ICL7139CPL Intersil, ICL7139CPL Datasheet - Page 9

• Manufacturer Part Number: ICL7139CPL
• Description: IC DMM 3 3/4 DIGIT AUTORANGE
• Manufacturer: Intersil
• Type: Multimeterr

Specifications of ICL7139CPL

• Rohs Status: RoHS non-compliant
• Voltage Supply Source: Dual ±
• Voltage - Supply: ±24V, 2.7 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 40-DIP (0.600", 15.24mm)
• Data Interface: -
• Sampling Rate (per Second): -
• Resolution (bits): -

Ratiometric
The ratiometric
integrating the voltage across an unknown resistor, R
effectively deintegrating the voltage across a known resistor
(R
R
between integration and deintegration. Like the current mea-
surements, the
ranges. LO
and the full scale ranges are 4k
ments use a 1M reference resistor, and the full scale ranges
are 0.4M
are the same as the measurement phases and timing for DC
current except: 1) During the integrate phases the input volt-
age is the voltage across the unknown resistor R
During the deintegrate phases, the input voltage is the voltage
across the reference resistor R
Continuity Indication
When the ICL7139 and ICL7149 are in the LO
measurement mode, the continuity circuit of Figure 9 will be
active. When the voltage across R
100mV, the beeper output will be on. When R
the beeper output will be on when R
R
INTV
UNKNOWN
KNOWN1
R
KNOWN
FIGURE 9. CONTINUITY BEEPER DRIVE CIRCUIT
does not affect the reading because it cancels exactly
R
X
and 4M . The measurement phases and timing
or R
R
LO
COM
X
measurements use a 10k
HI
Measurement
KNOWN2
R
R
KNOWN 1
KNOWN 2
R
measurements are split into two sets of
INTV
COMMON
+
-
INT V/
measurement is performed by first
V
FIGURE 8. DETAILED CIRCUIT DIAGRAM FOR RATIOMETRIC
X
LO
HI
+
-
of Figure 8). The shunting effect of
+
-
V
KNOWN1
REF
V
X
2kHz
LO
LOW
LOW
X
= 100mV
and 40k . HI
is less than approximately
X
is less than 1k .
or R
+
+
-
-
reference resistor,
KNOWN2
KNOWN
V+
V+
ICL7139, ICL7149
X
measure-
, and; 2)
is 10k ,
V
BEEPER
OUTPUT
.
DEINT+
T
X
REF
TRIPLE
, then
POINT
T
AZ
3-41
C
Common Voltage
The analog and digital common voltages of the ICL7139 and
ICL7149 are generated by an on-chip resistor/zener/diode
combination, shown in Figure 10. The resistor values are
chosen so the coefficient of the diode voltage cancels the
positive temperature coefficient of the zener voltage. This
voltage is then buffered to provide the analog common and
the digital common voltages. The nominal voltage between
V+ and analog common is 3V. The analog common buffer
can sink about 20mA, or source 0.01mA, with an output
impedance of 10 . A pullup resistor to V+ may be used if
more sourcing capability is desired. Analog common may be
used to generate the reference voltage, if desired.
Oscillator
The ICL7139 and ICL7149 use a parallel resonant-type
crystal in a Pierce oscillator configuration, as shown in
Figure 11, and requires no other external components. The
crystal eliminates the need to trim the oscillator frequency.
An external signal may be capacitively coupled in OSC IN,
with a signal level between 0.5V and 3V
DEINT+
6.7V
FIGURE 10. ANALOG AND DIGITAL COMMON VOLTAGE
AZ
C
5K
INTEGRATOR
AZ
C
AZ
+
-
125K
180K
INT
AZ
GENERATOR CIRCUIT
T = INT + DEINT
AZ = AUTOZERO
INT = INTEGRATE
+
-
80 A
C
INT
COMPARATOR
P
MEASUREMENT
R
ANALOG
COMMON
(PIN 10)
AZ
+
-
DEINT
3V
+
-
R
DEINT
3.1V
+
-
TO LOGIC SECTION
+
SECTION
LOGIC
P
DIGITAL
COMMON
(INTERNAL)
P-P
0.3V
. Because the
-
+
-
+
LO BAT
V+
V-