MERCURY+ ™ IC OCXO | NETWORKING & STRATUM 3E

ROM1490E
The ROM1490E uses Rakon’s market-leading proprietary Mercury+™ technology, delivering the world’s smallest footprint Stratum 3E OCXO
in a hermetic package. This product family delivers ±5 ppb frequency stability over -40 to 85°C and ageing of less than 1 ppb/day; fullycompliant with Stratum 3E specifications. The ROM1490E is an ideal solution for Telecom Boundary Clocks (T-BC) Class C and Class D, which
require low dynamic noise contribution from oscillators over the operating temperature range. Holdover of a few hours is available for selecttemperature profiles.
Mercury+™ ASIC-OCXOs enable lower Total Cost of Ownership of customer equipment through significantly enhanced reliability. With a smallform factor and few discrete components, the ROM1490E consumes only 0.4W at room temperature and has faster warm up times than
traditional OCXOs.

Features

Applications







 Stratum 3E
 PTP Enabled Ethernet Switches andStratum 3E grade stability and ageing
Miniature SC-cut crystalLow ADEV and RMS phase jitter
Fast warm up time
Ultra-reliable OTP memory programming
Lower customer Total Cost of Ownership
through VLSI ASIC-integration

14.2 x 9.2 x 6.5 mmRouters Cable Modem CMTS and Remote PHYs
 G.8262, G.8262.1, G.8263, G.8273.2,G.8273.3, G.8273.4

Standard Specifications
Parameter

Min.

Nominal frequency

Typ.

Max.

10 – 50

Unit

Test Condition / Description

MHz

Standard frequencies: 10, 12.8, 19.2, 20, 24.576,
25, 30.72, 38.4, 38.88, 49.152, 50 MHz

Frequency calibration±0.2ppm

Initial accuracy at 25°C ±2°C

Reflow shift±0.2ppm

Pre to post reflow ∆F (measured ≥ 60 minutes
after reflow)+85°C±5ppb

In still air. Reference to (FMAX + FMIN)/2±0.5ppb/°C

Temperature ramp ≤ 1°C/minute±4.6ppm

Including calibration, temperature, supply voltage& load changes and 20 years life, reference to Fn±2% variation, frequency ≤ 26 MHz±10% variation, reference to frequency ≤ 26 MHz
at 15 pF
Time needed for frequency to be within ±20 ppb
reference to frequency after 1 hour, at 25°C.
Parameter is frequency, assembly and operating
history dependent

Operating temperature range-40

Frequency stability temperature
Frequency slope ΔF/ΔT in still air±0.1

All causes stability
Supply voltage stability
Load sensitivity±5±5Warm-up time

15Long term stability (Ageing)

Root Allan Variance (ADEV)

30*10 -12
20*10 -12
15*10 -12
15*10 -12
70*10 -12

Supply voltage (Vcc)

2.7 – 5

Input power

1200
400

Wander generation

ppb
ppb
60

sec

10.3
2.5ppbppm

Per day, after 60 days of continuous operation
First year
20 yearstau = 0.1s
tau = 1.0s
tau = 10s
tau = 100s
tau = 1000sV±5%mW

Warm up
Steady state in still air at 25°C

1500440› TDEV compliant with GR-1244 fig 5-4 & G.812
types II & III fig 2› MTIE compliant with GR-1244 fig 5-5 & G.812
types II & III fig 1

Issue: B, 10 June 2021
Specifications are subject to change without notice
Copyright © 2019 Rakon Limited. All rights reserved

Oscillator stabilised 24 hours at constanttemperature (±1°C, still air). Data subjected torelevant loop filter values (-3dB cut-off, 2nd orderhigh pass)

Page 1 of 2sales@rakon.com

MERCURY+ ™ IC OCXO | NETWORKING & STRATUM 3E› TDEV & MTIE compliant with G.8262, G.8262.1,G.8263, G.8273.2, G.8273.3, G.8273.4
Regulated CMOS output (1.0, 1.8, 2.5V) or standard CMOS (options)

Oscillator output

Frequency Stability over Temperature @ 19.2 MHz

Fractional frequency(ppb)

Frequency Stability vs Temperature (5 units)-50-40-30-20

6Frequency Stability (ppb)5432
10-1 01020-2-3-4-5-6-1030

405060708090

Temperature (°C)

Warm-up Time @ 19.2 MHz40

Frequency Stability (ppb)20Time after power on (sec)0-200102030405060708090 100 110 120-40

Warm-up – The First Hour
Frequency Stability (ppb)

Frequency Stability (ppb)

Warm-up – The First 2 Minutes

40

Frequency Stability (ppb)20Time after power on (min)0-200102030405060-40

Model Outline and Recommended Pad Layout

PinConnections

1Do not connect (GND optional)

2

Do not connect (GND optional)

3GND

4

Output5NC

6Supply Voltage (Vcc)

NOTE
 Unit: mm
 Base: FR4
 Finish: 0.05 ~ 0.13 µm Goldover 3 ~ 6 µm Nickel

for correct operation decouple the supply voltage
with a 10 μF capacitor close to the oscillator

Issue: B, 10 June 2021
Specifications are subject to change without notice
Copyright © 2019 Rakon Limited. All rights reserved

Page 2 of 2sales@rakon.com