OPA357 Datasheet, PDF (12/23 Pages) Burr-Brown (TI) – 250MHz, Rail-to-Rail I/O, CMOS Operational Amplifier with Shutdown

OPA357
OPA2357
SBOS235C − MARCH 2002− REVISED MAY 2004
RAIL-TO-RAIL OUTPUT
A class AB output stage with common-source transistors
is used to achieve rail-to-rail output. For high-impedance
loads (> 200Ω), the output voltage swing is typically
100mV from the supply rails. With 10Ω loads, a useful
output swing can be achieved while maintaining high
open-loop gain. See the typical characteristic curve Output
Voltage Swing vs Output Current.
OUTPUT DRIVE
The OPA357’s output stage can supply a continuous
output current of ±100mA and still provide approximately
2.7V of output swing on a 5V supply, as shown in Figure 2.
For maximum reliability, it is not recommended to run a
continuous DC current in excess of ±100mA. Refer to the
typical characteristic curve Output Voltage Swing vs
Output Current. For supplying continuous output currents
greater than ±100mA, the OPA357 may be operated in
parallel as shown in Figure 3.
The OPA357 will provide peak currents up to 200mA,
which corresponds to the typical short-circuit current.
Therefore, an on-chip thermal shutdown circuit is provided
to protect the OPA357 from dangerously high junction
temperatures. At 160°C, the protection circuit will shut
down the amplifier. Normal operation will resume when the
junction temperature cools to below 140°C.
R₁
10kΩ
R₃
V_IN ^10kΩ
+
−
1V In = 100mA
Out, as Shown
R₂
1kΩ
C₁
50pF
1µF
V+
OPA357
V−
R₄
1kΩ
+
V₁
− ^5V
R_SHUNT
Laser Diode
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R₁
100kΩ
R₃
100kΩ
+
−
2V In = 200mA
Out, as Shown
R₂
10kΩ
C₁
200pF
+5V
1µF
OPA2357
R₅ = 1Ω
OPA2357
R₆ = 1Ω
R_SHUNT
1Ω
R₄
10kΩ
Laser Diode
Figure 3. Parallel Operation
VIDEO
The OPA357 output stage is capable of driving standard
back-terminated 75Ω video cables, as shown in Figure 4.
By back-terminating a transmission line, it does not exhibit
a capacitive load to its driver. A properly back-terminated
75Ω cable does not appear as capacitance; it presents
only a 150Ω resistive load to the OPA357 output.
Video
In
+2.5V
+5V
75Ω
75Ω ^OPA357
+2.5V
604Ω
To enable,
connect to V+
or drive with logic.
604Ω
Video
Output
Figure 2. Laser Diode Driver
Figure 4. Single-Supply Video Line Driver
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