ON Semiconductor NB2305A User Manual

NB2305A

3.3 V Zero Delay
Clock Buffer

The NB2305A is a versatile, 3.3 V zero delay buffer designed to
distribute high−speed clocks. It accepts one reference input and drives
out five low−skew clocks. It is available in a 8 pin package.

The −1H version of the NB2305A operates at up to 133 MHz, and
has higher drive than the −1 devices. All parts have on−chip PLL’s that
lock to an input clock on the REF pin. The PLL feedback is on−chip
and is obtained from the CLKOUT pad.

Multiple NB2305A devices can accept the same input clock and
distribute it. In this case the skew between the outputs of the two
devices is guaranteed to be less than 700 ps.

All outputs have less than 200 ps of cycle−to−cycle jitter. The input
and output propagation delay is guaranteed to be less than 350 ps, and
the output to output skew is guaranteed to be less than 250 ps.

The NB2305A is available in two different configurations, as shown
in the ordering information table. The NB2305AI is the base part. The
NB2305AI1H is the high drive version of the −1 and its rise and fall
times are much faster than −1 part.

Features

• 15 MHz to 133 MHz Operating Range, Compatible with CPU and

PCI Bus Frequencies

• Zero Input − Output Propagation Delay

• Multiple Low−Skew Outputs

• Output−Output Skew Less than 250 ps

• Device−Device Skew Less than 700 ps

• One Input Drives 5 Outputs

• Less than 200 ps Cycle−to−Cycle Jitter is Compatible with PentiumR

Based Systems

• Accepts Spread Spectrum Clock at the Input

• Available in 8 Pin, 150 mil SOIC Package and 8 Pin TSSOP 4.4 mm

• 3.3 V Operation, Advanced 0.35  CMOS Technology

• Guaranteed Across Commercial and Industrial Temperature Ranges

• These are Pb−Free Devices

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MARKING

DIAGRAMS*

8

1

SOIC−8
D SUFFIX
CASE 751

8

1

TSSOP−8

DT SUFFIX

CASE 948S

XXXX = Device Code
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G = Pb−Free Package

*For additional marking information, refer to

Application Note AND8002/D.

ORDERING INFORMATION

See detailed ordering, marking and shipping information in the
package dimensions section on page 6 of this data sheet.

8

XXXX
ALYW

G

1

8

XXX

YWW

A G

1

© Semiconductor Components Industries, LLC, 2015

May, 2015 − Rev. 11

1 Publication Order Number:

NB2305A/D

NB2305A

REF

PLL

CLKOUT

CLK1

CLK2

CLK3

CLK4

REF

CLK2

CLK1

GND

Figure 1. Block Diagram

Table 1. PIN DESCRIPTION

Pin # Pin Name Description

1 REF (Note1) Input reference frequency, 5 V tolerant input.
2 CLK2 (Note 2) Buffered clock output.
3 CLK1 (Note 2) Buffered clock output.
4 GND Ground.
5 CLK3 (Note 2) Buffered clock output.
6 V

DD

3.3 V supply.
7 CLK4 (Note 2) Buffered clock output.
8 CLKOUT (Note 2) Buffered clock output, internal feedback on this pin.

1. Weak pulldown.

2. Weak pulldown on all outputs.

1

2

NB2305A

3

4

Figure 2. Pin Configuration

8

7

6

5

CLKOUT

CLK4

V

DD

CLK3

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2

NB2305A

Table 2. MAXIMUM RATINGS

Parameter Min Max Unit

Supply Voltage to Ground Potential −0.5 +7.0 V
DC Input Voltage (Except REF) −0.5 VDD + 0.5 V
DC Input Voltage (REF) −0.5 7.0 V
Storage Temperature −65 +150 °C
Maximum Soldering Temperature (10 sec) 260 °C
Junction Temperature 150 °C
Static Discharge Voltage (per MIL−STD−883, Method 3015) >2000 V

Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.

Table 3. RECOMMENDED OPERATING CONDITIONS FOR INDUSTRIAL TEMPERATURE DEVICES

Parameter Description Min Max Unit

V

DD

T

A

C

L

C

L

C

IN

Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond
the Recommended Operating Ranges limits may affect device reliability.

Supply Voltage 3.0 3.6 V
Operating Temperature (Ambient Temperature) Industrial

Commercial

−40
0

85
70

°C

Load Capacitance, below 100 MHz 30 pF
Load Capacitance, from 100 MHz to 133 MHz 10 pF
Input Capacitance 7 pF

Table 4. ELECTRICAL CHARACTERISTICS V

Parameter

V

IL

V

IH

I

IL

I

IH

V

OL

V

OH

I

DD

I

DD

Input LOW Voltage (Note 3) 0.8 V
Input HIGH Voltage (Note 3) 2.0 V
Input LOW Current VIN = 0 V 50
Input HIGH Current VIN = V
Output LOW Voltage IOL = 8 mA (−1)

Output HIGH Voltage IOH = −8 mA (−1)

Supply Current (Commercial Temp) Unloaded outputs at 66.67 MHz,

Supply Current (Industrial Temp) Unloaded outputs at 100 MHz

Description Test Conditions Min Max Unit

= 3.0 V to 3.6 V, GND = 0 V, TA = −40°C to +85°C

CC

DD

I

= 12 mA (−1H)

OL

I

= −12 mA (−1H)

OH

Select inputs at V

DD

66.67 MHz
33 MHz

Select inputs at V
Temp

or GND, at Room

DD

A

100

A

0.4 V

2.4 V

34 mA

50

mA
34
19

Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product
performance may not be indicated by the Electrical Characteristics if operated under different conditions.

3. REF input has a threshold voltage of V

DD

/2.

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NB2305A

Table 5. SWITCHING CHARACTERISTICS V

Parameter

1/t

1/t

t

3

t

4

t

5

t

6

t

7

t

J

t

LOCK

1

1

Output Frequency 30 pF load

Duty Cycle = (t

Output Rise Time (−1)

Output Fall Time (−1)

Output−to−Output Skew All outputs equally loaded 250 ps
Delay, REF Rising Edge to CLKOUT

Rising Edge
Device−to−Device Skew Measured at VDD/2 on the CLKOUT pins of

Cycle−to−Cycle Jitter Measured at 66.67 MHz, loaded outputs 200 ps
PLL Lock Time Stable power supply, valid clock presented

4. All parameters specified with loaded outputs.

Description Test Conditions Min Typ Max Unit

/ t1) * 100 (−1, −1H)

2

(−1H)

(−1H)

(−1H)

= 3.0 V to 3.6 V, GND = 0 V, TA = −40°C to +85°C (Note 4)

CC

15

10 pF load
Measured at 1.4 V, F

= 66.67 MHz

OUT

< 50 MHz

15
40

45

50
50

Measured between 0.8 V and 2.0 V 2.5

Measured between 2.0 V and 0.8 V 2.5

Measured at VDD/2 0 ±350 ps

0 700 ps

the device

on REF pin

100

MHz

133

60
55

1.5

1.5

1.0 ms

%

ns

ns

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