FEATURES
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LT1638/LT1639
1.2MHz, 0.4V/μs
Over-The-Top Micropower
Rail-to-Rail Input and Output
Op Amps
DESCRIPTIO
The LT
®
1638 is a low power dual rail-to-rail input and output
operational amplifier available in the standard 8-pin PDIP and
SO packages as well as the 8-lead MSOP package. The
LT1639 is a low power quad rail-to-rail input and output
operational amplifier offered in the standard 14-pin PDIP and
surface mount packages. For space limited applications the
LT1638 is available in a 3mm x 3mm x 0.8mm dual fine pitch
leadless package (DFN).
The LT1638/LT1639 op amps operate on all single and
split supplies with a total voltage of 2.5V to 44V drawing
only 170μA of quiescent current per amplifier. These
amplifiers are reverse battery protected and draw no
current for reverse supply up to 18V.
The input range of the LT1638/LT1639 includes both
supplies, and a unique feature of this device is its capability
to operate over the top with either or both of its inputs
above V
+
. The inputs handle 44V, both differential and
common mode, independent of supply voltage. The input
stage incorporates phase reversal protection to prevent
false outputs from occurring when the inputs are below
the negative supply. Protective resistors are included in
the input leads so that current does not become excessive
when the inputs are forced below the negative supply. The
LT1638/LT1639 can drive loads up to 25mA and still
maintain rail-to-rail capability. The op amps are unity-gain
stable and drive all capacitive loads up to 1000pF when
optional output compensation is used.
Output Voltage vs Input Voltage
Operates with Inputs Above V
+
Rail-to-Rail Input and Output
Low Power: 230
μ
A per Amplifier Max
Gain Bandwidth Product: 1.2MHz
Slew Rate: 0.4V/μs
High Output Current: 25mA Min
Specified on 3V, 5V and
±15V
Supplies
Reverse Battery Protection to 18V
No Supply Sequencing Problems
High Voltage Gain: 1500V/mV
Single Supply Input Range: – 0.4V to 44V
High CMRR: 98dB
No Phase Reversal
Available in 14-Lead SO, 8-Lead MSOP and DFN
Packages
APPLICATIO S
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Battery- or Solar-Powered Systems
Portable Instrumentation
Sensor Conditioning
Supply Current Sensing
Battery Monitoring
Micropower Active Filters
4mA to 20mA Transmitters
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Over-The-Top is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
10k
V1
V
CC
1M
Over-The-Top
®
Comparator with
100mV Hysteresis Centered at 0mV
V
CC
1M
V
CC
5V
+
A
1/2 LT1638
+
B
1/2 LT1638
1M
V0
–
10k
V2
1M
–
0V
1638/39 TA01
V
CC
= 5V, V
CM
= 0V TO 44V, t
PD
= 27μs
U
U
U
20mV/DIV
1638/39 TA02
16389fd
1
LINER [ LINEAR TECHNOLOGY ]
