Philips Semiconductors Linear Products
Product specification
General purpose CMOS timer
ICM7555
DESCRIPTION
The ICM7555 is a CMOS timer providing significantly improved
performance over the standard NE/SE555 timer, while at the same
time being a direct replacement for those devices in most
applications. Improved parameters include low supply current, wide
operating supply voltage range, low THRESHOLD, TRIGGER, and
RESET currents, no crowbarring of the supply current during output
transitions, higher frequency performance and no requirement to
decouple CONTROL VOLTAGE for stable operation.
The ICM7555 is a stable controller capable of producing accurate
time delays or frequencies.
In the one-shot mode, the pulse width of each circuit is precisely
controlled by one external resistor and capacitor. For astable
operation as an oscillator, the free-running frequency and the duty
cycle are both accurately controlled by two external resistors and
one capacitor. Unlike the bipolar 555 device, the CONTROL
VOLTAGE terminal need not be decoupled with a capacitor. The
TRIGGER and RESET inputs are active low. The output inverter can
source or sink currents large enough to drive TTL loads or provide
minimal offsets to drive CMOS loads.
PIN CONFIGURATION
D and N Packages
GND
1
TRIGGER
OUTPUT
2
3
8
7
6
5
V
DD
DISCHARGE
THRESHOLD
CONTROL VOLTAGE
RESET
4
•
Timing from microseconds through hours
•
Operates in both astable and monostable modes
•
Adjustable duty cycle
•
High output source/sink driver can drive TTL/CMOS
•
Typical temperature stability of 0.005%/
o
C at 25
°
C
•
Rail-to-rail outputs
APPLICATIONS
FEATURES
•
Exact equivalent in most applications for NE/SE555
•
Low supply current: 80µA (typ)
•
Extremely low trigger, threshold, and reset currents: 20pA (typ)
•
High-speed operation: 500kHz guaranteed
•
Wide operating supply voltage range guaranteed 3 to 16V over full
automotive temperatures
•
Normal reset function; no crowbarring of supply during output
transition
•
Precision timing
•
Pulse generation
•
Sequential timing
•
Time delay generation
•
Pulse width modulation
•
Pulse position modulation
•
Missing pulse detector
•
Can be used with higher-impedance timing elements than the
bipolar 555 for longer time constants
ORDERING INFORMATION
DESCRIPTION
8-Pin Plastic Dual In-Line Package (DIP)
8-Pin Plastic Small Outline (SO) Package
8-Pin Plastic Dual In-Line Package (DIP)
8-Pin Plastic Small Outline (SO) Package
TEMPERATURE RANGE
0 to +70°C
0 to +70°C
-40 to +85°C
-40 to +85°C
ORDER CODE
ICM7555CN
ICM7555CD
ICM7555IN
ICM7555ID
DWG #
0404B
0174C
0404B
0174C
August 31, 1994
337
853-1192 13721
Philips Semiconductors Linear Products
Product specification
General purpose CMOS timer
ICM7555
EQUIVALENT BLOCK DIAGRAM
FLIP–FLOP
VDD
8
R
6
5
R
COMPARATOR
A
+
OUTPUT
DRIVERS
3
RESET
4
THRESHOLD
CONTROL
VOLTAGE
OUTPUT
–
DISCHARGE
COMPARATOR
B
+
7
N
1
2
TRIGGER
R
–
1
NOTE:
UNUSED INPUTS SHOULD BE CONNECTED TO APPROPRIATE VOLTAGE FROM TRUTH TABLE.
TRUTH TABLE
THRESHOLD VOLTAGE
DON’T CARE
>2/3(V+)
V
TH
< 2/3
DON’T CARE
TRIGGER VOLTAGE
DON’T CARE
> 1/3(V+)
V
TR
> 1/3
<1/3(V+)
RESET
1
LOW
HIGH
HIGH
HIGH
OUTPUT
LOW
LOW
STABLE
HIGH
DISCHARGE SWITCH
ON
ON
STABLE
OFF
NOTES:
1. RESET will dominate all other inputs: TRIGGER will dominate over THRESHOLD.
ABSOLUTE MAXIMUM RATINGS
1
SYMBOL
V
DD
V
TRIG1
V
CV
V
TH
V
RST
I
OUT
P
DMAX
Supply voltage
Trigger input voltage
Control voltage
Threshold input voltage
RESET input voltage
Output current
Maximum power dissipation, T
A
= 25
°
C (still air)
2
N package
D package
T
STG
T
SOLD
Storage temperature range
Lead temperature (Soldering 60s)
1160
780
-65 to +150
300
mW
mW
100
mA
> -0.3 to
<V
DD
+ 0.3
V
PARAMETER
RATING
+18
UNITS
V
°
C
°
C
NOTES:
1. Due to the SCR structure inherent in the CMOS process used to fabricate these devices, connecting any terminal to a voltage greater than
V
DD
+ 0.3V or less than GND -0.3V may cause destructive latch-up. For this reason it is recommended that no inputs from external sources
not operating from the same power supply be applied to the device before its power supply is established. In multiple systems, the supply of
the ICM7555 must be turned on first.
2. Derate above 25°C, at the following rates:
N package at 9.3mW/°C
D package at 6.2mW/°C
3. See “Power Dissipation Considerations” section.
August 31, 1994
338
Philips Semiconductors Linear Products
Product specification
General purpose CMOS timer
ICM7555
DC AND AC ELECTRICAL CHARACTERISTICS
T
A
= 25
°
C unless otherwise specified.
SYMBOL
V
DD
I
DD
LIMITS
PARAMETER
Supply voltage
Supply current
1
Astable mode timing
2
Initial accuracy
Drift with supply voltage
Drift with temperature
3
TEST CONDITIONS
MIN
T
MIN
< T
A
< T
MAX
V
DD
= V
MIN
V
DD
= V
MAX
R
A
, R
B
= 1k to 100k, C = 0.1
µ
F
5
V <V
DD
<15V
1.0
0.1
V
DD
= 5V
V
DD
= 10V
V
DD
= 15V
V
DD
= 5V
V
DD
= 5V
V
DD
= V
TRIG
= V
MAX
V
DD
= V
TRIG
= 5V
V
DD
= V
TRIG
= V
MIN
V
DD
= V
TH
= V
MAX
V
DD
= V
TH
= 5V
V
DD
= V
TH
= V
MIN
V
DD
= V
RST
= V
MAX
V
DD
= V
RST
= 5V
V
DD
= V
RST
= V
MIN
V
DD
= V
MIN
and V
MAX
V
DD
= 5V
V
DD
= V
MAX
, I
SINK
= 3.2mA
V
DD
= 5V, I
SINK
= 3.2mA
V
DD
= V
MAX
,
V
DD
= 5V,
I
SOURCE
= -1.0mA
I
SOURCE
= -1.0mA
15.25
4.0
0.4
0.62
0.63
0.29
50
75
100
0.65
0.31
50
10
1
50
10
1
100
20
2
0.7
0.65
0.1
0.2
15.7
4.5
0.2
45
20
500
0.4
75
75
1.0
0.67
0.4
0.4
0.67
0.34
5.0
3.0
%
%/V
ppm/
o
C
ppm/
o
C
ppm/
o
C
xV
DD
xV
DD
pA
pA
pA
pA
pA
pA
pA
pA
pA
V
xV
DD
V
V
V
DD
V
DD
V
ns
ns
kHz
3
50
180
ICM7555
TYP
MAX
16
200
300
V
UNITS
µ
A
µ
A
V
TH
V
TRIG
I
TRIG
Threshold voltage
Trigger voltage
Trigger current
I
TH
Threshold current
I
RST
V
RST
V
CV
V
OL
V
OH
V
DIS
t
R
t
F
F
MAX
Reset current
Reset voltage
Control voltage
Output voltage (low)
Output voltage (high)
Discharge output voltage
Rise time of
output
3
V
DD
= 5V, I
DIS
= 10.0mA
R
L
= 10M
Ω
, C
L
= 10pF, V
DD
=
5V
R
L
= 10M
Ω
, C
L
= 10pF, V
DD
=
5V
Fall time of output
3
Maximum oscillator frequency
(astable mode)
NOTES:
1. The supply current value is essentially independent of the TRIGGER, THRESHOLD, and RESET voltages.
1.38
. The components are defined in Figure 2.
2. Astable timing is calculated using the following equation: f =
(R
A
+ 2R
B
)C
3. Parameter is not 100% tested.
August 31, 1994
339
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