FEMTOCLOCK CRYSTAL-TO-LVCMOS/LVTTL ICS840021 CLOCK GENERATOR General Description Features The ICS840021 is a Gigabit Ethernet Clock One LVCMOS/LVTTL output, 7 output impedance TM ICS Generator and a member of the HiPerClocks Crystal oscillator interface designed for 25MHz, HiPerClockS family of high performance devices from IDT. The 18pF parallel resonant crystal ICS840021 uses a 25MHz crystal to synthesize Output frequency: 125MHz 125MHz. The ICS840021 has excellent phase jitter VCO range: 560MHz to 680MHz performance, over the 1.875MHz 20MHz integration range. The RMS phase jitter 125MHz, using a 25MHz crystal ICS840021 is packaged in a small 8-pin TSSOP, making it ideal for (1.875MHz - 20MHz): 0.34ps (typical) 3.3V use in systems with limited board space. RMS phase noise at 125MHz (typical) Phase noise: Offset Noise Power 100Hz ................-96.9 dBc/Hz 1kHz ..............-122.2 dBc/Hz 10kHz ..............-131.1 dBc/Hz 100Hz ..............-129.5 dBc/Hz 3.3V operating supply 0C to 70C ambient operating temperature Available in both standard (RoHS 5) and lead-free (RoHS 6) packages Pin Assignment Block Diagram Pullup OE VDDA 1 8 VDD OE Q0 2 7 25MHz XTAL OUT GND 3 6 XTAL IN Phase XTAL IN 4 5 RESERVED Q0 OSC VCO 5 Detector XTAL OUT ICS840021 25 8-Lead TSSOP (fixed) 4.40mm x 3.0mm x 0.925mm package body G Package Top View IDT / ICS LVCMOS CLOCK GENERATOR 1 ICS840021AG REV. B APRIL 28, 2009ICS840021 FEMTOCLOCKCRYSTAL-TO-LVCMOS/LVTTL CLOCK GENERATOR Table 1. Pin Descriptions Number Name Type Description 1V Power Analog supply pin. DDA Output enable pin. When HIGH, Q0 output is enabled. When LOW, forces Q0 to 2 OE Input Pullup high-impedance state. LVCMOS/LVTTL interface levels. 3, XTAL OUT, Input Crystal oscillator interface. XTAL IN is the input, XTAL OUT is the output. 4 XTAL IN 5 Reserved Reserved Reserve pin. 6 GND Power Power supply ground. Single-ended clock output. LVCMOS/LVTTL interface levels. 7 Q0 Output 7 output impedance. 8V Power Core supply pin. DD NOTE: Pullup refers to internal input resistors. See Table 1, Pin Characteristics, for typical values. Table 2. Pin Characteristics Symbol Parameter Test Conditions Minimum Typical Maximum Units C Input Capacitance 4 pF IN C Power Dissipation Capacitance V = 3.465V 24 pF PD DD R Input Pullup Resistor 51 k PULLUP R Output Impedance 5 7 12 OUT Function Table Table 3. Control Function Table Control Input Output OE Q0 0 High-Impedance 1Active IDT / ICS LVCMOS CLOCK GENERATOR 2 ICS840021AG REV. B APRIL 28, 2009