Oscillator and Frequency Divider
The quartz oscillator consists of an inverter, internal
feedback resistance to bias the input and integrated
capacitors. The values of the integrated capacitors are
selectable by metal mask. The oscillator is designed for
Motor Drive Output
The circuit contains two push-pull output buffers for driving
bipolar stepping motors. Between two pulses, both P-
channel transistor of the other buffer are conducting. The
outputs are protected against inductive voltage spikes with
diodes to both supply pins.
Both the motor pulse period and motor pulse width are
programmable by metal mask over a wide range of values
(see page 6 for available options).
The alarm is activated by connecting ALARMIN to VSS and is
deactivated by opening the connection. A metal mask
option is available to program a continuous activation of the
The alarm output driver contains a push-pull output buffer
to drive an external sound source by means of an external
bipolar transistor. A metal mask option is available to allow
the use of NPN or PNP-transistors.
The tone frequency, modulation frequency, modulation
frequency and cycle time (ON/OFF time) are metal mask
The ALARMIN pin fulfills three functions:
a) For normal operation, the ALARMIN pin is left open.
The circuit provides a square wave signal of 1024Hz,
which can be used to tune the oscillator.
b) If the pin is connected to VSS, the alarm signal is
provided at pin 6.
If the ALARMIN pin is connected to VDD, all output
frequencies are increased by a factor of 64, the alarm
modulation of fA1 = 8Hz and fA = 2kHz are suppressed.
Operating range of trimmer
Capacitance: 1.5 pF CTR 30 pF
Copyright 2016, EM Microelectronic-Marin SA
1344-DS, Version 2.1, 04/2017