Typical Applications (Continued)
Precision High Voltage Regulator
DS009064-30
Q1, Q2: NSD134 or similar
**
C1, C2: 1µF, 200V mylar
*
Heat sink
**
Mylar is a registered trademark of DuPont Co.
Tracking Regulator
Regulator With Trimmable Output Voltage
DS009064-32
Trim Procedure:
— If V is 23.08V or higher, cut out R3 (if lower, don’t cut it out).
OUT
— Then if V
— Then if V
is 22.47V or higher, cut out R4 (if lower, don’t).
is 22.16V or higher, cut out R5 (if lower, don’t).
OUT
OUT
±
This will trim the output to well within 1% of 22.00 V , without any of
DC
the expense or uncertainty of a trim pot (see LB-46). Of course, this
technique can be used at any output voltage level.
DS009064-31
A1 = LM301A, LM307, or LF13741 only
R1, R2 = matched resistors with good TC tracking
13
www.national.com
NSC [ National Semiconductor ]
