hi7131 Intersil Corporation, hi7131 Datasheet - Page 6

• Manufacturer Part Number: hi7131
• Description: 3 1/2 Digit, Low Power, High Cmrr, Lcd/led Display-type A/d Converters
• Manufacturer: Intersil Corporation

Design Information Summary Sheet
• OSCILLATOR FREQUENCY
• CLOCK FREQUENCY
• CLOCK PERIOD
• CONVERSION CYCLE
• SIGNAL INTEGRATION PERIOD
• 60/50Hz REJECTION CRITERIA
• OPTIMUM FULL SCALE ANALOG INPUT RANGE
• INPUTS VOLTAGE RANGE
• MAXIMUM INTEGRATION CURRENT
• INTEGRATOR MAXIMUM OUTPUT VOLTAGE SWING
Typical Integrator Amplifier Output Waveform (INT Pin)
f
C
R
C
f
t
T
For f
T
T
V
(V- + 1V) < V
I
Maximum integration current should be the maximum
buffer output current with no nonlinearity effect.
Maximum Buffer Output Current = 1 A
V
(V- + 0.5) < V
(Typ) V
OSC
CLOCK
CLOCK
INT(MAX)
CYC
INT
INT
INFS
INT(MAX)
NOTE: 1 Count = 1 Clock Cycle = 4 Oscillator Cycles.
OSC
OSC
OSC
AUTO-ZERO PHASE
990 - 2990 COUNTS
OSC
100 COUNTS OR
= 1000 x t
/ t
= 4000 x t
> 50k
= 50pF, R
= 200mV to 2V
INT(MAX)
60Hz
0.45/RC
= f
= 1/f
50pF
VOLTAGE SWING
= 40kHz; T
INTEGRATOR
= V
OSC
= (T
or T
CLOCK
IN LO
INT(MAX)
INFS
CLOCK
INT
/4
(OSC)
OSC
CLOCK
INT
= 2V
) (I
or V
/ R
/ t
CYC
INT(MAX)
= 180k ; f
INT
50Hz
IN HI
< (V+ - 0.5)
= 16000 x t
SIGNAL INTEGRATE
= 400ms
= Integer
PHASE FIXED
1000 COUNTS
< (V+ - 1V)
)/C
OSC
INT
OSC
4000 COUNTS: TOTAL OF EACH CONVERSION CYCLE
(Typ) = 48kHz
HI7131, HI7133
3-1831
DEINTEGRATE PHASE
0 - 2000 COUNTS
• INTEGRATING RESISTOR
• INTEGRATING CAPACITOR
• AUTO-ZERO CAPACITOR VALUE
• REFERENCE INPUTS VOLTAGE RANGE
• REFERENCE VOLTAGE
• COMMON PIN VOLTAGE
• DISPLAY TYPE
• POWER SUPPLY, V+ TO V-
• DISPLAY READING
R
C
REFERENCE CAPACITOR VALUE
0.1 F < C
V- < V
V
V
can be used as a reference. It is biased between V+ and
V- and regulation is lost at (V+ -V-) < 6.8V. V
does not have sink capability and can be externally pulled
down to lower voltages.
LCD, Non-Multiplexed
Single +9V or 5V Nominal, +5V to +12V Functional
Reading = 1000 x (V
Maximum Reading = 1999, for V
REF
COMMON
INT
INT
= V
= (T
REFLO
= V
INFS
INT
INFS
REF
= V+ - 2.8, (Typ), V
) (I
or V
/ I
/2
< 1 F
INT(MAX)
INT(MAX)
REFHI
IN
/ V
< V+
) / V
REF
INT(MAX)
)
COMMON
IN
ZERO INTEGRATE PHASE
= 1.999 x V
10 COUNTS OR
900 COUNTS
is regulated and
COMMON
REF
pin