OPA2237EA Burr-Brown, OPA2237EA Datasheet - Page 10

• Manufacturer Part Number: OPA2237EA
• Description: SINGLE-SUPPLY OPERATIONAL AMPLIFIERS MicroAmplifier Series
• Manufacturer: Burr-Brown

FIGURE 2. Low and High-Side Battery Current Sensing.
APPLICATIONS 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 capaci-
tors.
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 through-
out 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
®
NOTE: Low and high-side sensing circuits can be used independently.
+
OPA237, 2237, 4237
2.7V to ±15V
V+ for A
V– for A
10k
38.3k
R
1
1
R
6
, A
, A
10
10
1
R
R
I
I
2
2
H
L
H
L
Optional for I
38.3k
–In
+In
9.09k
R
R
3
7
OPA237
(R
100k
A2
7
V+
V–
R
= R
8
B
6
Cancellation
Current Sense
II R
Current Sense
Out
High-Side
8
)
Low-Side
20k
R
10
4
+5V supply with a 10k
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 in Figure 1, can drive
10,000pF with output currents up to 1.5mA.
FIGURE 1. Stability-Capacitive Load vs Output Current.
–In
+In
100k
19.1k
100
10k
1k
10
R
2
OPA237
–2
383k
A1
R
V+
V–
R
common-mode input to A1.
Common-mode range of A2
extends to V– for low-side sensing.
5
V
2
S
and R
–1.5
= +2.7V
OPERATION NOT
RECOMMENDED
Out
4
divide down the
–1
Output Current (mA)
–0.5
load to V
V
S
= +5V, ±15V
0
To Load
V
V
To Load
O
O
= 10 • I
= 10 • I
0.5
S
/2 is used. OPA237
H
L
• R
• R
1
L
H
1.5
2