STCL132K
32,768 Hz silicon oscillator
Features
■
Fixed frequency 32,768 Hz
■
±1.0% (0 to 70 °C), ±1.2% (–30 to 85 °C)
frequency accuracy over all conditions
■
1.65 to 1.95 V, 2.7 to 3.6 V operation
■
Low operating current, ultra low standby
current
■
Push-pull, CMOS compatible frequency
(square wave) output
■
Chip enable input, active high, internal 150 kΩ
pull-down
■
Fast and stable startup
■
No external components required
■
Temperature range: –30 to +85 °C
■
Package: SC70-5L
■
RoHS compliant
SOT323-5 (SC70-5L)
(W8)
Applications
■
Low-speed microprocessor clock
■
Display drivers
■
Any application with multiple inputs sharing
a common clock source
Description
The STCL132K silicon oscillator devices are reliable, easy to use, 5-pin low-cost silicon oscillators
developed primarily for microprocessor clock applications, display drivers or other system applications
where tighter clock accuracy is not critical. Compared to crystal oscillators, silicon oscillators offer the
advantages of faster startup, smaller size and improved immunity to shock, vibration and EMI.
The STCL132K silicon oscillator devices are equipped with chip enable input, offering an easy way to
stop microprocessor clocking during a power saving mode while at the same time significantly reducing
the oscillator current consumption.
April 2008
Rev 5
1/20
www.st.com
1
Contents
STCL132K
Contents
1
Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2
Typical application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1
Chip enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2
Transition to disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3
Fast startup and stable wakeup from disable . . . . . . . . . . . . . . . . . . . . . . . 7
4
Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6
Typical operating characteristics and scope plots . . . . . . . . . . . . . . . 11
7
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8
Package details SC70-5L (RoHS compliant) . . . . . . . . . . . . . . . . . . . . . 16
9
Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
10
Package marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
11
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2/20
STCL132K
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
DC and AC measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
SC70-5L – 5-lead small outline transistor package mechanical data . . . . . . . . . . . . . . . . . 15
Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Package marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3/20
List of figures
STCL132K
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
4/20
SC70-5L pin connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Microprocessor (MCU, microcontroller unit) clock – replacement of a 32 KHz crystal . . . . . 6
Frequency vs. temperature (STCL132KRxxx) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Duty cycle vs. temperature (STCL132KRxxx) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Active supply current vs. temperature (STCL132KRxxx) . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Standby supply current vs. temperature (STCL132KRxxx) . . . . . . . . . . . . . . . . . . . . . . . . 12
Startup time vs. temperature (STCL132KRxxx) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Startup output waveform: already the first cycle is within specifications
(power-on, VCC = 1.8 V, STCL132KRxxx) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
SC70-5L – 5-lead small outline transistor package outline. . . . . . . . . . . . . . . . . . . . . . . . . 14
Parts orientation in reel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Reel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
STCL132K
1
Pin descriptions
Pin descriptions
Figure 1.
SC70-5L pin connections
CE
1
NC
2
FOUT
3
5
VCC
4
GND
AI12658
Table 1.
Signal names
Symbol
Description
VCC
Positive supply voltage pin
FOUT
Frequency (square wave) output, CMOS compatible, push-pull
CE
GND
NC
Chip Enable input, CMOS level, active high, internal 150 kΩ pull-down resistor
Ground
No Connect
5/20
Typical application circuit
STCL132K
2
Typical application circuit
Figure 2.
Microprocessor (MCU, microcontroller unit) clock – replacement of a 32 KHz crystal
MCU
CE (2)
I/O
NC
Xtal1
(OSC1,
OSCin)
Xtal2
(OSC2,
OSCout)
VCC
1
FOUT
2
VCC
5
0.1 µF (1)
STCL132K
GND
3
4
GND
NC
AI12659a
1. For reliable operation and to further improve immunity to harsh environment, the minimum 0.1 µF decoupling capacitor is
recommended to be placed as close as possible to the VCC and GND pins of the oscillator device. The whole oscillator
block should then be placed near the microprocessor clock input.
2. Internal 150 kΩ pull-down resistor is implemented on the CE input. If the chip enable feature is not used, in active mode
connect the CE pin to VCC. In applications utilizing standby mode and where the CE pin is connected to the controlling I/O
port of the clocked microprocessor, for successful startup of the microprocessor at power-on, initial logic high level needs to
be secured on the CE pin to ensure clocking occurs during the power-on reset until the microprocessor program starts and
the controlling I/O port takes over the CE control.
6/20
STCL132K
3
Operation
Operation
Use of the STCL132K silicon oscillator device is very simple. Once power is applied to VCC
pin, a CMOS-compatible square wave output signal is provided on the FOUT output pin (in
active mode the Chip Enable (CE) input pin must be at a logic high level).
3.1
Chip enable
This feature allows the user to stop the clock and significantly reduce the current
consumption when the application is put into power saving mode.
When used to clock the microprocessor in place of a crystal, the need for chip enable input
stems from a difference in the way microprocessors normally disable their clock. In the case
of a crystal or ceramic resonator, when going into power saving mode, the processor simply
opens the internal Xtal inverter feedback which results in stopping the crystal oscillations;
however in the case of the silicon oscillators this would not work and the oscillator would
continue to run. So in order to use this feature, one of the microprocessor's output pins must
be configured to control the silicon oscillator's Chip Enable (CE) input, see typical
application circuit diagram in Figure 2.
3.2
Transition to disable
At the moment when the Chip Enable (CE) input goes low, the oscillator's output FOUT will
immediately go low; then during the disable period the output remains low.
Note:
For advanced microprocessor applications, other disable modes can be made available as
a product option (FOUT completes the last clock period, and then remains low or provides 32
additional cycles before going low to allow the processor to complete the pipelined
instructions, etc.). Also, a product option with output in a high-impedance state to allow the
system to alternate between several oscillators connected in parallel can be made available.
Contact local ST sales office for availability.
3.3
Fast startup and stable wakeup from disable
The total startup time until oscillations internally stabilize and remain within specifications is
typically 90 µs, i.e. shorter than duration of the first three periods of the generated output
signal, see Section 5: DC and AC parameters. This means that 90 µs after power-on or
wakeup from disable a first valid period of the output signal occurs on the FOUT pin and is
within the specified frequency and duty cycle range (in the meantime the output remains
low). This is in comparison to typically milliseconds for crystal oscillators.
7/20
Maximum rating
4
STCL132K
Maximum rating
Stressing the device above the rating listed in Table 2: Absolute maximum ratings may
cause permanent damage to the device. These are stress ratings only and operation of the
device at these or any other conditions above those indicated in the operating sections of
this specification is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability. Refer also to the STMicroelectronics SURE
program and other relevant quality documents.
Table 2.
Absolute maximum ratings
Symbol
TSTG
TSLD(1)
VI
VCC
Parameter
Storage temperature (VCC off)
Lead solder temperature for 10 seconds
Input voltage
Supply voltage
A(2)
ESD - MM
Machine Model JESD22-A115-A level
ESD - HBM
Human Body Model JESD22-A114-B level 2(2)
ESD - CDM
Charged Device
Model(2)
Value
Unit
–55 to 150
°C
260
°C
–0.3 to VCC +0.3
V
–0.3 to 4.6
V
100
V
2
kV
1
kV
1. Reflow at peak temperature of 260 °C (total thermal budget not to exceed 245 °C for more than 30 seconds).
2. For all external pins.
8/20
STCL132K
5
DC and AC parameters
DC and AC parameters
This section summarizes the operating and measurement conditions, as well as the DC and
AC characteristics of the device. The parameters in the following DC and AC characteristic
Table 4 are derived from tests performed under the measurement conditions listed in the
Table 3. Designers should check that the operating conditions in their projects match the
measurement conditions when using the quoted parameters.
Table 3.
DC and AC measurement conditions(1)
Parameter
VCC supply voltage
Ambient operating temperature
Load capacitance (CL)
STCL132KRxxx
STCL132KWxxx
1.65 to 1.95 V
2.7 to 3.6 V
0 to 70 °C, –30 to +85 °C
0 to 70 °C, –30 to +85 °C
12 pF
12 pF
1. Unless otherwise specified.
9/20
DC and AC parameters
Table 4.
DC and AC parameters
Symbol
VCC
ICC
STCL132K
Description
Test condition
Typ
Max
Unit
STCL132KRxxx
1.65
1.95
V
STCL132KWxxx
2.7
3.6
V
Operating voltage
VCC = 1.65 to 1.95 V,
(STCL132KRxxx)
output unloaded
60
85
µA
VCC = 2.7 to 3.6 V,
(STCL132KWxxx)
output unloaded
85
105
µA
1
µA
0.2 VCC
V
Operating current
=
ICC2
Standby current
CE
VOL
Output voltage low
IOL = 2 mA
VOH
Output voltage high
IOH = –2 mA
VIL
Input low voltage (CE)
VIH
Input high voltage (CE)
RPD
Internal pull-down
resistor
Frequency
accuracy(1)
GND
VCC – 0.2 V
V
0.35 V CC
0.65 VCC
V
V
150
kΩ
VCC = 1.65 to 1.95 V, –30 to +85 °C
(STCL132KRxxx)
–1.2
+1.2
%
VCC = 1.65 to 1.95 V, 0 to +70 °C
(STCL132KRxxx)
–1.0
+1.0
%
VCC = 2.7 to 3.6 V, –30 to +85 °C
(STCL132KWxxx)
–1.2
+1.2
%
VCC = 2.7 to 3.6 V, 0 to +70 °C
(STCL132KWxxx)
–1.0
+1.0
%
–150
+180
ppm/°C
Frequency temperature
coefficient
Jitter
Cycle-to-cycle, over 20 s
Duty cycle
Taken at half of the signal amplitude
tSTART
tR, tF
CL
Min
150
50
55
%
Startup time
From the point when VCC reached
min operating voltage or CE went
high until valid output signal occurs
on the F OUT pin (in the meantime
output remains low)
90
120
µs
Rise/fall time
CL = 12 pF; 10 to 90 % of the
amplitude
10
ns
12
pF
Load capacitance
45
nsP-P
1. Typical frequency shift due to aging is ±0.2%. Aging stresses include one solder reflow (260 °C peak) and 1000 hrs VCC
biased, 125 °C op-life.
10/20
STCL132K
Typical operating characteristics and scope plots
6
Typical operating characteristics and scope plots
Figure 3.
Frequency vs. temperature (STCL132KRxxx)
32.90
32.80
32.70
Mean
frequency 32.60
(kHz)
32.50
32.40
32.30
–40
–20
0
20
40
60
80
100
120
140
Temperature (˚C)
VCC = 1.65 V
VCC = 1.8 V
VCC = 1.95 V
AI14577
Figure 4.
Duty cycle vs. temperature (STCL132KRxxx)
53
52
Mean
duty
cycle (%)
51
50
49
48
47
–40
–20
0
20
40
60
80
100
120
140
Temperature (˚C)
VCC = 1.65 V
VCC = 1.8 V
VCC = 1.95 V
AI14578
11/20
Typical operating characteristics and scope plots
Figure 5.
STCL132K
Active supply current vs. temperature (STCL132KRxxx)
70
60
50
Mean
ICC (µA)
40
30
20
10
0
–40
–20
0
20
40
60
80
100
120
140
Temperature (˚C)
VCC = 1.65 V
Figure 6.
VCC = 1.8 V
VCC = 1.95 V
AI14579
Standby supply current vs. temperature (STCL132KRxxx)
100
90
80
70
60
Mean ICC
standby (nA)
50
40
30
20
10
0
–40
–20
0
20
40
60
80
100
120
140
Temperature (˚C)
VCC = 1.65 V
12/20
VCC = 1.8 V
VCC = 1.95 V
AI14580
STCL132K
Figure 7.
Typical operating characteristics and scope plots
Startup time vs. temperature (STCL132KRxxx)
70
60
50
Mean
startup
time (µs)
40
30
20
10
0
–40
–20
0
20
40
60
80
100
120
140
Temperature (˚C)
VCC = 1.65 V
Figure 8.
VCC = 1.8 V
VCC = 1.95 V
AI14581
Startup output waveform: already the first cycle is within specifications
(power-on, V CC = 1.8 V, STCL132KRxxx)
13/20
Package mechanical data
7
STCL132K
Package mechanical data
In order to meet environmental requirements, ST offers these devices in ECOPACK®
packages. These packages have a lead-free second level interconnect. The category of
second level interconnect is marked on the package and on the inner box label, in
compliance with JEDEC Standard JESD97. The maximum ratings related to soldering
conditions are also marked on the inner box label. ECOPACK is an ST trademark.
ECOPACK specifications are available at: www.st.com.
Figure 9.
SC70-5L – 5-lead small outline transistor package outline
SOT323-5L
1. Drawing is not to scale.
14/20
STCL132K
Package mechanical data
Table 5.
SC70-5L – 5-lead small outline transistor package mechanical data
mm
Inches
Symbol
Typ
Min
Max
Typ
Min
Max
A
—
0.80
1.10
—
0.031
0.043
A1
—
0
0.10
—
0
0.004
A2
0.90
—
—
0.035
—
—
b
—
0.15
0.30
—
0.006
0.012
C
—
0.10
0.20
—
0.004
0.008
D
2.00
1.80
2.20
0.079
0.071
0.087
E
2.10
1.80
2.40
0.083
0.071
0.094
E1
1.25
1.15
1.35
0.049
0.045
0.053
e
0.65
—
—
0.026
—
—
e1
1.30
—
—
0.051
—
—
L
0.36
0.26
0.46
0.014
0.010
0.018
s
—
0°
5°
—
0°
5°
15/20
Package details SC70-5L (RoHS compliant)
8
STCL132K
Package details SC70-5L (RoHS compliant)
Tape and reel specifications according to EIA-481B standard:
Figure 10. Parts orientation in reel
Sprocket hole
5
Cavity
4
5
4
Direction of feed
1
2
3
1
2
3
AI14588
Pin 1 located opposite to sprocket hole (lower left corner / quadrant 3 with reference to
EIA-481B standard).
Figure 11. Reel
Tapeslot
Trailer
Leader
Leader length = 500 mm minimum
Trailer length = 160 mm minimum
Peel strength: conforms to EIA 481 standard
Min: 10 gm
Max: 130 gm
16/20
AI14589
STCL132K
Part numbering
9
Part numbering
Table 6.
Ordering information scheme
STCL
1
32K
R
D
E
A
W8
9
Device type
STCL = Silicon oscillator
Product family
1 = Single frequency, fixed
Frequency
32K = 32.768 kHz
Operating voltage
R = 1.65 to 1.95 V
W = 2.7 to 3.6 V (1)
Accuracy
D = ±1.2%
Chip enable(2)
E = Single chip enable, active high, pull-down
Disable mode(2)
A = Immediate disable, output low during disable, output low during startup
Package(3)
W8 = SOT323-5 (SC70-5)
Temperature range
9 = –30 to +85 °C
1. Contact local ST sales office for availability of the 3 V VCC range ("W") version.
2. Contact local ST sales office for availability of other product options (chip enable active high or low, with or without internal
pull-up or pull-down, possibility of various disable modes, startup procedures, output low or in high-impedance when
disabled, etc.).
3. The shipping method is tape and reel only in ECOPACK® packages.
17/20
Package marking
10
STCL132K
Package marking
Table 7.
Package marking
Part number
VCC range
Topside marking(1)
STCL 1 32K R D E A W8 9
1.65 to 1.95 V
32Ax
STCL 1 32K W D E A W8 9
2.7 to 3.6 V
32Dx
1. x = letter assigned to indicate assembly work week (i.e., A = WW01 and WW02, B = WW03 and WW04,
C = WW05 and WW06..., Z = WW51, WW52, and WW53).
18/20
STCL132K
11
Revision history
Revision history
Table 8.
Document revision history
Date
Revision
Changes
23-May-2007
1
Initial release.
09-Aug-2007
2
Updated cover page; frequency accuracy in Table 4; Section 7:
Package mechanical data; and Section 9: Part numbering.
28-Feb-2008
3
Document reformatted, added STCL132KWxxx device and
commercial temperature range, Chapter 10, updated Chapter 6,
Chapter 8, Table 3 and 4, Figure 10 and 11, Chapter 9.
19-Mar-2008
4
Updated cover page, Table 2, 6, 7, and Figure 2, 8; minor text change.
24-Apr-2008
5
Changed status for STCL132K, added note below Table 6.
19/20
STCL132K
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20/20