Features Offers RoHS lead-free solder and lead-free solder products Provides power up to 5 A (28 W) Extended input range 9.6 to 14 VDC
No derating below 85°C (70°C at 5 V and 3.3 V)
Surface mount components Industry standard footprint and small footprint: 0.80" x 0.45" x 0.247 " (20.32mm x 11.43mm x 6.27mm)
Weight: 0.08 oz [2.26 g]
Coplanarity <0.003
Synchronous Buck Converter Topology Start-Up to Pre-Biased Output No Minimum Load Programmable Output Voltage Through External Resistors Operating Ambient Temperature: -40°C to 85°C
Remote On/Off Fixed Frequency Operation Auto Reset Output Over Current Protection Auto Reset Over Temperature Protection High Reliability, MTBF = 71.8 Million Hours, Calculated per Telcordia TR-332, Method I Case 1 All Materials Compliant with UL94, V-0 Flammability grade
UL60950 Recognized in the US and Canada, and DEMKO Certification to IEC/EN60950 Recommended for Use with Regulated Bus Converters in Intermediate Bus Architecture (IBA) Power Point Load Converter YNM12S05 Non-Isolated DC-DC Converter on Industry Standard Surface Delivering up to 5A of output current in a mount package When operating from 9.6 to 14 VDC input, the YNM12S05 converters are ideal for intermediate bus architectures where point-of-load power (POL) delivery is often required to provide extremely high performance. Tightly regulated, programmable output voltage from 0.7525 to 5.5 VDC.
Even in high temperature environments with minimal airflow, the YNM12S05 converter provides excellent thermal performance without the need for derating below 85°C even in natural convection conditions without airflow (for 5Vdc and 3.3Vdc outputs, no Requires derating below 70°C) This performance is achieved through the use of advanced circuit, packaging and processing techniques to enable designs with ultra-high efficiency, excellent thermal management and very low body profile.
The lower body profile and isolation of the heat sinks minimize resistance to system airflow, which enhances cooling of upstream and downstream equipment. 100 % automated assembly, coupled with advanced power electronics and thermal design, enables the product to have Extreme reliability.

Operation input and output impedance
Y-Series converters should be connected to a DC power supply through a low impedance. In many applications, the inductance associated with the distribution from the power supply to the converter input can affect converter stability. It is recommended to use decoupling capacitors (minimum 47µF) as close as possible to the input pins of the converter to ensure converter stability and reduce input ripple voltage. Internally, the converter has an input capacitance of 3.2µF (low ESR ceramic).
In typical applications, low ESR tantalum or POS capacitors are sufficient to provide adequate ripple voltage filtering at the converter input.
However, to reduce the input ripple voltage, it is recommended to use very low ESR ceramic capacitors 47-100µF at the input of the converter. They should be as close as possible to the input pins of the converter.
The YNM12S05 is designed for stable operation with or without external capacitors. It is recommended to place low ESR ceramic capacitors (47µF minimum) as close to the load as possible for better transient performance and lower output voltage ripple.
It is important to keep the resistance low and inductive PCB traces that connect the load to the output pins of the converter. This is necessary to maintain good load regulation because the converter is not used for compensation and is associated with the power distribution system on the PCB. the voltage drop detection pin.
On/Off (pin 1)
The ON/OFF pin (pin 1) is used to remotely turn the power converter on or off by a system signal referenced to ground (pin 4). Typical connections are shown in Figure A.
To turn on the converter, the on/off pin should be at logic low or left open, to turn off the converter, the on/off pin should be at logic high or connected to the VIN.
The open/close pin is pulled down internally. TTL or CMOS logic gates, open-collector (open-drain) transistors can be used to drive the on/off pins When using open-collector (open-drain) transistors, add a 75 kΩ to the VIN as shown in Figure a The pull-up resistor (R*)

Protection Features Input Undervoltage Lockout Input undervoltage lockout is standard on this converter. When the input voltage drops below a predetermined voltage, the converter will shut down; when the vehicle identification number (Vin) returns to the specified range, the converter will automatically start.
The input voltage must typically be 9.2V for the converter to turn on. Once the converter is turned on, it turns off when the input voltage drops below 8.4V.
Output Over Current Protection (OCP)
Converters are overcurrent and short circuit protected When an overcurrent condition is sensed, the converter will enter hiccup mode. Once the overload or short-circuit condition is removed, Vout will return to its nominal value.
Overheating Protection (OTP)
The inverter will shut down in an over-temperature state to protect itself from overheating caused by running outside the thermal derating curve or system fan failure, etc. After the torque converter cools down to a safe operating temperature, it will restart automatically.
Safety Requirements Converters are compatible with North American and international safety regulatory requirements in accordance with UL60950 and EN60950. Under any operating conditions, the maximum DC voltage between the two pins is VIN. Therefore, the device has an extra-low voltage (ELV) output that meets SELV requirements with all input voltages at ELV.
The converter has no internal fuse. To comply with safety agency requirements, a fuse rated at 15 amps must be used in series with the input line.
Features Basics The converter features a number of operational features, including thermal derating (maximum load current as a function of ambient temperature and airflow) for vertical and horizontal installations, efficiency, startup and shutdown parameters, output ripple, and noise , transient response to load step changes, overloads and short circuits.
where x represents different output voltages and y is related to a specific curve (y=1 for vertical thermal derating,...) For example, Figure x.1 usually refers to vertical thermal derating for all output voltages.
The following pages contain specific plots or waveforms related to the converter. The following are additional comments on specific data.
Test Conditions All data was obtained with the converter soldered to a test board, specifically a 0.060" thick four-layer printed wiring board (PWB). The top and bottom layers were not metallized. The two inner layers consist of two oz. Copper composition used to provide traces to connect to the converter.
The lack of outer metallization and limited thermal connections ensures that heat transfer from the converter to the PWB is minimized which provides a worst-case but consistent case for thermal derating purposes.
All measurements requiring airflow were performed in vertical and horizontal wind tunnels using infrared thermal imaging and thermocouples.
Ensuring that components on the converter do not exceed their ratings is important to maintain high reliability. If the converter is expected to operate at or near the maximum load specified on the transition curve, it is prudent to check the actual operating temperature in the application. Thermal imaging is best; if this capability is not available, a thermocouple is recommended to ensure measurement accuracy. Careful placement of the thermocouple leads will further reduce measurement errors. Refer to Figure C for optimal measurement thermocouple placement.

Location of thermocouples for thermal testing.
The maximum temperature for thermal decay effect is 120°C. Ambient temperatures vary between 25°C and 85°C, airflow rates from 30 to 500 LFM (0.15 m/s to 2.5 m/s), and vertical and horizontal converter installations. The airflow during the test was parallel to the long axis of the converter, from the input pins to the output pins.
For each set of conditions, the maximum load current is defined as:
(i) any MOSFET temperature not exceeding the maximum output current specified temperature (120°C), as shown in the thermal image, or (ii) the converter's maximum current rating (5 A)
During normal operation, the derating curve for a maximum FET temperature less than or equal to 120°C should not be exceeded. To operate within the derating curve, the temperature on the PCB at the thermocouple location shown in Figure C should not exceed 120°C.
efficiency
Efficiency vs. load current plot at 25°C ambient temperature, 200 LFM (1 m/s) airflow velocity, and input voltages of 9.6 V, 12 V, and 14 V.
power dissipation
Power consumption vs. load current at Ta=25°C, airflow velocity of 200 LFM (1 m/s), vertical installation, input voltages of 9.6 V, 12 V, and 14 V.
Ripple and Noise Output Voltage Ripple Waveforms Measured at Full Rated Load Current Note that all output voltage waveforms are measured with 1µF ceramic capacitors.
The output voltage ripple and input reflected ripple current waveforms were obtained using the test setup shown in Figure D.