Linear Technology LT1490CN8 Linear IC DIP8 Dual R-to-R I/O OA LT1490CN8 Data Sheet

Product codes
LT1490CN8
Page of 12
1
LT1490/LT1491
Dual and Quad
Micropower Rail-to-Rail
Input and Output Op Amps
Rail-to-Rail Input and Output
Single Supply Input Range: – 0.4V to 44V
Micropower: 50
µµµµµ
A/Amplifier Max
MSOP Package
Specified on 3V, 5V and 
±
15V Supplies
High Output Current: 20mA
Output Drives 10,000pF with Output Compensation
Reverse Battery Protection to 18V
No Supply Sequencing Problems
High Voltage Gain: 1500V/mV
High CMRR: 98dB
No Phase Reversal
Gain Bandwidth Product: 200kHz
The dual LT
®
1490 and quad LT1491 op amps operate on all
single and split supplies with a total voltage of 2V to 44V
drawing only 40
µ
A of quiescent current per amplifier. These
amplifiers are reverse supply protected; they draw no current
for reverse supply up to 18V. The input range of the LT1490/
LT1491 includes both supplies and the output swings to both
supplies. Unlike most micropower op amps, the LT1490/
LT1491 can drive heavy loads; their rail-to-rail outputs drive
20mA. The LT1490/LT1491 are unity-gain stable and drive all
capacitive loads up to 10,000pF when optional 0.22
µ
F and
150
Ω
 compensation is used.
The LT1490/LT1491 have a unique input stage that oper-
ates and remains high impedance when above the positive
supply. The inputs take 44V both differential and common
mode even when operating on a 3V supply. Built-in resis-
tors protect the inputs for faults below the negative supply
up to 22V. There is no phase reversal of the output for inputs
22V below V
 or 44V above V
, independent of V
+
.
The LT1490 dual op amp is available in the 8-pin MSOP,
SO and PDIP packages. The quad LT1491 is available in
the 14-pin SO and PDIP packages.
For new designs it is recommended that the LT1490A/
LT1491A be used instead of the LT1490/LT1491. See the
LT1490A/LT1491A data sheet for details.
Battery- or Solar-Powered Systems
Portable Instrumentation
Sensor Conditioning
Supply Current Sensing
Battery Monitoring
Micropower Active Filters
4mA to 20mA Transmitters
+
+
RA
2k
Q2
2N3904
S1
S1 = OPEN, GAIN = 1
S1 = CLOSED, GAIN = 10
R
A
 = R
B
V
S
 = 5V, 0V
10k
90.9k
V
OUT
LOGIC
1490/91 TA01
LOGIC HIGH (5V) = CHARGING
LOGIC LOW (0V) = DISCHARGING
R
G
10k
Q1
2N3904
R
S
0.2
Ω
CHARGER
VOLTAGE
A
1/4 LT1491
B
1/4 LT1491
R
A
'
2k
R
B
2k
V
BATT
 = 12V
I
BATT
+
R
B
'
2k
LOAD
+
+
C
1/4 LT1491
D
1/4 LT1491
V
OUT
(R
S
)(R
G
/R
A
)(GAIN)
V
OUT
GAIN
I
BATT
  =                                  =            AMPS  
Battery Monitor
FEATURES
DESCRIPTIO
U
APPLICATIO  S
U
TYPICAL APPLICATIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.