TC7107RCPL Microchip Technology, TC7107RCPL Datasheet - Page 14

• Manufacturer Part Number: TC7107RCPL
• Description: IC ADC 3 1/2DGT LED DVR REV40DIP
• Manufacturer: Microchip Technology

Specifications of TC7107RCPL

• Display Type: LED
• Configuration: 7 Segment
• Digits Or Characters: A/D 3.5 Digits
• Current - Supply: 800µA
• Voltage - Supply: 5V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: 40-DIP (0.600", 15.24mm)
• Resolution (bits): 3.5bit
• Input Channel Type: Differential
• Data Interface: Parallel
• Supply Voltage Range - Analog: 5V
• Supply Current: 800µA
• Digital Ic Case Style: DIP
• No. Of Pins: 40
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: Q834953

TC7106/A/TC7107/A
The differential reference can also be used when a dig-
ital zero reading is required when V
zero. This is common in temperature measuring instru-
mentation. A compensating offset voltage can be
applied between analog common and V
ducer output is connected between V
common.
The internal voltage reference potential available at
analog common will normally be used to supply the
converter's reference. This potential is stable when-
ever the supply potential is greater than approximately
7V. In applications where an externally generated ref-
erence voltage is desired, refer to Figure 7-1.
FIGURE 7-1:
8.0
8.1
The TC7106A/7017A is designed with true differential
inputs and accepts input signals within the input stage
common mode voltage range (V
is V+ – 1.0 to V+ + 1V. Common mode voltages are
removed from the system when the TC7106A/
TC7107A operates from a battery or floating power
source (isolated from measured system) and V
connected to analog common (V
In systems where Common mode voltages exist, the
86dB Common mode rejection ratio minimizes error.
Common mode voltages do, however, affect the inte-
grator output level. Integrator output saturation must be
prevented. A worst case condition exists if a large pos-
itive V
differential signal. The negative signal drives the inte-
grator output positive along with V
For such applications the integrator output swing can
be reduced below the recommended 2.0V full scale
swing. The integrator output will swing within 0.3V of
V+ or V- without increasing linearity errors.
DS21455B-page 14
TC7106A
TC7107A
V+
(a)
CM
V
V
REF
REF
DEVICE PIN FUNCTIONAL
DESCRIPTION
Differential Signal Inputs
V
exists in conjunction with a full scale negative
IN
+
-
+ (Pin 31), V
V+
6.8V
Zener
EXTERNAL REFERENCE
I
Z
IN
TC7106A
TC7107A
- (Pin 30)
CM
Common
COM
V+
(b)
V
CM
V
). The typical range
REF
REF
) (see Figure 8-2).
IN
(see Figure 8-1).
+
-
IN
is not equal to
IN
20kΩ
+ and analog
-. The trans-
V+
1.2V
Ref
6.8kΩ
IN
- is
FIGURE 8-1:
8.2
The reference voltage can be generated anywhere
within the V+ to V- power supply range.
To prevent rollover type errors being induced by large
Common mode voltages, C
pared to stray node capacitance.
The TC7106A/TC7107A circuits have a significantly
lower analog common temperature coefficient. This
gives a very stable voltage suitable for use as a refer-
ence. The temperature coefficient of analog common is
20ppm/°C typically.
8.3
The analog common pin is set at a voltage potential
approximately 3.0V below V+. The potential is between
2.7V and 3.35V below V+. Analog common is tied inter-
nally to the N channel FET capable of sinking 20mA.
This FET will hold the common line at 3.0V should an
external load attempt to pull the common line toward
V+. Analog common source current is limited to 10µA.
Analog common is, therefore, easily pulled to a more
negative voltage (i.e., below V+ – 3.0V).
The TC7106A connects the internal V
inputs to analog common during the auto-zero cycle.
During the reference integrate phase, V
nected to analog common. If V
nected to analog common, a Common mode voltage
exists. This is rejected by the converter's 86dB Com-
mon mode rejection ratio. In battery operation, analog
common and V
Common mode voltage concerns. In systems where V-
is connected to the power supply ground, or to a given
voltage, analog common should be connected to V
–
+
V
V
CM
IN
Differential Reference
V
Analog Common (Pin 32)
REF
+
–
Input Buffer
+ (Pin 36), V
IN
Where:
- are usually connected, removing
VOLTAGE REDUCES
AVAILABLE INTEGRATOR
SWING (V
COMMON MODE
T
C
R
V
©
R
I
I
I
I
2002 Microchip Technology Inc.
= Integration Time =
=
= Integration Capacitor
= Integration Resistor
I
REF
R
IN
T
I
REF
C
I
- is not externally con-
should be large com-
I
COM
- (Pin 35)
[
–
+
C
V
Integrator
≠ V
I
CM
IN
+ and V
IN
– V
IN
- is con-
)
IN
4000
F
OSC
[
V
IN
IN
I
-.
-