Sync Separator, 50% Slice, S-H, Filter, HOUT Features General Description • NTSC, PAL, and SECAM sync separation • Single supply, +5V operation • Precision 50% slicing • Built-in programmable color burst filter • Decodes non-standard vertical • Horizontal sync output • Sync. pulse amplitude output • Same socket can be used for 8-pin EL4581C • Low-power CMOS • Detects loss of signal • Resistor programmable scan rate • Few external components • Available in 16-pin PDIP and 16pin SO (0.150”) packages The EL4583C extracts timing from video sync in NTSC, PAL, and SECAM systems, and non standard formats, or from computer graphics operating at higher scan rates. Timing adjustment is via an external resistor. Input without valid vertical interval (no serration pulses) produces a default vertical output. Applications The level output pin provides a signal with twice the sync amplitude which may be used to control an external AGC function. A TTL/CMOS compatible No Signal Detect Output flags a loss or reduction in input signal level. A resistor sets the Set Detect Level. • • • • • • • • Video special effects Video test equipment Video distribution Multimedia Displays Imaging Video data capture Video triggers Outputs are: composite sync, vertical sync, filter, burst/back porch, horizontal, no signal detect, level, and odd/even output (in interlaced scan formats only). The EL4583C sync slice level is set to the mid-point between sync tip and the blanking level. This 50% point is determined by two internal sample and hold circuits that track sync tip and back porch levels. It provides hum and noise rejection and compensates for input levels of 0.5V to 2.0VP-P. A built in filter attenuates the chroma signal to prevent color burst from disturbing the 50% sync slice. Cut off frequency is set by a resistor to ground from the Filter Cut Off pin. Additionally, the filter can be by-passed and video signal fed directly to the Video Input. The EL4583C is manufactured using Elantec’s high performance analog CMOS process. Connection Diagram FILTER CUT OFF 1 Ordering Information SET DETECT LEVEL 2 COMPOSITE SYNC OUT 3 Package Tape & Reel Outline # EL4583CN 16-Pin PDIP - MDP0031 EL4583CS 16-Pin SO (0.150”) - MDP0027 EL4583CS-T7 16-Pin SO (0.150”) 7” MDP0027 EL4583CS-T13 16-Pin SO (0.150”) 13” MDP0027 Part No FILTER INPUT 4 VERTICAL SYNC OUT 5 DIGITAL GND 6 COMPOSITE VIDEO INPUT 8 16 ANALOG GND 15 HORIZONTAL SYNC OUT 14 VDD 13 ODD/EVEN OUTPUT 12 RSET* 11 BURST/BACK PORCH OUTPUT 10 NO SIGNAL DETECT OUTPUT 9 LEVEL OUTPUT EL4583C (8-Pin SO & 8-Pin PDIP) *Note: RSET must be a 1% register Manufactured under US Patent 5,528,303 Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation. August 6, 2001 FILTER OUTPUT 7 © 2001 Elantec Semiconductor, Inc. EL4583C EL4583C EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT Absolute Maximum Ratings (T VCC Supply Storage Temperature Pin Voltages A = 25°C) 7V -65°C to +150°C -0.5V to VCC +0.5V Operating Temperature Range Power Dissipation Die Junction Temperature -40°C to +85°C See Curves 150°C Important Note: All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA. DC Electrical Characteristics VDD = 5V, TA = 25°C, R SET = 681kΩ, RF = 22kΩ, RLV = 82kΩ Parameter Description IDD VDD = 5V [1] Clamp Voltage Pins 4, 8, unloaded Discharge Current Pins 4, 8, with Signal (VIN = 2V) Discharge Current Pins 4, 8, no Signal [2] Clamp Charge Current Pins 4, 8, VIN = 1V Ref. Voltage VREF Min Typ Max Unit 2.5 4 mA 1.3 1.55 1.8 V 3 6 12 µA 4 mA V 10 µA 2 3 Pin 12, VDD = 5V [3] 1.5 1.75 2 Filter Reference Voltage, VRF Pin 1 0.35 0.5 0.65 V Level Reference Current Pin 2 [4] 1.5 2.5 3.5 µA VOL Output Low Voltage IOL = 1.6mA 350 800 mV VOH Output High Voltage 1. 2. 3. 4. IOH = -40µA 4 IOH = -1.6mA 2.4 No video signal, outputs unloaded At loss of signal (pin 10 high) the pull down current source switches to a value of 10µA Tested for V DD 5V ±5% Current sourced from pin 2 is VREF/RSET 2 4 V Dynamic Characteristics RF = 22kΩ, RSET = 681kΩ, V DD = 5V, Video Input = 1VP-P, TA = 25°C, C L = 15pF, IOH = -1.6mA, IOL = 1.6mA Parameter Description Horizontal Pulse Width, Pin 15, tH [1] Vertical Sync Width, Pin 5, tVS [2] Burst/Back Porch Width, Pin 11, tB [1] Filter Attenuation Min Typ Max Unit 3.8 5 6.2 µs 195 2.7 FIN = 3.6MHz [3] 3.7 µs 4.7 12 Comp. Sync Prop. Delay, tCS VIN (Pin 4)—Comp Sync Input Dynamic Range p-p NTSC Signal 0.4 Input Voltage = 1Vp-p 40 50 60 VSLICE/VBLANK 40 50 60 500 600 700 27 36 57 µs 400 600 800 µs 250 400 ns Slice Level Level Out, Pin 9 Input Voltage = 1Vp-p, Pin 4 Vertical Sync Default Time, tVSD [4] Loss of Signal Time-Out Pin 10 Burst/Back Porch Delay, tBD See Figure 4 1. 2. 3. 4. 250 µs dB Width is a function of RSET c/s, Vertical, Back porch and H are all active low, V OH = 0.8V; vertical is 3H lines wide of NTSC signal Attenuation is a function of RF. See filter typical characteristics Vertical pulse width in absence of serrations on input signal 3 400 ns 2 V % mV EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT Pin Descriptions Pin No. Pin Name 1 Filter Cut-Off 2 Set Detect Level Function A resistor RF connected between this input and ground determines the input filter characteristic. Increasing RF increases the filter 3.58MHz color burst attenuation. See the typical performance characteristics. A resistor RLV connected between pin 2 and ground determines the value of the minimum signal which triggers the loss of signal output on pin 10. The relationship is V PMIN = 0.75RLV/RSET, where VPMIN is the minimum detected sync pulse amplitude applied to pin 4. See the typical performance characteristics. 3 Composite Sync Output 4 Filter Input This output replicates all the sync inputs on the input video. The filter is a 3 pole active filter with a gain of 2, designed to produce a constant phase delay of nominally 260ns with signal amplitude. Resistor RF on pin 1 controls the filter cut-off. An internal clamp sets the minimum voltage on pin 4 at 1.55V when the input becomes low impedance. Above the clamp voltage, an input current of 1µA charges the input coupling capacitor. With loss of signal, the current source switches to a value of 10µA, for faster signal recovery. 5 Vertical Sync Output The vertical sync output is synchronous with the first serration pulse rising edge in the vertical interval of the input signal and ends on the trailing edge of the first equalizing Output pulse after the vertical interval. It will therefore be slightly more than 3H lines wide. 6 Digital Ground 7 Filter Output Output of the active 3 pole filter which has its input on pin 4. It is recommended to ac couple the output to pin 8. 8 Video Input This input can be directly driven by the signal if it is desired to bypass the filter, for example, in the case of strong clean signals. This input is 6dB less sensitive than the filter input. 9 Level Output This pin provides an analog voltage which is nominally equal to twice the sync pulse amplitude of the video input signal applied to pin 4. It therefore provides an indication of signal strength. 10 No Signal Detect Output This is a digital output which goes high when either a) loss of input signal or b) the input signal level falls below a predetermined amplitude as set by RLV on pin 2. There will be several horizontal lines delay before the output is initiated. 11 Burst/Back Porch Output The start of back porch output is triggered on the trailing edge of normal H sync, and on the rising edge of serration pulses in the vertical interval. The pulse is timed out internally to produce a one-shot output. The pulse width is a function of RSET. This output can be used for d.c. restore functions where the back porch level is a known reference. 12 RSET The current through the resistor RSET determines the timing of the functions within the I.C. These functions include the sampling of the sync pulse 50% point, back porch output and the 2H eliminator. For faster scan rates, the resistor needs to be reduced inversely. For NTSC 15.7kHz scan rate RSET is 681k 1%. RSET must be a 1% resistor. 13 Odd/Even Output Odd-even output is low for even field and high for odd field. The operation of this circuit has been improved for rejecting spurious noise pulses such as those present in VCR signals. 14 VDD 5V 15 Horizontal Sync Output 16 Analog Ground This is the ground return for digital buffer outputs. The internal circuits are designed to have a high immunity to supply variations, although as with most I.C.s a 0.1µF decoupling capacitor is advisable. This output produces only true H pulses of nominal width 5µs. The leading edge is triggered from the leading edge of the input H sync, with the same prop. delay as the composite sync. The half line pulses present in the input signal during vertical blanking are eliminated with an internal 2H eliminator circuit. This is the ground return for the signal paths in the chips, RSET, RF and RLV. 4 Typical Performance Curves RSET vs Horizontal Frequency Back Porch Clamp On Time vs RSET Vertical Default Delay Time vs RSET Filter 3dB BW vs RF Level Out (Pin 9) vs Sync. Tip Amplitude Minimum Signal Detect vs RLV Filter Attenuation vs RF @ f = 3.58MHz 1.8 Package Power Dissipation vs Ambient Temp. JEDEC JESD51-3 Low Effective Thermal Conductivity Test Board 1.54W 1.6 θJ Power Dissipation (W) 1.4 1.2 1.136W A= PD IP 81 ° C/ 16 W 1 θJ 0.8 A =1 0.6 SO 16 10 °C/ W 0.4 0.2 0 0 25 50 75 85 100 125 Ambient Temperature (°C) Note 1: For RLV < 1000k¾, no signal detect output (pin 10) will default high at minimum signal sensitivity specification, or at complete loss of signal. 5 150 EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT Timing Diagram Notes: b. The composite sync output reproduces all the video input sync pulses, with a propagation delay. c. Vertical sync leading edge is coincident with the first vertical serration pulse leading edge, with a propagation delay. d. Odd-even output is low for even field, and high for odd field. e. Back porch goes low for a fixed pulse width on the trailing edge of video input sync pulses. Note that for serration pulses during vertical, the back porch starts on the rising edge of the serration pulse (with propagation delay). f. Horizontal sync output produces the true “H” pulses of nominal width of 5µs. It has the same delay as the composite sync. Figure 1. 6 Figure 2. Figure 3. 7 EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT Figure 4. Standard (NTSC Input) H. Sync Detail 8 Description of Operation A simplified block schematic is shown in Figure 1. The following description is intended to provide the user with sufficient information to understand the effects of the external components and signal conditions on the outputs of the integrated circuit. chip. Reference VR4 with op-amp A2 forces pin 12 to a reference voltage of 1.7V nominal. Consequently, it can be seen that the external resistance RSET will determine the value of the reference current ITR. The internal resistance R3 is only about 6kΩ, much less than RSET. All the internal timing functions on the chip are referenced to ITR and have excellent supply voltage rejection. The video signal is AC coupled to pin 4 via the capacitor C1, nominally 0.1µF. The clamp circuit A1 will prevent the input signal on pin 4 going more negative than 1.5V, the value of reference voltage V R1. Thus the sync tip, the most negative part of the video waveform, will be clamped at 1.5V. The current source I1, nominally 6µA, charges the coupling capacitor during the remaining portion of the H line, approximately 58µs for a 15.75kHz timebase. From I • t = C • V, the video time-constant can be calculated. It is important to note that the charge taken from the capacitor during video must be replaced during the sync tip time, which is much shorter, (ratio of x 12.5). The corresponding current to restore the charge during sync will therefore be an order of magnitude higher, and any resistance in series with CI will cause sync tip crushing. For this reason, the internal series resistance has been minimized and external high resistance values in series with the input coupling capacitor should be avoided. The user can exercise some control over the value of the input time constant by introducing an external pull-up resistance from pin 4 to the 5V supply. The maximum voltage across the resistance will be VDD less 1.5V, for black level. For a net discharge current greater than zero, the resistance should be greater than 450k. This will have the effect of increasing the time constant and reducing the degree of picture tilt. The current source I1 directly tracks reference current ITR and thus increases with scan rate adjustment, as explained later. To improve noise immunity, the output of the 3 pole filter is brought out to pin 7. It is recommended to AC couple the output to pin 8, the video input pin. In case of strong clean video signal, the video input pin, pin 8, can be driven by the signal directly. Comparator C2 on the input to the sample and hold block (S/H) compares the leading and trailing edges of the sync. pulse with a threshold voltage VR2 which is referenced at a fixed level above the clamp voltage VR1. The output of C2 initiates the timing one-shots for gating the sample and hold circuits. The sample of the sync tip is delayed by 0.8µs to enable the actual sample of 2µs to be taken on the optimum section of the sync. pulse tip. The acquisition time of the circuit is about three horizontal lines. The double poly CMOS technology enables long time constants to be achieved with small high quality on-chip capacitors. The back porch voltage is similarly derived from the trailing edge of sync, which also serves to cut off the tip sample if the gate time exceeds the tip period. Note that the sample and hold gating times will track RSET through IOT. The 50% level of the sync tip is derived through the resistor divider R1 and R2, from the sample and held voltages VTIP and VBP and applied to the plus input of comparator C1. This comparator has built in hysteresis to avoid false triggering. The output of C2 is a digital 5V signal which feeds the C/S output buffer B1, the vertical, back porch and odd/even functions. The signal is processed through an active 3 pole filter (F1) designed for minimum ripple with constant phase delay. The filter attenuates the color burst by 12dB and eliminates fast transient spikes without sync crushing. An external filter is not necessary. The filter also amplifies the video signal by 6dB to improve the detection accuracy. The filter cut-off frequency is controlled by an external resistor from pin 1 to ground. The vertical circuit senses C/S edges and initiates an integrator which is reset by the shorter horizontal sync pulses but times out with the longer vertical sync. pulse widths. The internal timing circuits are referenced to IOT and VR3, the timout period being inversely proportional to the timing current. The vertical output pulse is started on the first serration pulse in the vertical interval and is Internal reference voltages (block VREF ) with high immunity to supply voltage variation are derived on the 9 EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT then self-timed out. In the absence of a serration pulse, an internal timer will default the start of vertical. The Horizontal circuit senses C/S edges and produces the true horizontal pulses of nominal width 5µs. The leading edge is triggered from the leading edge of the input H sync, with the same prop. delay as composite sync. The half line pulses present in the input signal during vertical blanking are removed with an internal 2H eliminator circuit. The 2H eliminator initiates a time out period after a horizontal pulse is generated. The time out period is a function of IOT which is set by RSET. The back porch is triggered from the sync tip trailing edge and initiates a one-shot pulse. The period of this pulse is again a function of IOT and will therefore track the scan rate set by RESET. The odd/even circuit (O/E) tracks the relationship of the horizontal pulses to the leading edge of the vertical output and will switch on every field at the start of vertical. Pin 13 is high during an odd field. Loss of video signal can be detected by monitoring the No Signal Detect Output pin 10. The VTIP voltage held by the sample and hold is compared with a voltage level set by RLV on pin 2. Pin 10 output goes high when the VTIP falls below RLV set value. VTIP voltage is also passed through an amplifier with gain of 2 and buffed to pin 9. This provides an indication of signal strength. This signal (Level Output) can be used for AGC applications. 10 Block Diagram * Note: RSET must be a 1% resistor Figure 5. Standard (NTSC Input) H. Sync Detail 11 EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT EL4583C EL4583C Sync Separator, 50% Slice, S-H, Filter, HOUT General Disclaimer Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement. August 6, 2001 WARNING - Life Support Policy Elantec, Inc. products are not authorized for and should not be used within Life Support Systems without the specific written consent of Elantec, Inc. Life Support systems are equipment intended to support or sustain life and whose failure to perform when properly used in accordance with instructions provided can be reasonably expected to result in significant personal injury or death. Users contemplating application of Elantec, Inc. Products in Life Support Systems are requested to contact Elantec, Inc. factory headquarters to establish suitable terms & conditions for these applications. Elantec, Inc.’s warranty is limited to replacement of defective components and does not cover injury to persons or property or other consequential damages. Elantec Semiconductor, Inc. 675 Trade Zone Blvd. Milpitas, CA 95035 Telephone: (408) 945-1323 (888) ELANTEC Fax: (408) 945-9305 European Office: +44-118-977-6020 Japan Technical Center: +81-45-682-5820 12 Printed in U.S.A.