DATASHEET ICS726A 12 TO 36 MHZ 6TSOT VCXO Description Features Used in conjunction with an external pullable quartz crystal, this monolithic integrated circuit replaces more costly hybrid (canned) VCXO devices. The ICS726A is designed primarily for data and clock recovery applications such as ADSL modems, set-top box receivers, and telecom systems. • Uses an inexpensive 12 to 36 MHz external crystal • Output frequency range of 12 to 36 MHz • On-chip VCXO with guaranteed pull range of ±115 ppm minimum • VCXO tuning voltage 0 to 3.3 V • Packaged in 6-pin TSOT • Available in Pb (lead) free package The frequency of the on-chip VCXO is adjusted by an external control voltage to the VIN pin. Since VIN is a high impedance input, it can be driven directly from an PWM RC integrator circuit. Frequency output increases with VIN voltage input. The usable range of VIN is 0 to 3.3 V. NOTE: EOL for non-green parts to occur on 5/13/10 per PDN U-09-01 Block Diagram VDD VIN X1 12-36MHz Pullable Crystal Voltage Controlled Crystal Oscillator 12-36MHz X2 GND IDT™ / ICS™ 12 TO 36 MHZ 6TSOT VCXO 1 ICS726A REV C 092409 ICS726A 12 TO 36 MHZ 6TSOT VCXO VCXO Pin Assignment X2 1 6 X1 GND 2 5 VI N CLK 3 4 VDD T S OT - 2 3 - 6 Pin Descriptions Pin Number Pin Name Pin Type 1 X2 Input Crystal connection. Connect to the external pullable crystal. 2 GND Power Connect to ground. 3 CLK Output VCXO CMOS level clock output at the frequency of the crystal. 4 VDD Power Connect to +3.3 V (0.01µf decoupling capacitor recommended). 5 VIN Input Voltage input to VCXO — 0 to 3.3 V analog input which controls the oscillation frequency of the VCXO. 6 XI Input Crystal connection. Connect to the external pullable crystal. IDT™ / ICS™ 12 TO 36 MHZ 6TSOT VCXO Pin Description 2 ICS726A REV C 092409 ICS726A 12 TO 36 MHZ 6TSOT VCXO VCXO External Component Selection Required Crystal Parameters: Nominal Frequency as required MHz Initial Accuracy at 25° C -20 min/+20 max ppm Temperature Stability -30 min/+30 max ppm Aging, 1st year -5 min/+5 max ppm Aging, 10 years -20 min/+20 max ppm Operating Temp. Range, °C 0 min/+25 typ/+70 max or Operating Temp. Range, °C -40 min/+25 typ/+85 max Load Capacitance 10 pf Shunt Capacitance, C0 7 pF Max C0/C1 Ratio 270 Max Equivalent Series Resistance 35 Ω Max The ICS726A requires a minimum number of external components for proper operation. Decoupling Capacitor A decoupling capacitor of 0.01µF must be connected between VDD (pin 4) and GND (pin 2), as close to these pins as possible. For optimum device performance, the decoupling capacitor should be mounted on the component side of the PCB. Avoid the use of vias in the decoupling circuit. Series Termination Resistor The third overtone mode of the crystal and all spurs must be >100 ppm distant from the 3x fundamental resonance measured with a physical load of 10 pF. When the PCB trace between the clock output (CLK, pin 3) and the load is over 1 inch, series termination should be used. To series terminate a 50Ω trace (a commonly used trace impedance) place a 33Ω resistor in series with the clock line, as close to the clock output pin as possible. The nominal impedance of the clock output is 20Ω. The external crystal must be connected as close to the chip as possible and should be on the same side of the PCB as the ICS726A. There should be no vias between the crystal pins and the X1 and X2 device pins. There should be no signal traces underneath or close to the crystal. See application note MAN05. Quartz Crystal The ICS726A VCXO function consists of the external crystal and the integrated VCXO oscillator circuit. To assure the best system performance (frequency pull range) and reliability, a crystal device with the recommended parameters (shown below) must be used, and the layout guidelines discussed in the following section shown must be followed. Crystal Tuning Load Capacitors The crystal traces should include pads for small fixed capacitors, one between X1 and ground, and another between X2 and ground. The need for these capacitors is determined at system prototype evaluation, and is influenced by the particular crystal used (manufacture and frequency) and by PCB layout. The typical required capacitor value is 1 to 4 pF. The frequency of oscillation of a quartz crystal is determined by its “cut” and by the load capacitors connected to it. The ICS726A incorporates on-chip variable load capacitors that “pull” (change) the frequency of the crystal. The crystal specified for use with the ICS726A is designed to have zero frequency error when the total of on-chip + stray capacitance is 14 pF. IDT™ / ICS™ 12 TO 36 MHZ 6TSOT VCXO The procedure for determining the value of these capacitors can be found in application note MAN05. 3 ICS726A REV C 092409 ICS726A 12 TO 36 MHZ 6TSOT VCXO VCXO Absolute Maximum Ratings Stresses above the ratings listed below can cause permanent damage to the ICS726A. These ratings, which are standard values for IDT commercially rated parts, are stress ratings only. Functional operation of the device at these or any other conditions above those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods can affect product reliability. Electrical parameters are guaranteed only over the recommended operating temperature range. Item Rating Supply Voltage, VDD 7V All Inputs and Outputs -0.5 V to VDD+0.5 V Ambient Operating Temperature 0 to +70° C Storage Temperature -65 to +150° C Soldering Temperature 260° C Recommended Operating Conditions Parameter Min. Max. Units 0 +70 °C +3.15 +3.45 V Ambient Operating Temperature Power Supply Voltage (measured in respect to GND) Typ. Reference crystal parameters Refer to page 3 DC Electrical Characteristics VDD = 3.3 V ±5% , Ambient temperature 0 to +70° C, unless stated otherwise Parameter Symbol Conditions Operating Voltage VDD Output High Voltage VOH IOH = -12 mA Output Low Voltage VOL IOL = 12 mA Output High Voltage (CMOS Level) VOH IOH = -4 mA Operating Supply Current IDD Output = 12 MHz, no load Short Circuit Current IOS VIN, VCXO Control Voltage VIA IDT™ / ICS™ 12 TO 36 MHZ 6TSOT VCXO Min. Typ. 3.15 Units 3.45 V 2.4 V 0.4 VDD-0.4 0 4 Max. V V 5 mA ±50 mA 3.3 ICS726A V REV C 092409 ICS726A 12 TO 36 MHZ 6TSOT VCXO VCXO AC Electrical Characteristics VDD = 3.3 V ±5%, Ambient Temperature 0 to +70° C, unless stated otherwise Parameter Symbol Output Frequency FO Crystal Pullability, Note 2 FP VCXO Gain Conditions Min. Typ. 12 0V< VIN < 3.3 V, Note 1 Max. Units 36 ±115 MHz ppm VIN = VDD/2 ± 1 V, Note 1 140 ppm/V Output Rise Time tOR 0.8 to 2.0 V, CL=15 pF 0.8 1.5 ns Output Fall Time tOF 2.0 to 0.8 V, CL=15 pF 0.8 1.5 ns Output Clock Duty Cycle tD Measured at 1.4 V, CL=15 pF 50 60 % Maximum Output Jitter, short term tJ CL=15 pF 40 100 ps Note 1: External crystal device must conform with Pullable Crystal Specifications listed on page 3. Marking Diagrams (726AT) (726ATLF) 26AL 26AT Notes: 1. ‘26AT’ or ‘26AL’ denotes part number. 2. “L” denotes Pb (lead) free package. 3. Bottom marking: ‘####’ denotes last 4 digits of lot number IDT™ / ICS™ 12 TO 36 MHZ 6TSOT VCXO 5 ICS726A REV C 092409 ICS726A 12 TO 36 MHZ 6TSOT VCXO VCXO Package Outline and Package Dimensions (6-pin TSOT) Package dimensions are kept current with JEDEC Publication No. 95 Millimeters Min Max Symbol A A1 A2 b c D E E1 e e1 L L1 L2 θ — 1.00 0.01 0.10 0.84 0.90 0.30 0.45 0.12 0.20 2.90 BASIC 2.80 BASIC 1.60 BASIC 0.95 BASIC 1.90 BASIC 0.30 0.50 0.60 REF. 0.25 BASIC 0° 8° aaa — 0.10 Ordering Information Part / Order Number Marking Shipping Packaging Package Temperature 726ATT* 726ATLFT 26AT 26AL Tape and Reel Tape and Reel 6-pin TSOT 6-pin TSOT 0 to +70° C 0 to +70° C *NOTE: EOL for non-green parts to occur on 5/13/10 per PDN U-09-01 “A” denotes revision designator (will not corrrelate with datasheet revision) Parts that are ordered with a "LF" suffix to the part number are the Pb-Free configuration and are RoHS compliant. While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any IDT product for use in life support devices or critical medical instruments. IDT™ / ICS™ 12 TO 36 MHZ 6TSOT VCXO 6 ICS726A REV C 092409 ICS726A 12 TO 36 MHZ 6TSOT VCXO VCXO Innovate with IDT and accelerate your future networks. Contact: www.IDT.com For Sales For Tech Support 800-345-7015 408-284-8200 Fax: 408-284-2775 www.idt.com/go/clockhelp Corporate Headquarters Integrated Device Technology, Inc. www.idt.com © 2006 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice. IDT and the IDT logo are trademarks of Integrated Device Technology, Inc. Accelerated Thinking is a service mark of Integrated Device Technology, Inc. All other brands, product names and marks are or may be trademarks or registered trademarks used to identify products or services of their respective owners. Printed in USA