ICM7216A [INTERSIL]
8-Digit, Multi-Function, Frequency Counters/Timers; 8位，多功能，频率计数器/定时器
| 型号： | ICM7216A |
| 厂家： | 
Intersil |
| 描述： | 8-Digit, Multi-Function, Frequency Counters/Timers |
| 文件： | 总17页 (文件大小：144K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
ICM7216A, ICM7216B,
ICM7216D
8-Digit, Multi-Function,
August 1997
Frequency Counters/Timers
Features All Versions
Description
• Functions as a Frequency Counter (DC to 10MHz)
The ICM7216A and ICM7216B are fully integrated Timer
Counters with LED display drivers. They combine a high
• Four Internal Gate Times: 0.01s, 0.1s, 1s, 10s in
Frequency Counter Mode
frequency oscillator,
a decade timebase counter, an
8-decade data counter and latches, a 7-segment decoder,
digit multiplexers and 8-segment and 8-digit drivers which
directly drive large multiplexed LED displays. The counter
inputs have a maximum frequency of 10MHz in frequency
and unit counter modes and 2MHz in the other modes. Both
inputs are digital inputs. In many applications, amplification
and level shifting will be required to obtain proper digital
signals for these inputs.
• Directly Drives Digits and Segments of Large Multi-
plexed LED Displays (Common Anode and Common
Cathode Versions)
• Single Nominal 5V Supply Required
• Highly Stable Oscillator, Uses 1MHz or 10MHz Crystal
• Internally Generated Decimal Points, Interdigit Blanking,
Leading Zero Blanking and Overflow Indication
The ICM7216A and ICM7216B can function as a frequency
counter, period counter, frequency ratio (f /f ) counter, time
A
B
• Display Off Mode Turns Off Display and Puts Chip Into
Low Power Mode
interval counter or as a totalizing counter. The counter uses
either a 10MHz or 1MHz quartz crystal timebase. For period
and time interval, the 10MHz timebase gives a 0.1µs
resolution. In period average and time interval average, the
resolution can be in the nanosecond range. In the frequency
mode, the user can select accumulation times of 0.01s, 0.1s,
1s and 10s. With a 10s accumulation time, the frequency
can be displayed to a resolution of 0.1Hz in the least
significant digit. There is 0.2s between measurements in all
ranges.
• Hold and Reset Inputs for Additional Flexibility
Features ICM7216A and ICM7216B
• Functions Also as a Period Counter, Unit Counter,
Frequency Ratio Counter or Time Interval Counter
• 1 Cycle, 10 Cycles, 100 Cycles, 1000 Cycles in Period,
Frequency Ratio and Time Interval Modes
The ICM7216D functions as a frequency counter only, as
described above.
• Measures Period From 0.5µs to 10s
All versions of the ICM7216 incorporate leading zero
blanking. Frequency is displayed in kHz. In the ICM7216A
and ICM7216B, time is displayed in µs. The display is
multiplexed at 500Hz with a 12.2% duty cycle for each digit.
The ICM7216A is designed for common anode displays with
typical peak segment currents of 25mA. The ICM7216B and
ICM7216D are designed for common cathode displays with
typical peak segment currents of 12mA. In the display off
mode, both digit and segment drivers are turned off,
enabling the display to be used for other functions.
Features ICM7216D
• Decimal Point and Leading Zero Banking May Be
Externally Selected.
Ordering Information
TEMP.
PKG.
NO.
o
PART NUMBER RANGE ( C)
PACKAGE
ICM7216AlJl
ICM7216BlPl
ICM7216DlPl
-25 to 85 28 Ld CERDIP
-25 to 85 28 Ld PDIP
-25 to 85 28 Ld PDIP
F28.6
E28.6
E28.6
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
http://www.intersil.com or 407-727-9207 | Copyright © Intersil Corporation 1999
File Number 3166.1
9-10
ICM7216A, ICM7216B, ICM7216D
Pinouts
ICM7216A
COMMON ANODE
(CERDIP)
ICM7216B
COMMON CATHODE
(PDIP)
TOP VIEW
TOP VIEW
CONTROL INPUT
1
28 INPUT A
CONTROL INPUT
INPUT B
1
2
3
4
5
6
7
8
9
28 INPUT A
INPUT B
2
3
4
5
6
7
8
9
27 HOLD INPUT
26 OSC OUTPUT
25 OSC INPUT
27 HOLD INPUT
26 OSC OUTPUT
25 OSC INPUT
FUNCTION INPUT
DECIMAL POINT
OUTPUT
FUNCTION INPUT
DIGIT 1 OUTPUT
DIGIT 3 OUTPUT
DIGIT 2 OUTPUT
DIGIT 4 OUTPUT
SEG e OUTPUT
24 EXT OSC INPUT
23 DIGIT 1 OUTPUT
22 DIGIT 2 OUTPUT
21 DIGIT 3 OUTPUT
24 EXT OSC INPUT
DECIMAL POINT
OUTPUT
SEG g OUTPUT
SEG a OUTPUT
23
22 SEG g OUTPUT
V
V
21 SEG e OUTPUT
SS
SS
SEG d OUTPUT
20
DIGIT 5 OUTPUT
20
DIGIT 4 OUTPUT
19 DIGIT 5 OUTPUT
18 V
SEG a OUTPUT
19 SEG d OUTPUT
18 V
SEG b OUTPUT 10
SEG c OUTPUT 11
SEG f OUTPUT 12
RESET INPUT 13
RANGE INPUT 14
DIGIT 6 OUTPUT 10
DIGIT 7 OUTPUT 11
DIGIT 8 OUTPUT 12
RESET INPUT 13
RANGE INPUT 14
DD
DD
17 DIGIT 6 OUTPUT
16 DIGIT 7 OUTPUT
15 DIGIT 8 OUTPUT
17 SEG b OUTPUT
16 SEG c OUTPUT
15 SEG f OUTPUT
ICM7216D
COMMON CATHODE
(PDIP)
TOP VIEW
CONTROL INPUT
MEASUREMENT IN PROGRESS
DIGIT 1 OUTPUT
1
2
3
4
5
6
7
8
9
28 INPUT A
27 HOLD INPUT
26 OSC OUTPUT
25 OSC INPUT
DIGIT 3 OUTPUT
DIGIT 2 OUTPUT
24 EXT OSC INPUT
23 DECIMAL POINT OUTPUT
22 SEG g OUTPUT
21 SEG e OUTPUT
DIGIT 4 OUTPUT
V
SS
DIGIT 5 OUTPUT
DIGIT 6 OUTPUT
20
SEG a OUTPUT
19 SEG d OUTPUT
18 V
DIGIT 7 OUTPUT 10
DIGIT 8 OUTPUT 11
DD
RESET INPUT 12
17 SEG b OUTPUT
16 SEG c OUTPUT
15 SEG f OUTPUT
EX. DECIMAL POINT INPUT 13
RANGE INPUT 14
9-11
ICM7216A, ICM7216B, ICM7216D
Functional Block Diagram
EXT
OSC
INPUT
OSC
INPUT
3
8
8
OSC
SELECT
DIGIT
DRIVERS
DECODER
DIGIT
OUTPUTS
(8)
OSC
OUTPUT
REFERENCE
COUNTER
3
10
÷
RANGE
CONTROL
LOGIC
RANGE SELECT
LOGIC
RANGE
INPUT
100Hz
5
4
10 OR 10
÷
÷
5
STORE AND
RESET LOGIC
RESET
INPUT
CONTROL
LOGIC
6
CONTROL
INPUT
MAIN
3
EN
CL
10 COUNTER
÷
DP
LOGIC
OVERFLOW
EXT
DP
INPUT
(NOTE 2)
4
4
4
4
4
4
4
4
INPUT
CONTROL
LOGIC
INPUT A
DATA LATCHES AND
OUTPUT MUX
STORE
INPUT B
(NOTE 1)
DECODER
LOGIC
SEGMENT
DRIVER
4
7
8
SEGMENT
OUTPUTS
(8)
Q
D
MEASUREMENT
IN PROGRESS
OUTPUT
INPUT
CONTROL
LOGIC
CL
MAIN
FF
(NOTE 2)
FUNCTION
INPUT
FN
(NOTE 1)
CONTROL
LOGIC
6
HOLD
INPUT
NOTES:
1. Function input and input B available on ICM7216A/B only.
2. Ext DP input and MEASUREMENT IN PROGRESS output available on ICM7216D only.
9-12
ICM7216A, ICM7216B, ICM7216D
Absolute Maximum Ratings
Thermal Information
o
o
Maximum Supply Voltage (V
- V ). . . . . . . . . . . . . . . . . . . .6.5V
SS
Thermal Resistance (Typical, Note 2)
CERDIP Package . . . . . . . . . . . . . . . .
PDIP Package . . . . . . . . . . . . . . . . . . .
Maximum Junction Temperature
θ
( C/W)
θ
( C/W)
DD
JA
JC
Maximum Digit Output Current. . . . . . . . . . . . . . . . . . . . . . . .400mA
Maximum Segment Output Current . . . . . . . . . . . . . . . . . . . . .60mA
Voltage On Any Input or
50
55
10
N/A
o
Output Terminal (Note 1) . . . . . . . . . . . .(V
+0.3V) to (V -0.3V)
SS
CERDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 C
PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 C
Maximum Storage Temperature Range . . . . . . . . . .-65 C to 150 C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300 C
DD
o
o
o
Operating Conditions
o
o
o
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . -25 C to 85 C
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1. The ICM7216 may be triggered into a destructive latchup mode if either input signals are applied before the power supply is applied or if
input or outputs are forced to voltages exceeding V
DD
to V by more than 0.3V.
SS
2. θ is measured with the component mounted on an evaluation PC board in free air.
JA
o
Electrical Specifications
V
= 5.0V, V = 0V, T = 25 C, Unless Otherwise Specified
DD
SS
A
PARAMETER
ICM7216A/B
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Operating Supply Current, I
Display Off, Unused Inputs to V
-
2
-
5
6.0
-
mA
V
DD
SS
INPUT A, INPUT B Frequency at f
MAX
Supply Voltage Range (V
-V ), V
4.75
10
DD SS
SUPPLY
Maximum Frequency INPUT A, Pin 28, f
Figure 9, Function = Frequency, Ratio,
Unit Counter
-
MHz
A(MAX)
Function = Period, Time Interval
2.5
2.5
250
-
-
-
-
-
-
MHz
MHz
ns
Maximum Frequency INPUT B, Pin 2, f
Figure 10
Figure 1
B(MAX)
Minimum Separation INPUT A to INPUT B Time
Interval Function
Maximum Oscillator Frequency and External Oscillator
Frequency, f
10
-
-
MHz
OSC
Minimum External Oscillator Frequency, f
-
-
100
kHz
µS
OSC
o
Oscillator Transconductance, g
V
= 4.75V, T = 85 C
A
2000
-
-
-
-
M
DD
Multiplex Frequency, f
f
f
= 10MHz
= 10MHz
-
-
500
200
Hz
MUX
Time Between Measurements
Input Voltages: Pins 2, 13, 25, 27, 28
Input Low Voltage, V
OSC
OSC
ms
-
3.5
100
-
-
-
1.0
V
V
INL
Input High Voltage, V
-
-
lNH
Input Resistance to V
Pins 13, 24, R
V = V
IN DD
-1.0V
400
-
kΩ
DD
IN
Input Leakage Pins 27, 28, 2, I
20
-
µA
ILK
Input Range of Change, dV /dt
lN
Supplies Well Bypassed
-
15
mV/µs
ICM7216A
Digit Driver: Pins 15, 16, 17, 19, 20, 21, 22, 23
High Output Current, I
V
= V
-2.0V
-140
-
-180
0.3
-
-
mA
mA
OH
OUT DD
Low Output Current, I
V
= V +1.0V
SS
OL
OUT
Segment Driver: Pins 4, 5, 6, 7, 9,10, 11, 12
Low Output Current, I
V
= V +1.5V
20
-
35
-
-
mA
OL
High Output Current, I
OUT SS
V
= V
-2.5V
-100
µA
OH
Multiplex Inputs: Pins 1, 3, 14
Input Low Voltage, V
OUT DD
-
-
-
0.8
V
V
INL
Input High Voltage, V
2.0
50
-
-
INH
Input Resistance to V , R
V
= V +1.0V
IN SS
100
kΩ
SS IN
9-13
ICM7216A, ICM7216B, ICM7216D
o
Electrical Specifications
V
= 5.0V, V = 0V, T = 25 C, Unless Otherwise Specified (Continued)
DD
SS
A
PARAMETER
ICM7216B
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Digit Driver: Pins 4, 5, 6, 7, 9, 10, 11, 12
Low Output Current, I
V
= V +1.3V
50
-
75
-
-
mA
OL
High Output Current, I
OUT SS
V
= V
-2.5V
-100
µA
OH
Segment Driver: Pins 15, 16, 17, 19, 20, 21, 22, 23
High Output Current, I
OUT
DD
V
= V
= V
-2.0V
-2.5V
-10
-
-
-
-
mA
OH
SLK
Multiplex Inputs: Pins 1, 3, 14
Input Low Voltage, V
OUT
DD
Leakage Current, I
V
10
µA
OUT
DD
-
-
-
V
-2.0
DD
V
V
INL
Input High Voltage, V
V
-0.8
DD
-
lNH
Input Resistance to V , R
V
= V -2.5V
DD
100
360
-
kΩ
DD IN
lN
ICM7216D
Operating Supply Current, I
Display Off, Unused Inputs to V
-
2
-
5
6.0
-
mA
V
DD
-V ), V
SS
Supply Voltage Range (V
DD SS
INPUT A Frequency at f
Figure 9
4.75
10
SUPPLY
MAX
Maximum Frequency INPUT A, Pin 28, f
-
MHz
MHz
A(MAX)
Maximum Oscillator Frequency and External Oscillator
Frequency, f
10
-
-
OSC
Minimum External Oscillator Frequency, f
-
-
100
kHz
µS
OSC
o
Oscillator Transconductance, g
V
= 4.75V, T = 85 C
2000
-
-
-
-
M
DD
A
Multiplex Frequency, f
f
= 10MHz
= 10MHz
-
-
500
200
Hz
MUX
OSC
OSC
Time Between Measurements
Input Voltages: Pins 12, 27, 28
f
ms
Input Low Voltage, V
-
3.5
100
-
-
1.0
V
V
INL
Input High Voltage, V
-
400
-
-
-
INH
Input Resistance to V
Pins 12, 24, R
V = V
IN DD
-1.0V
kΩ
DD,
IN
Input Leakage, Pins 27, 28, I
20
-
µA
ILK
Output Current, Pin 2, I
Output Current, Pin 2, I
V
= +0.4V
0.36
265
-
-
mA
µA
OL
OL
V
= V
-0.8V
-
-
OH
OH DD
Input Rate of Change, dV /dt
lN
Supplies Well Bypassed
15
-
mV/µs
Digit Driver: Pins 3, 4, 5, 6, 8, 9, 10, 11
Low Output Current, I
OL
V
= +1.3V
50
-
75
-
-
mA
OUT
High Output Current, I
V
= V
-2.5V
100
µA
OH
Segment Driver: Pins 15, 16, 17, 19, 20, 21, 22, 23
High Output Current, I
OUT
DD
V
= V
= V
-2.0V
-2.5V
10
-
15
-
mA
OH
SLK
Multiplex Inputs: Pins 1, 13, 14
Input Low Voltage, V
OUT
DD
Leakage Current, I
V
10
µA
OUT
DD
-
-
-
V
-2.0
DD
V
V
lNL
Input High Voltage, V
V
-0.8
-
-
INH
DD
Input Resistance to V , R
V
= V
IN DD
-1.0V
100
360
kΩ
DD lN
9-14
ICM7216A, ICM7216B, ICM7216D
Timing Diagram
40ms
INTERNAL
STORE
30ms TO 40ms
60ms
40ms
UPDATE
190ms TO 200ms
FUNCTION:
TIME INTERVAL
INTERNAL
RESET
UPDATE
PRIMING
MEASUREMENT INTERVAL
MEASUREMENT
IN PROGRESS
(INTERNAL ON
7216A/B)
INPUT A
INPUT B
PRIMING EDGES
250ns MIN
MEASURED
INTERVAL
(FIRST)
MEASURED
INTERVAL
(LAST)
NOTE:
1. If range is set to 1 event, first and last measured interval will coincide.
FIGURE 1. WAVEFORMS FOR TIME INTERVAL MEASUREMENT (OTHERS ARE SIMILAR, BUT WITHOUT PRIMING PHASE)
Typical Performance Curves
20
15
10
5
300
200
100
0
4.5 ≤ V
DD
≤ 6.0V
f
(MAX) FREQUENCY UNIT COUNTER,
FREQUENCY RATIO MODES
A
f
(MAX) f (MAX) PERIOD,
B
A
TIME INTERVAL MODES
o
25 C
o
85 C
o
-20 C
o
T
= 25 C
A
0
0
1
2
3
3
4
5
6
V
-V (V)
DD SS
V
-V (V)
DD OUT
FIGURE 2. f (MAX), f (MAX) AS A FUNCTION OF SUPPLY
FIGURE 3. ICM7216A TYPICAL I
DIG
vs V -V
DD OUT
A
B
9-15
ICM7216A, ICM7216B, ICM7216D
Typical Performance Curves (Continued)
30
80
60
40
20
0
o
4.5 ≤ V
≤ 6V
o
T
= 25 C
DD
A
-20 C
V
V
= 5.5V
= 4.5V
DD
DD
o
25 C
V
= 5V
DD
20
10
o
85 C
0
0
1
2
3
0
1
2
3
V
-V (V)
V
(V)
DD OUT
OUT
FIGURE 4. ICM7216B AND ICM7216D TYPICAL I
vs V -V
DD OUT
FIGURE 5. ICM7216A TYPICAL I
vs V
OUT
SEG
SEG
200
80
60
40
20
0
o
-20 C
V
= 5V
V
= 5V
DD
DD
o
-20 C
o
25 C
o
25 C
150
100
50
o
o
85 C
85 C
0
0
1
2
3
0
1
2
3
V
(V)
V
(V)
OUT
OUT
FIGURE 6. ICM7216B AND ICM7216D TYPICAL I
vs V
FIGURE 7. ICM7216A TYPICAL I
vs V
OUT
DIGIT
OUT
SEG
200
o
T
= 25 C
A
V
= 5.5V
DD
50
100
50
V
= 5V
DD
V
= 4.5V
DD
0
0
1
2
3
V
(V)
OUT
FIGURE 8. ICM7216B AND ICM7216D TYPICAL I
vs V
OUT
DIGIT
9-16
ICM7216A, ICM7216B, ICM7216D
COUNTED
TRANSITIONS
Description
INPUTS A and B
INPUTS A and B are digital inputs with a typical switching
threshold of 2V at V = 5V. For optimum performance the
50ns MIN
4.5V
0.5V
DD
INPUT A
peak-to-peak input signal should be at least 50% of the
supply voltage and centered about the switching voltage.
When these inputs are being driven from TTL logic, it is
desirable to use a pullup resistor. The circuit counts high to
low transitions at both inputs. (INPUT B is available only on
lCM7216A and lCM7216B).
t = t = 10ns
50ns MIN
r
f
FIGURE 9. WAVEFORM FOR GUARANTEED MINIMUM f (MAX)
A
FUNCTION = FREQUENCY, FREQUENCY RATIO,
UNIT COUNTER
9.
Note that the amplitude of the input should not exceed the
device supply (above the V
and below the V ) by more
DD
SS
than 0.3V, otherwise the device may be damaged.
MEASURED
INTERVAL
Multiplexed Inputs
250ns
MIN
The FUNCTION, RANGE, CONTROL and EXTERNAL
DECIMAL POINT inputs are time multiplexed to select the
function desired. This is achieved by connecting the appro-
priate Digit driver output to the inputs. The function, range
and control inputs must be stable during the last half of each
digit output, (typically 125µs). The multiplexed inputs are
active high for the common anode lCM7216A and active low
for the common cathode lCM7216B and lCM7216D.
4.5V
0.5V
INPUT A OR
INPUT B
250ns
MIN
t
= t = 10s
f
r
FIGURE 10. WAVEFORM FOR GUARANTEED MINIMUM f (MAX)
B
AND f (MAX) FOR FUNCTION = PERIOD AND
A
TIME INTERVAL
Noise on the multiplex inputs can cause improper operation.
This is particularly true when the unit counter mode of
operation is selected, since changes in voltage on the digit
drivers can be capacitively coupled through the LED diodes
to the multiplex inputs. For maximum noise immunity, a 10kΩ
resistor should be placed in series with the multiplexed
inputs as shown in the application circuits.
Function Input
The six functions that can be selected are: Frequency,
Period, Time Interval, Unit Counter, Frequency Ratio and
Oscillator Frequency. This input is available on the
lCM7216A and lCM7216B only.
Table 1 shows the functions selected by each digit for these
inputs.
The implementation of different functions is done by routing
the different signals to two counters, called “Main Counter”
and “Reference Counter”. A simplified block diagram of the
device for functions realization is shown in Figure 11. Table 2
shows which signals will be routed to each counter in
different cases. The output of the Main Counter is the
information which goes to the display. The Reference
Counter divides its input by 1, 10, 100 and 1000. One of
these outputs will be selected through the range selector
and drive the enable input of the Main Counter. This means
that the Reference Counter, along with its associated blocks,
directs the Main Counter to begin counting and determines
the length of the counting period. Note that Figure 11 does
not show the complete functional diagram (See the
Functional Block Diagram). After the end of each counting
period, the output of the Main Counter will be latched and
displayed, then the counter will be reset and a new
measurement cycle will begin. Any change in the
FUNCTION INPUT will stop the present measurement
without updating the display and then initiate a new
measurement. This prevents an erroneous first reading after
the FUNCTION INPUT is changed. In all cases, the 1-0
transitions are counted or timed.
TABLE 1. MULTIPLEXED INPUT FUNCTIONS
FUNCTION
FUNCTION INPUT (Pin Frequency
DIGIT
D1
D8
D2
D5
D4
D3
D1
D2
D3
D4
3, lCM7216A and B
Only)
Period
Frequency Ratio
Time Interval
Unit Counter
Oscillator Frequency
RANGE INPUT, Pin 14 0.01s/1 Cycle
0.1s/10 Cycles
1s/100 Cycles
10s/1K Cycles
CONTROL INPUT,
Pin 1
Display Off
D4 and
Hold
Display Test
D8
D2
D1
D3
1MHz Select
External Oscillator Enable
External Decimal Point
Enable
External DP INPUT (Pin Decimal point is output for same digit
13, ICM7216D Only) that is connected to this input.
9-17
ICM7216A, ICM7216B, ICM7216D
INTERNAL CONTROL
INTERNAL CONTROL
100Hz
INPUT
SELECTOR
INPUT A
CLOCK
INPUT B
REFERENCE COUNTER
÷1
÷10 ÷100 ÷1000
INTERNAL CONTROL
RANGE SELECTOR
INTERNAL CONTROL
INTERNAL OR
EXTERNAL
OSCILLATOR
ENABLE
CLOCK
MAIN COUNTER
INPUT
SELECTOR
INPUT A
FIGURE 11. SIMPLIFIED BLOCK DIAGRAM OF FUNCTIONS IMPLEMENTATION
display becomes updated; note this when measuring long
TABLE 2. 7216A/B INPUT ROUTING
MAIN
time intervals to give enough time for measurement comple-
tion. The resolution in this mode is the same as for period
measurement. See the Time Interval Measurement section
also.
FUNCTION
COUNTER
REFERENCE COUNTER
5
4
Frequency (f )
Input A
100Hz (Oscillator ÷10 or 10 )
A
Unit Counter - In this mode, the Main Counter is always
enabled. The input A is counted by the Main Counter and
displayed continuously.
Period (t )
Oscillator
Input A
Input A
Input B
A
Ratio (f /f )
A
B
Time Interval
(A→B)
Oscillator
Input A
Input B
Oscillator Frequency - In this mode, the device makes a
frequency measurement on its timebase. This is a self test
mode for device functionality check. For 10MHz timebase
the display will show 10000.0, 10000.00, 10000.000 and
Overflow in different ranges.
Unit Counter
(Count A)
Input A
Not Applicable
5
4
Osc. Freq.
Oscillator
100Hz (Oscillator ÷10 or 10 )
(f
)
OSC
Range Input
Frequency - In this mode input A is counted by the Main
Counter for a precise period of time. This time is determined
by the time base oscillator and the selected range. For the
10MHz (or 1MHz) time base, the resolutions are 100Hz,
10Hz, 1Hz and 0.1Hz. The decimal point on the display is
set for kHz reading.
The RANGE INPUT selects whether the measurement
period is made for 1, 10, 100 or 1000 counts of the Refer-
ence Counter. As it is shown in Table 1, this gives different
counting windows for frequency measurement and various
cycles for other modes of measurement.
In all functional modes except Unit Counter, any change in
the RANGE INPUT will stop the present measurement
without updating the display and then initiate a new mea-
surement. This prevents an erroneous first reading after the
RANGE INPUT is changed.
Period - In this mode, the timebase oscillator is counted by
the Main Counter for the duration of 1, 10, 100 or 1000
(range selected) periods of the signal at input A. A 10MHz
timebase gives resolutions of 0.1µs to 0.0001µs for 1000
periods averaging. Note that the maximum input frequency
for period measurement is 2.5MHz.
Control Input
Frequency Ratio - In this mode, the input A is counted by
the Main Counter for the duration of 1, 10, 100 or 1000
(range selected) periods of the signal at input B. The fre-
quency at input A should be higher than input B for meaning-
ful result. The result in this case is unitless and its resolution
can go up to 3 digits after decimal point.
Unlike the other multiplexed inputs, to which only one of the
digit outputs can be connected at a time, this input can be
tied to different digit lines to select combination of controls.
In this case, isolation diodes must be used in digit lines to
avoid crosstalk between them (see Figure 17). The direction
of diodes depends on the device version, common anode or
common cathode. For maximum noise immunity at this input,
in addition to the 10K resistor which was mentioned before,
a 39pF to 100pF capacitor should also be placed between
Time Interval - In this mode, the timebase oscillator is
counted by the Main Counter for the duration of a 1-0 transi-
tion of input A until a 1-0 transition of input B. This means
input A starts the counting and input B stops it. If other ranges,
except 0.01s/1 cycle are selected the sequence of input A and
B transitions must happen 10, 100 or 1000 times until the
this input and the V
or V (See Figure 17).
DD
SS
Display Off - To disable the display drivers, it is necessary to
tie the D4 line to the CONTROL INPUT and have the HOLD
9-18
ICM7216A, ICM7216B, ICM7216D
input at V . While in Display Off mode, the segments and low) is stopped, the main counter is reset and the chip is
DD
digit drivers are all off, leaving the display lines floating, so the held ready to initiate a new measurement as soon as HOLD
display can be shared with other devices. In this mode, the goes low. The latches which hold the main counter data are
oscillator continues to run with a typical supply current of not updated, so the last complete measurement is displayed.
1.5mA with a 10MHz crystal, but no measurements are made In unit counter mode when HOLD input is at V , the
DD
and multiplexed inputs are inactive. A new measurement counter is not stopped or reset, but the display is frozen at
cycle will be initiated when the HOLD input is switched to that instantaneous value. When HOLD goes low the count
V
.
continues from the new value in the new counter.
SS
Display Test - Display will turn on with all the digits showing RESET Input
8s and all decimal points on. The display will be blanked if
Display Off is selected at the same time.
The RESET input resets the main counter, stops any
measurement in progress, and enables the main counter
1MHz Select - The 1MHz select mode allows use of a 1MHz latches, resulting in an all zero output. A capacitor to ground
crystal with the same digit multiplex rate and time between will prevent any hang-ups on power-up.
measurement as with a 10MHz crystal. This is done by
MEASUREMENT IN PROGRESS
4
5
dividing the oscillator frequency by 10 rather than 10 . The
decimal point is also shifted one digit to the right in period
and time interval, since the least significant digit will be in µs
increment rather than 0.1µs increment.
This output is provided in lCM7216D. It stays low during
measurements and goes high for intervals between mea-
surements. It is provided for system interfacing and can drive
a low power Schottky TTL or one ECL load if the ECL device
is powered from the same supply as lCM7216D.
External Oscillator Enable - In this mode, the signal at EXT
OSC INPUT is used as a timebase instead of the on-board
crystal oscillator (built around the OSC INPUT, OSC OUT-
PUT inputs). This input can be used for an external stable
temperature compensated crystal oscillator or for special
measurements with any external source. The on-board crys-
tal oscillator continues to work when the external oscillator is
selected. This is necessary to avoid hang-up problems, and
has no effect on the chip's functional operation. If the on-
board oscillator frequency is less than 1MHz or only the
external oscillator is used, THE OSC INPUT MUST BE
CONNECTED TO THE EXT OSC INPUT providing the time-
base has enough voltage swing for OSC INPUT (See Electri-
cal Specifications). If the external timebase is TTL level a
pullup resistor must be used for OSC INPUT. The other way
is to put a 22MΩ resistor between OSC INPUT and OSC
OUTPUT and capacitively couple the EXT OSC INPUT to
OSC INPUT. This will bias the OSC INPUT at its threshold
Decimal Point Position
Table 3 shows the decimal point position for different modes
of lCM7216 operation. Note that the digit 1 is the least signif-
icant digit. Table 3 is for 10MHz timebase frequency.
Overflow Indication
When overflow happens in any measurement it will be indicated
on the decimal point of the digit 8. A separate LED indicator can
be used. Figure 12 shows how to connect this indicator.
a
f
b
and the drive voltage will need to be only 2V
nal timebase frequency must be greater than 100kHz or the
chip will reset itself to enable the on-board oscillator.
. The exter-
g
P-P
e
c
DP
d
External Decimal Point Enable - In this mode, the EX DP
INPUT is enabled (lCM7216D only). A decimal point will be
displayed for the digit that its output line is connected to this
input (EX DP INPUT). Digit 8 should not be used since it will
override the overflow output. Leading zero blanking is effec-
tive for the digits to the left of selected decimal point.
FIGURE 12. SEGMENT IDENTIFICATION AND DISPLAY FONT
Overflow will be indicated on the decimal point output of
digit 8. A separate LED overflow indicator can be connected
as follows:
DEVICE
ICM7216A
ICM7216B/D
CATHODE
Decimal Point
D8
ANODE
D8
Hold Input
Except in the unit counter mode, when the HOLD input is
Decimal Point
at V , any measurement in progress (before STORE goes
DD
TABLE 3. DECIMAL POINT POSITIONS
FREQUENCY
RATIO
TIME
INTERVAL
UNIT
COUNTER
OSCILLATOR
FREQUENCY
RANGE
0.01s/1 Cycle
FREQUENCY
PERIOD
D2
D2
D3
D4
D5
D1
D2
D3
D4
D2
D3
D4
D5
D1
D1
D1
D1
D2
D3
D4
D5
0.1s/10 Cycle
1s/100 Cycle
10s/1K Cycle
D3
D4
D5
9-19
ICM7216A, ICM7216B, ICM7216D
Time Interval Measurement
C
R
C
C
= Crystal Static Capacitance
= Crystal Series Resistance
= Input Capacitance
O
When in the time interval mode and measuring a single
event, the lCM7216A and lCM7216B must first be “primed”
prior to measuring the event of interest. This is done by first
generating a negative going edge on Channel A followed by a
negative going edge on Channel B to start the “measurement
interval”. The inputs are then primed ready for the measure-
ment. Positive going edges on A and B, before or after the
priming, will be needed to restore the original condition.
S
IN
= Output Capacitance
OUT
ω = 2πf
The required g should not exceed 50% of the g specified
for the lCM7216 to insure reliable startup. The OSCillator
M
M
INPUT and OUTPUT pins each contribute about 5pF to C
IN
Priming can be easily accomplished using the circuit in
Figure 13.
and C
OUT
. For maximum stability of frequency, C and
IN
should be approximately twice the specified crystal
C
OUT
static capacitance.
SIGNAL A
2
2
INPUT A
INPUT B
In cases where non decade prescalers are used it may be
desirable to use a crystal which is neither 10MHz or 1MHz.
In that case both the multiplex rate and time between mea-
surements will be different. The multiplex rate is
SIGNAL B
V
V
DD
DD
f
f
OSC
OSC
f
= ------------------ for 10MHz mode and
f
= ------------------ for
MUX
MUX
PRIME
1
N.O.
150K
4
3
2 × 10
2 × 10
1
1
1
10K
the 1MHz mode. The time between measurements is
6
5
1N914
V
2 × 10
f
2 × 10
f
------------------
OSC
------------------
OSC
in the 10MHz mode and
in the 1MHz mode.
100K
0.1µF
10nF
V
V
SS
SS
SS
The crystal and oscillator components should be located as
close to the chip as practical to minimize pickup from other
signals. Coupling from the EXTERNAL OSClLLATOR INPUT
to the OSClLLATOR OUTPUT or INPUT can cause undesir-
able shifts in oscillator frequency.
DEVICE
TYPE
1
2
CD4049B Inverting Buffer
CD4070B Exclusive - OR
Display Considerations
FIGURE 13. PRIMING CIRCUIT, SIGNALS A AND B BOTH HIGH
OR LOW
The display is multiplexed at a 500Hz rate with a digit time of
244µs. An interdigit blanking time of 6µs is used to prevent
display ghosting (faint display of data from previous digit
superimposed on the next digit). Leading zero blanking is
provided, which blanks the left hand zeroes after decimal
Following the priming procedure (when in single event or 1
cycle range) the device is ready to measure one (only)
event.
When timing repetitive signals, it is not necessary to “prime” point or any non zero digits. Digits to the right of the decimal
the lCM7216A and lCM7216B as the first alternating signal point are always displayed. The leading zero blanking will be
states automatically prime the device. See Figure 1.
disabled when the Main Counter overflows.
During any time interval measurement cycle, the ICM7216A The lCM7216A is designed to drive common anode LED
and lCM7216B require 200ms following B going low to displays at peak current of 25mA/segment, using displays
update all internal logic. A new measurement cycle will not with V = 1.8V at 25mA. The average DC current will be over
F
take place until completion of this internal update time.
3mA under these conditions. The lCM7216B and lCM7216D
are designed to drive common cathode displays at peak cur-
rent of 15mA/segment using displays with V = 1.8V at
F
Oscillator Considerations
15mA. Resistors can be added in series with the segment
drivers to limit the display current in very efficient displays, if
required. The Typical Performance Curves show the digit
and segment currents as a function of output voltage.
The oscillator is a high gain CMOS inverter. An external
resistor of 10MΩ to 22MΩ should be connected between the
OSCillator INPUT and OUTPUT to provide biasing. The
oscillator is designed to work with a parallel resonant 10MHz
quartz crystal with a static capacitance of 22pF and a series
resistance of less than 35Ω.
To get additional brightness out of the displays, V
may be
DD
increased up to 6.0V. However, care should be taken to see
that maximum power and current ratings are not exceeded.
For a specific crystal and load capacitance, the required g
can be calculated as follows:
M
The segment and digit outputs in lCM7216s are not directly
compatible with either TTL or CMOS logic when driving
LEDs. Therefore, level shifting with discrete transistors may
be required to use these outputs as logic signals.
C
2
2
O
g
= ω
C
C
R
1 + --------
M
IN OUT
S
C
L
C
C
IN OUT
--------------------------------
where C
=
L
C
+ C
OUT
IN
9-20
ICM7216A, ICM7216B, ICM7216D
Accuracy
In addition, there is a quantization error inherent in any digital
measurement of ±1 count. Clearly this error is reduced by dis-
playing more digits. In the frequency mode the maximum
accuracy is obtained with high frequency inputs and in period
mode maximum accuracy is obtained with low frequency
inputs (as can be seen in Figure 14). In time interval mea-
surements there can be an error of 1 count per interval. As a
result there is the same inherent accuracy in all ranges as
shown in Figure 15. In frequency ratio measurement can be
more accurately obtained by averaging over more cycles of
INPUT B as shown in Figure 16.
In a Universal Counter crystal drift and quantization effects
cause errors. In frequency, period and time interval
modes, a signal derived from the oscillator is used in either
the Reference Counter or Main Counter. Therefore, in
these modes an error in the oscillator frequency will cause
an identical error in the measurement. For instance, an
o
oscillator temperature coefficient of 20
/ C will cause a
PPM
o
measurement error of 20
/ C.
PPM
0
1
0
FREQUENCY MEASURE
0.01s
0.1s
1s
2
2
4
6
8
MAXIMUM TIME INTERVAL
FOR 10 INTERVALS
3
3
10s
4
MAXIMUM TIME
1 CYCLE
10 CYCLES
10 CYCLES
10 CYCLES
INTERVAL FOR
5
2
2
3
10 INTERVALS
6
MAXIMUM TIME INTERVAL
FOR 10 INTERVALS
7
PERIOD MEASURE
= 10MHz
f
OSC
8
2
3
4
5
6
7
8
3
5
7
1
10
10
10
10
10
10
10
10
1
10
10
FREQUENCY (Hz)
10
10
TIME INTERVAL (µs)
FIGURE 14. MAXIMUM ACCURACY OF FREQUENCY AND
FIGURE 15. MAXIMUM ACCURACY OF TIME INTERVAL MEA-
SUREMENT DUE TO LIMITATIONS OF QUANTIZA-
TION ERRORS
PERIOD MEASUREMENTS DUE TO LIMITATIONS
OF QUANTIZATION ERRORS
0
1
2
3
4
5
6
7
RANGE
1 CYCLE
10 CYCLES
10 CYCLES
10 CYCLES
2
3
8
2
10
3
4
5
6
7
8
1
10
10
10
/f
10
10
10
10
f
A
B
FIGURE 16. MAXIMUM ACCURACY FOR FREQUENCY RATIO MEASUREMENT DUE TO LIMITATION OF QUANTIZATION ERRORS
9-21
ICM7216A, ICM7216B, ICM7216D
Test Circuit
V
V
DD
DD
INPUT A
V
DD
FUNCTION
DISPLAY DISPLAY
EXT
GENERATOR
BLANK
TEST
OSC
1MHz
TEST
39pF
TYP
10kΩ
10kΩ
HOLD
39pF
100pF
FUNCTION
GENERATOR
D4
D8
D2
D1
D5
1
2
28
27
26
25
24
23
22
21
20
19
18
17
16
15
INPUT B
22MΩ
1N914s
10MHz
CRYSTAL
3
EXT
OSC
INPUT
FUNCTION
10K
D1
DP
e
4
F
P
5
D8
D1
8
g
6
FR
TI.
D2
D5
D4
a
7
D2
D3
D4
D5
TYPICAL CRYSTAL SPECS:
F = 10MHz PARALLEL RESONANCE
ICM7216A
8
C
R
= 22pF
= <35Ω
L
S
U.C.
O.F.
d
b
c
f
9
D3
10
11
12
13
14
V
DD
D6
D7
D8
RANGE
RESET
D1
D4
.01/1
.1/10
1/100
10/1K
D2
D3
10kΩ
4
6
8
a
b
c
d
e
f
8
g
LED
OVERFLOW
INDICATOR
DP
D8
D8
D7
D6
D5
D4
D3
D2
D1
FIGURE 17. TEST CIRCUIT (ICM7216A SHOWN, OTHERS SIMILAR)
Typical Applications
The lCM7216 has been designed for use in a wide range of measurements is also lengthened to 800ms and the display
Universal and Frequency counters. In many cases, prescalers multiplex rate is decreased to 125Hz.
will be required to reduce the input frequencies to under 10MHz.
If the input frequency is prescaled by ten, then the oscillator
Because INPUT A and INPUT B are digital inputs, additional
can remain at 10MHz or 1MHz, but the decimal point must
circuitry is often required for input buffering, amplification,
be moved one digit to the right. Figure 20 shows a frequency
hysteresis, and level shifting to obtain a good digital signal.
counter with a ÷10 prescaler and an lCM7216A. Since there
The lCM7216A or lCM7216B can be used as a minimum is no external decimal point control with the lCM7216A and
component complete Universal Counter as shown in lCM7216B, the decimal point may be controlled externally
Figure 18. This circuit can use input frequencies up to with additional drivers as shown in Figure 20. Alternatively, if
10MHz at INPUT A and 2MHz at INPUT B. If the signal at separate anodes are available for the decimal points, they
INPUT A has a very low duty cycle it may be necessary to can be wired up to the adjacent digit anodes. Note that there
use a 74LS121 monostable multivibrator or similar circuit to can be one zero to the left of the decimal point since the
stretch the input pulse width to be able to guarantee that it is internal leading zero blanking cannot be changed. In
at least 50ns in duration.
Figure 21 additional logic has been added to count the input
directly in period mode for maximum accuracy. In Figures 20
To measure frequencies up to 40MHz the circuit of Figure
19 can be used. To obtain the correct measured value, it is
necessary to divide the oscillator frequency by four as well
as the input frequency. In doing this the time between
and 21, INPUT A comes from Q of the prescaler rather
C
than Q to obtain an input duty cycle of 40%.
D
9-22
ICM7216A, ICM7216B, ICM7216D
V
DD
EXT
V
DD
DISPLAY DISPLAY
BLANK
OSC
TEST ENABLE
INPUT A
10kΩ
39pF
TYP
100pF
CONTROL
SWITCHES
HOLD
22MΩ
D4
D8
D1
1
2
28
27
26
25
24
23
22
21
20
19
18
17
16
15
100kΩ
10MHz
CRYSTAL
IN914s
INPUT B
3
3
39pF
10kΩ
D1
D2
D3
4
EXT
OSC
INPUT
V
DD
F
P
D1
5
4
D8
D1
D4
RANGE
DP
g
6
D2
D3
F.R.
T.I.
D2
D5
SEC
0.01
0.1
CYCLES
1.0
D4
7
ICM7216B
10kΩ
D1
e
8
D2
D3
D4
10.0
U.C.
O.F.
D4
D5
D6
D7
D8
a
9
1.0
100.0
1K
D3
d
10
11
12
13
14
10.0
FUNCTION
V
DD
b
c
0.1µF
6
SEGMENT DRIVERS
8
8
RESET
f
8
8
a
b
c
d
e
f
COMMON CATHODE LED DISPLAY
DIGIT
DRIVERS
g
DP
D8
D7
D6
D5
D4
D3
D2
D1
D8
LED
OVERFLOW
INDICATOR
FIGURE 18. 10MHz UNIVERSAL COUNTER
9-23
ICM7216A, ICM7216B, ICM7216D
INPUT A
J
3
6
1
CL
K
Q
2
5
P
4
C
1
1
/ 74LS112
2
V+
15
Q
K 12
13 CL
J 11
V
V
DD
DD
EXT
10
P
C
/ 74LS112
2
OSC DISPLAY DISPLAY
ENABLE
V
14
DD
3kΩ
OFF
TEST
Q
9
Q
7
10kΩ
39pF
39pF
HOLD
100pF
100kΩ
D1
D4
D8
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
22MΩ
IN914s
3
2
3
2.5MHz
CRYSTAL
D1
D2
D3
4
EXT
OSC
5
DP
INPUT
8
6
D4
7
g
e
a
d
ICM7216D
D5
D6
D7
D8
8
9
0.1µF
10
11
12
13
14
V
DD
b
c
RESET
RANGE
8
D1
D4
f
D2
D3
10kΩ
4
a
b
c
d
e
f
a
COMMON CATHODE LED DISPLAY
b
c
d
e
f
g
g
DP
DP
LED
OVERFLOW
INDICATOR
D8
D8
D7
D6
D5
D4
D3
D2
D1
8
OVERFLOW
INDICATOR
FIGURE 19. 40MHz FREQUENCY COUNTER
9-24
ICM7216A, ICM7216B, ICM7216D
V
V
V
DD
DD
DD
INPUT B
INPUT A
DISPLAY
TEST
V
DD
10kΩ
10kΩ
100pF
CK1 CK2
QA
CK1 CK2
QA
30pF
TYP
3kΩ
39pF
QC
QC
HOLD
74LS90 OR
11C90
11C90
1N914
D7
1
2
28
27
26
25
24
23
22
21
20
19
18
17
16
15
22MΩ
10MHz
CRYSTAL
V
3kΩ
DD
3
DP
4
e
g
5
D1
8
6
a
7
D2
D3
D4
D5
ICM7216A
8
d
b
c
f
9
V
SS
10
11
12
13
14
4
4
0.1µF
V
DD
D6
D7
D8
1kΩ
RANGE
DP
D1
RESET
D1
D2
10kΩ
D2
1kΩ
D1
F
P
8
D3
D4
D3
10kΩ
COMMON ANODE LED DISPLAY
2N2222
D4
D8
D2
a
b
c
d
e
f
F.R.
40Ω
g
DP
D8
D8
D7
D6
D5
D4
D3
D2
D1
8
LED
OVERFLOW
INDICATOR
FIGURE 20. 100MHz MULTIFUNCTION COUNTER
9-25
ICM7216A, ICM7216B, ICM7216D
INPUT A
11C90
CK1
CK2 QA OC
3kΩ
74LS00
V
DD
V
V
V
DD
DD
DD
3kΩ
V
DD
10kΩ
10kΩ
39pF
TYP
100pF
100kΩ
39pF
10kΩ
10kΩ
V
DD
2N2222
HOLD
1
2
28
27
26
25
24
23
22
21
20
19
18
17
16
15
FUNCTION SWITCH
OPEN: FREQ.
CLOSED: PERIOD
D3
+
22MΩ
V
10MHz
CRYSTAL
3
DP
4
5
e
g
a
D1
8
6
7
D2
D3
D4
D5
ICM7216A
8
9
d
b
c
f
0.1µF
1kΩ
10
11
12
13
14
4
4
2N2222
V
DD
V
V
SS
SS
D6
D7
D8
RANGE
DP
D1
1kΩ
RESET
D1
D2
D2
1kΩ
10kΩ
8
D3
D4
D3
10kΩ
2N2222
1
D4
a
b
c
d
e
f
CONT
D1
13
COMMON CATHODE LED DISPLAY
2
40Ω
CD4016
4
g
D8
5
CONT
DP
3
D8
D8
D7
D6
D5
D4
D3
D2
D1
8
LED
OVERFLOW
INDICATOR
FIGURE 21. 100MHz FREQUENCY, 2MHz PERIOD COUNTER
All Intersil semiconductor products are manufactured, assembled and tested under ISO9000 quality systems certification.
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate
and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which
may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see web site http://www.intersil.com
9-26
相关型号：
©2020 ICPDF网 联系我们和版权申明