Philips PM2517E - Digital Control and Autoranging Circuit

48
3.4.4.
Digital Control and
Autoranging
cilcuit OO 0059
3.4.4.1.
General
with the oo oo59
a ADc
with delta
modulation
principle
can
be controlled.
The OO 0059 consists
of:
-
UP/DOWN
control
to determine
whether incoming
data should
be counted
up
or down
-
POLAR ITY detection circuit
-
T|\4
E R
+
12288
-
RANGING counter
for up/down
ranging.
From the ranging
counter the
digital
range
information
is
availabls.
Number of
ranges: 6.
-
UP/DOWN
counter
for counting
the result
-
LATCHES and
IMULTIPLEXERS
for controlling
a LED
or
LX display
-
LEVEL
DETECTOR
to determine
whether should
be ranged
up or
down in
the auto
range
mode
-
CONTROL
LOGIC
which
generates
the signals; auto
zero,
polarity,
overload
and to
which
the information;
auto
ranging and data
hold can be
given.
r-.
r,
r
r--
t_
L,
t,
t_
t
5,
t
t_
t,
t;
t-
r
L
?
t
t
L
L
t
t_
L
L_
DS
1
052
LÄEN
AUTO
RGXT
RNG
C
RNG 8
RNG
A
DOWN
.
TEST
(
8.5V
)
Fig.33.
GNO
!t
AO
ovR
DH
POL
OATA
CLOCK
0a
00
59
23
22
21
19
18
17
16
15
l3
vss
(-8.5V
)
GNo
V
TEST
:loi
:l0i
ir0i
UP/ DOWN CONTROL
POLARITY OETECT.
MU
LTIPL
EX E
R
RAN
G
ING
COUNTER
Fis.
34.