AD8515 Analog Devices, AD8515 Datasheet - Page 12

• Manufacturer Part Number: AD8515
• Description: 1.8 V Low Power CMOS Rail-to-Rail Input/Output Operational Amplifier
• Manufacturer: Analog Devices

Specifications of AD8515

• -3db Bandwidth: 5MHz
• Slew Rate: 2.7V/µs
• Vos: 1mV
• Ib: 2pA
• # Opamps Per Pkg: 1
• Input Noise (nv/rthz): 22nV/rtHz
• Vcc-vee: 1.8V to 6V
• Isy Per Amplifier: 500µA
• Packages: SC70,SOT

AD8515
THEORY OF OPERATION
The AD8515, offered in space-saving SOT-23 and SC70 packages,
is a rail-to-rail input and output operational amplifier that can
operate at supply voltages as low as 1.8 V. This product is fabri-
cated using 0.6 micron CMOS to achieve one of the best power
consumption-to-speed ratios (that is, bandwidth) in the industry.
With a small amount of supply current (less than 400 μA),
a wide unity gain bandwidth of 4.5 MHz is available for signal
processing.
The input stage consists of two parallel, complementary, differ-
ential pairs of PMOS and NMOS. The AD8515 exhibits no
phase reversal because the input signal exceeds the supply by
more than 0.6 V. Currents into the input pin must be limited
to 5 mA or less by the use of external series resistance(s). The
AD8515 has a very robust ESD design and can stand ESD
voltages of up to 4000 V.
POWER CONSUMPTION vs. BANDWIDTH
One of the strongest features of the AD8515 is the bandwidth
stability over the specified temperature range while consuming
small amounts of current. This effect is shown in Figure 2 through
Figure 4.
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This product solves the speed/power requirements for many
applications. The wide bandwidth is also stable even when operated
with low supply voltages. Figure 5 shows the relationship between
the supply voltage vs. the bandwidth for the AD8515.
The AD8515 is ideal for battery-powered instrumentation and
handheld devices because it can operate at the end of discharge
voltage of most popular batteries. Table 6 lists the nominal and
end of discharge voltages of several typical batteries.
Table 6. Typical Battery Life Voltage Range
Battery
Lead-Acid
Lithium
NiMH
NiCd
Carbon-Zinc
Nominal
Voltage (V)
2
2.6 to 3.6
1.2
1.2
1.5
End of Discharge
Voltage (V)
1.8
1.7 to 2.4
1
1
1.1