations yield improved rejection.
0.009
0.008
-80
VS=±5V
RL=10kΩ
VIN=220mVRMS
X-Talk (dB)
0.007
THD+ N (%)
1k
0.006
0.005
VS=±5V
RL=10kΩ
VIN=1VRMS
0.004
0.003
-100
-120
0.002
-140
0.001
1k
10k
Frequency (Hz)
1k
100k
10k
100k
Frequency (Hz)
7
1M
6M
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
Quad 12MHz Rail-to-Rail Input-Output Buffer
Small-Signal Overshoot vs Load Capacitance
Settling Time vs Step Size
90
VS=±5V
RL=10kΩ
VIN=±50mV
TA=25°C
4
VS=±5V
RL=10kΩ
CL=12pF
TA=25°C
3
2
Step Size (V)
70
Overshoot (%)
EL5421C
EL5421C
50
30
0.1%
1
0
-1
-2
0.1%
-3
10
-4
10
100
Load Capacitance (pF)
1000
0
200
400
600
Settling Time (nS)
Small Signal Transient Response
Large Signal Transient Response
1V
50mV
1µ S
200nS
VS=±5V
TA=25°C
RL=10kΩ
CL=12pF
VS=±5V
TA=25°C
RL=10kΩ
CL=12pF
8
800
Pin Description
EL5421C
Name
1
VOUTA
Function
Equivalent Circuit
Buffer A Output
VS+
VSGND
Circuit 1
2
VINA
Buffer A Input
VS+
VSCircuit 2
3
VS+
Positive Power Supply
4
VINB
Buffer B Input
(Reference Circuit 1)
5
VOUTB
Buffer B Output
(Reference Circuit 2)
6
VOUTC
Buffer C Output
(Reference Circuit 2)
7
VINC
Buffer C Input
(Reference Circuit 1)
8
VS-
9
VIND
10
VOUTD
Negative Power Supply
Buffer D Input
(Reference Circuit 2)
Buffer D Output
(Reference Circuit 1)
9
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
Quad 12MHz Rail-to-Rail Input-Output Buffer
Applications Information
Product Description
Short Circuit Current Limit
The EL5421C unity gain buffer is fabricated using a
high voltage CMOS process. It exhibits Rail-to-Rail
input and output capability, and has low power consumption (500µA per buffer). These features make the
EL5421C ideal for a wide range of general-purpose
applications. When driving a load of 10kΩ and 12pF, the
EL5421C has a -3dB bandwidth of 12 MHz and exhibits
10V/µS slew rate.
The EL5421C will limit the short circuit current to +/120mA if the output is directly shorted to the positive or
the negative supply. If an output is shorted indefinitely,
the power dissipation could easily increase such that the
device may be damaged. Maximum reliability is maintained if the output continuous current never exceeds +/30 mA. This limit is set by the design of the internal
metal interconnects.
Operating Voltage, Input, and Output
Output Phase Reversal
The EL5421C is specified with a single nominal supply
voltage from 5V to 15V or a split supply with its total
range from 5V to 15V. Correct operation is guaranteed
for a supply range of 4.5V to 16.5V. Most EL5421C
specifications are stable over both the full supply range
and operating temperatures of -40 °C to +85 °C. Parame t e r v a ri a t i o n s w i t h o p e ra ti n g v o l t a g e a n d / o r
temperature are shown in the typical performance
curves.
The EL5421C is immune to phase reversal as long as the
input voltage is limited from VS- - 0.5V to VS+ +0.5V.
Figure 2 shows a photo of the output of the device with
the input voltage driven beyond the supply rails.
Although the device's output will not change phase, the
input's overvoltage should be avoided. If an input voltage exceeds supply voltage by more than 0.6V,
electrostatic protection diodes placed in the input stage
of the device begin to conduct and overvoltage damage
could occur.
The output swings of the EL5421C typically extend to
within 80mV of positive and negative supply rails with
load currents of 5mA. Decreasing load currents will
extend the output voltage range even closer to the supply
rails. Figure 1 shows the input and output waveforms for
the device. Operation is from +/-5V supply with a 10kΩ
load connected to GND. The input is a 10Vp-p sinusoid.
The output voltage is approximately 9.985 VP-P.
5V
1V
10µ S
VS=±2.5V
TA=25°C
VIN=6VP-P
10µ S
VS=±5V
TA=25°C
VIN=10VP-P
Input
1V
Figure 2. Operation with Beyond-the-Rails
Input
Output
EL5421C
EL5421C
Power Dissipation
5V
With the high-output drive capability of the EL5421C
buffer, it is possible to exceed the 125°C 'absolute-maximum junction temperature' under certain load current
conditions. Therefore, it is important to calculate the
Figure 1. Operation with Rail-to-Rail Input and
Output
10
maximum junction temperature for the application to
determine if load conditions need to be modified for the
buffer to remain in the safe operating area.
equation, it is a simple matter to see if PDMAX exceeds
the device’s power derating curves. To ensure proper
operation, it is important to observe the recommended
derating curves shown in Figure 3 and Figure 4.
The maximum power dissipation allowed in a package is
determined according to:
MSOP10 Package Mounted on JEDEC JESD51-7
High Effective Thermal Conductivity Test Board
T JMAX – T AMAX
P DMAX = --------------------------------------------Θ JA
1200
MAX TJ=125°C
1000
Power Dissipation (mW)
870mW
where:
TJMAX = Maximum Junction Temperature
TAMAX= Maximum Ambient Temperature
θJA = Thermal Resistance of the Package
800
MS
600
OP
10
---
Θ
JA
=
11
5°
C
400
/W
200
PDMAX = Maximum Power Dissipation in the
Package
0
0
25
75 85
50
100
125
150
Ambient Temperature (°C)
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
loads, or:
Figure 3. Package Power Dissipation vs
Ambient Temperature
P DMAX = Σi [ V S × I SMA X + ( V S + – VOUT i ) × I LOAD i ]
MSOP10 Package Mounted on JEDEC JESD51-3
Low Effective Thermal Conductivity Test Board
when sourcing, and:
600
P DMA X = Σi [ V S × I SM AX + ( V OU T i – V S - ) × I LOAD i ]
Power Dissipation (mW)
500
when sinking.
Where:
i = 1 to 4 for Quad
VS = Total Supply Voltage
MAX TJ=125°C
485mW
400
MS
OP
10
--
300
-Θ
JA =
20
6°
200
C/
W
100
ISMAX = Maximum Supply Current Per Channel
0
0
VOUTi = Maximum Output Voltage of the
Application
25
50
75 85
100
125
150
Ambient Temperature (°C)
ILOADi = Load current
Figure 4. Package Power Dissipation vs
Ambient Temperature
If we set the two PDMAX equations equal to each other,
we can solve for RLOADi to avoid device overheat. Figure 3 and Figure 4 provide a convenient way to see if the
device will overheat. The maximum safe power dissipation can be found graphically, based on the package type
and the ambient temperature. By using the previous
Unused Buffers
It is recommended that any unused buffer have the input
tied to the ground plane.
11
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
Driving Capacitive Loads
Power Supply Bypassing and Printed Circuit
Board Layout
The EL5421C can drive a wide range of capacitive
loads. As load capacitance increases, however, the -3dB
bandwidth of the device will decrease and the peaking
increase. The buffers drive 10pF loads in parallel with
10 kΩ with just 1.5dB of peaking, and 100pF with 6.4dB
of peaking. If less peaking is desired in these applications, a small series resistor (usually between 5 Ω and 50
Ω) can be placed in series with the output. However, this
will obviously reduce the gain slightly. Another method
of reducing peaking is to add a "snubber" circuit at the
output. A snubber is a shunt load consisting of a resistor
in series with a capacitor. Values of 150Ω and 10nF are
typical. The advantage of a snubber is that it does not
draw any DC load current or reduce the gain
The EL5421C can provide gain at high frequency. As
with any high-frequency device, good printed circuit
board layout is necessary for optimum performance.
Ground plane construction is highly recommended, lead
lengths should be as short as possible and the power supply pins must be well bypassed to reduce the risk of
oscillation. For normal single supply operation, where
the VS- pin is connected to ground, a 0.1 µF ceramic
capacitor should be placed from VS+ to pin to VS- pin. A
4.7µF tantalum capacitor should then be connected in
parallel, placed in the region of the buffer. One 4.7µF
capacitor may be used for multiple devices. This same
capacitor combination should be placed at each supply
pin to ground if split supplies are to be used.
12
EL5421C
EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
General Disclaimer
Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any circuits described
herein and makes no representations that they are free from patent infringement.
October 2, 2000
WARNING - Life Support Policy
Elantec, Inc. products are not authorized for and should not be used
within Life Support Systems without the specific written consent of
Elantec, Inc. Life Support systems are equipment intended to support or sustain life and whose failure to perform when properly used
in accordance with instructions provided can be reasonably
expected to result in significant personal injury or death. Users contemplating application of Elantec, Inc. Products in Life Support
Systems are requested to contact Elantec, Inc. factory headquarters
to establish suitable terms & conditions for these applications. Elantec, Inc.’s warranty is limited to replacement of defective
components and does not cover injury to persons or property or
other consequential damages.
Elantec Semiconductor, Inc.
675 Trade Zone Blvd.
Milpitas, CA 95035
Telephone: (408) 945-1323
(888) ELANTEC
Fax:
(408) 945-9305
European Office: +44-118-977-6080
Japan Technical Center: +81-45-682-5820
13
Printed in U.S.A.
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