Datasheet ICM7555, ICM7556 (Intersil) - 5

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VDD P P P P R THRESHOLD N N NPN CONTROL VOLTAGE R OUTPUT P P TRIGGER R N N N N N N N GND RESET DISCHARGE R = 100k
Ω ±
20% (TYP)
FIGURE 2. SCHEMATIC DIAGRAM Application Information The ICM7555 and ICM7556 produce supply current spikes of only 2mA to 3mA instead of 300mA to 400mA and supply General decoupling is normally not necessary. Also, in most instances, the Control Voltage decoupling capacitors are not required The ICM7555 and ICM7556 devices are, in most instances, since the input impedance of the CMOS comparators on chip direct replacements for the SE/NE 555/556 devices. However, are very high. Thus, for many applications, two capacitors can it is possible to effect economies in the external component be saved using an ICM7555 and three capacitors with an count using the ICM7555 and ICM7556. Because the bipolar ICM7556. SE/NE 555/556 devices produce large crowbar currents in the output driver, it is necessary to decouple the power supply POWER SUPPLY CONSIDERATIONS lines with a good capacitor close to the device. The ICM7555 Although the supply current consumed by the ICM7555 and and ICM7556 devices produce no such transients (see ICM7556 devices is very low, the total system supply current Figure 3). can be high unless the timing components are high impedance. Therefore, use high values for R and low values for
500
C in Figures 4, 5, and 6.
TA = +25°C ) A 400 VDD T GND VDD 300 1 8 10k SE/NE 555 TRIGGER DISCHARGE URRENT (m 2 7 E OUTPU T C 200 A THRESHOLD LY P 3 6 P VDD U CONTROL 100 OUTPUT LTERN S 4 5 VOLTAGE A RESET 0 OPTIONAL R C ICM7555/556 CAPACITOR 0 200 400 600 800
FIGURE 4. ASTABLE OPERATION
TIME (ns)
FIGURE 3. SUPPLY CURRENT TRANSIENT COMPARED WITH A STANDARD BIPOLAR 555 DURING AN OUTPUT TRANSITION FN2867 Rev 1.00 Page 5 of 13 June 28, 2016