10 ppm Ultra-Low Power 32.768 kHz XTAL Replacement
Features
Applications
Smallest footprint in chip-scale (CSP): 1.5 x 0.8 mm
Fixed 32.768 kHz
<10 ppm frequency tolerance
Ultra-low power: <1 µA
Directly interfaces to XTAL inputs
Supports coin-cell or super-cap battery backup voltages
Vdd supply range: 1.5V to 3.63V over -40°C to +85°C
Oscillator output eliminates external load caps
Internal filtering eliminates external Vdd bypass cap
NanoDrive™ programmable output swing for lowest power
Pb-free, RoHS and REACH compliant
Mobile Phones
Tablets
Health and Wellness Monitors
Fitness Watches
Sport Video Cams
Wireless Keypads
Ultra-Small Notebook PC
Pulse-per-Second (pps) Timekeeping
RTC Reference Clock
Battery Management Timekeeping
Electrical Specifications
Table 1. Electrical Characteristics
Parameter
Fixed Output Frequency
Symbol
Fout
Min.
Typ.
32.768
Frequency Stability
10
Frequency Tolerance
[1]
Max.
Unit
kHz
ppm
ppm
Condition
Frequency and Stability
T
A
= 25°C, post reflow, Vdd: 1.5V – 3.63V.
T
A
= 25°C, post reflow with board-level underfill,
Vdd: 1.5V – 3.63V.
T
A
= -10°C to +70°C, Vdd: 1.5V – 3.63V.
T
A
= -40°C to +85°C, Vdd: 1.5V – 3.63V.
T
A
= -10°C to +70°C, Vdd: 1.2V – 1.5V.
F_tol
20
75
Frequency Stability
[2]
F_stab
100
250
ppm
25°C Aging
-1
1
ppm
1st Year
Supply Voltage and Current Consumption
Operating Supply Voltage
Vdd
1.2
1.5
0.90
Core Operating Current
[3]
Output Stage Operating Current
[3]
Power-Supply Ramp
Start-up Time at Power-up
[4]
Idd
1.3
1.4
Idd_out
t_Vdd
Ramp
t_start
180
0.065
0.125
100
300
450
Operating Temperature Range
Commercial Temperature
Industrial Temperature
T_use
-10
-40
70
85
°C
°C
μA/Vpp
ms
ms
μA
3.63
3.63
V
V
T
A
= -10°C to +70°C
T
A
= -40°C to +85°C
T
A
= 25°C, Vdd: 1.8V. No load
T
A
= -10°C to +70°C, Vdd max: 3.63V. No load
T
A
= -40°C to +85°C, Vdd max: 3.63V. No load
T
A
= -40°C to +85°C, Vdd: 1.5V – 3.63V. No load
Vdd Ramp-up from 0 to 90%, T
A
= -40°C to +85°C
T
A
= -40°C ≤ T
A
≤ +50°C, valid output
T
A
= +50°C < T
A
≤ +85°C, valid output
Notes:
1. Measured peak-to-peak. Tested with Agilent 53132A frequency counter. Due to the low operating frequency, the gate time must be ≥100 ms to ensure an
accurate frequency measurement.
2. Measured peak-to-peak. Inclusive of Initial Tolerance at 25°C, and variations over operating temperature, rated power supply voltage and load. Stability is
specified for two operating voltage ranges. Stability progressively degrades with supply voltage below 1.5V.
3. Core operating current does not include output driver operating current or load current. To derive total operating current (no load), add core operating
current + (0.065 µA/V) * (output voltage swing).
4. Measured from the time Vdd reaches 1.5V.
Rev 1.26
January 16, 2018
www.sitime.com
SiT1532
Smallest Footprint (1.2mm
2
) CSP, 10 ppm Ultra-Low Power 32.768 kHz XTAL Replacement
Table 1. Electrical Characteristics (continued)
Parameter
Symbol
Min.
Typ.
Max.
Unit
Condition
LVCMOS Output Option, T
A
= -40°C to +85°C, typical values are at T
A
= 25°C
Output Rise/Fall Time
Output Clock Duty Cycle
Output Voltage High
Output Voltage Low
Output Rise/Fall Time
Output Clock Duty Cycle
AC-coupled Programmable
Output Swing
DC-Biased Programmable
Output Voltage High Range
DC-Biased Programmable
Output Voltage Low Range
Programmable Output Voltage
Swing Tolerance
100
tr, tf
DC
VOH
VOL
tf, tf
DC
48
0.20 to
0.80
0.60 to
1.225
0.35 to
0.80
-0.055
0.055
Jitter
Period Jitter
T_jitt
35
nsRMS
Cycles = 10,000, T
A
= 25°C, Vdd = 1.5V – 3.63V
48
90%
10%
200
52
200
50
52
ns
%
V
V
ns
%
SiT1532 does not internally AC-couple. This output description
is intended for a receiver that is AC-coupled. See
Table 5
for
acceptable NanoDrive swing options.
Vdd: 1.5V – 3.63V, 10 pF Load, I
OH
/ I
OL
= ±0.2 μA.
Vdd: 1.5V – 3.63V. IOH = -0.2 μA, 10 pF Load. See
Table 4
for
acceptable VOH/VOL setting levels.
Vdd: 1.5V – 3.63V. I
OL
= 0.2 μA, 10 pF Load. See
Table 4
for
acceptable V
OH
/V
OL
setting levels.
T
A
= -40°C to +85°C, Vdd = 1.5V to 3.63V.
Vdd: 1.5V – 3.63V. I
OH
= -10 μA, 15 pF
Vdd: 1.5V – 3.63V. I
OL
= 10 μA, 15 pF
30-70% (V
OL
/V
OH
), 10 pF Load
10-90% (Vdd), 15 pF load, Vdd = 1.5V to 3.63V
10-90% (Vdd), 5 pF load, Vdd ≥ 1.62V
NanoDrive™ Programmable, Reduced Swing Output
V_sw
V
VOH
VOL
V
V
V
Table 2. Pin Configuration
Pin
1, 4
Symbol
GND
I/O
Power Supply
Ground
Functionality
Connect to ground. Acceptable to connect pin 1 and 4 together. Both pins
must be connected to GND.
Oscillator clock output. The CLK can drive into a Ref CLK input or into an
ASIC or chip-set’s 32kHz XTAL input. When driving into an ASIC or
chip-set oscillator input (X IN and X Out), the CLK Out is typically
connected directly to the XTAL IN pin. No need for load capacitors. The
output driver is intended to be insensitive to capacitive loading.
Connect to power supply 1.2V ≤ Vdd ≤ 3.63V. Under normal operating
conditions, Vdd does not require external bypass/decoupling
capacitor(s).
3
Vdd
Power
Supply
For more information about the internal power-supply filtering, see the
Power Supply Noise Immunity
section in the detailed description.
Contact factory for applications that require a wider operating supply
voltage range.
CSP Package (Top View)
GND
4
1
GND
2
CLK Out
OUT
CLK Out
2
3
Vdd
Figure 1. Pin Assignments
Rev 1.26
Page 2 of 12
www.sitime.com
SiT1532
Smallest Footprint (1.2mm
2
) CSP, 10 ppm Ultra-Low Power 32.768 kHz XTAL Replacement
System Block Diagram
MEMS Resonator
GND
Control
Regulators
Vdd
Trim
Prog
Prog
GND
Sustaining
Amp
Ultra-low
Power
PLL
Divider
Ultra-low
Power
Driver
CLK Out
Figure 2. SiT1532 Block Diagram
Table 3. Absolute Maximum Limits
Attempted operation outside the absolute maximum ratings may cause permanent damage to the part.
Actual performance of the IC is only guaranteed within the operational specifications, not at absolute maximum ratings.
Parameter
Continuous Power Supply Voltage Range (Vdd)
Short Duration Maximum Power Supply Voltage (Vdd)
Continuous Maximum Operating Temperature Range
Short Duration Maximum Operating Temperature Range
Human Body Model ESD Protection
Charge-Device Model (CDM) ESD Protection
Machine Model (MM) ESD Protection
Latch-up Tolerance
Mechanical Shock Resistance
Mechanical Vibration Resistance
1508 CSP Junction Temperature
Mil 883, Method 2002
Mil 883, Method 2007
<30 minutes
Vdd = 1.5V - 3.63V
Vdd = 1.5V - 3.63V, ≤30 mins
JESD22-A114
JESD22-C101
JESD22-A115
Test Condition
Value
-0.5 to 3.63
4.0
105
125
3000
750
300
JESD78 Compliant
10,000
70
150
g
g
°C
Unit
V
V
°C
°C
V
V
V
Rev 1.26
Page 3 of 12
www.sitime.com
SiT1532
Smallest Footprint (1.2mm
2
) CSP, 10 ppm Ultra-Low Power 32.768 kHz XTAL Replacement
Description
The SiT1532 is the world’s smallest, lowest power 32 kHz
oscillator optimized for mobile and other battery-powered
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