H1137 Datasheet, PDF (4/6 Pages) EM Microelectronic - MARIN SA – CMOS circuit for Analog Quartz Watches

R
Block Diagram
O scilla to r
O S C _IN
O SC_OUT
H1137
In itia l D ivid e r
P u lse W id th
D ivid e r
D ivide r 1 H z
M o to r L o g ic
P u ls e R e p e titio n
D ivid e r
Test Lo gic
M o to r D rive r
M aster R eset
TEST
MOT₁
MOT₂
RESET
Fig. 4
Pin Assignments
Name
V_N
V_P
OSC_IN
OSC_OUT
MOT₁
MOT₂
RESET
TEST
Function
Negative supply voltage
Positive supply voltage
Oscillator input
Oscillator output
Motor drive output 1
Motor drive output 2
Reset input
Test input / output
Functional Description
Oscillator
The 32’768Hz clock frequency is generated by a crystal
oscillator. Input and output capacitors are integrated in
the chip. Their values are metal mask selectable.
Motor drive output
The H1137 contains two push-pull output buffers for driv-
ing bipolar stepping motors (see Fig. 3). Between two
pulses, the two p-channel devices are active for motor
damping.
Reset
Pulling the RESET input to V_P resets the frequency di-
viders and disables the motor pulses. Motor pulses in
progress when the RESET function is applied, will be
completed. After releasing the RESET pad from V_P, the
next motor pulse appears with a delay of one half motor
cycle on the drive output MOT₁ if the last motor pulse
appeared on MOT₂ or vice-versa (see Fig. 3). Due to the
debounce circuitry on the RESET input, V_P must be ap-
plied for at least 23.4 ms to be accepted as RESET.
Test mode
The TEST pad fulfils two functions:
a) For normal operation, the TEST pad is left open. The
circuit outputs a square wave signal of 512Hz which
can be used for tuning the oscillator.
b) If the TEST pad is connected to V_P, the period for
the motor pulses changes to either 2 x 31.25 ms or
2 x 62.5 ms (mask options), while the motor pulse
width remains unchanged (fast motor test).
Test
Test Pad
Connected to
V_P
Open
Function
Fast motor
test
Normal
operation
Description
Increase the frequency for the
motor pulses to 16Hz (32Hz)
Output of square wave signal
(512Hz)
Test configuration
VP
VP
RL
Reset
Test
C_TR
VN
VP
Operating range of Trimmer Capacitance:
3pF ≤ CTR ≤ 30 pF
Fig. 5
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