Integrated Circuit Systems, Inc. ICS2509C 3.3V Phase-Lock Loop Clock Driver General Description Features The ICS2509C is a high performance, low skew, low jitter clock driver. It uses a phase lock loop (PLL) technology to align, in both phase and frequency, the CLKIN signal with the CLKOUT signal. It is specifically designed for use with synchronous SDRAMs. The ICS2509C operates at 3.3V VCC and drives up to nine clock loads. • One bank of five outputs and one bank of four outputs provide nine low-skew, low-jitter copies of CLKIN. Output signal duty cycles are adjusted to 50 percent, independent of the duty cycle at CLKIN. Each bank of outputs can be enabled or disabled separately via control (OEA and OEB) inputs. When the OE inputs are high, the outputs align in phase and frequency with CLKIN; when the OE inputs are low, the outputs are disabled to the logic low state. • • • • • • • • Meets or exceeds PC133 registered DIMM specification 1.1 Spread Spectrum Clock Compatible Distributes one clock input to one bank of five and one bank of four outputs Separate output enable(OEA,OEB) for each output bank Operating frequency 25 MHz to 175 Mhz External feedback input (FBIN) terminal is used to synchrionize the outputs to the clock input No external RC network required Operates at 3.3V Vcc Plastic 24-pin 173mil TSSOP package The ICS2509C does not require external RC filter components. The loop filter for the PLL is included on-chip, minimizing component count, board space, and cost. The buffer mode shuts off the PLL and connects the input directly to the output buffer. This buffer mode, the ICS2509C can be use as low skew fanout clock buffer device. The ICS2509C comes in 24 pin 173mil Thin Shrink Small-Outline package (TSSOP) package. FBOUT CLKA0 CLKA1 FBIN CLKIN PLL CLKA2 CLKA3 AVCC CLKA4 AGND VCC CLKA0 CLKA1 CLKA2 GND GND CLKA3 CLKA4 VCC OEA FBOUT 1 2 3 4 5 6 7 8 9 10 11 12 ICS2509C Pin Configuration Block Diagram 24 23 22 21 20 19 18 17 16 15 14 13 CLKIN AVCC VCC CLKB0 CLKB1 GND GND CLKB2 CLKB3 VCC OEB FBIN OEA CLKB0 24 Pin TSSOP 4.40 mm. Body, 0.65 mm. pitch CLKB1 CLKB2 CLKB3 OEB 2509 C Rev C 06/15/01 ICS reserves the right to make changes in the device data identified in this publication without further notice. ICS advises its customers to obtain the latest version of all device data to verify that any information being relied upon by the customer is current and accurate. ICS2509C Pin Descriptions PIN NUM BER 1 2, 10, 15 3 4 5 6, 7, 18, 19 8 9 PIN NAM E AGND VCC CLKA0 CLKA1 CLKA2 GND CLKA3 CLKA4 TYPE PWR PWR OUT OUT OUT PWR OUT OUT 11 OEA1 12 13 FBOUT FBIN 14 OEB 1 16 17 20 21 22 CLKB3 CLKB2 CLKB1 CLKB0 VCC OUT OUT OUT OUT PWR 23 AVCC IN 24 CLKIN IN IN OUT IN IN DESCRIPTION Analog Ground Power Supply (3.3V) Buffered clock output, Bank A Buffered clock output, Bank A Buffered clock output, Bank A Ground Buffered clock output, Bank A Buffered clock output, Bank A Output enable (has internal pull_up). When high, normal operation. When low bank A clock outputs are disabled to a logic low state. Feedback output Feedback input Output enable (has internal pull_up). When high, normal operation. When low bank B clock outputs are disabled to a logic low state. Buffered clock output. Bank B Buffered clock output. Bank B Buffered clock output. Bank B Buffered clock output. Bank B Power Supply (3.3V) digital supply. Analog power supply (3.3V). When input is ground PLL is off and bypassed. Clock input Note: 1. Weak pull-ups on these inputs Functionality INPUTS OEA OEB AVCC 0 0 1 1 0 1 0 1 3.33 3.33 3.33 3.33 CLKA (0:4) 0 0 Driven Driven OUTPUTS CLKB FBOUT (0:3) 0 Driven Driven Driven 0 Driven Driven Driven Source PLL Shutdown PLL PLL PLL PLL N N N N Buffer M ode 0 0 0 0 0 Driven CLKIN Y 0 1 0 0 Driven Driven CLKIN Y 1 0 0 Driven 0 Driven CLKIN Y Driven Driven 1 1 0 Driven CLKIN Y Test mode: When AVCC is 0, shuts off the PLL and connects the input directly to the output buffers 2 ICS2509C Absolute Maximum Ratings Supply Voltage (AVCC) . . . . . . . . . . . . . . . . . . . Supply Voltage (VCC) . . . . . . . . . . . . . . . . . . . . Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ambient Operating Temperature . . . . . . . . . . . . Storage Temperature . . . . . . . . . . . . . . . . . . . . . . AVCC < (Vcc + 0.7V) 4.3 V GND –0.5 V to Vcc +0.5 V 0°C to +70°C –65°C to +150°C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are stress specifications only and functional operation of the device at these or any other conditions above those listed in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. Electrical Characteristics - OUTPUT TA = 0 - 70C; VDD = VDDL = 3.3 V +/-10%; CL = 20 - 30 pF; RL = 470 Ohms (unless otherwise stated) PARAMETER SYMBOL CONDITIONS MIN TYP Output Impedance RDSP VO = VDD*(0.5) 36 VO = VDD*(0.5) 32 Output Impedance RDSN IOH = -8 mA 2.4 2.9 Output High Voltage VOH IOL = 8 mA 0.25 Output Low Voltage VOL -26 VOH = 2.4 V IOH Output High Current -37 VOH = 2.0 V 19 25 VOL = 0.8 V IOL Output Low Current 13 17 VOL = 0.55 V Rise Time1 Tr VOL = 0.8 V, VOH = 2.0 V 0.5 1.4 Fall Time1 Tf VOH = 2.0 V, VOL = 0.8 V 0.5 1.5 1 Duty Cycle Dt VT = 1.5 V;CL=30 pF 45 50 at 66-100 MHz ; loaded outputs 52 Tcyc-cyc Cycle to Cycle jitter1 at 133 MHz ; loaded outputs 39 1 Absolute Jitter Tjabs 10000 cycles; CL = 30 pF 57 Skew1 Tsk VT = 1.5 V (Window) Output to Output 80 Phase error1 Tpe VT = Vdd/2; CLKIN-FBIN -150 40 3 Phase error Jitter1 Tpe VT = Vdd/2; CLKIN-FBIN; Delay Jitter -50 35 Delay Input-Output1 DR1 VT = 1.5 V; PLL_EN = 0 3.3 1 Guaranteed by design, not 100% tested in production. 3 MAX UNITS 0.4 -13.6 -22 Ω Ω V V mA mA 2.1 2.7 55 100 75 150 150 50 3.7 ns ns % ps ps ps ps ps ns ICS2509C Electrical Characteristics - Input & Supply TA = 0 - 70C; Supply Voltage VDD = 3.3 V +/-10% (unless otherwise stated) PARAMETER SYMBOL CONDITIONS Input High Voltage VIH Input Low Voltage VIL Input High Current IIH VIN = VDD Input Low Current IIL VIN = 0 V; Operating current IDD1 CL = 0 pF; FIN @ 66M 1 Input Capacitance CIN Logic Inputs CO1 Output Capacitance Logic Outputs MIN 2 VSS-0.3 TYP 0.1 19 140 4 8 MAX UNITS VDD+0.3 V 0.8 V 100 uA 50 uA 170 mA pF pF 1 Guarenteed by design, not 100% tested in production. Timing requirements over recommended ranges of supply voltage and operating free-air temperature Symbol Fclk Parameter Test Conditions Input clock frequency Min. Max. Unit 25 175 MHz Input clock frequency 40 60 % duty cycle Stabilization time After power up 1 ms Note: Time required for the PLL circuit to obtain phase lock of its feedback signal to its reference In order for phase lock to be obtained, a fixed-frequency, fixed-phase reference signal must be Until phase lock is obtained, the specifications for parameters given in the switching characteristics table are not 4 ICS2509C PARAMETER MEASUREMENT INFORMATION From Output Under Test 30 pF 500 Ω Figure 1. Load Circuit for Outputs Notes: Figure 2. Voltage Waveforms 1. CL includes probe and jig capacitance. Propagation Delay Times 2. All input pulses are supplied by generators having the following characteristics: PRR ≤ 133 MHz, Z O = 5 0 Ω, Tr ≤ 1.2 ns, Tf ≤ 1.2 ns. 3. The outputs are measured one at a time with one transition per measurement. Figure 3. Phase Error and Skew Calculations 5 ICS2509C General Layout Precautions: An ICS2509C is used as an example. It is similar to the ICS2510C. The same rules and methods apply. 1) Use copper flooded ground on the top signal layer under the clock buffer The area under U1 in figure 1 on the right is an example. 2) Use power vias for power and ground. Vias 20 mil or larger in diameter have lower high frequency impedance. Vias for signals may be minimum drill size. 3) Make all power and ground traces are as wide as the via pad for lower inductance. 4) VAA for pin 23 has a low pass RC filter to decouple the digital and analog supplies. C9-11 may be replaced with a single low ESR (0.8 ohm or less) device with the same total capacitance. 5) Notice that ground vias are never shared. 6) All VCC pins have a decoupling capacitor. Power is always routed from the plane connection via to the capacitor pad to the VCC pin on the clock buffer. 7) Component R1 is located at the clock source. Figure 1. Component Values: C1= As necessary for delay adjust C[7:2]=.01uF C8,C13=0.1uF C[11:9]=4.7Uf R1=10 ohm. Locate at driver R2=10 ohm. 6 ICS2509C c N L E1 INDEX AREA E 1 2 α D A A2 In Millimeters SYMBOL COMMON DIMENSIONS MIN MAX A -1.20 A1 0.05 0.15 A2 0.80 1.05 b 0.19 0.30 c 0.09 0.20 D SEE VARIATIONS E 6.40 BASIC E1 4.30 4.50 e 0.65 BASIC L 0.45 0.75 N SEE VARIATIONS α 0° 8° aaa -0.10 VARIATIONS A1 b SEATING PLANE aaa C D mm. N -Ce In Inches COMMON DIMENSIONS MIN MAX -.047 .002 .006 .032 .041 .007 .012 .0035 .008 SEE VARIATIONS 0.252 BASIC .169 .177 0.0256 BASIC .018 .030 SEE VARIATIONS 0° 8° -.004 MIN 7.70 24 D (inch) MAX 7.90 MIN .303 MAX .311 Reference Doc.: JEDEC Publication 95, MO-153 10-0035 4.40 mm. Body, 0.65 mm. pitch TSSOP (0.0256 Inch) (173 mil) Ordering Information ICS2509CyG-T Example: ICS XXXX y G - PPP - T Designation for tape and reel packaging Pattern Number (2 or 3 digit number for parts with ROM code patterns) Package Type G=TSSOP Revision Designator (will not correlate with datasheet revision) Device Type (consists of 3 or 4 digit numbers) Prefix ICS, AV = Standard Device 7 ICS reserves the right to make changes in the device data identified in this publication without further notice. ICS advises its customers to obtain the latest version of all device data to verify that any information being relied upon by the customer is current and accurate.