LT1638/LT1639
1
16389fg
TYPICAL APPLICATION
DESCRIPTION
1.2MHz, 0.4V/µs
Over-The-Top Micropower
Rail-to-Rail Input and Output
Op Amps
The LT
®
1638 is a low p wer dual rail-to-rail input and output
operational amplifi er 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 amplifi er 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
fi ne 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 amplifi er. These ampli-
fi ers are reverse battery protected and draw no current
for reverse supply up to 18V.
The input range of the LT1638/LT1639 includes both sup-
plies, 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.
FEATURES
APPLICATIONS
n
Operates with Inputs Above V
+
n
Rail-to-Rail Input and Output
n
Low Power: 230μA per Amplifi er Max
n
Gain Bandwidth Product: 1.2MHz
n
Slew Rate: 0.4V/μs
n
High Output Current: 25mA Min
n
Specifi ed on 3V, 5V and ±15V Supplies
n
Reverse Battery Protection to 18V
n
No Supply Sequencing Problems
n
High Voltage Gain: 1500V/mV
n
Single Supply Input Range: –0.4V to 44V
n
High CMRR: 98dB
n
No Phase Reversal
n
Available in 14-Lead SO, 8-Lead MSOP and DFN
Packages
n
Battery- or Solar-Powered Systems
Portable Instrumentation
Sensor Conditioning
n
Supply Current Sensing
n
Battery Monitoring
n
Micropower Active Filters
n
4mA to 20mA Transmitters
V
CC
V
CC
V1
V2
V0
–
+
A
1/2 LT1638
–
+
B
1/2 LT1638
V
CC
1M
1M
1M
10k
10k
V
CC
= 5V, V
CM
= 0V TO 44V, t
PD
= 27μs
1638/39 TA01
1M
Over-The-Top
®
Comparator with
100mV Hysteresis Centered at 0mV
Output Voltage vs Input Voltage
5V
0V
1638/39 TA02
20mV/DIV
L, LT, LTC, LTM, Over-The-Top, Linear Technology and the Linear logo are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
