ROHM BU2192F

Multimedia ICs
Clock generator for personal
computers
BU2192F
The BU2192F is a clock generator IC for personal computers, and uses a single crystal resonator to generate the
three clock signals needed for personal computers.
Applications
•Personal
computers
•1)Features
Clock signals of two different types can be generated with a single attached crystal generator.
2) Internal PLL loop filter, eliminating the need for an
attached component.
3) Single 5V power supply.
4) SOP 8-pin package.
•Block diagram
XTAL1
XTAL
OSC
14.3181MHz
CLK1
1/2
PLL1
33.8680MHz
DATA1
CLK2
1/4
DATA2
PLL2
24.5795MHz
VREF
1
Multimedia ICs
BU2192F
•Pin descriptions
Pin No.
Pin name
1
CLK2
Clock output 2 (f2 = 24.5795MHz)
A
2
GND
GND
—
3
XTAL I
Reference oscillation input
B
4
N.C.
5
CLK1
Function
Circuit
—
—
Clock output 1 (f1 = 33.8680MHz)
A
6
N.C.
7
DVDD
Digital power supply
—
8
AVDD
Analog power supply
—
—
—
•Input / output circuits
Type A
Type B
Pin
Pin
From inside
To inside
1•5
3
•Absolute maximum ratings (Ta = 25°C)
Parameter
Applied voltage
Input voltage
Storage temperature
Power dissipation
Symbol
Limits
Unit
VDD
– 0.5 ~ + 7.0
V
VIN
– 0.5 ~ VDD + 0.5
V
Tstg
– 30 ~ + 125
°C
Pd
450∗
mW
䊊 Do not represent guaranteed performance.
∗ Reduced by 4.5mW for each increase in Ta of 1°C over 25°C.
䊊 Not designed for radiation resistance.
•Recommended operating conditions (Ta = 25°C)
Parameter
Symbol
Power supply voltage
VDD
Input high level voltage
VIH
Input low level voltage
VIL
Operating temperature
Topr
Output load
2
CL
Limits
Unit
– 4.5 ~ + 5.5
V
0.8 × VDD ~ VDD
V
0.0 ~ 0.2 × VDD
V
– 5 ~ + 70
°C
15 (Max.)
pF
Multimedia ICs
BU2192F
otherwise noted, Ta = 0 to 70°C, V
•Electrical characteristics (unless
XTALI [f ] = 14.3181MHz)
DD
(AVDD) = 4.5V to 5.5V, CL ⬉ 15pF,
REF
Parameter
Input Vth XTALI
Symbol
Min.
Typ.
Max.
Unit
Conditions
Vth
0.8
—
2.2
V
—
Output low level voltage
VOL
—
—
0.4
V
lOL = 4.0mA
Output high level voltage
VOH
VDD – 0.5
—
—
V
lOL = – 4.0mA
Operating circuit current
IDD
—
30
50
mA
Output frequency 1
f1
– 100ppm 33.8680 + 100ppm
MHz
fREF × 123 / 26 / 2
Output frequency 2
f2
– 100ppm 24.5795 + 100ppm
MHz
fREF × 103 / 15 / 4
Rise time
tR
—
—
5
nsec
VDD × 0.2 to VDD × 0.8
Fall time
tF
—
—
5
nsec
VDD × 0.8 to VDD × 0.2
Jitter
J1s
—
80
250
psec
1sigma
Jitter
Jabs
—
300
1
nsec
MIN-MAX width
tPT
—
—
10
msec
∗
Duty
45
50
55
%
Power up time
Duty
fREF = 14.3181MHz, no load
Measure with Vth = 1 / 2VDD
∗ The time for the output to stabilize after the power supply reaches 90% after being turned on.
However, if the power supply rise (to rise condition) takes the entire time, this requirement is satisfied.
•Application example
24.5795MHz
1
CLK2
AVDD
8
0.1µF
2
GND
DVDD
7
3
XTALI
N.C.
6
4
N.C.
CLK1
5
fREF = 14.3181MHz
33.8680MHz
3
Multimedia ICs
BU2192F
•External dimensions (Units: mm)
1
4
0.11
1.27
0.15 ± 0.1
4.4 ± 0.2
5
1.5 ± 0.1
6.2 ± 0.3
5.0 ± 0.2
8
0.4 ± 0.1
0.3Min.
0.15
SOP8
4