11640-223 - ON Semiconductor L.L.C.

This document contains information on a preproduction product. Specifications and information herein are subject to change without notice. 2.28.02

FS6245

FS6245FS6245

FS6245

Dual PLL VCXO Clock Generator IC

Dual PLL VCXO Clock Generator ICDual PLL VCXO Clock Generator IC

Dual PLL VCXO Clock Generator IC

ISO9001

ISO9001ISO9001

ISO9001

1.0 Features

• On-chip tunable voltage-controlled crystal oscillator

circuitry (VCXO) allows precise system frequency

tuning (pull range typically 300ppm)

• VCXO tuning range: 0-3V

• Uses inexpensive fundamental-mode crystals

• Two integrated phase-locked loops (PLL) multiply

VCXO frequency to the higher system frequencies

needed

• 5V core supply voltage (contact factory for 3.3V)

• 3.3V / 5V output supply voltage

• Small circuit board footprint (20-pin SOIC)

• Custom frequency selections available - contact your

local AMI Sales Representative for more information

Figure 1: Pin Configuration

n/c

XOUT

XIN

VDD

XTUNE

VSS

n/c

CLKB

VSS

VDDO

n/c

FS6245

CLKA

n/c

CLKC

n/c

2.0 Description

The FS6245 is a monolithic CMOS clock generator IC

designed to m inim ize cost a nd com ponen t count in digi tal

video/audio systems.

At the core of the FS6245 is circuitry that implements a

voltage-controlled crystal oscillator when an external

resonator is attached. The VCXO allows device frequen-

cies to b e prec isel y adjust ed for us e in s ystem s that hav e

frequenc y m atching r equir em ents, s uch as digit al s atel lite

receivers.

Two high-resolution phase-locked loops generate the

output clock frequencies (CLKA, CLKB, and CLKC).

These frequencies are phase-locked and frequency-

locked to the VCXO frequency. Synthesis error of the

PLLs is +/-0 ppm unless otherwise noted.

Table 1: Crystal / Output Frequencies

DEVICE fXIN (MHz) CLKA (MHz) CLKB (MHz) CLKC (MHz)

FS6245-01 13.500 11.0592 18.432 27.000

NOTE: Contact AMI for custom PLL frequencies

Figure 2: Block Diagram

VCXO

FS6245

PLL

XOUT

XIN CLKA

XTUNE

Divider

Array

CLKB

PLL

CLKC

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FS6245FS6245

FS6245

Dual PLL

Dual PLLDual PLL

Dual PLL VCXO Clock Generator IC

VCXO Clock Genera tor ICVCXO Clock Genera tor IC

VCXO Clock Genera tor IC

ISO9001

ISO9001ISO9001

ISO9001

Table 2: Pin Descriptions

Key: AI = Analog Input; AO = Analog Output; DI = Digital Input; DIU = Input with Internal Pull-Up; DID = Input with Internal Pull-Down; DIO = Digital Input/Output; DI-3 = Three-Level Digital Input,

DO = Digital Output; P = Power/Ground; # = Active Low pin

PIN TYPE NAME DESCRIPTION

1 - N/C No Connection

2 AI XIN VCXO Crystal Feedback

3 AO XOUT / FREF VCXO Crystal Drive / External Ref erence Clock Input

4 P VDD Core Power Supply

5 AI XTUNE VCXO Tune Input

6 - N/C No Connection

7 P VSS Ground

8DI

UOE Output Enable

9DOCLKAClock Output “A”

10 - N/C No Connection

11 - N/C No Connection

12 - N/C No Connection

13 DO CLKB Clock Output “B”

14 P VSS Ground

15 P VDDO Output Power Supply (must be les s than or equal to VDD)

16 - N/C No Connection

17 - N/C No Connection

18 DO CLKC Clock Outp ut “C”

19 - N/C No Connection

20 - N/C No Connection

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FS6245

FS6245FS6245

FS6245

Dual PLL VCXO Clock Generator IC

Dual PLL VCXO Clock Generator ICDual PLL VCXO Clock Generator IC

Dual PLL VCXO Clock Generator IC

ISO9001

ISO9001ISO9001

ISO9001

3.0 Functional Bl ock Descripti on

3.1 Phase-Locked Loop (PLL)

The on-chip PLL is a standard frequency- and phase-

lock ed loop archi tec tur e. The PLL multip lies t he r ef er enc e

oscillator to the desired frequency by a ratio of integers.

The frequency multiplication is exact with a zero synthe-

sis error (unless otherwise noted).

3.2 Voltage-Controlled Crystal

Oscillator (VCXO)

The VCXO provides a tunable, low-jitter frequency refer-

ence for the rest of the FS6245 system components.

Loading capacitance for the crystal is internal to the

FS6245. No external components (other than the crystal

resonator itself) are required for operation of the VCXO.

Continuous fine-tuning of the VCXO frequency is accom -

plished by varying the voltage on the XTUNE pin.

The oscillator operates the crystal resonator in the paral-

lel-reso nant mode. Cr ystal warpin g, or the “pul ling” of the

crystal oscillation frequency, is accomplished by altering

the eff ective load ca pacitance presented to the crystal b y

the oscillator circuit. T he actual amount that changin g the

load capacitance alters the oscillator frequency will be

dependent o n the charac teristics of the cr ystal as well as

the oscillator circuit itself.

Specificall y, the m otional capacitance of the cr ystal (usu-

ally referr ed to by cr ystal m anufactur ers as C1), the st atic

capacitance of the crystal (C0), and the load capacitance

(CL) of the oscillator determine the “warping” or “pulling”

capability of the crystal in the oscillator circuit.

A simple formula to obtain the warping capability of a

cry stal oscillator is:

()

()()

CCCC CCC

ppmf LL

1020

121

210

)( +×+× ×−×

=∆

where CL1 and CL2 are the two extremes of the applied

load capacitance.

EXAMPLE: A crystal with the following parameters is

used. W ith C1 = 0.025pF, C0 = 6pF, CL1 = 10pF, and CL2

= 20pF, the tuning range is

()

()()

ppm

f300

1062062 106

10200250 =

+×+× ×−×

=∆ .

FS6245 Typical VCXO Deviation vs. XTUNE Input

-200

-150

-100

-50

100

150

200

250

00.511.522.53

V(XTUN E) - volts

Deviation from 13.500MHz - ppm

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FS6245

FS6245FS6245

FS6245

Dual PLL

Dual PLLDual PLL

Dual PLL VCXO Clock Generator IC

VCXO Clock Genera tor ICVCXO Clock Genera tor IC

VCXO Clock Genera tor IC

ISO9001

ISO9001ISO9001

ISO9001

4.0 Electrical Specifications

Table 3: Absolute Maximum Ratings

Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These conditions represent a stress rating only, and functional operation of the device at

these or any other conditions above the operational limits noted in this specification is not implied. Exposure to maximum rating conditions for extended conditions may affect device performance,

functionality, and reliability.

PARAMETER SYMBOL MIN. MAX. UNITS

Supply Voltage (VSS = ground) VDD VSS-0.5 7 V

Input Voltage, dc VIVSS-0.5 VDD+0.5 V

Output Voltage, dc VOVSS-0.5 VDD+0.5 V

Input Clamp Current, dc (V I < 0 or VI > V DD)I

IK -50 50 mA

Output Clamp Current, dc (VI < 0 or VI > VDD)I

OK -50 50 mA

Storage Temperature Range (non-condensing) TS-65 150 °C

Ambient Temperature Range, Under Bias TA-55 125 °C

Junction Temperature TJ125 °C

Lead Temperature (soldering, 10s) 260 °C

Input Static Disc harge Voltage Protection (MIL-STD 883E, Method 3015.7) 2 kV

CAUTION: ELECTROSTATIC SENSITIVE DEVICE

Permanent damage res ulting in a loss of functi onality or performance may occur if this devi ce is subjected to a high-energy elec-

trostatic discharge.

Table 4: Operating Conditions

PARAMETER SYMBOL CONDITIONS/DESCRIPTION MIN. TYP. MAX. UNITS

Core Supply Voltage (VDD) VDD 5V ± 10% 4.75 5 5.25 V

CLK Pin Supply Voltage (VDDO) VDDO 3.0 - VDD+0.3 V

Ambient Operating Temperature Range TA070°C

Crystal Resonator Frequency fXTAL Fundamental Mode 5 13.5 18 MHz

Crystal Resonator Motional Capacitance C1(xtal) AT cut 25 fF

Crystal Load Capacitance CL(xtal) AT cut 14 pF

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FS6245

FS6245FS6245

FS6245

Dual PLL VCXO Clock Generator IC

Dual PLL VCXO Clock Generator ICDual PLL VCXO Clock Generator IC

Dual PLL VCXO Clock Generator IC

ISO9001

ISO9001ISO9001

ISO9001

Table 5: DC Electrical Specifications

Unless otherwise stated, VDD = 5V ± 10%, no load on any output, and ambient temperature range TA = 0°C to 70°C. Parameters denoted with an asterisk ( * ) represent nominal characterization data

and are not production tested to any specific limits. Where given, MIN and MAX characterization data are ± 3σ from typical. Negative currents indicate current flows out of the device.

PARAMETER SYMBOL CONDITIONS/DESCRIPTION MIN. TYP. MAX. UNITS

Overall

Supply Current, Dynamic, with Loaded

Outputs IDD fXTAL = 13.5MHz; CL = 10pF 20 mA

Voltage Controlled Crystal Oscillator - VDD=5.0V

Crystal Loadi ng Capaci tance CL(xtal) As seen by a crystal connec t ed to XIN and

XOUT (@ VXTUNE = 1.65V) 14 pF

Crystal Resonator Motional Capacitance C1(xtal) AT cut 25 fF

VCXO Tuning Range fXTAL = 13.5MHz; CL(xtal) = 14pF; C1(xtal) = 25fF 300 ppm

VCXO Tuning Characterist ic Note: positive ∆F for positive ∆V100 ppm/V

Crystal Dri ve Level RXTAL=20Ω; CL(xtal) = 14pF 200 uW

Clock Outputs (CLKx) - VDDO=3.3V

High-Level Output Source Current * IOH VO = 2.0V -40 mA

Low-Level Output Sink Current * IOL VO = 0.4V 17 mA

zOH VO = 0.5VDD; output drivi ng hi gh 30

Output Impedance * zOL VO = 0.5VDD; output dri ving l ow 30 Ω

Short Circuit S ource Current * IOSH VO = 0V; shorted for 30s, max. -55 mA

Short Circuit S i nk Current * IOSL VO = 3.3V; shorted for 30s, max. 55 mA

Clock Outputs (CLKx) - VDDO=5.0V

High-Level Output Source Current * IOH VO = 4.5V -30 mA

Low-Level Output Sink Current * IOL VO = 0.4V 26 mA

zOH VO = 0.5VDD; output drivi ng hi gh 25

Output Impedance * zOL VO = 0.5VDD; output dri ving l ow 25 Ω

Short Circuit S ource Current * IOSH VO = 0V; shorted for 30s, max. -100 mA

Short Circuit S i nk Current * IOSL VO = 5V; shorted for 30s, max. 100 mA

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FS6245

FS6245FS6245

FS6245

Dual PLL

Dual PLLDual PLL

Dual PLL VCXO Clock Generator IC

VCXO Clock Genera tor ICVCXO Clock Genera tor IC

VCXO Clock Genera tor IC

ISO9001

ISO9001ISO9001

ISO9001

Table 6: AC Timing Specifications

Unless otherwise stated, VDD = 5V ± 10%, no load on any output, and ambient temperature range TA = 0°C to 70°C. Parameters denoted with an asterisk ( * ) represent nominal characterization data

and are not production tested to any specific limits. Where given, MIN and MAX characterization data are ± 3σ from typical.

PARAMETER SYMBOL CONDITIONS/DESCRIPTION MIN. TYP. MAX. UNITS

Overall

VCXO Stabilization Time * tVCXOSTB From power valid 10 ms

PLL Stabilization Time * tPLLSTB From V CXO stable 500 us

Output Frequency Synthesis Error (unless otherwise noted in Frequency Table) 0 ppm

Clock Output (CLK)

Duty Cycle * Ratio of high pulse width (as measured f rom rising

edge to next falling edge at VDD/2) to one clock period 45 55 %

Jitter, Period (peak-peak) * tj(∆P) From rising edge to next ris i ng edge at VDD/2, CL =

10pF 300 ps

Jitter, Long Term (σy(τ)) * tj(LT) From 0-500µs at VDD/2, CL = 10pF

compared to ideal clock source 150 ps

Rise Time * trVDD = 5V; VDDO = 3. 3V; V O = 0.3V to 3.0V; CL = 10pF 1.8 ns

Fall Time * tfVDD = 5V; VDDO = 3.3V; VO = 0.3V to 3.0V; CL = 10pF 1.4 ns

Rise Time * trVDD = 5V; VDDO = 5. 0V; V O = 0.5V to 4.5V; CL = 10pF 1.4 ns

Fall Time * tfVDD = 5V; VDDO = 5.0V; VO = 4.5V to 0.5V; CL = 10pF 1.25 ns

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FS6245

FS6245FS6245

FS6245

Dual PLL VCXO Clock Generator IC

Dual PLL VCXO Clock Generator ICDual PLL VCXO Clock Generator IC

Dual PLL VCXO Clock Generator IC

ISO9001

ISO9001ISO9001

ISO9001

5.0 Package Information

Table 7: 20-pin SOIC (0.300") Package Dimensions

DIMENSIONS

INCHES MILLIMETERS

MIN. MAX. MIN. MAX.

A 0.0926 0.1043 2.35 2.65

A10.004 0.0118 0.10 0.30

B 0.013 0.020 0.33 0.51

C 0.0091 0.0125 0.23 0.32

D 0.4961 0.5118 12.60 13.00

E 0.2914 0.2992 7.40 7.60

e 0.05 BSC 1.27 BSC

H 0.394 0.419 10.00 10.65

h 0.010 0.029 0.25 0.75

L 0.016 0.050 0.40 1.27

Θ0°8°0°8°

SEATING PL ANE

BASE PLANE

AMERICAN MICROSYSTEMS, INC .

h x 45°

Table 8: 20-pin SOIC (0.300") Package Characteristics

PARAMETER SYMBOL CONDITIONS/DESCRIPTION TYP. UNITS

Thermal Impedance, Junction to Free-Air ΘJA Air flow = 0 m/s 80 °C/W

Lead Inductanc e, Self L11 Center lead 2.5 nH

Lead Inductanc e, Mutual L12 Center lead to any adjacent lead 0.85 nH

Lead Capacitance, Bulk C11 Center lead to VSS 0.42 pF

Lead Capacitance, Mutual C12 Cent er l ead t o any adjac ent lead 0.08 pF

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FS6245

FS6245FS6245

FS6245

Dual PLL

Dual PLLDual PLL

Dual PLL VCXO Clock Generator IC

VCXO Clock Genera tor ICVCXO Clock Genera tor IC

VCXO Clock Genera tor IC

ISO9001

ISO9001ISO9001

ISO9001

6.0 Ordering Information

ORDERING CODE DEVICE NUMBER P ACKAGE TYPE OPERATING

TEM PE RATURE RANGE SHIPPING

CONFIGURATION

11640-223 FS6245-01 20-pin (0.300”) S OIC

(Small Outl i ne Package) 0°C to 70°C (Commercial) Tape and Reel

Devices sold by AMI are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. AMI

makes no warranty, express, statutory implied or by description, regarding the information set forth herein or regarding the freedom

of the described devices from patent infringement. AMI makes no warranty of merchantability or fitness for any purposes. AMI re-

serves the right to discontinue production and change specifications and prices at any time and without notice. AMI’s products are

intended for use in commercial applications. Applications requiring extended temperature range, unusual environmental require-

ments, or high reliability applications, such as military, medical life-support or life-sustaining equipment, are specifically not recom-

mended without additional processing by AMI for such applications.

American Microsystems, Inc., 2300 Buckskin Rd., Pocatello, ID 83201, (208) 233-4690, FAX (208) 234-6796,

WWW Address: http://www.amis.com E-mail: tgp@amis.com