TC835CKW Microchip Technology, TC835CKW Datasheet - Page 7

• Manufacturer Part Number: TC835CKW
• Description: IC ADC 4 1/2DGT BCD 44-MQFP
• Manufacturer: Microchip Technology

Specifications of TC835CKW

• Display Type: LED
• Configuration: 7 Segment
• Interface: BCD
• Digits Or Characters: A/D 4.5 Digits
• Current - Supply: 1mA
• Voltage - Supply: 4 V ~ 6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 44-MQFP, 44-PQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

FIGURE 3-2:
3.2.2
The TC835 integrates the differential voltage between
the +INPUT and -INPUT pins. The differential voltage
must be within the device Common mode range (-1V
from either supply rail, typically). The input signal polar-
ity is determined at the end of this phase (see
Figure
FIGURE 3-3:
Phase.
3.2.3
The previously charged reference capacitor is con-
nected with the proper polarity to ramp the integrator
output back to zero (see
ing displayed is:
TABLE 3-6:
© 2007 Microchip Technology Inc.
Analog
Common
Analog
Common
Conversion Cycle Phase
System Zero
Input Signal Integration
Reference Voltage Integration
Integrator Output Zero
*Note:
REF
+IN
+IN
REF
IN
IN
IN
IN
SW
SW
SW
SW
3-3).
SW
SW
SW
SW
Z
Z
R
Reading = 10,000
R
I
I
I
I
Assumes a positive polarity input signal. SW
ANALOG INPUT SIGNAL
INTEGRATION
REFERENCE VOLTAGE
INTEGRATION
C
C
REF
REF
INTERNAL ANALOG GATE STATUS
SW
SW
Input Buffer
Input Buffer
1
1
Analog
Analog
SW
SW
+
-
System Zero Phase.
+
–
Input Signal Integration
SW
SW
IZ
IZ
Figure
Z
Z
[Differential Input]
SW
SW
R
R
INT
INT
Z
Z
3-4). The digital read-
Integrator
Integrator
Closed
V
SW
C
C
REF
C
C
—
—
—
+
-
+
–
SZ
SZ
INT
Switch Open
Switch Closed
INT
Switch Open
Switch Closed
I
Closed*
+
–
+
-
SW
Comparator
Comparator
—
—
—
RI
+
To
Digital
Section
To
Digital
Section
RI
SW
would be closed for a negative input signal.
—
—
—
—
RI
-
Closed
SW
—
—
—
FIGURE 3-4:
Integration Cycle.
3.2.4
This phase guarantees the integrator output is at 0V
when the system zero phase is entered and that the
true system offset voltages are compensated for. This
phase normally lasts 100 to 200 clock cycles. If an
overrange condition exists, the phase is extended to
6200 clock cycles (see
FIGURE 3-5:
Phase.
Analog
Common
Analog
Common
Z
REF
REF
+IN
+IN
IN
IN
IN
IN
SW
SW
SW
SW
SW
Closed
SW
SW
SW
SW
Z
Z
—
—
—
R
R
I
I
I
I
R
INTEGRATOR OUTPUT ZERO
C
C
REF
REF
Closed
Closed
Closed
SW
SW
SW
—
Input Buffer
Input Buffer
1
1
1
Analog
SW
Analog
SW
+
–
Reference Voltage
Integrator Output Zero
+
SW
–
SW
Figure
IZ
IZ
Z
Closed
Z
SW
SW
—
—
—
SW
R
R
IZ
3-5).
INT
Z
INT
Z
Integrator
Integrator
C
C
C
C
Reference Figures
+
–
+
SZ
–
SZ
INT
INT
Switch Open
Switch Closed
Switch Open
Switch Closed
DS21478C-page 7
TC835
Figure 3-2
Figure 3-3
Figure 3-4
Figure 3-5
+
–
+
–
Comparator
Comparator
To
Digital
Section
To
Digital
Section