PI6C918/919 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 3.3V Precision Clock Generator Features Description • • • • • • • • • • The PI6C918 and PI6C919 are high-precision, low-voltage general-purpose clock generators that reach a maximum output frequency of 120 MHz. These devices use an external low-cost crystal to generate very accurate and stable system clocks. No external capacitors (919 only) Excellent signal quality Very low jitter Precise frequencies Minimal undershoot, ringback or overshoot Nearly perfect 50% duty cycle Four selectable clock frequencies Operates at Vcc = 3.3V Output may be disabled to save power Small 150-mil wide SOIC -8 (W8) package saves board area These frequency synthesizers include a crystal oscillator, a programmable PLL and an output buffer. Any one of four different output frequencies can be selected via two select pins (S0, S1). The frequency multipliers are: 2, 4, 5, and 7. The PI6C919 has on-chip capacitors, eliminating the need for external capacitors at the X1, X2 pins. This reduces overall parts count and board area, and increases reliability. The OE (output enable) pin may be pulled down to disable the output buffer and save system power. Pin Configuration The small surface-mount SOIC-8 package is ideal for compact portable equipment applications. OE 1 8 Vcc X1 2 7 S1 X2 3 6 S0 GND 4 5 CLK 8-PIN W8 Pin Description Pin Name Pin # I/O S0 6 I S1 7 I X1 2 C X2 3 C CLK 5 O OE 1 I Output CLK Frequency Selection Clock Clock Clock (using10 (using 16.6 (using 20 MHz Xtal) MHz Xtal) MHz Xtal) Clock (using 22.1 MHz Xtal) – 33.3(1) 40 44.2 4 40(1) 66.6(1) 80(1) 88.4 10 5 50(1) 83 100(1) 110.5 11 7 70(1) 116 – – Selection S 1, S 0 N/M(2) 00 2 01 Description Select 0, internal pull-up Select 1, internal pull-up Crystal or clock input, 8 to 23 MHz Crystal connection or no connect Clock output OE = 1 Enable CLK output OE = 0 Disable CLK output Note: 1. I = Input, O = Output, C = Crystal Product Speed Grades Part No. PI6C918/919 PI6C918A/919A PI6C918B/919B Notes: 1. Indicates popular target frequencies. 2. The ratio of N/M may be changed by mask option. 1 Max CLK Output Freq. 80 MHz 100 MHz 120 MHz Max VCO Frequency 160 MHz 200 MHz 240 MHz PS7038B 09/08/97 PI6C918/919 3.3V Precision Clock Generator 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 Maximum Ratings Note: Stresses greater than those listed under MAXIMUM RATINGS may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability. Storage Temperature ................................................................. –65°C to +150°C Ambient Temperature with Power Applied .................................... 0°C to +70°C Supply Voltage to Ground Potential (Inputs & Vcc Only) .......... –0.5V to +7.0V Supply Voltage to Ground Potential (Outputs & D/O Only) ....... –0.5V to +7.0V DC Input Voltage ......................................................................... –0.5V to +7.0V DC Output Current ................................................................................... 120 mA Power Dissipation ......................................................................................... 0.5W DC Electrical Characteristics Operating Range, VCC = 3.3V ±10% (918/919/918A/919A). Vcc = 3.3V ±5% (918B/919B), Temperature 0°C to +70°C Symbol Description Test Conditions Min. Typ. Max. VOH = - 8mA VCC - 0.4 - - VOL = 8mA - - 0.4 2.0 - - - - 0.8 Units VOH Output HIGH Voltage VOL Output LOW Voltage VIH Select Input HIGH Voltage VIL Select Input LOW Voltage VIH Select Input HIGH Current VCC = Max., VIN = VCC - - 5 VIL Select Input LOW Current VCC = Max., VIN = 0V - - - 10 ICC Supply Current VCC = Max., CLK frequency = 40 MHz - 10 20 mA RL X1, X2 Negative Resistance - 1,000 - 2,000 - Ω RFB On- chip X1, X2 Internal Feedback Resistance 227 - - kΩ Vcc = Min., VIN = VIH or VIL V VCC = 5V µA Note: 1. There is no guarantee that on-chip capacitance eliminates the need for external capacitors. AC Electrical Characteristics Operating Range, VCC = 3.3V ±10% (918/919/918A/919A). Vcc = 3.3V ±5% (918B/919B), Temperature 0°C to +70°C Symbol Description Test Conditions(1) dT Duty Cycle, VTH = 1.4V Tr, Tf Rise/Fall Time 20% and 80% Vcc tPU Power-up Time(2) FXTAL Crystal Input Frequency Tj1s One Sigma Jitter Min. Typ. Max. Units 45 50 55 % — — 3 ns — — 10 ms MHz 918/918A/919/919A 10 — 20 918B/919B 10 — 24 fVCO ≥ 60 MHz — — 60 ps Note: 1. Test load of 15 pF, 2-inch trace 2. Time from when the power supply reaches 90% until locked clock output waveform is reached. 2 PS7038B 09/08/97 PI6C918/919 3.3V Precision Clock Generator 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 Crystal Specifications External Circuit It is the customer’s responsibility to procure the prototype and production crystals directly from crystal vendors. µ Typical Characte ris tic(1) Frequency, F Value 18.43200 MHz nominal Frequency Tolerance at 25° C ±50 ppm Ω Notes: a. Locate crystal as close to X1, X2 pins as possible. b. Connect a 0.1 µF bypass capacitor at Vcc (Pin 8). Ordering Information Part No. M ax. Fre q. Package Frequency Stability vs. Temperature vs. Aging ±35 ppm (0°C to 70°C) ±15 ppm/4 years Oscillation Mode Fundamental Calibration Mode Parallel resonant Load Capacitance, CL 20 pF, Fundamental Shunt Capacitance, CO 7 pF max., Fundamental Series Resistance, R1 50Ω Typical PI6C918W 80MHz Drive Level 1mΩ Typical PI6C918AW 100MHz Operating Temperature 0° to 70°C PI6C918BW 120MHz Storage Temperature - 40° to 85°C Narrow SOIC- 8 PI6C919W 80MHz PI6C919AW 100MHz PI6C919BW 120MHz Pericom Semiconductor Corporation 2380 Bering Drive • San Jose, CA 95131 • 1-800-435-2336 • Fax (408) 435-1100 • http://www.pericom.com 3 PS7038B 09/08/97