DATASHEET
ICM7555, ICM7556
FN2867
Rev 1.00
June 28, 2016
General Purpose Timers
The ICM7555 and ICM7556 are CMOS RC timers providing
significantly improved performance over the standard
SE/NE 555/556 and 355 timers, while at the same time being
direct replacements 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.
Features
Specifically, the ICM7555 and ICM7556 are stable controllers
capable of producing accurate time delays or frequencies. The
ICM7556 is a dual ICM7555, with the two timers operating
independently of each other, sharing only V+ and GND. 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 regular bipolar
SE/NE 555/556 devices, the Control Voltage terminal need not
be decoupled with a capacitor. The circuits are triggered and
reset on falling (negative) waveforms, and the output inverter
can source or sink currents large enough to drive TTL loads, or
provide minimal offsets to drive CMOS loads.
• High speed operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1MHz
• Exact equivalent in most cases for SE/NE 555/556 or
TLC555/556
• Low supply current
- ICM7555 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60µA
- ICM7556 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120µA
• Extremely low input currents . . . . . . . . . . . . . . . . . . . . . . 20pA
• Guaranteed supply voltage range . . . . . . . . . . . . . . 2V to 18V
• Temperature stability . . . . . . . . . . . . . 0.005%/°C at +25°C
• Normal reset function - no crowbarring of supply during
output transition
• Can be used with higher impedance timing elements than
regular 555/556 for longer RC time constants
• Timing from microseconds through hours
• Operates in both astable and monostable modes
• Adjustable duty cycle
• High output source/sink driver can drive TTL/CMOS
• Outputs have very low offsets, HIGH and LOW
• Pb-free (RoHS Compliant)
Applications
• Precision timing
• Pulse generation
• Sequential timing
• Time delay generation
• Pulse width modulation
• Pulse position modulation
• Missing pulse detector
Pin Configurations
GND 1
ICM7555
(8 LD PDIP, SOIC)
ICM7556
(14 LD PDIP, CERDIP)
TOP VIEW
TOP VIEW
8 VDD
TRIGGER 2
7 DISCHARGE
OUTPUT 3
6 THRESHOLD
RESET 4
5 CONTROL
VOLTAGE
DISCHARGE1 1
14 VDD
THRESHOLD1 2
13 DISCHARGE2
CONTROL 3
VOLTAGE1
12 THRESHOLD2
RESET1 4
OUTPUT1 5
TRIGGER1 6
GND 7
FN2867 Rev 1.00
June 28, 2016
11 CONTROL
VOLTAGE2
10 RESET2
9 OUTPUT2
8 TRIGGER2
Page 1 of 13
ICM7555, ICM7556
Ordering Information
PART NUMBER
PART MARKING
TEMP. RANGE
(°C)
TAPE AND REEL
(UNITS)
PACKAGE
(RoHS COMPLIANT)
ICM7555CBAZ (Notes 2, 3)
7555 CBAZ
0 to +70
ICM7555CBAZ-T (Notes 1, 2, 3)
7555 CBAZ
0 to +70
ICM7555IBAZ (Notes 2, 3)
7555 IBAZ
-25 to +85
ICM7555IBAZ-T (Notes 1, 2, 3)
7555 IBAZ
-25 to +85
ICM7555IPAZ (Notes 2, 3)
7555 IPAZ
-25 to +85
8 Ld PDIP
E8.3
ICM7556IPDZ (Notes 2, 3)
ICM7556IPDZ
-25 to +85
14 Ld PDIP
E14.3
-55 to +125
14 Ld Cerdip
F14.3
ICM7556MJD
ICM7556MJD
(No longer available or supported)
8 Ld SOIC
PKG. DWG. #
2.5k
8 Ld SOIC (Tape and Reel) M8.15
8 Ld SOIC
2.5k
M8.15
M8.15
8 Ld SOIC (Tape and Reel) M8.15
NOTES:
1. Please refer to TB347 for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte
tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil
Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level (MSL), please see product information page for ICM7555, ICM7556. For more information on MSL, please see tech brief
TB363.
FN2867 Rev 1.00
June 28, 2016
Page 2 of 13
ICM7555, ICM7556
Absolute Maximum Ratings
Thermal Information
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +18V
Input Voltage
Trigger, Control Voltage, Threshold,
Reset (Note 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V+ +0.3V to GND -0.3V
Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100mA
Thermal Resistance (Typical, Notes 5, 6)
JA (°C/W) JC (°C/W)
14 Ld CERDIP Package . . . . . . . . . . . . . . .
80
24
14 Ld PDIP Package* . . . . . . . . . . . . . . . .
115
46
8 Ld PDIP Package* . . . . . . . . . . . . . . . . .
130
69
8 Ld SOIC Package. . . . . . . . . . . . . . . . . . .
170
67
Maximum Junction Temperature (Hermetic Package) . . . . . . . . . . . .+175°C
Maximum Junction Temperature (Plastic Package) . . . . . . . . . . . .+150°C
Maximum Storage Temperature Range . . . . . . . . . . . . . -65°C to +150°C
* Pb-free PDIPs can be used for through-hole wave solder
processing only. They are not intended for use in Reflow solder
processing applications.
Operating Conditions
Temperature Range
ICM7555C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
ICM7555I, ICM7556I . . . . . . . . . . . . . . . . . . . . . . . . . . . . -25°C to +85°C
ICM7556M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-55°C to +125°C
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product
reliability and result in failures not covered by warranty.
NOTES:
4. Due to the SCR structure inherent in the CMOS process used to fabricate these devices, connecting any terminal to a voltage greater than V+ +0.3V
or less than V- -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 supply systems, the supply of the ICM7555 and
ICM7556 must be turned on first.
5. JA is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
6. For JC, the “case temp” location is taken at the package top center.
Electrical Specifications
Applies to ICM7555 and ICM7556, unless otherwise specified.
(Note 8)
-55°C TO+125°C
TA = +25°C
PARAMETER
Static Supply Current
SYMBOL
IDD
ICM7555
ICM7556
Monostable Timing Accuracy
TYP
MAX
MAX
UNIT
VDD = 5V
40
200
300
µA
VDD = 15V
60
300
300
µA
VDD = 5V
80
400
600
µA
VDD = 15V
120
600
600
µA
TEST CONDITIONS
MIN
RA = 10k, C = 0.1µF, VDD = 5V
MIN
TYP
2
%
858
Drift with Temperature
(Note 7)
1161
VDD = 5V
150
ppm/°C
VDD = 10V
200
ppm/°C
VDD = 15V
250
ppm/°C
0.5
%/V
Drift with Supply (Note 7)
VDD = 5V to 15V
Astable Timing Accuracy
RA = RB = 10k, C = 0.1µF, VDD = 5V
0.5
2
%
1717
Drift with Temperature
(Note 7)
Drift with Supply (Note 7)
Threshold Voltage
µs
2323
µs
VDD = 5V
150
ppm/°C
VDD = 10V
200
ppm/°C
VDD = 15V
250
ppm/°C
0.5
%/V
VDD = 5V to 15V
0.5
V TH
VDD = 15V
62
67
71
61
72
% VDD
Trigger Voltage
VTRIG
VDD = 15V
28
32
36
27
37
% VDD
Trigger Current
ITRIG
VDD = 15V
10
50
nA
Threshold Current
ITH
VDD = 15V
10
50
nA
Control Voltage
VCV
VDD = 15V
72
% VDD
FN2867 Rev 1.00
June 28, 2016
62
67
71
61
Page 3 of 13
ICM7555, ICM7556
Electrical Specifications
Applies to ICM7555 and ICM7556, unless otherwise specified. (Continued)
(Note 8)
-55°C TO+125°C
TA = +25°C
PARAMETER
SYMBOL
MIN
TEST CONDITIONS
TYP
MIN
1.0
0.2
TYP
MAX
UNIT
1.2
V
Reset Voltage
VRST
VDD = 2V to 15V
Reset Current
IRST
VDD = 15V
10
50
nA
Discharge Leakage
IDIS
VDD = 15V
10
50
nA
Output Voltage
VOL
VDD = 15V, ISINK = 20mA
0.4
1.0
1.25
V
VDD = 5V, ISINK = 3.2mA
0.2
0.4
0.5
V
VOH
Discharge Output Voltage
VDIS
0.4
MAX
VDD = 15V, ISOURCE = 0.8mA
14.3
14.6
14.2
V
VDD = 5V, ISOURCE = 0.8mA
4.0
4.3
3.8
V
VDD = 5V, ISINK = 15mA
0.2
0.4
VDD = 15V, ISINK = 15mA
Supply Voltage (Note 7)
VDD
Functional Operation
2.0
18.0
3.0
0.6
V
0.4
V
16.0
V
Output Rise Time (Note 7)
tR
RL = 10M, CL = 10pF, VDD = 5V
75
ns
Output Fall Time (Note 7)
tF
RL = 10M, CL = 10pF, VDD = 5V
75
ns
VDD = 5V, RA = 470Ω, RB = 270Ω,
C = 200pF
1
MHz
Oscillator Frequency
(Note 7)
fMAX
NOTES:
7. These parameters are based upon characterization data and are not tested.
8. Applies only to military temperature range product (M suffix).
Functional Diagram
VDD
8
R
THRESHOLD
6
5
CONTROL
VOLTAGE
4
FLIP-FLOP
RESET
OUTPUT
DRIVERS
COMPARATOR
A
+
-
3
7
R
DISCHARGE
n
+
TRIGGER
2
OUTPUT
1
COMPARATOR
B
1
GND
R
NOTE: This functional diagram reduces the circuitry down to its simplest equivalent components. Tie down unused inputs.
FIGURE 1. FUNCTIONAL DIAGRAM
TRUTH TABLE
THRESHOLD VOLTAGE
TRIGGER VOLTAGE
RESET
OUTPUT
DISCHARGE SWITCH
Don’t Care
Don’t Care
Low
Low
On
>2/3(V+)
>1/3(V+)
High
Low
On
1/3(V+)
High
Stable
Stable
Don’t Care