Applications Intermediate Bus Architecture Telecom Data Communication Distributed Power Architecture Servers, Workstations High Efficiency – No Heat Sink Required Reduces Total Solution Board Area Tape and Reel Packaging Compatible with Pick and Place Equipment Minimize Part Numbers in Inventory Low Cost Products: Y-Series Features RoHS lead-free solder and lead-free solder provide product delivery up to 16 A (88 W) extended input range 9.6 V–14 V high efficiency ( 0.948 at 5 V output) surface mount components with industry standard footprint and pinout small size and Low Profile: 1.30" x 0.53" x 0.314 " (33.02 x 13.46 x 7.98 mm) Weight: 0.23 oz [6.50 g] Maximum Coplanarity Less than 0.003 Synchronous Buck Converter Topology Start-Up to Pre-Biased Output No Minimum Load Required Programmable output voltage via external resistors Operating ambient temperature: -40°C to 85°C Remote output detection Remote on/off (positive or negative) Fixed frequency operation Automatic reset output Overcurrent protection Automatic reset Overtemperature protection High reliability , MTBF approximately 27.2 million hours Calculated per Telcordia TR-332, Method I Case 1 All materials meet UL94, V-0 flammability rating UL 60950 recognized in the US and Canada, and DEMKO certified to IEC/EN 60950 It is recommended to use a power point converter with an intermediate regulated bus converter using a bus architecture (IBA). The YS12S16 non-isolated DC-DC converter is available in an industry standard surface mount package. Using a 9.6-14 volt DC input, the YS12S16 converter is Ideal for intermediate bus architectures, often requiring point-of-load power supply. They offer extremely tight programmable output voltages from 0.7525 V to 5.5 V.
The YS12S16 converter provides excellent thermal performance even in high temperature environments with minimal airflow. This is achieved through the use of advanced circuitry, packaging and processing to achieve ultra-efficient, superior thermal management and low-energy design technical body contours.
The lower body profile and exclusion of fins minimize resistance to system airflow, enhancing cooling of upstream and downstream equipment. Assembly is 100 % automated, coupled with advanced power electronics and thermal design, resulting in a product with high reliability.

Operation input and output impedance
The YS12S16 converter should have low impedance through the DC source. In many applications, the connection from the power supply to the inverter will affect the stability of the inverter. It is recommended to use decoupling capacitors (minimum 47µF) as close as possible to the converter input pins to ensure reduced input ripple voltage. Internally, the converter has an input capacitance of 30µF (low esr ceramic). In a typical application, a low esr tantalum or pos capacitor will suffice to provide adequate ripple voltage filtering at the converter input. However, a low esr ceramic capacitor of 47µF- is recommended in order to reduce the input ripple voltage. They should be placed as close as possible to the input pins of the converter. The YS12S16 is designed to stabilize operation with or without external capacitors. Low esr ceramic capacitors placed as close as possible are recommended for improved transient performance and reduced output voltage ripple.
It is important to keep low resistance and low resistance connected to the load to the converter's output pins in order to maintain good load regulation.
The on/off (pin 1) switch pin is used to turn the power converter on or off remotely via a system signal. There are two remote options available, positive logic (standard option) and negative logic, both referenced to GND. A typical connection is a circuit configuration where R is used only for the negative logic option Y series on/off function.
The negative logic version turns on the converter when the ON/OFF pin is at logic low or left open, and when the ON/OFF pin is at logic high or connected to a VIN.
The open/close pin is internally pulled up to the active logic version. TTL or CMOS logic gates, open collector (open drain) transistors can be used to drive on/off pins. When using an open collector (open drain) transistor with negative logic option, add a 75K pull-up resistor (R*) to the VIN; this device must be able to:
- sinks 0.8 volts at 0.2 mA at low level
- Supplies up to 0.25mA at high logic levels 2.3V-5V
- Source up to 0.75mA when connected to VIN (vin). The remote control feature of the remote control (pin 2) of the inverter compensates only for the voltage drop that occurs at the output pin (pin 4) of the converter and loads. The sensor (pin 2) pin should be connected to the load or point output that needs to be regulated. There is no detection function ground return pin, and a solid ground plane should provide a low voltage drop. If remote sensing is not required, the sense pin must be connected to the output pin (pin 4) to ensure that the converter will regulate the voltage at the specified output. If these connections are not made, the converter will output a value slightly higher than the specified value.

Protection Features Input Undervoltage Lockout Input undervoltage lockout is standard on the converter. When the input voltage drops below a predetermined voltage; when the VIN returns to the specified range.
The input voltage must be at least 9.6V (usually 9V) for the converter to turn on. Once the converter is turned on, when the input voltage falls below 8.5 volts.
Output Over Current Protection (OCP) The drive has over current protection and short circuit conditions. When an overcurrent condition is sensed, the converter will enter the hiccup state mode. Once the overload or short circuit condition is removed, vout will return to the nominal value.
Over-Temperature Protection (OTP) The drive will shut down in an over-temperature condition to protect itself from the over-temperature derating curve caused by operating outside the thermal system, or operating under abnormal conditions such as a system fan failure. Automatically restarts when the converter cools down to a safe operating temperature.
Safety requirements converters comply with North American and international safety regulatory requirements UL60950 and EN60950. Maximum DC Voltage VIN condition between any two pins. Therefore, the device has an ELV (Extra Low Voltage) output; under the condition that all input voltages are ELV.
The converter has no internal fuse. To comply with safety agency requirements, recognized fuses with a maximum rating of 15 amps must be used in series with the input line.
Features General Information Converters are characterized by operational aspects, including thermal derating (maximum load current as a function of ambient temperature and airflow) for vertical mounting, efficiency, start-up and shutdown parameters, output ripple and noise, load step changing transient response, overload and short circuit. Numbers are numbered by plot xy, where x indicates different output voltages, and y is associated with a particular plot (Y=1 for vertical thermal derating...).

For example, the vertical thermal derating general voltage for all outputs will be referenced.
The following pages contain specific plots or transducer-related waveforms. Additional specific data comments are as follows.
Test Conditions All data shown was collected with converters soldered to a test board, specifically a 0.060" thick four-layer printed wiring board (PWB). No metallization on top bottom layer. Two intrinsic layers consisting of two ounces of copper Used to provide connection tracking to the converter.
The lack of metallization of the outer layers ensures that the transfer of heat from the converter to the PWB is minimized due to the limited thermal connection. This provides a worst-case but consistent scheme for thermal derating purposes.
All measurements requiring airflow were made using infrared thermal imaging and thermocouple temperature measurements at vertical and horizontal wind tunnel facilities.

Exceeding their ratings is important to maintain high reliability. If one wants to operate the converter at or near the specified maximum load derating curve, it is prudent to check the operating temperature in the actual application. Thermal imaging is preferred; if such capabilities are not available, thermocouples may be utilized. .AWG 40 measurement thermocouple is recommended to ensure measurement accuracy. Careful placement of thermocouple leads will further reduce measurement errors. Refer to the best measurement thermocouple location.
Location of thermocouples for thermal testing.
The thermal decay effect load current versus ambient temperature and airflow rate is shown in the figure. Maximum temperature X.1 ambient temperature at 25°C and 85°C, airflow velocity from 30 to 500LFM (0.15 m/s to 2.5 m/s) and vertical converter installation. Airflow during testing with the converter's stub shaft, starting from pin 1 and pin 6 connected to pins 2–5.
For each set of conditions, the maximum load current is defined as the lowest of: (i) the output current temperature of any mosfet does not exceed the specified maximum temperature (120°C), as shown in the thermal image, or (ii) the converter The maximum rated current (16A) during normal operation, the derating curve maximum FET temperature less than or equal to 120°C should not be exceeded. The temperature on the thermocouple location on the PCB, as shown in Figure D, should not exceed 120°C in order to operate within the derating curve.
Efficiency shows a plot of efficiency vs. load current for an ambient temperature of 25°C, airflow velocity of 200LFM (1 m/s) and 9.6 V, 12 V and 14 V.
The relationship between power consumption and load current
Plot at Ta = 25°C, airflow velocity 200 lfm (1 m/s) vertical mounting and input voltages of 9.6 V, 12 V and 14 V.
Ripple and Noise Output voltage ripple waveform at full rated load current. Note that all output voltages are measured on 1∏f ceramic waveform capacitors.
The output voltage ripple and input reflected ripple current waveforms are obtained through the test device as shown in Figure E.