NCP431BCSNT1G

Overview

The NCP431BCSNT1G is a three-terminal programmable shunt regulator diode from onsemi, operating within the NCP431 series. It functions as a low temperature coefficient zener reference, adjustable from Vref to 36 V using two external resistors. The device features a typical voltage reference tolerance of ±0.5% at 25°C and an equivalent full-range temperature coefficient of 50 ppm/°C. It supports a cathode current range of 40 µA to 100 mA with a typical dynamic impedance of 0.22 Ω. Packaged in SOT-23-3, it operates over a commercial temperature range of 0°C to +70°C.

Feature Summary

• Programmable output voltage adjustable up to 36 V via external resistors
• High precision with ±0.5% typical voltage reference tolerance at 25°C
• Low minimum operating current enabling extremely low no-load consumption
• Temperature compensated for stable operation across the rated ambient range

Applications

• Voltage adapters
• Switching power supplies (SMPS)
• Precision voltage references
• Battery chargers
• Instrumentation circuits

Procurement Notes

Verify the specific suffix CSNT1G corresponds to the SOT-23-3 package and the 0°C to +70°C commercial temperature grade. Confirm that the B designation indicates the tighter ±0.5% initial accuracy tolerance compared to standard A-grade variants. Ensure compatibility with lead-free manufacturing processes as indicated by the G suffix.

Selection Notes

Select this component when a precise, adjustable shunt reference is required with tight initial accuracy. The NCP431B variant offers superior tolerance compared to the NCP431A series. Consider the low minimum operating current for secondary side regulation in SMPS applications where minimizing parasitic power consumption is critical. Verify thermal resistance requirements for the SOT-23 package under expected load conditions.

Part Context

This part belongs to the NCP431/NCP432 family of programmable precision references. It serves as a direct replacement for traditional Zener diodes in digital voltmeters and op-amp circuitry. The device integrates 20 active transistors to provide stable regulation. It is designed to facilitate stable reference generation from 5.0 V logic supplies and can function as either a positive or negative voltage reference.

Replacement Considerations

NCP431AISNT1G: Offers wider temperature range (-40°C to 85°C) but has 1% tolerance. SCV431B: Automotive qualified version with similar electrical characteristics but requires site control verification.