DS4425 Maxim Integrated Products, DS4425 Datasheet - Page 5

• Manufacturer Part Number: DS4425
• Description: (DS4106 - DS4425) Clock Oscillators
• Manufacturer: Maxim Integrated Products

The DS4106/DS4212/DS4425 combine a crystal and an
IC to form a precision clock. Figure 1 shows a function-
al diagram of the devices. The IC consists of a crystal
oscillator, a low-noise PLL, selectable clock-divider cir-
cuitry, and an output buffer. The PLL consists of a digi-
tal phase/frequency detector (PFD) and low-jitter
generation VCO. The VCO signal is scaled by a clock-
divider circuit and applied to the output buffer.
Figure 1. Functional Diagram
2, 7–10
PIN
—
1
3
4
5
6
OSCILLATOR
AMPLIFIER
DS4106/
DS4212/
DS4425
NAME
OUTN
OUTP
GND
N.C.
V
_______________________________________________________________________________________
OE
EP
CC
Detailed Description
Output Enable. On-chip pullup resistor. Connect OE to logic-high, V
output clock. Connect OE to logic-low or GND to disable the output clock. The LVPECL output
clock is set to high impedance when disabled. The LVDS output clock is latched to a differential
high when disabled.
No Connection
Ground
Positive Clock Output, LVPECL or LVDS
Negative Clock Output, LVPECL or LVDS
+3.3V Supply
Exposed Paddle. The exposed pad must be used for thermal relief. This pad can be connected to
ground.
PFD
106.25MHz/212.5MHz/425MHz
LOOP FILTER
V
CC
COUNTER N
All devices are available with either LVPECL
(DS4106A/DS4212A/DS4425A) or LVDS (DS4106B/
DS4212B/DS4425B) output buffers. When not needed,
the output buffers can be disabled. When disabled, the
LVPECL output buffer goes to a high-impedance state.
However, the LVDS outputs go to a differential logic
one (OUTP latched high and OUTN latched low) when
the outputs are disabled.
For more available frequencies, refer to the DS4125
data sheet at www.maxim-ic.com/DS4125.
VCO
FUNCTION
Clock Oscillators
COUNTER M
Additional Information
CC
, or leave open to enable the
Pin Description
OUTPUT
BUFFER
V
Output Drivers
CC
OUTP
OUTN
OE
GND
5