ICS5250708 Datasheet, PDF (1/9 Pages) Integrated Circuit Systems – LVCMOS User Configurable Clock

PRELIMINARY INFORMATION _ICS525-07/08
LVCMOS User Configurable Clock
Description
The ICS525-07/08 are the most flexible way to
generate a high-quality clock output from an
inexpensive crystal or clock input at low supply
voltages. The user can configure the device to produce
nearly any output frequency from any input frequency
by grounding or floating the select pins or by driving or
hard wiring the select pins high or low. Neither
microcontroller, software, nor device programmer are
needed to set the frequency. Using Phase-Locked
Loop (PLL) techniques, the device accepts a standard
fundamental mode, inexpensive crystal to produce
output clocks up to 250 MHz. It can also produce a
highly accurate output clock from a given input clock,
keeping them frequency locked.
For similar capability with a serial interface, use the
ICS307.
This product is intended for clock generation. It has low
output jitter (variation in the output period), but input to
output skew is not defined nor guaranteed.
Features
• Packaged as 28-pin SSOP (150 mil body)
• Available in Pb (lead) free package
• User determines the output frequency by setting all
internal dividers
• Eliminates need for custom oscillators
• Low voltage operation
• Pull-ups on all select inputs
• Input crystal frequency of 5 - 27 MHz
• Input clock frequency of 2 - 50 MHz
• Compensated loop bandwidth
• Enhanced low frequency operation (-08 version)
• Low jitter
• Duty cycle of 45/55 up to 200 MHz
• Operating voltage of 1.8 V to 2.5 V
• Ideal for oscillator replacement
• Available in commercial and industrial temperature
ranges
Block Diagram
2 VDD
PD
REF
X1/ICLK
Crystal or clock
input
X2
Crystal
Oscillator
Reference
Divider
Phase Comparator,
Charge Pump, and
Loop Filter
VCO
Output
Div_ider
C_LK
V_VCO
O_Op_pt_ti_io_on_na_al_l c_cr_ry_yss_tt_aa_ll _cc_aa_pp_aac_cii_tt_oor_rs_s
D_Di_iv_vi_idde_er_r
R_{R C}C_oo_nn_ff_ii_gg_uu_rr_aa_tt_ii_oo_nn _PP_ii_nn_ss
V^V C^Co^onⁿf^fiⁱg^gu^ur^ra^at^tiⁱo^onⁿ P^Piⁱnⁿs^s
2_{2 GGNNDD}
S^S C^Co^onⁿf^fiⁱg^gu^ur^ra^at^tiⁱo^onⁿ P^Piⁱnⁿs^s
MDS 525-07/08 A
1
Revision 101105
Integrated Circuit Systems, Inc. ● 525 Race Street, San Jose, CA 95126 ● tel [phone] ● www.icst.com