A reliable composite video transmission solution with battery short circuit protection

Connection / reference device

ADV7391 / ADV7393 low-power, chip-level, 16 / 8-bit SD / HD video encoder

ADA4432-1 single-ended standard definition video filter amplifier, the output has battery short circuit protection function

ADA4433-1 differential standard definition video filter amplifier, the output has battery short circuit protection function

Evaluation and design support

Circuit Evaluation Board

CN-0264 Circuit Evaluation Board (EVAL-CN0264-EB1Z)

Design and integration files

Schematic diagram, layout file, bill of materials

Circuit function and advantages

The circuit in Figure 1 shows that the digital-to-analog video converter is paired with a low-cost, low-power, fully integrated reconfigurable video filter with output short-circuit (STB) protection, which is very suitable for harsh infotainment environments ( For example, in the automotive field) CVBS video transmission. Although many video encoders (video DACs) such as the ADV7391 can directly drive the video load, it is usually beneficial to place a video driver at the output of the video encoder, which can be used to implement power saving, filtering, line driving, and overvoltage circuits. Protective function. The video driver is usually configured as an active filter (also known as a reconstruction filter), and its main uses are reflected in two aspects: to prevent the introduction of high-frequency components of the video signal during sampling (above the Nyquist frequency); to provide gain To drive the 75 Ω external cable connected to the video display.

Designers of infotainment and other video systems, such as rear-view cameras and rear-seat entertainment systems, tend to use this circuit to transmit video for the reasons described above. However, there is a third urgent design problem, which is robustness. The ADA4432-1 and ADA4433-1 provide analog video designers with integrated ICs with critical overvoltage protection, enhanced ESD tolerance, excellent video characteristics, lower power consumption, and line diagnostics Features.

ADA4432-1 and ADA4433-1 are fully integrated video reconstruction filters, which are single-ended and differential types, respectively. Both make the output end have overvoltage protection (STB protection) function up to 18 V, and also have low power consumption characteristics and line diagnosis function. The line diagnosis function is provided through a logic output, which can be activated when a fault condition occurs. ADA4432-1 and ADA4433-1 have a built-in high-order filter. The 3 dB cut-off frequency is 10 MHz and provides 45 dB suppression at 27 MHz.

With STB protection and robust ESD tolerance, the ADA4432-1 and ADA4433-1 can provide excellent protection in harsh environments.

The ADV7391 and ADA4432-1 are fully compliant with automotive application standards and are very suitable for infotainment systems and visual security systems in automotive applications. The ADV7391, ADA4432-1 and ADA4433-1 are available in very small LFCSP packages and are suitable for small space applications.

Reliable composite video transmission solution with output battery short circuit protection

Circuit description

The ADV7391 is a low-power, fully integrated digital video encoder capable of converting digital 8-bit component video data from CMOS imaging devices into a standard analog baseband video signal compatible with global standards. Three 10-bit digital-to-analog video converters (operating with VAA = 2.6 V to 3.46 V) support composite (CVBS), S-video (YC), or component (YPrPb / RGB) in standard definition (SD) or high definition (HD) video formats Analog output. The circuit in Figure 1 is configured to provide low output drive only through DAC1. To further reduce power consumption, other DACs and phase-locked loops (PLLs) have been turned off. Low drive mode is defined as 4.33 mA full-scale output current. The ADV7391 contains a RSET pin. A resistor is connected between the RSET pin and AGND to control the full-scale output current. For low drive operation, RSET must be equal to 4.12 kΩ and RL must be equal to 300 Ω. The resistor connected to the RSET pin must have a 1% tolerance.

The ADV7391 contains an on-chip PLL that allows oversampling of video data. As shown in Figure 1, the PLL has been disabled (subaddress 0x00, Bit 1 = 1), thus providing a 2x SD oversampling rate. With the PLL disabled, to save space and cost, the external loop filter components are removed.

The ADA4432-1 can be used as a pseudo-differential (single-ended) driver with unbalanced transmission lines. The pseudo-differential mode uses one conductor to carry the unbalanced data signal transmitted from the driver to the receiver, and the other conductor is used as a ground reference signal.

The positive conductor connects the output of the ADA4432-1 to the positive input of the differential receiver. The negative line or ground conductor from the source circuit is connected to the negative input of the receiver. The output termination resistance of the ADA4432-1 should match the impedance of the input termination resistance of the receiver. For example, in a 75 Ω system, each output of the ADA4432-1 is rear-terminated with 75 Ω resistors, which are connected to a 75 Ω resistor at the receiver.

In Figure 1, the ADA4432-1 is configured as a single-ended to single-ended driver, allowing unbalanced transmission using twisted pair, untwisted pair, or coaxial cable.

Low power consumption considerations

Compared with driving the video cable directly through the DAC output, using the ADA4432-1 or ADA4433-1 and series source termination and parallel load termination at a low power supply voltage can achieve significant power savings. Figure 2 shows the video DAC driving the cable directly. Properly terminated DAC drive transmission lines require two 75 Ω loads in parallel, requiring more than 33 mA to achieve a 1.3 V full-scale voltage level. Figure 3 shows the use of ADA4432-1 and series-parallel termination to drive the same video load. This requires twice the output voltage to drive the 150 Ω equivalent resistance, but requires only a little over 15 mA to achieve full-scale output. When using the same power supply voltage as the DAC, this can save 74% compared to the circuit in Figure 2. The high-order filtering function provided by the ADA4432-1 can reduce the DAC oversampling rate requirements, thereby further reducing power consumption. The main source for power saving in the configuration shown in Figure 3 is the low drive mode setting of the ADV7391. Combined with oversampling requirements (PLL off) and the reduction in required load current, this mode can significantly reduce power consumption.

For details on the low drive mode, please refer to the ADV7391 data sheet.

Reliable composite video transmission solution with output battery short circuit protection

Touchless Sensor-Makes it germ Free

Environment Friendly-Prevents Contamination

Ideal fit for Kitchen/Bathroom/Bedroom

 

As users hands or debris enter the zone 6 inches (15cm) from the infrared sensor on top of the dustbin, the lid will automatically open.

 

The Lid will remain open if hand or debris is within the 6 inch (15cm) range of the infrared sensor. Lid will close 7 seconds after users hands move away.

 

The new touch switch panel has higher stability and efficiency. you can use it effortlessly. There are [OPEN" & [CLOSE" buttons for manual operation, and there is a ON/OFF power switch on the back of the dustbin.

 

The new removable plastic rim is easy to lift out, and the plastic ring helps leave no excess plastic bag visible (w/o liner).

Two liners (30L+20L) for easy recycling


Features:

-100% [Hands-Free" operation.

-[Germ-Free"-Prevents cross-contamination

- Trash Bag Retainer Ring stops full, heavy bag from falling in and keeps bag ends neatly out of view

-Rubber feet keeps this trash can in place and protects floors from scratches

-Removable hard ABS plastic head for easy cleaning

-Uses 4 AA-Sized batteries 1.5V(LR6) (Not included)

-Low energy-consuming

-Multiple colors to satisfy your different requirements.

-Capacity:30L+20L

-Dimensions: 34W x 48 L x 64H CM

-1 Year Manufacturer`s Warranty included


Rectangular Sensor Automatic Dustbin 2-Compartment 30L+20L

Automatic Dustbin,Hand Sensing Dustbin,Hotel Dustbin,Environmental Dustbin

NINGBO ZIXING ELECTRONIC CO.,LTD. , https://www.zixingautobin.com