IDT5V7855 Datasheet, PDF (1/14 Pages) Integrated Device Technology – EEPROM Programmable PLL Die for LVCMOS Crystal Oscillator

EEPROM Programmable PLL Die for
LVCMOS Crystal Oscillator
IDT5V7855
DATA SHEET
General Description
The IDT5V7855 is a programmable PLL-based clock generator used
for crystal oscillator modules. The device incorporates an on-chip
crystal oscillator with a programmable capacitor tuning array to
support direct connection with fundamental-mode crystals between
16MHz – 50MHz. The capacitor tuning array offers a total of 9 bits of
resolution and provides a step of 0.01pF.
The device incorporates on-chip non-volatile EEPROM cells which
can store all the device settings and maintain them even when there
is no power. The serial programming interface is implemented with
dual-use pins for the clock and data. The CONT input can be
programmed as either a power down input or an output enable input.
Crystal oscillator modules using this device can be stocked as blank
parts and custom frequencies programmed in package at the last
stage before shipping. This enables fast-turn manufacture of custom
and standard crystal oscillators without the need for expensive
dedicated crystals.
The IDT PLL uses a patent-pending fractional multiplier technique to
provide ultra-high resolution multiplication and division from input to
output with low jitter. In addition, prescaler and post-
divider circuits are included to enhance the granularity of clock
scaling. The PLL may also be bypassed in order to operate the
device as a non-PLL fundamental-mode crystal oscillator for
applications that do not require frequency multiplication. The device
is fabricated using advance technology and can support both 2.5V
and 3.3V operation. The device is small enough to fit into
small-footprint crystal oscillators. This is the industry’s smallest
programmable die and can support crystal oscillator packages as
small as 20mm x 16mm.
Features
• Input: 16MHz – 50MHz fundamental mode crystal
• Output frequency range: 1MHz – 170MHz in PLL mode,
1MHz – 50MHz in non-PLL mode
• On-chip EEPROM to store device configuration
– 19-bit high-resolution fractional programmable multiplier
– 3-bit prescaler
– 7-bit output divider
– 9-bit crystal oscillator tuning capacitor array
– Selectable function power down or OE control pin
• In-package serial programming interface through dual-use pins
• Full 2.5V and 3.3V operating supply
• Maximum frequency shift across supply voltage: ±1ppm
• Available in die pack, lead-free RoHS compliant
• ESD Human Body Model (HBM) and Machine Model (MM):
– HBM: 2000V
– MM: 200V
• Small die size: 0.75mm x 0.75mm
• Supports 20mm x 16mm package size
• -40°C to 85°C ambient operating temperature
Functional Block Diagram
xg
x2
OSC
Pre-Scaler
PFD
VCO
xd
3-bit
Tuning
Cap
9-bit
Fractional
Multiplier
19-bit
CONT ^Pullup
EEPROM
0
Output
1
Divider ^÷2
7-bit
Pad Assignment
OUT
V_DD 1
V_DD 2
xd 3
8 OUT
xg 4
CONT 5
6 7 VSS
IDT5V7855
0.75mm x 0.75mm Die
IDT5V7855-DPK REVISION A MARCH 11, 2010
1
©2010 Integrated Device Technology, Inc.