Precision Micropower Low Dropout Voltage Reference
The LM4121 is a precision bandgap voltage reference avail-
able in a fixed 1.25V and adjustable version with up to 5 mA
current source and sink capability.
This series reference operates with input voltages as low as
1.8V and up to 12V consuming 160 µA (Typ.) supply current.
In power down mode, device current drops to less than 2 µA.
The LM4121 comes in two grades A and Standard. The best
grade devices (A) have an initial accuracy of 0.2%, while the
standard have an initial accuracy of 0.5%, both with a
tempco of 50ppm/˚C guaranteed from −40˚C to +125˚C.
The very low operating voltage, low supply current and
power-down capability of the LM4121 makes this product an
ideal choice for battery powered and portable applications.
The device performance is guaranteed over the industrial
temperature range (−40˚C to +85˚C), while certain specs are
guaranteed over the extended temperature range (−40˚C to
+125˚C). Please contact National for full specifications over
the extended temperature range. The LM4121 is available in
a standard 5-pin SOT-23 package.
n Small SOT23-5 package
n Low voltage operation
n High output voltage accuracy:
n Source and Sink current output:
n Supply current:
160 µA Typ.
n Low Temperature Coefficient:
n Enable pin
n Output voltages:
1.25V and Adjustable
n Industrial temperature Range:
−40˚C to +85˚C
n (For extended temperature range, −40˚C to 125˚C,
contact National Semiconductor)
n Portable, battery powered equipment
n Instrumentation and process control
n Automotive & Industrial
n Test equipment
n Data acquisition systems
n Precision regulators
n Battery chargers
n Base stations
n Medical equipment
LM4121-1.2 Block Diagram
* Resistors are removed on the LM4121-ADJ
Refer to the Ordering Information Table in this Data Sheet for Specific
SOT23-5 Surface Mount Package
© 2000 National Semiconductor Corporation DS101291