TYPICAL APPLICATION
SM1125ABV
2.0 to 3.6V
B+
CONTROLLER
RO
91kΩ
CO 200pF
OSC
SI
SC
ST
VSS
VDD
MTO
TEST
OSCILLATOR FREQUENCY MEASUREMENT
The measurement circuit below shows a SM1125ABV with built-in RC oscillator circuit and external RC
oscillator components capacitor CO and resistor RO.
When ST is switched to VDD, the oscillator starts and outputs a pulse on MTO. The output pulse is counted
using a frequency counter.
RO
CO
Switch
91kΩ
SM1125ABV
OSC
SI
SC
ST
VSS
VDD
MTO
TEST
Frequency Counter
Note that the board mounting and wiring will marginally affect the output frequency, even for equivalent values for RO and CO.
SEIKO NPC CORPORATION —7