EL5421C Elantec Semiconductor, Inc. (acquired by Intersil), EL5421C Datasheet - Page 10

• Manufacturer Part Number: EL5421C
• Description: Quad 12MHz Rail-to-rail I/o Buffer
• Manufacturer: Elantec Semiconductor, Inc. (acquired by Intersil)

EL5421C
Quad 12MHz Rail-to-Rail Input-Output Buffer
Applications Information
Product Description
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 con-
sumption (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.
Operating Voltage, Input, and Output
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. Param-
e 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 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 V
Figure 1. Operation with Rail-to-Rail Input and
5V
5V
Output
10µ S
V
T
V
S
A
IN
=25°C
=±5V
=10V
P-P
P-P
.
10
Short Circuit Current Limit
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 main-
tained if the output continuous current never exceeds +/-
30 mA. This limit is set by the design of the internal
metal interconnects.
Output Phase Reversal
The EL5421C is immune to phase reversal as long as the
input voltage is limited from V
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 volt-
age 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.
Power Dissipation
With the high-output drive capability of the EL5421C
buffer, it is possible to exceed the 125°C 'absolute-max-
imum junction temperature' under certain load current
conditions. Therefore, it is important to calculate the
Figure 2. Operation with Beyond-the-Rails
1V
1V
Input
10µ S
S
- - 0.5V to V
V
T
V
S
A
IN
=25°C
=±2.5V
=6V
P-P
S
+ +0.5V.