AV9173-01 Integrated Circuit Systems, Inc. Video Genlock PLL General Description Features The AV9173-01 provides the analog circuit blocks required for implementing a video genlock dot (pixel) clock generator. It contains a phase detector, charge pump, loop filter, and voltage-controlled oscillator (VCO). By grouping these critical analog blocks into one IC and utilizing external digital functions, performance and design flexibility are optimized as are development time and system cost. • • • When used with an external clock divider, the AV9173-01 forms a Phase-Locked Loop configured as a frequency synthesizer. The AV9173-01 is designed to accept video horizontal synchronization (h-sync) pulses and produce a video dot clock. A separated, negative-going sync input reference pulse is required at pin 2 (I N). • • • • • • Phase-detector/VCO circuit block Ideal for genlock system Reference clock range 25 kHz to 1 MHz for full output clock range Input clocks down to 12 kHz possible with restricted output conditions (see Table 1) Output clock range 1.25 to 75MHz On-chip loop filter Single 5 volt power supply Low power CMOS technology Small 8-pin DIP or SOIC package The AV9173-01 is also suited for other clock recovery applications in such areas as data communications. Block Diagram AV9173-01RevC052197P 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. AV9173-01 Pin Configuration 8-Pin DIP or SOIC Pin Descriptions PIN NUMBER 1 2 3 4 5 6 7 8 PIN NAME FBIN IN GND FS0 OE CLK1 VDD CLK2 TYPE DESCRIPTION Input Input — Input Input Output — Output Feedback Input Input for reference sync pulse Ground Frequency Select 0 input Output Enable Clock Output 1 Power Supply (+5V) Clock Output 2 (Divided-by-2 from Clock 1) Table 1: Allowable Input Frequency to Output Frequency (Outputs in MHz) fIN (kHz) 12 ≤ f IN ≤ 14 kHz 14 < f IN ≤ 17 kHz 17 < f IN ≤ 30 kHz 30 < f IN ≤ 35 kHz 35 < f IN ≤ 1000 kHz f OUT for FS = 0 (MHz) CLK1 Output CLK2 Output 44.0 to 75 22.0 to 37.5 30.0 to 75 15.0 to 37.5 25.0 to 75 12.5 to 37.5 7.5 to 37.5 15.0 to 75 5.0 to 37.5 10.0 to 75 2 f OUT for FS = 1 (MHz) CLK1 Output CLK2 Output 11.0 to 18.75 5.5 to 9.375 7.5 to 18.75 3.75 to 9.375 6.25 to 18.75 3.125 to 9.375 3.75 to 18.75 1.875 to 9.375 2.5 to 18.75 1.25 to 9.375 AV9173-01 Using the AV9173-01 Most video sources, such as video cameras, are asynchronous, free-running devices. To digitize video or synchronize one video source to another free-running reference video source, a video “genlock” (generator lock) circuit is required. The AV9173-01 integrates the analog blocks which make the task much easier. AC specifications (VCO frequency), an input as low as 12kHz (such as NTSC or PAL h-sync) can be used. The output hook-up of the AV9173-01 is dictated by the desired dot clock frequency. The primary consideration is the internal VCO which operates over a frequency range of 10 MHz to 75 MHz. Because of the selectable VCO output divider and the additional divider on output CLK2, four distinct output frequency ranges can be achieved. The following Table lists these ranges and the corresponding device configuration. In the complete video genlock circuit, the primary function of the AV9173-01 is to provide the analog circuitry required to generate the video dot clock within a PLL. This application is illustrated in Figure 1. The input reference signal for this circuit is the horizontal synchronization (h-sync) signal. If a composite video reference source is being used, the h-sync pulses must be separated from the composite signal. A video sync separator circuit, such as the National Semiconductor LM1881, can be used for this purpose. FS0 State 0 0 1 1 The clock feedback divider shown in Figure 1 is a digital divider used within the PLL to multiply the reference frequency. Its divide ratio establishes how many video dot clock cycles occur per h-sync pulse. For example, if 880 pixel clocks are desired per h-sync pulse, then the divider ratio is set to 880. Hence, together the h-sync frequency and external divider ratio establish the dot clock frequency: Output Used CLK1 CLK2 CLK1 CLK2 Frequency Range 10 - 75 MHz 5 - 37.5 MHz 2.5 - 18.75 MHz 1.25 - 9.375 MHz Note that both outputs, CLK1 and CLK2, are available during operation even though only one is fed back via the external clock divider. Pin 5, OE, tristates both CLK1 and CLK2 upon logic low input. This feature can be used to revert dot clock control to the system clock when not in genlock mode (hence, when in genlock mode the system dot clock must be tristated). fOUT = f IN • N where N is external divide ratio Both AV9173-01 input pins IN and FBIN respond only to negative-going clock edges of the input signal. The h-sync signal must be constant frequency in the 25 kHz to 1 MHz range and stable (low clock jitter) for creation of a stable output clock. When unused, inputs FS0 and OE must be tied to either GND (logic low) or VDD (logic high). For further discussion of VCO/PLL operation as it applies to the AV9173-01, please refer to the AV9170 application note. The AV9170 is a similar device with fixed feedback dividers for skew control applications. Refer to Application Brief (AB01) for additional details on use of input frequencies below 25kHz. By following the guidelines in this brief and meeting the test conditions in the Figure 1: Typical Application of AV9173-01 in a Video Genlock System 3 AV9173-01 Absolute Maximum Ratings VDD (referenced to GND) . . . . . . . . . . . . . . . . 7.0 V Operating Temperature under Bias . . . . . . . . . 0° C to +70° C Storage Temperature . . . . . . . . . . . . . . . . . . . . – 65°C to +150°C Voltage on I/O pins referenced to GND . . . . . GND – 0.5 V to VDD + 0.5 V Power Dissipation . . . . . . . . . . . . . . . . . . . . . . 0.5 watts Stresses above those listed under Absolute Maximum Ratings above 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 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 Characteristic VDD = +5V ±5%, TA = 0°C to 70°C, unless otherwise stated DC CHARACTERISTICS PARAMETER Input Low Voltage Input High Voltage Input Low Current Input High Current Output Low Voltage1 SYMBOL VIL V IH IIL I IH VOL Output High Voltage1 VOH1 Output High Voltage1 VOH2 Output High Voltage1 Supply Current VOH3 IDD TEST CONDITIONS MIN V DD = 5V — V DD = 5V 2.0 V IN = 0V -5 V IN = V DD -5 I OL = 8mA — I OH = -1mA, V DD -0.4V V DD = 5.0V I OH = -4mA, V DD -0.8V V DD = 5.0V I OH = -8mA 2.4 Unloaded, 50 MHZ — TYP — — — — — MAX 0.8 — — 5 0.4 UNITS V V µA µA V — — V — — V — 20 — 50 V mA Notes: 1. Duty cycle measured at 1.4V. 2. Input Reference Frequency = 25 kHz, Output Frequency = 25 MHz. Jitter measured between adjacent vertical pixels. 3. CLK1 frequency applies for FS = 0. For FS = 1 condition, divide allowable CLK1 range by the factor of 4. 4 AV9173-01 Electrical Characteristics VDD = +5V ±5%, TA = 0°C to 70°C, unless otherwise stated AC CHARACTERISTICS PARAMETER Input Clock Rise Time1 Input Clock Fall Time1 Output Rise Time1 SYMBOL TEST CONDITIONS r ICLK ICLK f tr 1 15pF load; 0.8 to 2.0V 15pF load; 1 Output Rise time tr 2 20% to 80% VDD tf 1 15pF load; 2.0 to 0.8V Output Fall time1 15pF load; 1 Output Fall time tf 2 80% to 20% VDD dt 15pF load Output Duty Cycle1 T1s1 CLK1 frequency≥ 25 MHz Jitter, one sigma1 Tabs 1 CLK1 frequency≥ 25 MHz Jitter, absolute1 1 T1s2 CLK1 frequency< 25 MHz Jitter, one sigma Tabs 2 CLK1 frequency< 25 MHz Jitter, absolute1 Line-to-line jitter,1 absolute2 TL abs fi See allowable f i below: Input Frequency,1 IN or FBIN 12 ≤ f i ≤ 14 kHz 14 < f i ≤ 17 kHz fCLK1 17 < f i ≤ 30 kHz CLK1 Frequency1, 3, 4 30 < f i ≤ 35 kHz 35 < f i ≤ 1000 kHz MIN — — — TYP — — 0.6 MAX 10 10 1.5 UNITS ns ns ns — 1.6 3.0 ns — 1.0 2.0 ns — 0.9 2.0 ns 40 — -400 — — — 12 44.0 30.0 25.0 15.0 10.0 47 120 ±250 — — ±4 — — — — — — 55 250 400 1 2 — 1000 75 75 75 75 75 % ps ps % % ns kHz MHz MHz MHz MHz MHz Notes: 1. Parameter is guaranteed by design and characterization. Not 100% tested in production. 2. Input Reference Frequency = 25 kHz, Output Frequency = 25 MHz. Jitter measured between adjacent vertical pixels. 3. CLK1 frequency applies for FS = 0. For FS = 1 condition, divide allowable CLK1 range by the factor of 4. 4. An Application Brief (AB01) documents the operation of the AV9173 for low input frequencies. This provides guidelines for usable output frequencies and feedback ratios required to use inputs below 25 kHz. By following these guidelines, the AV9173 will operate down to 12 kHz inputs across temperature, voltage and lot-to-lot variation. 5 AV9173-01 8-Pin DIP PACKAGE 8-Pin SOIC PACKAGE Ordering Information AV9173-01CN08 - or - AV9173-01CS08 Example: XXX XXXX - PPP M X#W Lead Count & Package Width Lead Count = 1, 2 or 3 digits W = 0.3" SOIC or 0.6" DIP; None = Standard Width Package Type N = DIP (Plastic) S = SOIC Pattern Number (2 or 3 digit number for parts with ROM code patterns) Device Type (consists of 3 or 4 digit numbers) Prefix ICS, AV = Standard Device 6 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.