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OPA237 Datasheet, PDF (10/22 Pages) Burr-Brown (TI) – SINGLE-SUPPLY OPERATIONAL AMPLIFIERS MicroAmplifier ™ Series | |||
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OPA237
OPA2237
OPA4237
SBOS057A â OCTOBER 1996 â REVISED FEBRUARY 2007
APPLICATION INFORMATION
OPA237 series op amps are unity-gain stable and suitable
for a wide range of general-purpose applications. Power
supply pins should be bypassed with 10nF ceramic
capacitors.
OPERATING VOLTAGE
OPA237 series op amps operate from single (+2.7V to
+36V) or dual (±1.35V to ±18V) supplies with excellent
performance. Most behavior remains unchanged
throughout the full operating voltage range. Parameters
which vary significantly with operating voltage are shown
in typical performance curves. Specifications are
production tested with +2.7V, +5V, and ±15V supplies.
OUTPUT CURRENT AND STABILITY
OPA237 series op amps can drive large capacitive loads.
However, under certain limited output conditions any op
amp may become unstable. Figure 1 shows the region
where the OPA237 has a potential for instability. These
load conditions are rarely encountered, especially for
single supply applications. For example, take the case
when a +5V supply with a 10k⦠load to VS/2 is used.
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OPA237 series op amps remain stable with capacitive
loads up to 4,000pF, if sinking current and up to 10,000pF,
if sourcing current. Furthermore, in single-supply
applications where the load is connected to ground, the op
amp is only sourcing current, and as shown Figure 1, can
drive 10,000pF with output currents up to 1.5mA.
100k
10k
OPERATION NOT
RECOMMENDED
1k
VS = +5V, ±15V
100
VS = +2.7V
10
â2 â1.5 â1 â0.5 0 0.5 1
Output Current (mA)
1.5 2
Figure 1. Stability-Capacitive Load vs Output
Current
RH
10â¦
IH
R1
38.3kâ¦
R3
38.3kâ¦
HighâSide
Current Sense
R5
383kâ¦
V+
âIn
A1
Out
+In OPA237
To Load
VO = 10 ⢠IH ⢠RH
V+ for A1, A2
+
2.7V to = ±15V
R8
100kâ¦
R4
20kâ¦
R2 Vâ
19.1kâ¦
R2 and R4 divide down the
commonâmode input to A1.
Vâ for A1, A2
V+
âIn
A2
Out
+In OPA237
VO = 10 ⢠IL ⢠RL
R6
10kâ¦
RL
10â¦
R7 Vâ
9.09kâ¦
LowâSide
Current Sense
Optional for IB Cancellation
(R7 = R6 II R8)
Commonâmode range of A2
extends to Vâ for lowâside sensing
To Load
IL
NOTE: Low and highâside sensing circuits can be used independently.
Figure 2. Low and High-Side Battery Current Sensing
10
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