Sn51dp Datasheet -
In the world of power electronics, finding a reliable and efficient switching regulator IC is crucial for any design. While many components come and go, certain part numbers—like the SN51DP—maintain a quiet but significant presence in power supply designs, particularly in Japanese and Asian market equipment. If you have landed on this article, you are likely searching for the SN51DP datasheet. Whether you are repairing a power supply, designing a new DC-DC converter, or cross-referencing a part, understanding the raw technical data of this IC is essential.
Unfortunately, official datasheets for the SN51DP can be elusive due to its age and specific manufacturing lineage (often associated with Sanken Electric Co., Ltd.). This article consolidates verified technical information, pinout configurations, electrical characteristics, typical application circuits, and practical tips for sourcing or substituting this component.
Disclaimer: The information provided here is aggregated from historical technical documents, service manuals, and application notes. Always verify with original manufacturer specifications where available.
A: The SN51DP does not have a dedicated enable pin. To achieve low standby power, you must remove input voltage or use a separate MOSFET switch on the VIN line. sn51dp datasheet
Exceeding these values will destroy the IC. These are non-recoverable limits.
| Parameter | Symbol | Rating | Unit | | :--- | :--- | :--- | :--- | | Input Voltage | VIN | 45 (60 for -H variant) | V | | Switch Output Voltage | VSW | VIN + 0.5 | V | | Feedback Voltage | VFB | -0.3 to +7 | V | | Peak Switch Current | ISW(peak) | 4.5 | A | | Power Dissipation (Tc=25°C) | PD | 25 | W | | Operating Temperature | Topr | -20 to +125 | °C | | Storage Temperature | Tstg | -40 to +150 | °C |
A: The datasheet primary application is buck. While theoretically possible, no official reference design exists for boost. Use a dedicated boost controller instead. In the world of power electronics, finding a
| Part | Zero-Crossing? | Output Current | Isolation | Best for | |------|----------------|----------------|-----------|-----------| | SN51DP | Yes | 100 mA | 5 kVrms | General purpose, low EMI AC switching | | MOC3063 | Yes | 100 mA | 5 kVrms | Similar, widely available | | MOC3021 | No | 100 mA | 5 kVrms | Phase control (dimmers) | | FODM3063 | Yes | 70 mA | 3.75 kVrms | SMD, lower profile | | SSR (e.g., Crydom) | Yes | 2–50 A | 4 kVrms | Integrated high-power, costly |
Understanding the pinout is the primary reason engineers search for the SN51DP datasheet. The pin assignment (seen from the front, pins facing down) is as follows:
| Pin Number | Name | Description | | :--- | :--- | :--- | | 1 | VIN | Input voltage (unregulated DC supply). Bypass with a low-ESR capacitor close to this pin. | | 2 | SW (Output) | Switching node – connects to the inductor and catch diode. Handles high current. | | 3 | GND | Ground reference. Must be connected to the system ground plane. | | 4 | FB (Feedback) | Voltage feedback input. Connected to a resistor divider from the output to set the desired voltage. | | 5 | COMP (Compensation) | Frequency compensation pin. A capacitor and resistor network to ground stabilizes the control loop. | A: The SN51DP does not have a dedicated enable pin
Note: Some variants may swap pins 4 and 5 or include an enable function. Always verify with a multimeter and known schematic.
The SN51DP is available in a small package, often a TSSOP (Thin Shrink Small-Outline Package) or similar, making it suitable for compact designs and portable equipment.