Intersil Corporation ICM7226A, ICM7226B Datasheet

August 1997

ICM7226A,

ICM7226B

8-Digit, Multi-Function,

Frequency Counter/Timer

Features

• CMOS Design for Very Low Power

• Output Drivers Directly Drive Both Digits and
Segments of Large 8-Digit LED Displays

• Measures Frequencies from DC to 10MHz; Periods
from 0.5µs to 10s

• Stable High Frequency Oscillator uses either 1MHz or
10MHz Crystal

• Both Common Anode and Common Cathode Available

• Control Signals Available for External Systems
Interfacing

• Multiplexed BCD Outputs

Applications

• Frequency Counter

• Period Counter

• Unit Counter

• Frequency Ratio Counter

• Time Interval Counter

Ordering Information

TEMP.

PART NUMBER

ICM7226AlJL -25 to 85 40 Ld CERDIP F40.6
ICM7226BlPL -25 to 85 40 Ld PDIP E40.6

RANGE (oC) PACKAGE

PKG.

NO.

Description

The ICM7226 is a fully integrated Universal Counter and
LED display driver. It combines a high frequency oscillator, a
decade timebase counter, an 8-decade data counter and
latches, a 7-segment decoder, digit multiplexer and segment
and digit drivers which can directly drive large LED displays.
The counter inputs accept 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.

The ICM7226 can function as a frequency counter, period
counter, frequency ratio (f
or as a totalizing counter. The devices require either a
10MHz or 1MHz quartz crystal timebase, or if desired an
external timebase can also be used. 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. There is 0.2s between mea­surements in all ranges. Control signals are provided to
enable gating and storing of prescaler data.

Leading zero blanking has been incorporated with frequency
display in kHz and time in µs. The display is multiplexed at a
500Hz rate with a 12.2% duty cycle for each digit. The
ICM7226A is designed for common anode displays with typi­cal peak segment currents of 25mA, and the ICM7226B is
designed for common cathode displays with typical segment
currents of 12mA. In the display off mode, both digit drivers
and segment drivers are turned off, allowing the display to
be used for other functions.

) counter, time interval counter

A/fB

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

9-15

File Number 3169.1

ICM7226A, ICM7226B

Pinouts

CONTROL INPUT

INPUT B

MEASUREMENT IN PROGRESS

FUNCTION

STORE

BCD 4
BCD 8

DP

SEG
SEG g
SEG a

V

SEG d
SEG b
SEG c

SEG f

BCD 2
BCD 1

RST INPUT

EXT DP IN

ICM7226A

COMMON ANODE (CERDIP)

TOP VIEW

1
2
3
4
5
6
7
8

e

9
10
11
12

SS

13
14
15
16
17
18
19
20

40

INPUT A

39

HOLD

38

BUF OSC OUT

37

NC (NOTE 1)

36

OSC OUT

35

OSC IN

34

NC (NOTE 1)

33

EXT OSC IN

32

RST OUT

31

EXT RANGE
D1

30

D2

29

D3

28

D4

27

D5

26

V

25

DD

24

D6

23

D7

22

D8

21

RANGE

COMMON CATHODE (PDIP)

BCD 4
BCD 8

D1
D3
D2
D4

V

D5
D6
D7

D8
BCD 2
BCD 1

SS

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15
16
17
18
19
20

CONTROL INPUT

INPUT B

MEASUREMENT IN PROGRESS

FUNCTION

STORE

RST INPUT

EXT DP IN

NOTE:

1. For maximum frequency stability, connect to VDD or VSS.

ICM7226B

TOP VIEW

40

INPUT A

39

HOLD

38

BUF OSC OUT

37

NC (NOTE 1)

36

OSC OUT

35

OSC IN

34

NC (NOTE 1)

33

EXT OSC IN

32

RST OUT

31

EXT RANGE
DP OUT

30

SEG

29

SEG

28

SEG a

27

SEG d

26

V

25

DD

24

SEG b

23

SEG c

22

SEG f

21

RANGE

g
e

9-16

Functional Block Diagram

EXT OSC

INPUT

OSC

INPUT

OSC

OUTPUT

BUF OSC

OUTPUT

RESET

INPUT

OSC

SELECT

DECODER

3

104 OR

5

10

ICM7226A, ICM7226B

8

100Hz

DIGIT

DRIVERS

STORE

AND RESET

LOGIC

REFERENCE

COUNTER

3

+10

RANGE

SELECT

LOGIC

6

RANGE

CONTROL

LOGIC

5

CONTROL

LOGIC

DIGIT

OUTPUTS

8

RANGE

INPUT

EXT RANGE

INPUT

CONTROL

INPUT

(8)

INPUT A

INPUT B

FUNCTION

INPUT

MEAS IN

PROGRESS

OUTPUT

HOLD

INPUT

INPUT

CONTROL

LOGIC

INPUT

CONTROL

LOGIC

FN

CONTROL

LOGIC

MAIN

EN

COUNTER

3

÷10

CL

44444444

8

D

CL

6

DATA LATCHES

OUTPUT MUX

Q

MAIN

FF

R

RESET

OVERFLOW

STORE

478

DP

LOGIC

DECODER

AND LZB

LOGIC

4 4

SEGMENT

DRIVERS

EXT

DP

INPUT

SEGMENT
OUTPUTS

(8)

BCD

OUTPUTS

(4)

RESET

OUTPUT

STORE

OUTPUT

9-17

ICM7226A, ICM7226B

Absolute Maximum Ratings Thermal Information

Maximum Supply Voltage (VDD - VSS). . . . . . . . . . . . . . . . . . . .6.5V

Maximum Digit Output Current. . . . . . . . . . . . . . . . . . . . . . . .400mA

Maximum Segment Output Current . . . . . . . . . . . . . . . . . . . . .60mA

Voltage On Any Input or

Output Terminal (Note 1) . . . . . . . . . . . . . . VDD +0.3V to VSS -0.3V

Operating Conditions

Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . -25oC to 85oC

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. Destructive latchup may occur if input signals are applied bef ore the po w er supply is estab lished or if inputs or outputs are f orced to
voltages exceeding VDD or VSS by 0.3V.

2. θJA is measured with the component mounted on an evaluation PC board in free air.

Thermal Resistance (Typical, Note 2) θJA (oC/W) θJC (oC/W)

CERDIP Package . . . . . . . . . . . . . . . . 45 9

PDIP Package. . . . . . . . . . . . . . . . . . . 50 N/A

Maximum Junction Temperature

CERDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175oC

PDIP Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150oC

Maximum Storage Temperature Range . . . . . . . . . .-55oC to 150oC

Maximum Lead Temperature (Soldering 10s). . . . . . . . . . . . .300oC

Electrical Specifications V

= 5.0V, TA = 25oC, Unless Otherwise Specified

DD

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

Operating Supply Current, I
Supply Voltage Range (V

Maximum Frequency INPUT A, Pin 40, f

Maximum Frequency INPUT B, Pin 2, f

DD

-VSS), V

DD

SUPPLY

A(MAX)

B(MAX)

Minimum Separation INPUT A to INPUT B,
Time Interval Function

Oscillator Frequency and External Oscillator Frequency,
f

OSC

Oscillator Transconductance, g
Multiplex Frequency, f

MUX

M

Time Between Measurements f
Input Rate of Charge, dV

/dt Inputs A, B - 15 - mV/µs

IN

Input Voltages: Pins 2, 19, 33, 39, 40, 35

Input Low Voltage, V

Input High Voltage, V
Pins 2, 39, 40, Input Leakage, A, B, I
Input Resistance to V
Input Resistance to V

IL

lH

Pins 19, 33, R

DD

Pin 31, R

SS

ILK

IN

IN

Output Current

Low Output Current, Pins 3, 5-7, 17, 18, 32, 38, I

High Output Current, Pins 5-7, 17, 18, 32, H

High Output Current, Pins 3, 38, H

OL

OLVOL

OL

ICM7226A

Segment Driver: Pins 8-11, 13-16

Low Output Current, I

High Output Current, I

OL

OH

Display Off, Unused Inputs to V

-25oC to 85oC, INPUT A,
INPUT B Frequency at f

MAX

-25oC to 85oC

SS

-25mA

4.75 - 6.0 V

10 14 - MHz

4.75V < VDD < 6.0V, Figure 9
Function = Frequency, Ratio,
Unit Counter

Function = Period, Time Interval 2.5 - - MHz

-25oC to 85oC

2.5 - - MHz

4.75V < VDD < 6.0V, Figure 10

o

-25

C to 85oC

250 - - ns

4.75V < VDD < 6.0V, Figure 1

-25oC to 85oC

0.1 - 10 MHz

4.75V < VDD < 6.0V
VDD -4.75V, TA = 85oC 2000 - - µS
f

= 10MHz - 500 - Hz

OSC

= 10MHz - 200 - ms

OSC

-25oC to 85oC - - 1.0 V

3.5 - - V

--20µA
VIN = VDD -1.0V 100 400 - kΩ
VIN = +1.0V 50 100 - kΩ

= +0.4V 400 - - µA
VOH = +2.4V 100 - - µA
VOH = VDD -0.8V 265 - - µA

VO = +1.5V 25 35 - mA
VO = VDD -1.0V - 100 - µA

9-18

ICM7226A, ICM7226B

Electrical Specifications V

= 5.0V, TA = 25oC, Unless Otherwise Specified (Continued)

DD

PARAMETER TEST CONDITIONS MIN TYP MAX UNITS

Multiplex Inputs: Pins 1, 4, 20, 21

Input Low Voltage, V
Input High Voltage, V
Input Resistance to V

IL

IH
SS,RIN

VIN = +1.0V 50 100 - kΩ

Digit Driver: Pins 22-24, 26-30

Low Output Current, I
High Output Current, I

OL

OH

VO = +1.0V - -0.3 - mA
VO = VDD -2.0V 150 180 - mA

ICM7226B

Segment Driver: Pins 22-24, 26-30

Leakage Current, I

L

High Output Current, I

OH

VO = V

SS

VO = VDD -2.0V 10 15 - mA

Multiplex Inputs: Pins 1, 4, 20, 21

Input Low Voltage, V
Input High Voltage, V
Input Resistance to V

IL

IH
SS,RIN

VIN = VDD -1.0V 100 360 - kΩ

Digit Driver: Pins 8-11, 13-16

Low Output Current, I
High Output Current, I

OL

OH

VO = +1.0V 50 75 - mA
VO = VDD -2.5V - 100 - µA

NOTES:

1. Assumes all leads soldered or welded to PC board and free air flow.

2. Typical values are not tested.

- - 0.8 V

2.0 - - V

--10µA

--V

-2.0 V

DD

VDD-0.8 - - V

Timing Waveform

40ms

STORE

30ms TO 40ms

RESET

UPDATE

190ms TO 200ms

MEASUREMENT

IN PROGRESS

INPUT A

INPUT B

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)

60ms

40ms

FUNCTION:
TIME INTERVAL

PRIMING

PRIMING EDGES

MEASUREMENT INTERVAL

250ns MIN

MEASURED

INTERVAL

(FIRST)

MEASURED

INTERVAL

(LAST)

UPDATE

9-19

Typical Performance Curves

ICM7226A, ICM7226B

200

TA = 25oC

50

(mA)

100

DIGIT

I

50

0

01 2 3

VDD = 5.0V

V

OUT

FIGURE 2. ICM7226B TYPICAL I

30

4.5 ≤ VDD≤ 6.0V

20

(mA)

SEG

I

10

(V)

VDD = 5.5V

VDD = 4.5V

vs V

DIGIT

25oC

OUT

-20oC

85oC

300

4.5 ≤ VDD≤ 6.0V

200

(mA)

DIG

I

100

85oC

0

0

123

FIGURE 3. ICM7226A TYPICAL I

80

TA = 25oC

(mA)

SEG

I

60

40

20

VDD = 5.0V

V

DD-VOUT

-20oC

(V)

DIG

25oC

vs VDD-V

VDD = 5.5V

VDD = 4.5V

OUT

0

0 123

DD-VOUT

V

(V)

OUT

(V)

SEG

DIGIT

vs VDD-V

-20oC

vs V

OUT

25oC

85oC

OUT

V

FIGURE 4. ICM7226B TYPICAL I

200

VDD = 5.0V

150

(mA)

100

DIGIT

I

50

0

0 123

FIGURE 6. ICM7226B TYPICAL I

0

01 2 3

V

(V)

OUT

FIGURE 5. ICM7226A TYPICAL I

80

VDD = 5.0V

60

(mA)

40

SEG

I

20

0

0 123

(V)

V

OUT

FIGURE 7. ICM7226A TYPICAL I

SEG

SEG

vs V

-20oC

vs V

OUT

25oC

85oC

OUT

9-20