WS7106 / WS7107
Design Information Summary Sheet
• OSCILLATOR FREQUENCY
f
OSC
= 0.45/RC
C
OSC
> 50pF; R
OSC
> 50kΩ
f
OSC
(Typ) = 48kHz
• OSCILLATOR PERIOD
t
OSC
= RC/0.45
• INTEGRATION CLOCK FREQUENCY
f
CLOCK
= f
OSC
/4
• INTEGRATION PERIOD
t
INT
= 1000 x (4/f
OSC
)
• 60/50Hz REJECTION CRITERION
t
INT
/t
60Hz
or t
lNT
/t
60Hz
= Integer
• OPTIMUM INTEGRATION CURRENT
I
INT
= 4µA
• FULL SCALE ANALOG INPUT VOLTAGE
V
lNFS
(Typ) = 200mV or 2V
• INTEGRATE RESISTOR
V
INFS
R
INT
= ----------------
-
I
INT
• DISPLAY COUNT
V
IN
-
COUNT
=
1000
×
--------------
V
REF
• CONVERSION CYCLE
t
CYC
= t
CL0CK
x 4000
t
CYC
= t
OSC
x 16,000
when f
OSC
= 48kHz; t
CYC
= 333ms
• COMMON MODE INPUT VOLTAGE
(V- + 1V) < V
lN
< (V+ - 0.5V)
• AUTO-ZERO CAPACITOR
0.01µF < C
AZ
< 1µF
• REFERENCE CAPACITOR
0.1µF < C
REF
< 1µF
• V
COM
Biased between Vi and V-.
• V
COM
≅
V+ - 2.8V
Regulation lost when V+ to V- <
≅6.8V
If V
COM
is externally pulled down to (V+ to V-)/2,
the V
COM
circuit will turn off.
WS 7106 POWER SUPPLY: SINGLE 9V
V+ - V- = 9V
Digital supply is generated internally
V
GND
≅
V+ - 4.5V
• WS7106 DISPLAY: LCD
Type: Direct drive with digital logic supply amplitude.
_
•
WS7107 POWER SUPPLY: DUAL +5.0V
V+ = +5V to GND
V- = -5V to GND
Digital Logic and LED driver supply V+ to GND
•
WS7107 DISPLAY: LED
Type: Non-Multiplexed Common Anode
• INTEGRATE CAPACITOR
(
t
INT
) (
I
INT
)
C
INT
= -------------------------------
-
V
INT
• INTEGRATOR OUTPUT VOLTAGE SWING
(
t
INT
) (
I
INT
)
V
INT
= -------------------------------
-
C
INT
• V
INT
MAXIMUM SWING:
(V- + 0.5V) < V
INT
< (V+ - 0.5V), V
INT
(Typ) = 2V
Typical Integrator Amplifier Output Waveform (INT Pin)
AUTO ZERO PHASE
(COUNTS)
2999 - 1000
SIGNAL INTEGRATE
PHASE FIXED
1000 COUNTS
DE-INTEGRATE PHASE
0 - 1999 COUNTS
TOTAL CONVERSION TIME = 4000 x t
CLOCK
= 16,000 x t
OSC
4
WINGS [ WING SHING COMPUTER COMPONENTS ]
