The LMx17HV is an adjustable 3-terminal positive voltage regulator capable of supplying
1.5 A or more currents over a 1.25-V to 57-V output voltage range. It requires only two external
resistors to set the output voltage. The LMx17HV is packaged in standard transistor packages that
are easily mounted and handled.
The LMx17HV offers overload protection like current limit, thermal overload protection
and safe area protection, which make the device blowout proof. The overload protection circuitry
remains fully functional even if the adjustment terminal is disconnected.
Typically, no capacitors are needed unless the device is situated more than 6 inches from
the input filter capacitors, in which case an input bypass is needed. An optional output capacitor
can be added to improve transient response. The adjustment terminal can be bypassed to achieve very
high ripple rejection ratios which are difficult to achieve with standard 3-terminal
Since the regulator is floating and sees only the
input-to-output differential voltage, supplies of several hundred volts can be regulated as long as
the maximum input to output differential is not exceeded, or in other words, do not short the
output to ground.
By connecting a fixed resistor between the adjustment and output, the LMx17HV can also be
used as a precision current regulator. Supplies with electronic shutdown can be achieved by
clamping the adjustment terminal to ground, which programs the output to 1.25 V where most loads
draw little current.