EURO
QUARTZ
Miniature SMD package 7 x 5 x 2.5mm
Real-time clock frequency: 32.768kHz
Stability from ±1.0ppm over -30° to +75°C
±1.5ppm over -40 to +85°C available
Supply voltage 2.8 Volts to 5.0 Volts
0.01uF decoupling capacitor built-in
DESCRIPTION
VEM57T 32.768kHz TCXOs provide tight control of the 32.768kHz
real time clock frequency in a small, industry-standard package. The
TCXOs are packaged in 7x5mm SMD format. With HCMOS output,
close tolerances are available from ±1.0ppm over -10° to +60°C.
SPECIFICATION
Product:
Frequency:
Output Waveform:
Initial Calibration Tolerance*:
Operating Temperature Range:
Frequency Stability
vs. Ageing:
vs. Voltage Change:
vs. Load Change:
vs. Reflow:
Supply Voltage:
VEM57T-32.768
32.768kHz
Square wave HCMOS
±3ppm at 25°C
VCON = +1.5VDC
See table
±1.0 ppm max. first year
±0.3 ppm max. ±5% change
±0.3 ppm max. ±10% change
±1ppm max. for one reflow
(Measured after 24 hours)
+2.8 VDC (Code ‘28’)
+3.0 VDC (Code ‘3’)
+3.3 VDC (Code ‘33’)
+5.0 VDC (Code ‘5’)
2.7V minimum
10% Vdd maximum
3ns typical (20~80% Vdd)
50%±10% (at 50%Vdd)
2ms typical
3.5mA typical at Vdd = 3.3V
7.0mA typical at Vdd = 5.0V
±5 to ±12ppm, Vcon = 1.5V
All supply voltage variants
have Vcon = 1.5 ±1VDC
Positive (increase
of Vcon
increases output frequency)
15pF
See table
AC block, DC coupled
-50° to +100°C
VEM57T 32.768kHz TCXO
Voltage-controlled HCMOS 7 x 5 x 2.5mm SMD
VEM57T-32.768 - OUTLINES AND DIMENSIONS
Output Voltage Level (Vdd = 3.0V)
Logic ‘1’ HIGH:
Logic ‘0’ LOW:
Rise & Fall Times:
Duty Cycle (Symmetry):
Start-up Time:
Current Consumption:
Electronic Frequency Tuning (EFC)
VEM57T-32.768 - TEST CIRCUIT
Slope Polarity:
Output Load:
SSB Phase Noise:
Output Format:
Storage Temperature:
* Stability over temperature will be from this measured initial frequency
FREQUENCY STABILITY
Frequency Stability (ppm)
0 ~ +50
-10 ~ +60
Temperature
Range (°C)
-20 ~ +70
-30 ~ +75
-40 ~ +85
x
±1.0
±1.5
±2.0
±2.5
VEM57T-32.768 - PART NUMBERING PROCEDURE
Example:
VEM57T3-32.768k-2.5/-30+75
= available
x = not available
PHASE NOISE
Offset
(Hz)
SSB Phase
Noise
at 25°C
EM57T
32.768kHz
(dBc/Hz)
10
100
1k
10k
100k
Series Description
Supply Voltage
28 = 2.8 VDC
3 = 3.0 VDC
33 = 3.3 VDC
5 = 5.0 VDC
Frequency
Stability over OTR (±ppm)
Operating Temperature Range (OTR) (°C)
-65
-100
-130
-150
-150
EUROQUARTZ LIMITED Blacknell Lane CREWKERNE Somerset UK TA18 7HE
Tel: +44 (0)1460 230000 Fax: +44 (0)1460 230001 info@euroquartz.co.uk
www.euroquartz.co.uk
Embedded System
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