DATASHEET TRIPLE PLL FIELD PROG. SPREAD SPECTRUM CLOCK SYNTHESIZER ICS291 Description Features The ICS291 field programmable spread spectrum clock Packaged as 20-pin TSSOP Pb-free, RoHS compliant synthesizer generates up to six high-quality, high-frequency Eight addressable registers clock outputs including multiple reference clocks from a Replaces multiple crystals and oscillators low-frequency crystal input. It is designed to replace Output frequencies up to 200 MHz at 3.3 V crystals, crystal oscillators and stand alone spread Configurable Spread Spectrum Modulation spectrum devices in most electronic systems. Input crystal frequency of 5 to 27 MHz TM Using IDTs VersaClock software to configure PLLs and Clock input frequency of 3 to 166 MHz outputs, the ICS291 contains a One-Time Programmable Up to six reference outputs (OTP) ROM for field programmability. Programming Separate 1.8 to 3.3 V VDDO output level controls for features include input/output frequencies, spread spectrum each bank of 3 outputs amount, eight selectable configuration registers and up to Up to two sets of three low-skew outputs two sets of three low-skew outputs. Operating voltages of 3.3 V Each of the two output groups are powered by a separate Controllable output drive levels VDDO voltage. VDDO may vary from 1.8 V to VDD. Advanced, low-power CMOS process Using Phase-Locked Loop (PLL) techniques, the device runs from a standard fundamental mode, inexpensive crystal, or clock. It can replace multiple crystals and oscillators, saving board space and cost. The ICS291 is also available in factory programmed custom versions for high-volume applications. Block Diagram VDDO1 3 VDD PLL1 with 3 Spread S2:S0 OTP CLK1 Spectrum ROM with PLL CLK2 Divide Values Logic CLK3 PLL2 and Output Enable CLK4 Control PLL3 CLK5 X1/ICLK Crystal CLK6 Crystal or Oscillator Clock Input X2 3 External capacitors GND are required with a crystal input. VDDO2 PDTS IDT / ICS TRIPLE PLL FIELD PROG. SPREAD SPECTRUM CLOCK SYNTHESIZER 1 ICS291 REV F 051310ICS291 TRIPLE PLL FIELD PROG. SPREAD SPECTRUM CLOCK SYNTHESIZER EPROM CLOCK SYNTHESIZER Pin Assignment 1 20 GND S2 S0 2 19 VDD 3 18 PDTS S1 4 17 VDD GND VDDO1 5 16 CLK6 6 15 CLK1 CLK5 7 14 CLK2 CLK4 8 13 CLK3 VDDO2 9 12 GND VDD X1/ICLK 10 11 X2 20 pin (173 mil) TSSOP Pin Descriptions Pin Pin Pin Pin Description Number Name Type 1 GND Power Connect to ground. 2 S0 Input Select pin 0. Internal pull-up resistor. 3 S1 Input Select pin 1. Internal pull-up resistor. Connect to +3.3 V. 4VDD Power 5 VDDO1 Power Power supply for outputs CLK1-CLK3. 6 CLK1 Output Output clock 1. Weak internal pull-down when tri-state. 7 CLK2 Output Output clock 2. Weak internal pull-down when tri-state. 8 CLK3 Output Output clock 3. Weak internal pull-down when tri-state. 9 GND Power Connect to ground. 10 X1/ICLK XI Crystal input. Connect this pin to a crystal or external input clock. 11 X2 XO Crystal Output. Connect this pin to a crystal. Float for clock input. Connect to +3.3 V. 12 VDD Power 13 VDDO2 Power Power supply for outputs CLK4-CLK6. 14 CLK4 Output Output clock 4. Weak internal pull-down when tri-state. 15 CLK5 Output Output clock 5. Weak internal pull-down when tri-state. 16 CLK6 Output Output clock 6. Weak internal pull-down when tri-state. 17 GND Power Connect to ground. Power-down tri-state. Powers down entire chip and tri-states clock outputs 18 PDTS Input when low. Internal pull-up resistor. Connect to +3.3 V. 19 VDD Power 20 S2 Input Select pin 2. Internal pull-up resistor. IDT / ICS TRIPLE PLL FIELD PROG. SPREAD SPECTRUM CLOCK SYNTHESIZER 2 ICS291 REV F 051310