Datasheet BU2185F Datasheet (ROHM)

1

Multimedia ICs

Clock generator

BU2185F

This IC generates the different clock used for DVD. Generates clocks for CD use, sound use, and MPEG use.

•

Applications

DVD players

•

Features

1) By connecting a crystal oscillating element, the dif­ferent clock signals are generated.

2) Enables selection of the reference clock directly or
with 1 / 2 output.

3) SOP 16-pin package.

4) Single 3.3V power supply.

5) With the standard clock output, an independent 5V
power supply can be applied for a 5V output.

•

Block diagram

DATA1A

XTAL1
OSC

XTAL2
OSC

PLL1

PLL2

DATA1B

DATA2A
DATA2B

XTAL1 IN

XTAL1 OUT

CTRL1

CTRL2

XTAL2 IN

XTAL 2OUT

OE

H

SW

L

1 / 2

CLK2

(27.0000MHz )

CLK1
(36.8640MHz)
(18.4320MHz)

CLK3
(33.8688MHz)

CTRL1 CTRL2

L
L
H
H

H
L
H
L

H
L
H
L

DATA1A
DATA1A
DATA1B
DATA1B

DATA2A
DATA2A
DATA2B
DATA2B

SW PLL1 PLL2

DATA1A = XTAL2 ∗ 375 / 128 / 4
DATA1B = XTAL2 ∗ 375 / 64 / 4
DATA2A = XTAL2 ∗ 147 / 40 / 4
DATA2B = XTAL2 ∗ 147 / 20 / 4

2

Multimedia ICs BU2185F

•

Pin descriptions

Pin No.

1

Pin name Pin descriptions Circuit
XTAL1-IN

Reference oscillation input 1 (not used)
Reference oscillation output 1
XTAL setting (Low: XTAL = 36.8MHz mode; High: XTAL = 18.4MHz mode)
Analog GND
Digital GND
Independent power supply for XTAL2-IN and XTAL2-OUT pins
Reference oscillation input 2 (36.864MHz or 18.432MHz)
Reference oscillation output 2
Reference clock output (36.864MHz or 18.432MHz)
Independent power supply for CLK1 output buffer
Clock output 2 (27.000MHz)
Digital V

DD

Analog V

DD

Clock output 3 (33.8688MHz)
CLK1 output selector (High: 36.864MHz; Low: 18.432MHz)
Output enable (High: enable; Low: disable)

2

D

XTAL1-OUT

3

D

CTRL2

4

A

AGND

5

—

DGND

6

—

DV

DD

7

—

XTAL2-IN

8

D

XTAL2-OUT

9

D

CLK1

10

C

DV

DD

11

—

CLK2

12

C

DV

DD

13

—

AVDD

14

—

CLK3

15

C

CTRL1

16

A

OE B

•

Absolute maximum ratings (Ta = 25°C)

•

Recommended operating conditions (Ta = 25°C)

Parameter Symbol Limits

– 0.5 ~ + 7.0
– 0.5 ~ V

DD + 0.5

450

∗

Unit

V
V

mW

V

DD

VIN
Pd

Applied voltage
Input voltage

– 30 ~ + 125 °CTstgStorage temperature

Power dissipation

䊊Does not represent guaranteed performance.

∗

Reduced by 4.5mW for increase in Ta of 1°C over 25°C.

䊊Not designed for radiation resistance.

Parameter Symbol Limits

3.0

0.8 × V

DD

0.0

– 5

~ 3.6
~ V

DD

~ 0.2 × VDD
~ + 70

15 (Max.)

Unit

V
V

V
°C
pF

V

DD

VIH
VIL

Topr

C

L

Power supply voltage
Input high level voltage
Input low level voltage
Operating temperature
Output load

3

Multimedia ICs BU2185F

•

Input / output circuits

To inside

Pin

Type A

3, 15

To inside

Pin

16

Type B

From inside

Pin

9, 11, 14

Type C

To inside

Pin

Pin

1, 2, 7, 8

Type D

4

Multimedia ICs BU2185F

Parameter Symbol Min.

—

0.7

×

V

DD

—

2.4

Typ.

—
—
—
—

Max.

0.3 × V

DD

—

0.4
—

V

IL

VIH
VOL
VOH

Input low level voltage
Input high level voltage
Output low level voltage
Output high level voltage

Unit

V
V
V
V

Conditions

I OL = 4.0mA CLK1, CLK2, CLK3

CTRL1, CTRL2, OE

CTRL1, CTRL2, OE

I OH = – 4.0mA CLK1, CLK2, CLK3

——0.4VOL

Output low level voltage

V I OL = 0.5mA XTAL1OUT, XTAL2OUT

DVDD-0.5

——VOH

Output high level voltage

V I OH = – 0.5mA XTAL1OUT, XTAL2OUT

— 40 60IDD

Operating circuit current

mA No load

〈When XTAL2 = 36.864MHz〉 (XTAL1 is shorted to GND)

36.8640CLK1-1CLK1 frequency1 MHz XTAL2 output

CTRL1 = H, CTRL2 = L

18.4320CLK1-2CLK1 frequency2 MHz XTAL2 1 / 2 output

CTRL1 = L, CTRL2 = L

27.0000CLK2CLK2 frequency MHz XTAL2 × 375 / 128 / 4 — CTRL2 = L

33.8688CLK3CLK3 frequency MHz XTAL2 × 147 / 40 / 4 — CTRL2 = L

〈When XTAL2 = 18.432MHz〉 (XTAL1 is shorted to GND)

18.4320CLK1CLK1 frequency1 MHz XTAL2 output CTRL1 = H, CTRL2 = H

27.0000CLK2CLK2 frequency MHz XTAL2 × 375 / 64 / 4 — CTRL2 = H

33.8688CLK3CLK3 frequency MHz XTAL2 × 147 / 20 / 4 — CTRL2 = H

45 50 55DUTYDUTY % 1 / 2VDD
— 100 —J1sJITTER psec

Reference value (1sigma)

— 600 —
——

——
——
——
——

——
——
——

JabsJITTER psec

Reference value (min.-to-max. width for jitter)

65CLK2SN27MHz S / N dB

27MHz ± 20kHz RBW = 1kHz, SPAN = 200kHz

•

Electrical characteristics (unless otherwise noted, Ta = 25°C, VDD (AVDD) = 3.3V, CL ⬉ 15PF, XTAL1 = shorted to

GND, XTAL2 = 36.864MHz, 18.43MHz) )

5

Multimedia ICs BU2185F

•

Application example

•

Attached components
Since high frequencies are handles, use this IC mounted on a PC board. If used mounted by a socket, the proper
characteristics may not be able to be obtained. Be sure to connect a 0.1µF capacitor between the analog power sup­ply and analog GND.

XTAL1 IN

XTAL1 OUT

CTRL2

AGND

DGND

DV

DD

AGND

AV

DD

DVDD

DVDD

DGND

DV

DD

36.8640MHz

36.8640MHz

18.4320MHz

27.0000MHz

33.8688MHz

H : 36.864MHz
L : 18.432MHz

H : ENABLE
L : DISABLE

XTAL2 IN

XTAL2 OUT

OE

CTRL1

CLK3

AV

DD

DVDD

CLK2

DV

DD

CLK1

L

0.1µF

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

AGND

AV

DD

DVDD

DVDD

DGND

DV

DD

18.4320MHz

18.4320MHz

27.0000MHz

33.8688MHz

H : 18.432MHz

H : ENABLE
L : DISABLE

OE

H

0.1µF

XTAL1 IN

XTAL1 OUT

CTRL2

AGND

DGND

DV

DD

XTAL2 IN

XTAL2 OUT

1

2

3

4

5

6

7

8

CTRL1

CLK3

AV

DD

DVDD

CLK2

DV

DD

CLK1

16

15

14

13

12

11

10

9

6

Multimedia ICs BU2185F

0.4 ± 0.11.27

0.15

0.15 ± 0.1

0.3Min.

4.4 ± 0.2

6.2 ± 0.3

0.11

1.5 ± 0.1

1

16

10.0 ± 0.2

8

9

SOP16

•

External dimensions (Units: mm)