Features
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32-kHz Crystal Oscillator
1.1 V to 2.2 V Operating-voltage Range
Integrated Capacitors for Digital Trimming
Suitable for up to 12.5 pF Quartz
Output Pulse Formers
Mask Options for Motor Period and Pulse Width
Low Resistance Output for Bipolar Stepping Motor
Motor Fast-test Function
Description
The e1466D is an integrated circuit in CMOS Silicon Gate Technology for analog
clocks. It consists of a 32-kHz oscillator, frequency divider, output pulse formers and
push-pull motor drivers. Integrated capacitors are mask-selectable to accomodate the
external quartz crystal. Additional capacitance can be selected through pad bonding
for trimming the oscillator frequency.
32-kHz Clock
CMOS IC with
Digital
Trimming
e1466D
4731A–CLOCK–06/03
1
Pad Configuration
Figure 1.
Pinning
C4 C3 C2 C1
VDD
(1)
OSCIN
OSCOUT
(1)
VSS
e1466D
TEST
(2)
MOT1
(2)
(1)
The
(2)
MOT2
MOT1
pads VDD and OSCOUT are interchangeable per mask option
The pads TEST and MOT1 are interchangeable per mask option
Pin Description
Name
VDD
VSS
OSCIN
OSCOUT
MOT1/2
C1, C2, C3, C4
TEST
Description
Positive supply voltage
Negative supply voltage
Oscillator input
Oscillator output
Motor drive outputs
Oscillator trimming inputs
TEST input/output
2
e1466D
4731A–CLOCK–06/03
e1466D
Functional Descripion
Oscillator
An oscillator inverter with feedback resistor is provided to generate the 32768 Hz clock fre-
quency. Values for the fixed capacitors at OSCIN and OSCOUT are mask-selectable (see
note 3 of “Operating Characteristics”). Four capacitor pads, C1 to C4, enable the users to add
integrated trimming capacitors to OSCIN, providing 15 tuning steps.
A frequency variation of typically 4 ppm for each tuning step is obtained by bonding the capac-
itor pads to OSCIN. As none of these pads are bonded, the IC is in an untrimmed state. Figure
3 shows the trimming curve characteristic.
Note:
For applications which utilize this integrated trimming feature, Atmel will determine optimum val-
ues for the integrated capacitors COSCIN and COSCOUT.
Trimming
Capacitors
Capacitor pads C1 to C4: 0 = open, 1 = connected to OSCIN
Combination C1 + C4 is redundant and therefore eliminated from the list
Table 1.
Frequency Trimming Table
Capacitor Pads
C4
0
0
0
0
1
0
0
0
1
1
0
1
1
1
1
C3
0
0
0
1
0
0
1
1
0
1
1
0
1
1
1
C2
0
0
1
0
0
1
0
1
1
0
1
1
0
1
1
C1
0
1
0
0
0
1
1
0
0
0
1
1
1
0
1
Trimming Step
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Motor Drive
Output
The e1466D contains two push-pull output buffers for driving bipolar stepping motors. During a
motor pulse, the N-channel device of one buffer and the P-channel device of the other buffer
will be activated. Both N-channel transistors are on and conducting between output pulses.
The outputs are protected against inductive voltage spikes with diodes to both supply pins.
The motor output period and pulse width are mask-programmable, as listed below:
Available motor periods (T
M
): 125, 250, 500 ms and 2, 16 s
Available max. pulse widths (t
M
): 15, 6, 23.4, 31.25, 46.9 ms and 1 s
Available motor periods for motor test (T
MT
): 250, 500 ms and 1 s
Note:
The following constraints for combination of motor period and pulse widths have to be consid-
ered: T
M
> 4
´
t
M
, T
MT
> 4
´
t
M
or alternatively T
M
= 2
´
t
M
, T
MT
= 2
´
t
M
3
4731A–CLOCK–06/03
Test Functions
For test purposes, the TEST pad is open. With a high resistance probe (R
³
10 M
W
,
C
³
20 pF), a test frequency f
TEST
of 128 Hz can be measured at the TEST pad. Connecting
TEST (for at least 32 ms) to V
DD
changes the motor period from the selected value to T
MT
(mask-selectable) while the pulse width remains unaffected. This feature can be used for test-
ing the mechanical parts of the clock.
Absolute Maximum Ratings
Absolute maximum ratings define parameter limits which, if exceeded, may permanently change or damage the device.
All inputs and outputs on Atmel’s circuits are protected against electrostatic discharges. However, precautions to minimize
the build-up of electrostatic charges during handling are recommended.
The circuit is protected against supply voltage reversal for typically 5 minutes.
Parameters
Supply voltage
Input voltage range, all inputs
Output short-circuit duration
Power dissipation (DIL package)
Operating ambient temperature range
Storage temperature range
Lead temperature during soldering at 2 mm distance, 10 s
P
tot
T
amb
T
stg
T
sld
Symbol
V
SS
V
IN
Value
-0.3 to 5 V
(V
SS
- 0.3 V)
£
V
IN
£
(V
DD
+ 0.3 V)
indefinite
125
-20 to +70
-40 to +125
260
mW
°C
°C
°C
Unit
V
V
4
e1466D
4731A–CLOCK–06/03
e1466D
Operating Characteristics
V
SS
= 0 V, V
DD
= 1.5 V, T
amb
= +25°C, unless otherwise specified.
All voltage levels are measured with reference to V
SS
. Test crystal as specified below.
Parameters
Operating voltage
Operating temperature
Operating current
Motor Drive Output
Motor output current
Motor period
Motor period during motor test
Motor pulse width
Oscillator
Startup voltage
Frequency stability
Integrated input capacitance
Integrated output capacitance
(4)
Test Conditions
Symbol
V
DD
T
amb
Min.
1.1
-20
Typ.
1.5
2
Max.
2.2
+70
5
Unit
V
°C
mA
mA
R
1
=
¥
(2)
V
DD
= 1.2 V, R
1
= 200
W
I
DD
I
M
T
M
T
MT
t
M
±4.3
See option list
See option list
See option list
1.2
1
See option list
See option list
3
4
5
6
0.6
-0.6
23.4
3
-3
10
-10
31.2
pF
pF
pF
pF
µA
µA
ms
2.2
V
ppm
Within 2 s
DV
DD
= 100 mV, V
DD
= 1.1 to 2.2 V
(3)
V
START
Df/f
C
OSCIN
C
OSCOUT
C1
C2
C3
C4
I
TINH
I
TINL
t
TIN
Integrated capacitance for bond option
TEST Input
Input current
Input current
Input debounce delay
Notes:
1.
2.
3.
4.
TEST = V
DD
peak current
TEST = V
SS
peak current
Typical parameters represent the statistical mean values
See test circuit
Values can be selected in 1 pF steps. A total capacitance (C
OSCIN
+ C
OSCOUT
) of 38 pF is available
These values are valid for 10 pF quartz applications. For C
L
= 12.5 pF these values change to 4.5, 6, 7.5, 9 pF
Figure 2.
Functional Test
VDD
C4 C3 C2 C1
OSCIN
VSS
OSCOUT
e1466D
TEST
MOT2
R
1
MOT1
MOT1
5
4731A–CLOCK–06/03
Microchip MCU
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