TC14433/A
3-1/2 Digit, Analog-to-Digital Converter
Features
•
•
•
•
•
•
•
•
•
•
Accuracy: ±0.05% of Reading ±1 Count
Two Voltage Ranges: 1.999V and 199.9 mV
Up to 25 Conversions Per Second
Z
IN
> 1000M Ohms
Single Positive Voltage Reference
Auto-Polarity and Auto-Zero
Overrange and Underrange Signals Available
Operates in Auto-Ranging Circuits
Uses On-Chip System Clock or External Clock
Wide Supply Range: ±4.5V to ±8V
Package Type
24-Pin PDIP (Wide)
24-Pin CERDIP (Wide)
24-Pin SOIC (Wide)
V
AG
V
REF
V
X
1
2
3
24 V
DD
23 Q
3
22 Q
2
21 Q
1
R
1
4
R
1
/C
1
5
TC14433/A
20 Q0
19 DS
1
18 DS
2
17 DS
3
16 DS
4
15 OR
14 EOC
13 V
SS
C
1
6
CO
1
7
Applications
•
•
•
•
•
•
•
Portable Instruments
Digital Voltmeters
Digital Panel Meters
Digital Scales
Digital Thermometers
Remote A/D Sensing Systems
MPU Systems
CO
2
8
DU
9
CLK1 10
CLK0
11
V
EE
12
Device Selection Table
Part Number
TC14433AEJG
TC14433AELI
TC14433AEPG
TC14433COG
TC14433EJG
TC14433ELI
TC14433EPG
Package
24-Pin CERDIP
(Wide)
28-Pin PLCC
24-Pin PDIP
(Wide)
24-Pin SOIC
(Wide)
24-Pin CERDIP
(Wide)
28-Pin PLCC
24-Pin PDIP
(Wide)
Temperature
Range
-40°C to +85°C
R
1
5
V
X
28-Pin PLCC
V
REF
V
AG
V
DD
NC
Q
3
Q
2
25 Q
1
24 Q
0
23 DS
1
22 NC
21 DS
2
20 DS
3
4
3
2
1
28 27 26
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
R1/C
1
6
C
1
7
NC 8
CO1 9
CO
2
10
DU 11
12 13 14 15 16 17 18
EOC
CLK1
CLK0
V
EE
V
SS
NC
OR
TC14433/A
19 DS
4
Note 1:
NC = No internal connection (In 28-Pin PLCC).
2:
24-Pin SOIC (Wide) package, only for
TC14433 device.
2002 Microchip Technology Inc.
DS21394B-page 1
©
TC14433/A
General Description
The TC14433 is a low power, high performance,
monolithic CMOS 3-1/2 digit A/D converter. The
TC14433 combines both analog and digital circuits on
a single IC, thus minimizing the number of external
components.
This dual slope A/D converter provides automatic
polarity and zero correction with the addition of two
external resistors and two capacitors. The full scale
voltage range of this ratiometric IC extends from 199.9
millivolts to 1.999 volts. The TC14433 can operate over
a wide range of power supply voltages, including
batteries and standard 5-volt supplies.
The TC14433A features improved performance over
the industry standard TC14433. Rollover, which is the
measurement of identical positive and negative
signals, is specified to have the same reading within
one count for the TC14433A. Power consumption of
the TC14433A is typically 4mW, approximately one-
half that of the industry standard TC14433.
The TC14433/A is available in 24-Pin PDIP, 24-Pin
CERDIP, 24-Pin SOIC (TC14433 device only), and
28-Pin PLCC packages.
Typical Application
MCP1525
+5V
V
IN
V
OUT
V
SS
1µF
V
X
R
1
*
1µF
300k
R
C
11 10 2 12 24
23
22
21
4
20
5
TC14433
6
13
3
1
7
8
9
14
15 19 18 17 16
+5V
0.1
20k
-5V
+5V
0.1µF
1
4
2
3
5
-5V
16
7
6
5
4
3
2
1
-5V
-5V
10
11
12
13
14
15
16
1413
Minus Sign
f g e d c b a
+5V
Segment
Resistors
150Ω (7)
0.1µF**
0.1µF**
9
10
11
12
13
4543B 14
15
8 6 7
-5V
-5V
6
5 S 1
Q
2
3 D
C RQ
4
8
9 D S Q 13
11 C Q 12
R
710 14
+5V
*R
1
= 470kΩ for 2V Range
R
1
= 27kΩ for 200mV Range
**Mylar Capacitor
14013B
200Ω
MPS-A12 Plus Sign
-5V
110Ω
51k
Common
Anode Led
+5V
Display
50µF
0.1µF
MPS-A12
(4)
-5V
DS4
DS3
DS2
DS1
-5V
©
DS21394B-page 2
2002 Microchip Technology Inc.
TC14433/A
1.0
ELECTRICAL
CHARACTERISTICS
*Stresses above those listed under "Absolute Maximum
Ratings" may cause permanent damage to the device. These
are stress ratings only and functional operation of the device
at these or any other conditions above those indicated in the
operation sections of the specifications is not implied.
Exposure to Absolute Maximum Rating conditions for
extended periods may affect device reliability.
Absolute Maximum Ratings*
Supply Voltage (V
DD
– V
EE
) ................... -0.5V to +18V
Voltage on Any Pin:
Reference to V
EE
.....................-0.5V to (V
DD
+ 0.5)
DC Current, Any Pin: ........................................ ±10mA
Power Dissipation (T
A
≤
70°C):
Plastic PLCC ................................................. 1.0W
Plastic PDIP.................................................. 940W
SOIC ............................................................. 940W
CERDIP ....................................................... 1.45W
Operating Temperature Range ............... 0°C to +70°C
Storage Temperature Range .............. -65°C to +160°C
TC14433/A ELECTRICAL SPECIFICATIONS
Electrical Characteristics:
V
DD
= +5V, V
EE
= -5V, C
1
= 0.1µF, (Mylar), C
0
= 0.1µF, R
C
= 300kΩ, R
1
= 470kΩ @ V
REF
= 2V,
R
1
= 27kΩ @ V
REF
= 200mV, unless otherwise specified.
Symbol
Analog Input
SYE
Rollover Error (Positive) and
Negative Full Scale
Symmetry
Linearity Output Reading
(Note 1)
Stability Output Reading
(Note 2)
-1
Parameter
Min
Typ
T
A
= +25°C
—
+1
—
Max
Min
Typ
T
A
= +25°C
—
—
Counts 200mV Full Scale
V
IN
-V
IN
= +V
IN
%rdg
%rdg
LSD
LSD
LSD
pA
pA
pA
dB
V
X
= 1.4V, V
REF
= 2V,
F
OC
= 32kHz
V
REF
= 2V
V
REF
= 200mV
V
X
= 1.99V,
V
REF
= 2V
V
X
= 199mV,
V
REF
= 200mV
V
X
= 0V, V
REF
= 2V
Max
Units
Test Conditions
NL
SOR
-0.05
-1 count
—
—
+0.05
—
—
—
0
±20
±20
±20
65
+0.05
+1 count
2
3
0
±100
±100
±100
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
ZOR
I
IN
Zero Output Reading
Bias Current: Analog Input
Reference Input
Analog Ground
—
—
—
—
—
CMRR
Common mode Rejection
Note 1:
Accuracy - The accuracy of the meter at full scale is the accuracy of the setting of the reference voltage. Zero is
recalculated during each conversion cycle. The meaningful specification is linearity. In other words, the deviation from
correct reading for all inputs other than positive full scale and zero is defined as the linearity specification.
2:
The LSD stability for 200mV scale is defined as the range that the LSD will occupy 95% of the time.
3:
Pin numbers refer to 24-pin PDIP.
2002 Microchip Technology Inc.
DS21394B-page 3
©
TC14433/A
TC14433/A ELECTRICAL SPECIFICATIONS (CONTINUED)
Electrical Characteristics:
V
DD
= +5V, V
EE
= -5V, C
1
= 0.1µF, (Mylar), C
0
= 0.1µF, R
C
= 300kΩ, R
1
= 470kΩ @ V
REF
= 2V,
R
1
= 27kΩ @ V
REF
= 200mV, unless otherwise specified.
Symbol
Digital
V
OL
Output Voltage
(Pins 14 to 23)
(Note 3)
Output Voltage
(Pins 14 to 23)
(Note 3)
Output Current
(Pins 14 to 23)
—
—
V
OH
4.95
4.95
I
OH
-0.2
- 0.5
I
OL
Output Current
(Pins 14 to 23)
0.51
1.3
f
CLK
I
DU
Power
I
Q
Quiescent Current: 14433A:
—
—
—
Quiescent Current: 14433:
—
—
—
PSRR
Supply Rejection
—
—
0.4
1.4
—
0.9
1.8
0.5
—
2
4
—
2
4
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
3.7
7.4
—
3.7
7.4
—
—
mA
mA
—
mA
mA
mV/V
V
DD
to V
EE
, I
SS
= 0
V
DD
= 5, V
EE
= -5
V
DD
= 8, V
EE
= -8
V
DD
to V
EE
, I
SS
= 0
V
DD
= 5, V
EE
= -5
V
DD
= 8, V
EE
= -8
V
DD
to V
EE
, I
SS
= 0,
V
REF
= 2V,
V
DD
= 5, V
EE
= -5
Clock Frequency
Input Current -DU
—
—
0
-5
5
5
-0.36
-0.9
0.88
2.25
66
±0.00001
0.05
-4.95
—
—
—
—
—
—
—
±0.3
—
—
4.95
4.95
-0.14
-0.35
0.36
0.9
—
—
—
—
—
—
—
—
—
—
—
—
0.05
-4.95
—
—
—
—
—
—
—
±1
V
V
V
V
mA
mA
mA
mA
kHz
µA
V
SS
= 0 V, "0" Level
V
SS
= -5V, "0" Level
V
SS
= 0V, "1" Level
V
SS
= -5V, "1" Level
V
SS
= 0V, V
OH
= 4.6V
Source
V
SS
= -5V, V
OH
= 5V
Source
V
SS
= 0V, V
OL
= 0.4V
Sink
V
SS
= -5V,
V
OL
= -4.5V Sink
R
C
= 300kΩ
Parameter
Min
Typ
Max
Min
Typ
Max
Units
Test Conditions
Note 1:
Accuracy - The accuracy of the meter at full scale is the accuracy of the setting of the reference voltage. Zero is
recalculated during each conversion cycle. The meaningful specification is linearity. In other words, the deviation from
correct reading for all inputs other than positive full scale and zero is defined as the linearity specification.
2:
The LSD stability for 200mV scale is defined as the range that the LSD will occupy 95% of the time.
3:
Pin numbers refer to 24-pin PDIP.
©
DS21394B-page 4
2002 Microchip Technology Inc.
TC14433/A
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2.0.
TABLE 2-1:
Pin No.
(24-Pin PDIP)
(24-Pin CERDIP)
(24-Pin SOIC)
1
2
PIN FUNCTION TABLE
Pin No.
Symbol
(28-Pin PLCC)
2
3
V
AG
V
REF
Description
This is the analog ground. It has a high input impedance. The pin determines the
reference level for the unknown input voltage (V
X
) and the reference voltage (V
REF
).
Reference voltage - Full scale output is equal to the voltage applied to V
REF
.
Therefore, full scale voltage of 1.999V requires 2V reference and 199.9mV full scale
requires a 200mV reference. V
REF
functions as system reset also. When switched
to V
EE
, the system is reset to the beginning of the conversion cycle.
The unknown input voltage (V
X
) is measured as a ratio of the reference voltage
(V
REF
) in a rationetric A/D conversion.
This pin is for external components used for the integration function in the dual
slope conversion. Typical values are 0.1µF (mylar) capacitor for C
1
.
R
1
= 470kΩ (resistor) for 2V full scale.
R
1
= 27kΩ (resistor) for 200mV full scale. Clock frequency of 66kHz gives 250msec
conversion time.
These pins are used for connecting the offset correction capacitor.
The recommended value is 0.1µF.
These pins are used for connecting the offset correction capacitor.
The recommended value is 0.1µF.
Display update input pin. When DU is connected to the EOC output, every
conversion is displayed. New data will be strobed into the output latches during the
conversion cycle if a positive edge is received on DU, prior to the ramp down cycle.
When this pin is driven from an external source, the voltage should be referenced
to V
SS
.
Clock input pins. The TC14433 has its own oscillator system clock. Connecting a
single resistor between CLK
1
and CLK
0
sets the clock frequency.
A crystal or OC circuit may be inserted in lieu of a resistor for improved CLK
1
, the
clock input, can be driven from an external clock source, which need only have
standard CMOS output drive. This pin is referenced to V
EE
for external clock inputs.
A 300kΩ resistor yields a clock frequency of about 66kHz. See Section 5.0 Typical
Characteristics. (Also see Figure 4-3 for alternate circuits.)
Negative power current. Connection pin for the most negative supply. Please note
the current for the output drive circuit is returned through V
SS
. Typical supply
current is 0.8mA.
Negative power supply for output circuitry. This pin sets the low voltage level for the
output pins (BCD, Digit Selects, EOC, OR). When connected to analog ground, the
output voltage is from analog ground to V
DD
. If connected to V
EE
, the output swing
is from V
EE
to V
DD
. The recommended operating range for V
SS
is between the
V
DD
-3 volts and V
EE
.
End of conversion output generates a pulse at the end of each conversion cycle.
This generated pulse width is equal to one half the period of the system clock.
Overrange pin. Normally this pin is set high. When V
X
exceeds V
REF
the OR is low.
Digit select pin. The digit select output goes high when the respective digit is
selected. The MSD (1/2 digit turns on immediately after an EOC pulse).
The remaining digits turn on in sequence from MSD to LSD.
To ensure that the BCD data has settled, an inter digit blanking time of two clock
periods is included.
Clock frequency divided by 80 equals multiplex rate. For example, a system clock of
60kHz gives a multiplex rate of 0.8kHz.
See Figure 4-4 for digit select timing diagram.
3
4
5
6
7
8
9
4
5
6
7
9
10
11
V
X
R
1
R
1
/C
1
C
1
CO
1
CO
2
DU
10
11
12
13
CLK
1
CLK
0
12
14
V
EE
13
16
V
SS
14
15
16
17
18
19
20
17
18
19
20
21
23
24
EOC
OR
DS
4
DS
3
DS
2
DS
1
Q
0
2002 Microchip Technology Inc.
DS21394B-page 5
©
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