ROHM BU2185F Datasheet
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
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