32 Clock Generators 527

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Part RoHS Manufacturer Peripheral IC Type Temperature Grade Terminal Form No. of Terminals Package Code Package Shape Package Body Material Surface Mount Maximum Supply Voltage Screening Level Address Bus Width Maximum Output Clock Frequency DAC Channels Power Supplies (V) Package Style (Meter) Package Equivalence Code Minimum Supply Voltage Maximum Operating Temperature Minimum Operating Temperature Terminal Finish ADC Channels Terminal Position DMA Channels Maximum Seated Height Width Additional Features External Data Bus Width Maximum Time At Peak Reflow Temperature (s) Peak Reflow Temperature (C) Length Total Dose (V) Technology Maximum Supply Current Nominal Supply Voltage PWM Channels Sub-Category ROM Programmability Terminal Pitch JESD-30 Code Moisture Sensitivity Level (MSL) Qualification Speed Nominal Primary Clock/Crystal Frequency JESD-609 Code No. of I/O Lines

ICS8430DYI-11T

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

700 MHz

FLATPACK, LOW PROFILE

3.135 V

85 Cel

-40 Cel

TIN LEAD

QUAD

1.6 mm

7 mm

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

3

Not Qualified

27 MHz

e0

ICS8430S07AKILFT

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

133.333 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

3.135 V

85 Cel

-40 Cel

MATTE TIN

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

25 MHz

e3

8V97051LNLGI

Renesas Electronics

CLOCK GENERATOR, OTHER

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

4400 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

3.135 V

85 Cel

-40 Cel

TIN

QUAD

1 mm

5 mm

260

5 mm

CMOS

97 mA

3.3 V

.5 mm

S-XQCC-N32

3

310 MHz

e3

ICS841003AKI-02T

Renesas Electronics

CLOCK GENERATOR, PROCESSOR SPECIFIC

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.63 V

625 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

2.97 V

85 Cel

-40 Cel

TIN LEAD

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

31.25 MHz

e0

ICS8430DYI-01

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

500 MHz

FLATPACK, LOW PROFILE

3.135 V

85 Cel

-40 Cel

TIN LEAD

QUAD

1.6 mm

7 mm

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

3

Not Qualified

27 MHz

e0

8T49N004A-DDDNLGI8

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

2.625 V

1228.88 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

2.375 V

85 Cel

-40 Cel

QUAD

1 mm

5 mm

ALSO OPERATES AT 3.3 V SUPPLY; Differential Input Frequency-312.5 AVAILABLE

5 mm

CMOS

192 mA

2.5 V

.5 mm

S-XQCC-N32

156.25 MHz

8T49N004A-048NLGI8

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

84329BYLFT

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

700 MHz

3.3

FLATPACK, LOW PROFILE

QFP32,.35SQ,32

3.135 V

70 Cel

0 Cel

MATTE TIN

QUAD

1.6 mm

7 mm

30

260

7 mm

CMOS

3.3 V

Clock Generators

.8 mm

S-PQFP-G32

3

Not Qualified

25 MHz

e3

ICS841003AKI-02

Renesas Electronics

CLOCK GENERATOR, PROCESSOR SPECIFIC

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.63 V

625 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

2.97 V

85 Cel

-40 Cel

TIN LEAD

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

31.25 MHz

e0

8T49N004A-062NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

ICS87950AY-T

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

180 MHz

FLATPACK, LOW PROFILE

3.135 V

70 Cel

0 Cel

TIN LEAD

QUAD

1.6 mm

7 mm

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

3

Not Qualified

e0

ICS840S07BYILFT

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

GULL WING

32

HTQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

167.67 MHz

FLATPACK, HEAT SINK/SLUG, THIN PROFILE

3.135 V

85 Cel

-40 Cel

MATTE TIN

QUAD

1.2 mm

7 mm

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

Not Qualified

25 MHz

e3

ICS843002BKI-72LF

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

122.88 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

3.135 V

85 Cel

-40 Cel

MATTE TIN

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

19.2 MHz

e3

ICS8440258AKI-46LTF

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

2.625 V

125 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

2.375 V

85 Cel

-40 Cel

TIN LEAD

QUAD

1 mm

5 mm

5 mm

CMOS

2.5 V

.5 mm

S-XQCC-N32

Not Qualified

25 MHz

e0

ICS87950AY

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

180 MHz

FLATPACK, LOW PROFILE

3.135 V

70 Cel

0 Cel

TIN LEAD

QUAD

1.6 mm

7 mm

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

3

Not Qualified

e0

8T49N004A-056NLGI8

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

ICS87950AYLF-T

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

180 MHz

FLATPACK, LOW PROFILE

3.135 V

70 Cel

0 Cel

MATTE TIN

QUAD

1.6 mm

7 mm

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

3

Not Qualified

e3

8T49N004A-066NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

8T49N004A-060NLGI

Renesas Electronics

CLOCK GENERATOR, PROCESSOR SPECIFIC

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.625 V

1228.88 MHz

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

2.375 V

85 Cel

-40 Cel

QUAD

1 mm

5 mm

5 mm

CMOS

192 mA

2.5 V

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

800 MHz

8T49N004A-066NLGI8

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

8T49N004A-033NLGI8

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

8432CY-51LF

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

700 MHz

FLATPACK, LOW PROFILE

3.135 V

70 Cel

0 Cel

TIN

QUAD

1.6 mm

7 mm

260

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

3

50 MHz

e3

8T49N004A-067NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

ICS844204BK-245T

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

250 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

3.135 V

70 Cel

0 Cel

TIN LEAD

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

25 MHz

e0

8T49N004A-013NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

8T49N004A-047NLGI8

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

9FGV0431AKILFT

Renesas Electronics

CLOCK GENERATOR, PROCESSOR SPECIFIC

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

1.9 V

100 MHz

1.8

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

1.7 V

85 Cel

-40 Cel

MATTE TIN

QUAD

1 mm

5 mm

260

5 mm

CMOS

30 mA

1.8 V

Clock Generators

.5 mm

S-XQCC-N32

3

Not Qualified

27 MHz

e3

8T49N004A-057NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

8T49N004A-054NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

8T49N004A-058NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

ICS814252CKI-02

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

312.5 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

3.135 V

85 Cel

-40 Cel

TIN LEAD

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

25 MHz

e0

84321AYILF

Renesas Electronics

CLOCK GENERATOR, OTHER

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

260 MHz

FLATPACK, LOW PROFILE

QFP32,.35SQ,32

3.135 V

85 Cel

-40 Cel

TIN

QUAD

1.6 mm

7 mm

260

7 mm

CMOS

180 mA

3.3 V

.8 mm

S-PQFP-G32

3

40 MHz

e3

ICS841003AKI-04

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.63 V

680 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

2.97 V

85 Cel

-40 Cel

TIN LEAD

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

27.2 MHz

e0

ICS87930AY

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

140 MHz

FLATPACK, LOW PROFILE

3.135 V

70 Cel

0 Cel

TIN LEAD

QUAD

1.6 mm

7 mm

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

Not Qualified

25 MHz

e0

8V97051NLGI8

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

4400 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

3.135 V

85 Cel

-40 Cel

Matte Tin (Sn)

QUAD

1 mm

5 mm

NOT SPECIFIED

260

5 mm

CMOS

97 mA

3.3 V

.5 mm

S-XQCC-N32

3

310 MHz

e3

8T49N004A-999NLGI8

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

TIN

QUAD

260

192 mA

Clock Generators

.5 mm

S-PQCC-N32

3

Not Qualified

e3

ICS8430AYI-61T

Renesas Electronics

CLOCK GENERATOR, OTHER

INDUSTRIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

500 MHz

3.3

FLATPACK, LOW PROFILE

QFP32,.35SQ,32

3.135 V

85 Cel

-40 Cel

TIN LEAD

QUAD

1.6 mm

7 mm

20

225

7 mm

CMOS

3.3 V

Clock Generators

.8 mm

S-PQFP-G32

3

Not Qualified

27 MHz

e0

ICS8430AY-51

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

GULL WING

32

LQFP

SQUARE

PLASTIC/EPOXY

YES

3.465 V

600 MHz

FLATPACK, LOW PROFILE

3.135 V

70 Cel

0 Cel

TIN LEAD

QUAD

1.6 mm

7 mm

7 mm

CMOS

3.3 V

.8 mm

S-PQFP-G32

3

Not Qualified

25 MHz

e0

8T49N004A-044NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

8432CK-51LFT

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

700 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

3.135 V

70 Cel

0 Cel

TIN

QUAD

1 mm

5 mm

260

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

3

50 MHz

e3

9FGV0431AKLFT

Renesas Electronics

CLOCK GENERATOR, PROCESSOR SPECIFIC

COMMERCIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

1.9 V

100 MHz

1.8

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

1.7 V

70 Cel

0 Cel

MATTE TIN

QUAD

1 mm

5 mm

260

5 mm

CMOS

30 mA

1.8 V

Clock Generators

.5 mm

S-XQCC-N32

3

Not Qualified

27 MHz

e3

ICS844202BK-245LFT

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

250 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

3.135 V

70 Cel

0 Cel

MATTE TIN

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

35 MHz

e3

8T49N004A-060NLGI8

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

ICS844204BK-245

Renesas Electronics

CLOCK GENERATOR, OTHER

COMMERCIAL

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

250 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

3.135 V

70 Cel

0 Cel

TIN LEAD

QUAD

1 mm

5 mm

5 mm

CMOS

3.3 V

.5 mm

S-XQCC-N32

Not Qualified

25 MHz

e0

8V97051ANLGI/W

Renesas Electronics

JITTER ATTENUATOR

NO LEAD

32

HVQCCN

SQUARE

YES

3.465 V

4400 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

3.135 V

85 Cel

-40 Cel

TIN

QUAD

1 mm

5 mm

260

5 mm

CMOS

97 mA

3.3 V

.5 mm

S-XQCC-N32

3

310 MHz

e3

8V97053LNLGI/W

Renesas Electronics

CLOCK GENERATOR, PROCESSOR SPECIFIC

NO LEAD

32

HVQCCN

SQUARE

UNSPECIFIED

YES

3.465 V

4400 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

3.135 V

85 Cel

-40 Cel

TIN

QUAD

1 mm

5 mm

260

5 mm

CMOS

105 mA

3.3 V

.5 mm

S-XQCC-N32

3

310 MHz

e3

8T49N004A-052NLGI

Renesas Electronics

INDUSTRIAL

NO LEAD

32

QCCN

SQUARE

PLASTIC/EPOXY

YES

2.5/3.3

CHIP CARRIER

LCC32,.2SQ,20

85 Cel

-40 Cel

QUAD

192 mA

Clock Generators

.5 mm

S-PQCC-N32

Not Qualified

8V97051ANLGI8

Renesas Electronics

JITTER ATTENUATOR

NO LEAD

32

HVQCCN

SQUARE

YES

3.465 V

4400 MHz

CHIP CARRIER, HEAT SINK/SLUG, VERY THIN PROFILE

LCC32,.2SQ,20

3.135 V

85 Cel

-40 Cel

TIN

QUAD

1 mm

5 mm

260

5 mm

CMOS

97 mA

3.3 V

.5 mm

S-XQCC-N32

3

310 MHz

e3

Clock Generators

A clock generator is an electronic circuit that generates an electrical signal that serves as a timing reference for other circuits in a system. Clock generators are used in many electronic devices, such as computers, cell phones, and digital cameras. The clock signal is used to synchronize the operation of different components in the system, such as microprocessors, memory devices, and input/output interfaces.

Clock generators can be classified based on their output frequency and stability. Some clock generators produce a fixed frequency output, while others have a programmable output frequency. The stability of the clock signal is also an important parameter, and clock generators can be designed to produce a stable frequency output over a wide range of temperature and voltage conditions.

Clock generators can also include additional features such as frequency multiplication, frequency division, and phase locking. Frequency multiplication allows the output frequency to be multiplied by an integer value, while frequency division allows the output frequency to be divided by an integer value. Phase locking is used to ensure that the output frequency of the clock generator is synchronized with an external reference signal.