OPA4705EA BURR-BROWN [Burr-Brown Corporation], OPA4705EA Datasheet - Page 8

• Manufacturer Part Number: OPA4705EA
• Description: Low-Cost, CMOS, Rail-to-Rail, I/O OPERATIONAL AMPLIFIERS
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

FIGURE 1. Rail-to-Rail Input and Output.
FIGURE 2. Simplified Schematic.
APPLICATIONS INFORMATION
OPA705 series op amps can operate on 160 A quiescent
current from a single (or split) supply in the range of 4V to
12V ( 2V to 6V), making them highly versatile and easy
to use. The OPA705 is unity-gain stable and offers 1MHz
bandwidth and 0.6V/ s slew rate.
Rail-to-rail input and output swing helps maintain dynamic
range, especially in low supply applications. Figure 1 shows
the input and output waveforms for the OPA705 in unity-
gain configuration. Operation is from a 5V supply with a
100k
sinusoid. Output voltage is approximately 10Vp-p.
8
V
V+
V–
IN
+
load connected to V
Output (inverted on scope)
Input
200 s/div
S
/2. The input is a 10Vp-p
G = +1, V
S
= 5V
V
IN
–
Power-supply pins should be bypassed with 1000pF ceramic
capacitors in parallel with 1 F tantalum capacitors.
OPERATING VOLTAGE
OPA705 series op amps are fully specified and guaranteed
from +4V to +12V over a temperature range of –40ºC to
+85ºC. Parameters that vary significantly with operating volt-
ages or temperature are shown in the Typical Characteristics.
RAIL-TO-RAIL INPUT
The input common-mode voltage range of the OPA705 series
extends 300mV beyond the supply rails at room temperature.
This is achieved with a complementary input stage—an N-
channel input differential pair in parallel with a P-channel
differential pair, as shown in Figure 2. The N-channel pair is
active for input voltages close to the positive rail, typically
(V+) – 2.0V to 300mV above the positive supply, while the P-
channel pair is on for inputs from 300mV below the negative
supply to approximately (V+) – 1.5V. There is a small
transition region, typically (V+) – 2.0V to (V+) – 1.5V, in
which both pairs are on. This 500mV transition region can
vary 100mV with process variation. Thus, the transition
region (both stages on) can range from (V+) – 2.1V to (V+)
– 1.4V on the low end, up to (V+) – 1.9V to (V+) – 1.6V on
the high end. Within the 500mV transition region PSRR,
CMRR, offset voltage, and offset drift, and THD may vary
compared to operation outside this region.
OPA705, 2705, 4705
SBOS182A
V
O