AN856

2

Rev. 1.0

Substituting the output frequency of 1 Hz and a standard capacitor value of 0.1

μF, the necessary R

7.14 M

 can be calculated.

In setting the output frequency of both timers, the TS3004 offers an advantage because it only requires one

component instead of the two external components required by the CMOS555.

To compare the supply currents of both timers side-by-side, a few supply voltages were applied while both supply

currents were recorded. Table 1 displays the results.

As shown in Table 1, at 1.5 V, the TS3004 consumes a factor of 26 less supply current. With a 2.5 V supply, the

TS3004 consumes a factor of 40 less supply current. With a 3.3 V supply, the TS3004 consumes a factor of 38 less

supply current. In summary, the CMOS555 IC uses much more supply current than can be supported in battery or

portable applications.

For all voltages within its supply range, the TS3004 saves a significant amount of supply current, which can help

extend battery life in battery-powered applications. These applications include ultra-long life, low-frequency

battery-powered/portable applications, such as micropower PWM control, pulse-position modulation control, clock

generation, and sequential timing. The TS3004 can also be used as a low-parts-count micropower oscillator and

compact replacement for crystal and ceramic oscillators.

For additional information, see the following:

Table 1. Supply Current per Supply Voltage

Supply Voltage

TS3004

Supply Current

CMOS555

Supply Current

1.5 V

1.9

μA50 μA

2.5 V

2.0

μA81 μA

3.3 V

2.3

μA87 μA