ICS650-40 E THERNET S WITCH C LOCK S OURCE

Description

The ICS650-40 is a clock chip designed for use in Ethernet Switch applications. Using ICS’ patented Phase-Locked Loop (PLL) techniques, the device takes a 25 MHz crystal input and produces various output clock frequencies as listed in Output Select Table.Features

?Packaged in 16-pin TSSOP ?Available in Pb (lead) free package ?Operating voltage of 3.3 V ?Low power consumption

?Input frequency of 25 MHz ?Low long-term jitter

? 2.5 V to 3.3 V clock outputs

Block Diagram

E THERNET S WITCH C LOCK S OURCE

Pin Assignment

Output Select Table (MHz)

Pin Descriptions

S1S0CLKA (MHz)CLKB (MHz)0012712701133133101571571

1

189

189

Pin Number

Pin Name

Pin Type

Pin Description

1X1/ICLK Input Crystal or clock input. Connect to a 25 MHz crystal or single ended clock.

2VDD Power Connect to +3.3 V.3GND Power Connect to ground.

4VDDOA Power

Connect to +2.5 V or +3.3 V. For clock output buffer A only.

5CLKA Output Clock A output with weak pull-down resistor.6CLKB Output Clock B output with weak pull-down resistor.7VDDOB Power Connect to +2.5 V or +3.3 V. For clock output buffer B only.8GND Power Connect to ground.9S0Input Select pin 0. 10S1Input Select pin 1. 11VDD Power Connect to +3.3 V.12VDD Power Connect to +3.3 V.13GND Power Connect to ground.

14OE Input Output enable tri-states outputs and device is not shut down. Internal pull-up resistor.15GND Power

Connect to ground.

16

X2

Output Crystal connection. Leave unconnected for clock input.

E THERNET S WITCH C LOCK S OURCE

External Components

A minimum number of external components are required for proper operation. Decoupling capacitors of 0.01 μF should be connected between VDD and GND pairs. The capacitors should be placed between pins VDD and GND, and VDDO and GND, as close to the device as possible. A 33? series terminating resistor should be used on each clock output if the trace is longer than 1 inch. A 25 MHz fundamental mode parallel resonant crystal should be used with C L =18 pF .

On chip capacitors. On Chip capacitors are used for a 18 pF load crystal. Small 2 to 3 pf trimming capacitors are used from pins X1 to ground and X2 to ground to optimize the initial accuracy.

Absolute Maximum Ratings

Stresses above the ratings listed below can cause permanent damage to the ICS650-40. These ratings, which are standard values for ICS 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.

Recommended Operation Conditions

Item

Rating

Supply Voltage, VDD 7 V

All Inputs and Outputs

-0.5 V to VDD+0.5 V Ambient Operating T emperature 0 to +70°C Storage Temperature -65 to +150°C Junction T emperature 125°C Soldering T emperature

260°C

Parameter

Min.

Typ.Max.

Units

Ambient Operating Temperature

0+70°C Power Supply Voltage (measured in respect to GND)

+3.15

+3.45

V

E THERNET S WITCH C LOCK S OURCE

DC Electrical Characteristics

Unless otherwise specified, VDD=3.3 V ±5%, Ambient Temperature 0 to +70°C

Note: 1. Nominal switching threshold is VDD/2.

AC Electrical Characteristics

, VDD = 3.3 V ±5%, VDDO = 2.5 - 3.3 V ±5%, C L =10 pF Ambient Temperature 0 to +70° C

Parameter

Symbol

Conditions Min.

Typ.Max.

Units

Operating Voltage VDD 3.15 3.45V Output Operating Voltage VDDOA,B

2.375

3.45V Input High Voltage, ICLK V IH Note 1VDD/2+0.5

V Input Low Voltage, ICLK V IL Note 1

VDD/2-0.5

V Input High Voltage, S1:S0:OE V IH 2

VDD V Input Low Voltage, S1:S0:OE V IL 0.4

V Output High Voltage V OH I OH = -12 mA 2

V Output Low Voltage V OL I OL = 12 mA 0.4

V Operating Supply Current IDD

No load 40mA IDD at Output Disable Condition(OE low)No load

16mA Short Circuit Current I OS Each output ±35mA Internal Pull-up Resistor R PUP OE pin 250k ?Internal Pull-down Resistor

R PD

CLK outputs

525

k ?

Parameter

Symbol

Conditions

Min.Typ.

Max.Units

Input Frequency 25MHz Output Rise Time t OR 20% to 80% of VDD 1.6ns Output Fall Time t OF

80% to 20% of VDD 1.6

ns

Output Clock Duty Cycle at VDD/24049-5160%Frequency Error

all clocks

ppm Output to Output Skew

between clocks of the same frequency

250

ps

Absolute Jitter, Short-term P-P variation from mean ±100±200ps Absolute Jitter, Short-term C-C 200400ps Long-term Jitter

1000 clock cycles

250

400

ps

E THERNET S WITCH C LOCK S OURCE

Thermal Characteristics (16-pin TSSOP)

Marking Diagram

Marking Diagram

Notes:

1. ###### is the lot code.

2. YYWW is the last two digits of the year, and the week number that the part was assembled.

3. “LF” designates Pb (lead ) free package.

4. Bottom marking: (origin). Origin = country of origin if not USA.

Parameter

Symbol

Conditions

Min.Typ.

Max.Units

Thermal Resistance Junction to Ambient

θJA Still air 78°C/W

θJA 1 m/s air flow 70°C/W θJA 3 m/s air flow

68°C/W Thermal Resistance Junction to Case

θJC

37

°

C/W

E THERNET S WITCH C LOCK S OURCE

Package Outline and Package Dimensions (16-pin TSSOP, 173 Mil. Narrow Body)

Package dimensions are kept current with JEDEC Publication No. 95

Ordering Information

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 Circuit Systems (ICS) 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 ICS. ICS reserves the right to change any circuitry or specifications without notice. ICS does not authorize or warrant any ICS product for use in life support devices or critical medical instruments.

Part / Order Number

Marking

Shipping Packaging

Package

Temperature

ICS650G-40See Page 6

Tubes 16-pin TSSOP 0 to +70° C ICS650G-40T Tape and Reel

16-pin TSSOP 0 to +70° C ICS650G-40LF See Page 6

Tubes 16-pin TSSOP 0 to +70° C ICS650G-40LFT

Tape and Reel

16-pin TSSOP

0 to +70° C