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TC7116A
Technical data
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MICROCHIP TC7116A, TC7117, TC7117A Technical data

TC7116/A/TC7117/A
3-1/2 Digit Analog-to-Digital Converters with Hold
Features
• Low Temperature Drift Internal Reference
- TC7116/TC7117 80 ppm/°C Typ.
- TC7116A/TC7117A 20 ppm/°C Typ.
• Display Hold Function
• Zero Reading with Zero Input
• Low Noise for Stable Display
- 2V or 200mV Full Scale Range (FSR)
• Auto-Zero Cycle Eliminates Need for Zero
• AdjustmentPotentiometer
• True Polarity Indication for Precision Null Applications
• Convenient 9V Battery Operation: (TC7116/TC7116A)
• High Impedance CMOS Differential Inputs: 10
• Low Power Operation: 10mW
12
Applications
• Thermometry
• Bridge Readouts: StrainGauges, Load Cells, Null Detectors
• Digital Meters: Voltage/Current/Ohms/Power, pH
• Digital Scales, Process Monitors
• PortableInstrumentation
Device Selection Table
Package Code Package Temperature Range
CPL 40-Pin PDIP 0°Cto+70°C
IJL 40-Pin CERDIP -25°Cto+85°C
CKW 44-Pin PQFP 0°Cto+70°C
CLW 44-Pin PLCC 0°Cto+70°C
General Description
The TC7116A/TC7117A are 3-1/2 digit CMOS analog­to-digital converters (ADCs) containing all the active componentsnecessarytoconstructa 0.05% resolution measurement system. Seven-segment decoders, polarity and digit drivers, voltage reference, and clock circuit are integrated on-chip. The TC7116A drives liq­uid crystal displays (LCDs) and includes a backplane driver. The TC7117A drives common anode light emit­ting diode (LED) displays directly with an 8mA drive current per segment.
These devices incorporate a display hold (HLDR) func­tion. The displayed reading remains indefinitely, as long as HLDR is held high. Conversions continue, but output data display latches are not updated. The refer­ence l ow input (V
Ω
TC7106/7107. V mon in the TC7116A/7117A devices.
The TC7116A/7117A reduces linearity error to less than 1 count. Rollover error (the difference in readings for equal magnitude but opposite polarity input signals) is below ±1 count. High-impedance differential inputs offer 1pA leakage current and a 10 ance. The 15µV solid” reading. The auto-zero cycle ensuresa zero dis­play reading with a 0V input.
The TC7116A and TC7117A feature a precision, low drift internal reference, and ar e functionally identical to the TC7116/TC7117. A low drift external reference is not normally required with the TC7116A/TC7117A.
-) is not available, as it is with the
REF
-istiedinternallytoanalogcom-
REF
12
Ω input imped-
noise performance enables a “rock
P-P
2002 Microchip TechnologyInc. DS21457B-page 1
TC7116/A/TC7117/A
Package Type
40-Pin PDIP 40-Pin CERDIP
40
OSC1
39
OSC2
38
OSC3
37
TEST
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
+
V
REF
V+
C
+
REF
C
-
REF
COMMON
+
V
IN
-
V
IN
C
AZ
V
BUFF
V
INT
V-
G
2
C
3
100's
A
3
G
3
BP/GND
(TC7116/7117) (TC7116A/TC7117A)
1's
10's
100's
1000's
(Minus Sign)
HLDR
D
C
B
A
F
G
E
D
C
B
A
F
E
D
B
F
E
AB
POL
1
2
1
3
1
4
1
5
1
6
1
7
1
8
1
TC7116CPL
9
TC7116ACPL
2
TC7117CPL
10
2
TC7117ACPL
11
2
12
2
13
2
14
2
15
3
16
3
17
3
18
3
19
4
20
1's
10's
100's
1000's
(Minus Sign)
HLDR
D
C
B
A
F
G
E
D
C
B
A
F
E
D
B
F
E
AB
POL
1
2
1
3
1
4
1
5
1
6
1 1
7
8
1
9
2
10
2
11
2
12
2
13
2
14
2
15
3
16
3
17
3
18
3
19
4
20
TC7116IJL
TC7116AIJL
TC7117IJL
TC7117AIJL
40
OSC1
39
OSC2
38
OSC3
37
TEST
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
+
V
REF
V+
C
+
REF
-
C
REF
COMMON
+
V
IN
-
V
IN
C
AZ
V
BUFF
V
INT
V-
G
2
C
3
100's
A
3
G
3
BP/GND
(TC7116/7117) (TC7116A/TC7117A)
44-Pin PLCC 44-Pin PQFP
+
+
1
A
6543 1442
F
7
1
G
8
1
E
9
1
D
10
2
C
11
2
12
NC
B2
13
A
2
F
2
E
2
D
3
18 19 20 21 23 24
3
B
Note 1: NC = No internal connection.
2: Pins 9, 25, 40 and 56 are connected to the die substrate. Thepotential at thesepins is approximately V+. No external
connections should be made.
1
B1C1D
TC7116CLW
TC7116ACLW
TC7117CLW
TC7117ACLW
4
3
3
F
E
AB
22
HLDR
NC
NC
POL
OSC1
OSC242OSC341TEST40V
43
25 26 27 28
3A3C3G2
G
BP/
GND
REF
39
38
37
36
35
34
33
3214
3115
3016
2917
V+
C
+
REF
-
C
REF
COMMON
VIN+
NC
V
-
IN
C
AZ
V
BUFF
V
INT
V-
NC
NC
TEST
OSC3
NC
OSC2
OSC1
HLDR
D
C
B
+
REF
V
44 43 42 41 39 3840
1
2
3
4
5
6
7
8
9
1
10
1
11
1
12 13 14 15 17 18
1F1G1E1
A
-
REF
REF
V+
C
C
TC7116CKW
TC7116ACKW
TC7117CKW
TC7117ACKW
16
+
-
IN
IN
COMMON
V
V
2B2A2F2E2
D2C
AZ
BUFF
C
V
37
36
35
19 20 21 22
V
INT
34
V-
33
NC
32
G
3
C
31
3
30
A
3
29
G
3
BP/
28
GND
27
POL
26
AB
4
E
25
3
F
24
3
23
B
3
3
D
DS21457B-page 2
2002 Microchip TechnologyInc.
Typical Application
TC7116/A/TC7117/A
TC7116/A TC7117/A
+
Analog
Input
–
1MΩ
0.01µF
47kΩ
0.22µF
0.47µF
34
31
V
30
V
ANALOG
32
COMMON
28
V
C
29
27
V
OSC2
39 38
0.1µF
REF
+
IN
-
IN
BUFF
AZ
INT
R
100kΩ
+
OSC
33
C
REF
100pF
Display Hold
HLDR
-C
2–19
22–25
POL
BP/GND
V
REF
OSC1OSC3
C
OSC
LCD Display (TC7116/7116A)
1
V+
+
V-
40
3 Conversions Per Second
or Common Anode LED Display
(TC7117/7117A)
Segment Drive
20
Minus Sign
21
35
24kΩ
V
36
REF
100mV
26
1kΩ
To Analog Common (Pin 32)
Backplane Drive
+
9V
2002 Microchip TechnologyInc. DS21457B-page 3
TC7116/A/TC7117/A
1.0 ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings*
Supply Voltage:
TC7116/TC7116A (V+ to V-) ...........................15V
TC7117/TC7117A (V+ to GND).......................+6V
V- to GND.........................................................-9V
Analog Input Voltage(Either Input) (Note 1)... V+ to V-
Reference Input Voltage (Either Input)............V+ to V-
Clock Input:
TC7116/TC7116A............................... TEST to V+
TC7117/TC7117A.................................GND to V+
Package Power Dissipation;T
40-Pin CDIP ................................................2.29W
40-Pin PDIP ................................................1.23W
44-Pin PLCC ...............................................1.23W
44-Pin PQFP...............................................1.00W
Operating Temperature:
C (Commercial) Device ................... 0°C to +70°C
I (Commercial) Device.................... 0°C to +70°C
Storage Temperature..........................-65°C to +150°C
≤ 70°C (Note 2)
A
*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 affectdevice reliability.
TC7116/A AND TC7117/A ELECTRICAL SPECIFICATIONS
Electrical Characteristics: Unless otherwise noted, specifications apply to both the TC7116/A and TC7117/A at TA=25°C,
f
= 48kHz. Partsare testedin the circuitof the Typical Operating Circuit.
CLOCK
Symbol Parameter Min Typ Max Unit Test Conditions
Z
IR
R/O RolloverError(DifferenceinReading f or
CMRR Common Mode Rejection Ra ti o
e
N
I
L
Note 1: Inputvoltages may exceed the supply voltages providedtheinputcurrent is limited to ±100µA.
Zero Input Reading — ±0 — Digital
Ratiometric Reading 999 999/1000 1000 Digital
-1 ±0.2 +1 Counts V Equal Positive and Negative Readings Near Full Scale)
Linearity (MaximumDeviation fromBest Straight Line Fit)
(Note 3)
Noise (Peak to Peak 95% of Time) — 15 — µVVIN=0V
Leakage Current at Input — 1 10 pA VIN=0V Zero Reading Drift — 0.2 1 µV/°C V
2: Dissipationratingassumes device is mounted with all leads solderedtoprinted circuit board. 3: Refer to “Differential Input” discussion. 4: Backplane drive is in phasewithsegment drive for “OFF” segment,180°out of phase for “ON” segment. Frequency is
20 times conversion rate. Average DC component is less than 50mV.
5: The TC7116/TC7116A logicinputs have aninternal pull-down resistor connectedfrom HLDR, Pin 1 to TEST, Pin 37.The
TC7117/TC7117A logic inputs have an internal pull-down resistor connected from HLDR, Pin 1 to GND, Pin 21.
-1 ±0.2 +1 Counts Full Scale = 200mV or 2V
—50—µV/V V
—1.02µV/°C “I”Device=-25°Cto+85°C
Reading
Reading
VIN=0V Full Scale= 200mV
V
IN=VREF
V
=100mV
REF
-=+VIN+ ≅ 200mV
IN
or ≈ 2V
=±1V,VIN=0V
CM
Full Scale= 200mV
Full Scale= 200mV
=0V
IN
“C” Device= 0°C to +70°C
DS21457B-page 4
2002 Microchip TechnologyInc.
TC7116/A/TC7117/A
TC7116/A AND TC7117/A ELECTRICAL SPECIFICATIONS (CONTINUED)
Electrical Characteristics: Unless otherwise noted, specifications apply to both the TC7116/A and TC7117/A at TA= 25°C,
f
= 48kHz. Partsare testedin the circuitof the Typical Operating Circuit.
CLOCK
Symbol Parameter Min Typ Max Unit Test Conditions
TC
I
DD
V
C
V
CTC
V
SD
V
BD
Note 1: Inputvoltages may exceed the supply voltages providedtheinputcurrent is limited to ±100µA.
Scale FactorTemperatureCoefficient — 1 5 ppm/°C VIN=199mV,
SF
“C” Device= 0°C to +70°C (Ext. Ref = 0ppm°C)
— — 20 ppm/°C “I” Device = -25°C to + 85°C
Input Resistance,Pin 1 30 70 — kΩ (Note 5)
Pin 1 — — Test + 1.5 V TC7116/A Only
V
IL,
Pin 1 — — GND + 1.5 V TC7117/A Only
V
IL,
Pin 1 V+- 1.5 — — V Both
V
IH,
SupplyCurrent (Does not Include LED
—0.81.8mAV
IN
=0V
Current for TC7117/A) AnalogCommonVoltage
(with Respectto PositiveSupply) T emperature Coefficient of Analog
Common (with Respectto Positive Supply)
TC7116/TC7117A ONLYPeakto Peak SegmentDriveVoltage
TC7116A/TC7116AONLY Peakto Peak Backplane Drive Voltage
TC7117/TC7117A ONLY SegmentSinking Current
2.4 3.05 3.35 V 25kΩ BetweenCommon and Positive Supply
“C” Device: 0°C to +70°C
——
20 80
— 50 —
— ppm/°C ppm/°C
TC7116A/TC7117A TC7116/TC7117
456VV+toV-=9V
(Note 4)
456VV+toV-=9V
(Note 4)
5 8 — mA V+=5.0V
Segment Voltage = 3V
(Except Pin 19) TC7117/TC7117A ONLY
SegmentSinking Current (Pin19 Only)
10 16 — mA V+=5.0V
Segment Voltage = 3V
2: Dissipationratingassumes device is mounted with all leads solderedtoprinted circuit board. 3: Refer to “Differential Input” discussion. 4: Backplane drive is in phasewithsegment drive for “OFF” segment,180°out of phase for “ON” segment. Frequency is
20 times conversion rate. Average DC component is less than 50mV.
5: The TC7116/TC7116A logicinputs have aninternal pull-down resistor connectedfrom HLDR, Pin 1 to TEST, Pin 37.The
TC7117/TC7117A logic inputs have an internal pull-down resistor connected from HLDR, Pin 1 to GND, Pin 21.
2002 Microchip TechnologyInc. DS21457B-page 5
TC7116/A/TC7117/A
2.0 PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1: PIN FUNCTION TABLE
Pin Number
(40-Pin PDIP)
(40-Pin CERDIP)
1 8 HLDR Hold pin, Logic 1 holdspresent display reading. 29D 310C 411B 512A 613F 714G 815E 916D
10 17 C
11 18 B 12 19 A 13 20 F 14 21 E 15 22 D 16 23 B 17 24 F 18 25 E 19 26 AB 20 27 POL Activates the negative polarity display. 21 28 BP/
22 29 G 23 30 A 24 31 C 25 32 G 26 34 V- Negative power supply voltage. 27 35 V
28 36 V
29 37 C
30 38 V 31 39 V 32 40 COMMON This pin is primarilyusedto set the Analog Common mode voltagefor battery
33 41 C 34 42 C
Pin Number
(44-Pin PQFP)
Symbol Description
1 1 1 1 1 1 1 2 2 2 2 2 2 3 3 3 3
4
GND
3 3 3 2
INT
BUFF
AZ
- The analog LOW input is connectedto this pin.
IN
+ The analog HIGH input signalis connected to this pin.
IN
-SeePin34.
REF
+A0.1µF capacitor is used in most applications. If a large Common mode voltage
REF
Activates the D section of the units display. Activates the C section of the units display. Activates the B section of the units display. Activates the A section of the units display. Activates the F section of the unitsdisplay. Activates the G section of the unitsdisplay. Activates the E section of the units display. Activates the D section of the t ens display. Activates the C section of the t ens display. Activates the B section of the tens display. Activates the A section of the tens display. Activates the F section of the tensdisplay. Activates the E section of the tens display. Activates the D section of thehundreds display. Activates the B section of the hundreds display. Activates the F section of the hundreds display. Activates the E section of the hundreds display. Activates both halves of the 1 in the thousands display.
LCD backplane drive output (TC7116/TC7116A).Digital ground (TC7117/TC7117A).
Activates the G section of the hundreds display. Activates the A section of the hundreds display. Activates the C section of thehundreds display. Activates the G section of thetensdisplay.
Integrator output. Connection point for integration capacitor. See Section4.3, IntegratingCapacitorfor more details.
Integration resistor connection. Use a 47kΩ resistor for a 200mV full scale range and a 470kΩ resistorfor 2V full scale range.
The size of the auto-zerocapacitorinfluences systemnoise. Use a 0.47µF capacitor for 200mV full scale, and a 0.047µF capacitor for 2V full scale. See Section4.1,Auto-Zero Capacitor for more details.
operation,orinsystems wheretheinput signalisreferencedtothepower supply. It also acts as a reference voltage source. See Section3.1.6,Analog Common for more details.
exists (for example,the V used, a 1µF capacitoris recommended and will hold the rollover errorto
- pin is not at analog common),anda 200mV scaleis
IN
0.5 count.
DS21457B-page 6
2002 Microchip TechnologyInc.
TABLE 2-1: PIN FUNCTION TABLE (CONTINUED)
Pin Number
(40-Pin PDIP)
(40-Pin CERDIP)
35 43 V+ Positive Power SupplyVoltage. 36 44 V
37 3 TEST Lamp test. When pulled HIGH (to V+), all segments will be turned on and the dis-
38 4 OSC3 See Pin 40. 39 6 OSC2 See Pin 40. 40 7 OSC1 Pins 40, 39, 38 make up the oscillator section. For a 48kHz clock (3 readings per
Pin Number
(44-Pin PQFP)
Symbol Description
+ The analog input required to generate a full scale output (1999 counts). Place
REF
100mVbetween Pins 32 and 36 for 199.9mV full scale. Place 1V between Pins 35 and 36 for 2V full scale.See Section 4.6, ReferenceVoltage.
play should read -1888. It may also be used as a negative supply for externally generated decimal points. See Section 3.1.7, TEST for additional information.
section), connect Pin 40 to the junction of a 100kΩ resistor and a 100pF capaci­tor. The 100kΩ resistoris tied to Pin 39 andthe 100pF capacitor is tied to Pin 38.
TC7116/A/TC7117/A
3.0 DETAILED DESCRIPTION
(All Pin Designations Refer to 40-Pin PDIP.)
3.1 Analog Section
Figure 3-1 shows the block diagram of the analog sec­tion for the TC7116/TC7116A and TC7117/TC7117A. Each measurement cycle is divided into three phases: (1) Auto-Zero (AZ), (2) Signal Integrate (INT), and (3) Reference Integrate (REF), or De-integrate (DE).
3.1.1 AUTO-ZERO PHASE
Highand low inputsaredisconnected from the pins and internally shorted to analog common. The reference capacitor is charged to the reference voltage. A feed­back loop is closed around the system to charge t he auto-zerocapacitor (C ages in the buffer amplifier, integrator,and comparator. Since the comparator is included in the loop, AZ accu­racy is limited only by systemnoise.The offsetreferred to the input is less than 10µV.
) to compensate for offset volt-
AZ
3.1.2 SIGNAL INTEGRATE PHASE
The auto-zero loop is opened, the internal short is removed, and the internal high and low inputs are con­nected to the external pins. The converter then inte­grates the differential voltages between V for a fixed time. This differential voltage can be within a wide Common mode range: 1V of either supply. How­ever,i f the input signal has no returnwith respectto the converter power supply, V
- can be tied to analog
IN
common to establish the correct Common m ode volt­age. At the end of this phase, the polarity of the integrated signal is determined.
+ and VIN-
IN
2002 Microchip TechnologyInc. DS21457B-page 7
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