ROHM BU2185F

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
•1)Features
By connecting a crystal oscillating element, the dif-
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.
ferent clock signals are generated.
2) Enables selection of the reference clock directly or
with 1 / 2 output.
•Block diagram
DATA1A
DATA1B
XTAL1 IN
XTAL1
OSC
PLL1
CLK2
(27.0000MHz )
XTAL1 OUT
SW
H
CTRL1
CLK1
(36.8640MHz)
(18.4320MHz)
L
CTRL2
1/2
XTAL2 IN
XTAL2
OSC
PLL2
CLK3
(33.8688MHz)
XTAL 2OUT
DATA2A
DATA2B
OE
CTRL1
CTRL2
SW
PLL1
PLL2
H
L
H
DATA1A
DATA2A
L
L
L
DATA1A
DATA2A
H
H
H
DATA1B
DATA2B
L
H
L
DATA1B
DATA2B
DATA1A = XTAL2 ∗
DATA1B = XTAL2 ∗
DATA2A = XTAL2 ∗
DATA2B = XTAL2 ∗
375 / 128 / 4
375 / 64 / 4
147 / 40 / 4
147 / 20 / 4
1
Multimedia ICs
BU2185F
•Absolute maximum ratings (Ta = 25°C)
Parameter
Symbol
Limits
Unit
Applied voltage
VDD
– 0.5 ~ + 7.0
V
Input voltage
VIN
– 0.5 ~ VDD + 0.5
V
Power dissipation
Storage temperature
Pd
450∗
mW
Tstg
– 30 ~ + 125
°C
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.
•Recommended operating conditions (Ta = 25°C)
Parameter
Symbol
Limits
Unit
Power supply voltage
VDD
3.0 ~ 3.6
V
Input high level voltage
VIH
0.8 × VDD ~ VDD
V
Input low level voltage
VIL
0.0 ~ 0.2 × VDD
V
Operating temperature
Topr
– 5 ~ + 70
°C
CL
15 (Max.)
pF
Output load
•Pin descriptions
2
Pin No.
Pin name
1
XTAL1-IN
Pin descriptions
Circuit
Reference oscillation input 1 (not used)
D
2
XTAL1-OUT
Reference oscillation output 1
D
3
CTRL2
XTAL setting (Low: XTAL = 36.8MHz mode; High: XTAL = 18.4MHz mode)
A
4
AGND
Analog GND
—
5
DGND
Digital GND
—
6
DVDD
Independent power supply for XTAL2-IN and XTAL2-OUT pins
—
7
XTAL2-IN
8
XTAL2-OUT
Reference oscillation input 2 (36.864MHz or 18.432MHz)
D
Reference oscillation output 2
D
9
CLK1
Reference clock output (36.864MHz or 18.432MHz)
C
10
DVDD
Independent power supply for CLK1 output buffer
—
11
CLK2
Clock output 2 (27.000MHz)
C
12
DVDD
Digital VDD
—
13
AVDD
Analog VDD
—
14
CLK3
Clock output 3 (33.8688MHz)
C
15
CTRL1
CLK1 output selector (High: 36.864MHz; Low: 18.432MHz)
A
16
OE
Output enable (High: enable; Low: disable)
B
Multimedia ICs
BU2185F
•Input / output circuits
Type A
Type B
Pin
Pin
To inside
3, 15
16
Type D
Type C
Pin
To inside
From inside
Pin
To inside
9, 11, 14
Pin
1, 2, 7, 8
3
Multimedia ICs
BU2185F
otherwise noted, Ta = 25°C, V (AV
•Electrical characteristics (unless
GND, XTAL2 = 36.864MHz, 18.43MHz) )
DD
Parameter
Symbol
DD)
Min.
Typ.
Max.
Unit
= 3.3V, CL ⬉ 15PF, XTAL1 = shorted to
Conditions
Input low level voltage
VIL
—
—
0.3 × VDD
V
CTRL1, CTRL2, OE
Input high level voltage
VIH
0.7 × VDD
—
—
V
CTRL1, CTRL2, OE
Output low level voltage
VOL
—
—
0.4
V
I OL = 4.0mA CLK1, CLK2, CLK3
Output high level voltage
VOH
2.4
—
—
V
I OH = – 4.0mA CLK1, CLK2, CLK3
Output low level voltage
VOL
—
—
0.4
V
I OL = 0.5mA XTAL1OUT, XTAL2OUT
Output high level voltage
VOH
DVDD-0.5
—
—
V
I OH = – 0.5mA XTAL1OUT, XTAL2OUT
Operating circuit current
IDD
—
40
60
mA
No load
〈When XTAL2 = 36.864MHz〉 (XTAL1 is shorted to GND)
CLK1 frequency1
CLK1-1
—
36.8640
—
MHz
XTAL2 output
CTRL1 = H, CTRL2 = L
CLK1 frequency2
CLK1-2
—
18.4320
—
MHz
XTAL2 1 / 2 output CTRL1 = L, CTRL2 = L
CLK2 frequency
CLK2
—
27.0000
—
MHz
XTAL2 × 375 / 128 / 4
—
CTRL2 = L
CLK3 frequency
CLK3
—
33.8688
—
MHz
XTAL2 × 147 / 40 / 4
—
CTRL2 = L
〈When XTAL2 = 18.432MHz〉 (XTAL1 is shorted to GND)
CLK1 frequency1
CLK1
—
18.4320
—
MHz
XTAL2 output
CLK2 frequency
CLK2
—
27.0000
—
MHz
XTAL2 × 375 / 64 / 4
—
CTRL2 = H
CLK3 frequency
CLK3
—
33.8688
—
MHz
XTAL2 × 147 / 20 / 4
—
CTRL2 = H
DUTY
DUTY
45
50
55
%
JITTER
J1s
—
100
—
psec
Reference value (1sigma)
JITTER
Jabs
—
600
—
psec
Reference value (min.-to-max. width for jitter)
CLK2SN
—
65
—
dB
27MHz ± 20kHz RBW = 1kHz, SPAN = 200kHz
27MHz S / N
4
CTRL1 = H, CTRL2 = H
1 / 2VDD
Multimedia ICs
BU2185F
•Application example
OE
16
H : ENABLE
L : DISABLE
CTRL1
15
H : 36.864MHz
L : 18.432MHz
CTRL2
CLK3
14
33.8688MHz
4
AGND
AVDD
13
AVDD
DGND
5
DGND
DVDD
12
DVDD
DVDD
6
DVDD
CLK2
11
27.0000MHz
7
XTAL2 IN
DVDD
10
DVDD
8
XTAL2 OUT
CLK1
9
36.8640MHz
18.4320MHz
1
XTAL1 IN
2
XTAL1 OUT
L
3
AGND
36.8640MHz
0.1µF
OE
16
H : ENABLE
L : DISABLE
CTRL1
15
H : 18.432MHz
CTRL2
CLK3
14
33.8688MHz
4
AGND
AVDD
13
AVDD
DGND
5
DGND
DVDD
12
DVDD
DVDD
6
DVDD
CLK2
11
27.0000MHz
7
XTAL2 IN
DVDD
10
DVDD
8
XTAL2 OUT
CLK1
9
18.4320MHz
1
XTAL1 IN
2
XTAL1 OUT
H
3
AGND
18.4320MHz
0.1µF
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.
5
Multimedia ICs
BU2185F
•External dimensions (Units: mm)
16
9
1
8
1.27
0.4 ± 0.1
0.15 ± 0.1
4.4 ± 0.2
0.11
1.5 ± 0.1
6.2 ± 0.3
10.0 ± 0.2
0.3Min.
0.15
SOP16
6