TC811 TelCom Semiconductor, TC811 Datasheet - Page 2

• Manufacturer Part Number: TC811
• Description: 3-1/2 DIGIT A/D CONVERTER WITH HOLD AND DIFFERENTIAL REFERENCE INPUTS
• Manufacturer: TelCom Semiconductor

TC811
GENERAL DESCRIPTION
analog-to-digital converter. This device incorporates both a
display hold feature and differential reference inputs. A
crystal oscillator, which only requires two pins, permits
added features while retaining a 40-pin package. An addi-
tional feature is an "Integrator Output Zero" phase which
guarantees rapid input overrange recovery.
"freeze" the LCD display. The displayed reading will remain
indefinitely as long as HLDR is held high. Conversions
continue but the output data display latches are not updated.
The TC811 also includes a differential reference for easy
ratiometric measurements. Circuits which use the
7106/26/36 can easily be upgraded to include the hold
function with the TC811.
voltage circuit which maintains the Analog Common tem-
perature drift to 35ppm/ C (typical) and 75ppm/ C (maxi-
mum). This represents an improvement of two to four times
over similar 3-1/2 digit converters, eliminating the need for
a costly, space consuming external reference source.
both the 200mV and the 2.00V full-scale ranges. 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 currents
and a 10
mance guarantees a “rock solid” reading. The Auto Zero
cycle guarantees a zero display readout for a zero volt input.
devices for a 3-1/2 digit analog to digital converter to directly
drive an LCD display. Onboard oscillator, precision voltage
reference and display segment and backplane drivers sim-
3-138
ELECTRICAL CHARACTERISTICS:
Symbol
Input
—
—
—
NL
E
e
I
CMRR
L
N
R
The TC811 is a low power, 3-1/2 digit, LCD display
The TC811 display hold (HLDR) function can be used to
The TC811 has an improved internal zener reference
The TC811 limits linearity error to less than one count on
The single chip CMOS TC811 incorporates all the active
12
input impedance. The 15 V
Parameter
Zero Input Reading
Zero Reading Drift
Ratiometric Reading
Linearity Error
Roll Over Error
Noise
Input Leakage Current
Common-Mode Rejection
p-p
Test Conditions
V
V
V
V
V
V
V
V
V
V
noise perfor-
V
IN
FS
IN
IN
FS
IN
IN
IN
CM
FS
Supply
– = V
= 0V
= 0V, 0 C
= V
= 0V, V
= 0V
= 200mV
= 200mV or 2.000V
= 200mV
= 1V, V
3-1/2 DIGIT A/D CONVERTER WITH HOLD AND
REF
= 9V, f
IN
+
, V
FS
REF
IN
200mV
= 200mV
CLOCK
= 0V,
T
A
= 100mV
plify system integration, reduce board space requirements
and lower total cost. A low cost, high resolution (0.05%)
indicating meter requires only a TC811, an LCD display, five
resistors, six capacitors, a crystal, and a 9V battery. Com-
pact, hand held multimeter designs benefit from the TelCom
Semiconductor small footprint package option.
which will reject interference signals if the converters inte-
gration time is set to a multiple of the interference signal
period. This is especially useful in industrial measurement
environments where 50, 60 and 400Hz line frequency sig-
nals are present.
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage (V
Analog Input voltage (Either Input)
Reference Input Voltage ...................................... V
Clock Input ...................................................... TEST to V
Power Dissipation
Operating Temperature Range
Storage Temperature Range ................ – 65 C to +150 C
Lead Temperature (Soldering, 10 sec) ................. +300 C
*Static-sensitive device. Unused devices must be stored in conductive
material. Protect devices from static discharge and static fields. Stresses
above those listed under "Absolute Maximum Ratings" may cause perma-
nent 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.
70 C
= 32.768kHz, and T
DIFFERENTIAL REFERENCE INPUTS
The TC811 uses a dual slope conversion technique
44-Pin Flat Package .........................................1.00W
40-Pin Plastic DIP .............................................1.23W
Commercial Package (C) ...................... 0 C to +70 C
Industrial Package (I) ........................ – 25 C to +85 C
+
2
(T
– 000.0
to V
A
Min
999
= 25 C, unless otherwise noted.
– 1
– 1
TELCOM SEMICONDUCTOR, INC.
A
—
—
—
—
–
)............................................ 15V
70 C)
999/1000
Typ
000.0
0.2
15
50
0.2
0.2
1
1
..................... V
+000.0
1000
Max
+1
+1
—
10
—
1
Reading
Reading
Unit
Counts
Counts
Digital
Digital
+
+
V/ C
V
pA
V/V
to V
to V
P-P
–
–
+