EM1537 Datasheet, PDF (1/7 Pages) EM Microelectronic - MARIN SA – Low Power 32 kHz Circuit for Analog Quartz Watches

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EM MICROELECTRONIC - MARIN SA
EM1537
Low Power 32 kHz Circuit for Analog Quartz Watches
Description
The EM1537 is an integrated circuit in a low power CMOS
technology for battery operated wristwatches with bipolar
stepping motors. Time base is a 32 kHz crystal oscillator.
It has a very low current consumption of typ. 100 nA in a
wide voltage range of 1.2 to 3.6 Volt.
The IC is available in two voltage ranges - 1.2 to 1.8 Volt
and 1.8 to 3.6 V.
Motor pulse width is programmable from 0.098 ms to
14.65 ms in steps of 0.98 ms by metal mask.
Motor period is programmable from 2 x 1s to 2 x 60 s in
steps of 1 s selectable by metal mask.
Motor pulse chopping is programmable from 1/8 to 8/8 in
steps of 1/8 with chopping frequencies of 1024 Hz or 2048
Hz selectable by metal mask.
Motor period in Motor test mode is selectable 2 x 31.25
ms or 2 x 62.5 ms by metal mask
Input and output capacitors are integrated on chip and
also programmable by metal mask.
With a fully debounced RESET pad the motor can be
stopped.
A multi-functional bidirectional pad MTEST acts as output
for a 32 Hz or 512 Hz for frequency tuning - if open, or – if
connected to Vp – accelerates the motor period by a
factor of 16 or 32.
Features
ƒ Low power 32 kHz Quartz oscillator
ƒ Operating voltage ranges 1.55V and 3 Volt.
ƒ Very low current consumption typ. 100 nA at 1.5V.
ƒ Motor pulse width motor period and motor pulse
chopping is programmable in a wide range by metal
mask and don’t require additional bonds.
ƒ Fully debounced RESET input for accurate time setting
and power saving during shelf life.
ƒ Integrated capacitors, mask selectable is steps of 1 pF up to
35 pF.
ƒ Operation temperature range: -10°C to +60°C
ƒ Available in chip form, SO8 package
Applications
ƒ Analog watches
ƒ Driver for bipolar stepping motors
Functional Diagram
Vn
RESET
Vn
RESET
V_P
V_P
MOT1
C_TR
H1537
OSCIN
MOT2
Rm
(Stepping Motor)
OSCOUT
V_P
V_P
Operating range of Trimmer Capacitance:
3pF ≤ C_TR ≤ 30 pF
Copyright © 2006, EM Microelectronic-Marin SA
1
10/06 – rev.A
www.emmicroelectronic.com