PCA2002
32 kHz watch circuit with programmable output period and
pulse width
Rev. 8 — 25 November 2011
Product data sheet
1. General description
The PCA2002 is a CMOS
1
integrated circuit for battery operated wrist watches with a
32 kHz quartz crystal as the timing element and a bipolar stepping motor. The quartz
crystal oscillator and the frequency divider are optimized for minimum current
consumption. A timing accuracy of 1 ppm is achieved with a programmable, digital
frequency adjustment.
The output period and the output pulse width can be programmed. It can be selected
between a full output pulse or a chopped output pulse with a duty cycle of 75 %. In
addition, a stretching pulse can be added to the primary driving pulse.
A pad RESET is provided (used for stopping the motor) for accurate time setting and for
accelerated testing of the watch.
2. Features and benefits
Amplitude-regulated 32 kHz quartz crystal oscillator, with excellent frequency stability
and high immunity to leakage currents
Electrically programmable time calibration with 1 ppm resolution stored in One Time
Programmable (OTP) memory
The quartz crystal is the only external component required
Very low current consumption: typically 90 nA
Output pulses for bipolar stepping motors
Five different programmable output periods (1 s to 30 s)
Output pulse width programmable between 1 ms and 8 ms
Full or chopped motor pulse and pulse stretching, selectable
Stop function for accurate time setting and current saving during shelf life
Test mode for accelerated testing of the mechanical parts of the watch
Test bits for type recognition
3. Applications
Driver circuits for bipolar stepping motors
High immunity motor drive circuits
High production volumes
1.
The definition of the abbreviations and acronyms used in this data sheet can be found in
Section 15.
NXP Semiconductors
PCA2002
32 kHz watch circuit with programmable output period and pulse width
4. Ordering information
Table 1.
Ordering information
Package
Name
PCA2002U/AB/1
wire bond
die
Description
8 bonding pads;
1.16
0.86
0.22 mm
8 bonding pads;
1.16
0.86
0.22 mm
wafer level chip-size package;
8 bumps
wafer level chip-size package;
8 bumps
Delivery form
bare die; chip in tray
sawn wafer on Film Frame
Carrier (FFC), see
Figure 15 on
page 22
unsawn wafer with lead free solder
bumps
sawn wafer with lead free solder
bumps on Film Frame Carrier (FFC),
see
Figure 16 on page 22
Version
PCA200xU
PCA200xU
Type number
PCA2002U/10AB/1 wire bond
die
PCA2002CX8/5/1
WLCSP8
PCA200xCX
PCA200xCX
PCA2002CX8/12/1 WLCSP8
5. Marking
Table 2.
Marking codes
Marking code
PC
2002-1
PC
2002-1
PC
2002-1
PC
2002-1
Type number
PCA2002U/AB/1
PCA2002U/10AB/1
PCA2002CX8/5/1
PCA2002CX8/12/1
PCA2002
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2011. All rights reserved.
Product data sheet
Rev. 8 — 25 November 2011
2 of 30
NXP Semiconductors
PCA2002
32 kHz watch circuit with programmable output period and pulse width
6. Block diagram
OSCIN
OSCILLATOR
OSCOUT
32 Hz
8 kHz
÷4
DIVIDER
RESET
RESET
TIMING ADJUSTMENT,
INHIBITION
reset
V
DD
V
SS
VOLTAGE DETECTOR,
OTP-CONTROLLER
OTP-MEMORY
1 Hz
MOTOR CONTROL
PCA2002
i.c.
mbl568
MOT1
n.c.
n.c.
M
MOT2
Fig 1.
Block diagram of PCA2002
PCA2002
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2011. All rights reserved.
Product data sheet
Rev. 8 — 25 November 2011
3 of 30
NXP Semiconductors
PCA2002
32 kHz watch circuit with programmable output period and pulse width
7. Pinning information
7.1 Pinning
PCA200xU
V
SS
i.c.
1
2
x
0
OSCIN
OSCOUT
3
4
0
y
6
5
001aai177
PCA200xCX
8
7
RESET
MOT2
V
SS
i.c.
1
2
x
0
MOT1
V
DD
OSCIN
OSCOUT
3
4
0
y
6
5
001aai176
8
7
RESET
MOT2
MOT1
V
DD
Top view. For mechanical details, see
Figure 10 on page 16.
Top view. For mechanical details, see
Figure 11 on page 17
Fig 2.
Pin configuration of PCA2002
7.2 Pin description
Table 3.
Symbol
V
SS
i.c.
OSCIN
OSCOUT
V
DD
MOT1
MOT2
RESET
Pin description
Pin
1
2
3
4
5
6
7
8
Description
ground
internally connected
oscillator input
oscillator output
supply voltage
motor 1 output
motor 2 output
reset input
PCA2002
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2011. All rights reserved.
Product data sheet
Rev. 8 — 25 November 2011
4 of 30
NXP Semiconductors
PCA2002
32 kHz watch circuit with programmable output period and pulse width
8. Functional description
8.1 Motor pulse
The motor driver delivers pulses with an alternating polarity. The output waveform across
the motor terminals is illustrated in
Figure 3.
Between the motor pulses, both terminals are
connected to V
DD
, which means that the motor is short-circuit.
The following parameters can be selected and are stored in a One Time Programmable
(OTP) memory:
•
•
•
•
Output periods of 1 s, 5 s, 10 s, 20 s and 30 s
Pulse width (t
p
) between 0.98 ms and 7.8 ms in steps of 0.98 ms
Full or chopped (75 %) output pulse
Pulse stretching: an enlargement pulse is added to the primary motor pulse. This
enlargement pulse has a duty cycle of 25 % and a width, which is twice the
programmed motor pulse width.
period
full pulse
chopped
pulse
full pulse
with stretching
chopped pulse
with stretching
t
p
2t
p
t
p
2t
p
mgu718
Fig 3.
Motor output waveforms
8.2 Time calibration
The quartz crystal oscillator has an integrated capacitance of 5.2 pF, which is lower than
the specified capacitance (C
L
) of 8.2 pF for the quartz crystal (see
Table 10).
Therefore,
the oscillator frequency is typically 60 ppm higher than 32.768 kHz. This positive
frequency offset is compensated by removing the appropriate number of 8192 Hz pulses
in the divider chain (maximum 127 pulses), every 1 or 2 minutes. The time correction is
given in
Table 4.
PCA2002
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2011. All rights reserved.
Product data sheet
Rev. 8 — 25 November 2011
5 of 30
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