2252-DEMO THAT Corporation, 2252-DEMO Datasheet - Page 10

• Manufacturer Part Number: 2252-DEMO
• Description: Power Management Modules & Development Tools RMS Detector Demo Board
• Manufacturer: THAT Corporation
• Type: AC/DC Switching Convertersr

Specifications of 2252-DEMO

• Input Voltage: 12 V
• Maximum Operating Temperature: + 75 C
• Minimum Operating Temperature: - 20 C
• Product: Power Management Modules
• Supply Current: 1 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Page 10
With this tech nique, the fre quency re sponse is ex -
tended to dc, while a slight loss in low-level ac cu -
racy re sults from the ad di tional bias cur rent
drawn by OA2.
Tem per a ture-Compensated Mea sure ments
In cer tain ap pli ca tions, the 2252 may be used for
high-precision mea sure ments where the 0.33% / °C
vari a tion in out put scal ing may be un ac cept able.
For these sit u a tions, the out put should be tem per -
a ture
3300ppm / °C re sis tor. Such re sis tors are avail able
from RCD Com po nents, Inc., 3301 Bed ford St.,
Man ches ter,
KOA/Speer Elec tron ics, PO Box 547, Brad ford, PA,
16701 USA [(814)-362-5536]. Fig ure 13 shows a
typ i cal cir cuit. For good re sults, R1 should be lo -
cated phys i cally close to the 2252 to op ti mize tem -
per a ture track ing.
Un usual Ap pli ca tions
Since the 2252 con tains a pre ci sion rec ti fier fol -
lowed by a log ging stage, it is pos si ble to think of
other ways to ap ply the part be yond its con ven -
tional use as an rms-level de tec tor.
Log Am pli fier
In ap pli ca tions where pre ci sion log ging is re -
quired, the rec ti fier can be en tirely by passed by
driv ing the in put with a sin gle-sided dc sig nal, and
the logged out put used di rectly. In such cases, the
tim ing ca pac i tor (C
SYM
50k
V+
IN
Fig ure 13. Tem per a ture Com pen sating the 2252
20u
Cin
com pen sated
47k
V-
24k
20
Rin
10k
1u
NH,
1
560k
IN
SYM
V-
V-
THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA
Rb
5
2252
4
R T
2M2
GND
USA
IBIAS
T
2
3
Rf 22M
) con nected to the pin 6
Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com
CAP
OUT
V+
through
6
8
7
10u
1k
+3300ppm
[(603)-669-0054]
C T
10u
R1 2k
V+
the
R2
2k
OA1
use
of
OUT
and
a
should be re duced to a small value (1~10 nf) to
quiet noise in the out put while avoid ing sig nif i cant
de lay in the re sponse.
Log-Responsive Peak De tec tor
Where peak de tec tion is de sired, the 2252 may be
con fig ured with very fast time con stants (as in the
Log Am pli fier above), and fol lowed by a peak hold
am pli fier. The ad van tage of us ing the 2252 for this
ap pli ca tion is that the 2252 pro vides rec ti fi ca tion
and log ging be fore the peak de tec tor, which al lows
ex tremely wide dy namic range in the re sult ing sig -
nal.
Closing Thoughts
THAT Cor po ra tion wel comes com ments, ques tions
and sug ges tions re gard ing this de vice, its de sign
and ap pli ca tion. Our en gi neer ing staff has ex ten -
sive ex pe ri ence in ap ply ing this part to com mer cial
cir cuits. We are pleased to of fer as sis tance in op ti -
miz ing your cir cuitry to adapt the 2252 to your
par tic u lar ap pli ca tion. Please feel free to con tact
us with your thoughts and ques tions.
1
ITEM
A
B
C
D
E
F
G
H
J
K
L
M
N
I
Fig ure 14. SIP Pack age Out line
MILLIMETERS
19.5 +0.2/-0
1.25
0.65
0.85
2.54 ±0.2
0.9
1.2
5.8 +0.2/-0
2.8 +0.1/-0
10.5 ±0.5
1.3
0.3
3.5 ±0.5
17.78 ±0.3
C
D
B
A
N
THAT 2252 RMS-Level De tec tor
E TYP.
F
INCHES
0.77 +0.008/-0
0.049
0.026
0.033
0.100 ±0.008
0.04
0.05
0.23 +0.008/-0
0.11 +0.004/-0
0.413 ±0.02
0.05
0.012
0.14 ±0.02
0.700 ±0.012
H
G
M
J
L
I
K