- 您现在的位置：买卖IC网 > Datasheet目录690 > ICM7216DIPI (Intersil)IC COUNTER/TIMER FREQ 8DIG 28DIP Datasheet资料下载
参数资料
| 型号： | ICM7216DIPI |
| 厂商： | Intersil |
| 文件页数： | 11/18页 |
| 文件大小： | 0K |
| 描述： | IC COUNTER/TIMER FREQ 8DIG 28DIP |
| 标准包装： | 78 |
| 系列： | * |
| 其它名称： | 7216DIPI NT5007 |
ICM7216B, ICM7216D
INPUT and OUTPUT pins each contribute about 5pF to CIN
SIGNAL A
and COUT . For maximum stability of frequency, CIN and
SIGNAL B
2
2
INPUT A
INPUT B
COUT should be approximately twice the specified crystal
static capacitance.
In cases where non decade prescalers are used it may be
V DD
V DD
desirable to use a crystal which is neither 10MHz or 1MHz.
In that case both the multiplex rate and time between
N.O.
PRIME
150K
measurements will be different. The multiplex rate is
f MUX = ------------------- for 10MHz mode and f MUX = ------------------- for
2 × 10
2 × 10
1
100K
1N914
1
0.1 μ F
1
10K
1
10nF
f OSC f OSC
4 3
the 1MHz mode. The time between measurements is
× 10
2 × 10
V SS
DEVICE
V SS
TYPE
V SS
6
2 -------------------
f OSC
5
in the 10MHz mode and ------------------- in the 1MHz mode.
f OSC
1
2
CD4049B Inverting Buffer
CD4070B Exclusive - OR
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
g M = ω C IN C OUT R S ? 1 + -------- ?
where C L = ? --------------------------------- ?
oscillator temperature coefficient of 20 PPM will cause a
measurement error of 20 PPM
-------------------
FIGURE 10. PRIMING CIRCUIT, SIGNALS A AND B BOTH
HIGH OR LOW
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”
the lCM7216B as the first alternating signal states
automatically prime the device. See Figure 1.
During any time interval measurement cycle, the lCM7216B
require 200ms following B going low to update all internal
logic. A new measurement cycle will not take place until
completion of this internal update time.
Oscillator Considerations
The oscillator is a high gain CMOS inverter. An external
resistor of 10M ? to 22M ? 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 35 ? .
For a specific crystal and load capacitance, the required gM
can be calculated as follows:
2 ? C O ? 2
? C L ?
? C IN C OUT ?
? C IN + C OUT ?
CO = Crystal Static Capacitance
RS = Crystal Series Resistance
CIN = Input Capacitance
COUT = Output Capacitance
ω = 2 π f
The required gM should not exceed 50% of the gM specified
for the lCM7216 to insure reliable startup. The OSCillator
11
INPUT to the OSClLLATOR OUTPUT or INPUT can cause
undesirable shifts in oscillator frequency.
Display Considerations
The display is multiplexed at a 500Hz rate with a digit time of
244 μ s. An interdigit blanking time of 6 μ s 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
point or any non zero digits. Digits to the right of the decimal
point are always displayed. The leading zero blanking will be
disabled when the Main Counter overflows.
The lCM7216B and lCM7216D are designed to drive
common cathode displays at peak current of 15mA/segment
using displays with VF = 1.8V at 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.
To get additional brightness out of the displays, VDD may be
increased up to 6.0V. However, care should be taken to see
that maximum power and current ratings are not exceeded.
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.
Accuracy
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
C
o
C
相关PDF资料 |
PDF描述 |
|---|---|
| IKH1003000 | SWITCH DIP 1/2 PITCH |
| IKN0203000 | DIP SWITCH |
| IN421WB-E | FLASHLIGHT SWIVEL HEAD W/4AA |
| INL2AAE | FLASHLIGHT MID-RANGE IND 2AA LED |
| INL2DE | FLASHLIGHT MID-RANGE IND 2D LED |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ICM7216DIPI WAF | 制造商:Intersil Corporation 功能描述: |
| ICM7216DLPL | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:8-Digit, Multi-Function, Frequency Counters/Timers |
| ICM7217 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:4 Digit (LED) Presettable Up/Down Counter |
| ICM7217_01 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:4-Digit LED Display, Programmable Up/Down Counter |
| ICM7217A | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Analog IC |
发布紧急采购，3分钟左右您将得到回复。