
8
FN7426.1
May 4, 2007
Applications Information
Product Description
The EL5027 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 (500A
per buffer). These features make the EL5027 ideal for a wide
range of general-purpose applications. When driving a load
of 10k
Ω and 12pF, the EL5027 has a -3dB bandwidth of
2.5MHz and exhibits 2.2V/s slew rate.
Operating Voltage, Input, and Output
The EL5027 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 EL5027 specifications are stable over
both the full supply range and operating temperatures of
-40°C to +85°C. Parameter variations with operating voltage
and/or temperature are shown in the typical performance
curves.
The output swings of the EL5027 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 10k
Ω load connected to GND. The
input is a 10VP-P sinusoid. The output voltage is
approximately 9.985VP-P.
FIGURE 18. OPERATION WITH RAIL-TO-RAIL INPUT AND
OUTPUT
Short-Circuit Current Limit
The EL5027 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 ±30mA. This limit is set by
the design of the internal metal interconnects.
Output Phase Reversal
The EL5027 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
Pin Descriptions
6 LD TSOT
PIN NAME
FUNCTION
EQUIVALENT CIRCUIT
1
VINA
Buffer A Input
CIRCUIT 1
2
VS-
Negative Supply Voltage
3
VINB
Buffer B Input
(Reference Circuit 1)
4
VOUTB
Buffer B Output
CIRCUIT 2
5
VS+
Positive Supply Voltage
6
VOUTA
Buffer A Output
(Reference Circuit 2)
VS+
VS-
VS+
GND
VS-
OUT
P
UT
IN
PUT
5V
10s
VS=±5V
TA=25°C
VIN=10VP-P
EL5027