R
EM1537
Functional Description
Oscillator
(Pads OSCIN/OSCOUT)
Time-base is a 32 kHz quartz crystal. Special care was
taken at design of crystal oscillator and initial divider
chain to achieve very low power consumption and a wide
operating voltage range.
Input and output capacitances are integrated on-chip;
their values are metal mask selectable.
The oscillator frequency can be adjusted with an external
trimmer (C
TR
) connected on Pad OSCIN.
Motor Drive Output
(Pads MOT1, MOT2)
The
EM1537 contains two push-pull output buffers for
driving a bipolar stepping motor. Between two motor
pulses, the two p-channel devices are active for damping
the motor. A special circuitry prevents transfer current
spikes during switching.
Reset Input
(Pad RESET)
The reset input is fully debounced with a debounce-delay
between 7.8 ms and 23.4 ms.
Pulling the RESET input to Vp, resets the frequency
dividers and disables motor pulses. Motor pulses in
progress when the RESET function is applied will be
completed. After releasing the RESET pad from Vp the
next motor pulse appears with a delay of one half motor
cycle +/- 5% on the drive output MOT1 if the last pulse
appeared on MOT2 and vice-versa. The RESET input
has an internal pull-down.
Test Mode
(Pad MTEST)
The Pad MTEST is a bidirectional port. In its input mode
it is fully debounced with a debounce-delay between
31.25 ms and 62.5 ms.
The MTEST pad fulfils two functions:
- For normal operation the MTEST pad is left open. The
circuit outputs a square wave signal of 32 Hz or 512 Hz
(ftst) which can be used for tuning the oscillator
frequency.
- If the MTEST pad is connected to Vp the period of
motor pulses changes either to 2x31.25 ms or 2x62.5
ms (mask option) while the motor pulse width and
chopping remains unchanged (fast motor test).
Factory Test
(Pad TEST):
Test pad for Wafer sorting at the EM-Microelectronic. It
has a pull-up transistor.
Typical Operating Characteristics
140
120
Idyn [nA]
100
80
60
40
20
0
0.5
1
1.5
2
2.5
3
3.5
4
Vp [V]
Test Configuration
Reset
Vn
Test
Vp
C
TR
MTEST
H1137
OSCIN
MOT2
MOT1
Rm
Vn
RESET
Vp
OSCOUT
Vp
Vp
Copyright
©
2006, EM Microelectronic-Marin SA
10/06 – rev.A
6
www.emmicroelectronic.com
EMMICRO [ EM MICROELECTRONIC - MARIN SA ]
