ABV0235/-37/-38/-39

750kHz – 800MHz Low Phase Noise Multiplier VCXO

Universal Low Phase Noise IC’s

30332 Esperanza., Rancho Santa Margarita, Ca 92688 Ph: 949-546-8000 Fax: 949-546-8001 www.Abracon.com 03/21/05 Page 1

FEATURES

• Selectable 750kHz to 800MHz range.

• Low phase noise output (@ 10kHz frequency

offset, -142dBc/Hz for 19.44MHz, -125dBc/Hz for

155.52MHz, -115dBc/Hz for 622.08MHz).

• CMOS (ABV0237), PECL (ABV0235 and

ABV0238) or LVDS (ABV0239) output.

• 12 to 25MHz crystal input.

• No external load capacitor or varicap required.

• Output Enable selector.

• Wide pull range (+/-200 ppm)

• Selectable 1/16 to 32x frequency multiplier.

• 3.3V operation.

• Available in 16-Pin (TSSOP or 3x3mm QFN).

DESCRIPTION

The ABV0235 (PECL with inverted OE), ABV0237

(CMOS), ABV0238 (PECL), and ABV0239 (LVDS)

are high performance and low phase noise VCXO IC

chips. They provide phase noise performance as low

as –125dBc at 10kHz offset (at 155MHz), by multi-

plying the input crystal frequency up to 32x. The

wide pull range (+/- 200 ppm) and very low jitter

make them ideal for a wide range of applications,

including SONET/SDH and FEC. They accept fun-

damental parallel resonant mode crystals from 12 to

25MHz.

BLOCK DIAGRAM

PIN CONFIGURATION

(Top View)

^: Internal pull-up

*: On 3x3 package, ABV0235/-38 do not have SEL0 available: Pin

10 is VDD, pin 11 is GND. However, ABV0237/-39 have SEL0 (pin

10), and pin11 is VDD. See pin assignment table for details.

OUTPUT ENABLE LOGICAL LEVELS

Part #

OE

State

0 (Default)

Output enabled

ABV0238

1

Tri-state

0

Tri-state

ABV0235

ABV0237

ABV0239

1 (Default)

Output enabled

OE input: Logical states defined by PECL levels for ABV0238

Logical states defined by CMOS levels for ABV0237/-39

1

2

3

4

5

6

7

8

VDD

9

1

0

1

1

1

2

1

3

1

4

1

5

1

6

XIN

XOUT

SEL3^

SEL2^

OE

VCON

GND

SEL0^

SEL1^

GND

CLKC

VDD

CLKT

GND

GND

A023x

GND

VDD

CLKT

CLKC

12

3

4

12

11

10

9

13

14

15

16

8

7

6

5

SEL3^

XOUT

SEL2^

OE

X+

X-

OE

Q

ABV023x

Vi

n

Q

PLL by-pass

SEL

PLL

(Phase

Locked

Loop)

Oscillator

Amplifier

w/

integrated

varicaps