1 Features
1• Low-Voltage Operation/Wide Adjust Range
(1.24 V/30 V)
• 0.5% Initial Tolerance (LMV431B)
• Temperature Compensated for Industrial
Temperature Range (39 PPM/°C for the
LMV431AI)
• Low Operation Current (55 μA)
• Low Output Impedance (0.25 Ω)
• Fast Turn-On Response
• Low Cost

2 Applications
• Shunt Regulator
• Series Regulator
• Current Source or Sink
• Voltage Monitor
• Error Amplifier
• 3-V Off-Line Switching Regulator
• Low Dropout N-Channel Series Regulator

3 Description
The LMV431, LMV431A and LMV431B are precision
1.24 V shunt regulators capable of adjustment to 30
V. Negative feedback from the cathode to the adjust
pin controls the cathode voltage, much like a non-
inverting op amp configuration (Refer to Symbol and
Functional Diagrams). A two-resistor voltage divider
terminated at the adjust pin controls the gain of a
1.24 V band-gap reference. Shorting the cathode to the adjust pin (voltage follower) provides a cathode
voltage of a 1.24 V.
The LMV431, LMV431A and LMV431B have
respective initial tolerances of 1.5%, 1%, and 0.5%,
and functionally lend themselves to several
applications that require zener diode type
performance at low voltages. Applications include a 3 V to 2.7 V low drop-out regulator, an error amplifier in
a 3 V off-line switching regulator and even as a
voltage detector. These parts are typically stable with
capacitive loads greater than 10 nF and less than 50
pF.
The LMV431, LMV431A and LMV431B provide
performance at a competitive price.