Vishay IHLP-4040DZ-01 Power Inductor Selection: Saturation Current, DCR and Temperature Rise

Vishay IHLP-4040DZ-01 Power Inductor Selection Guide

The Vishay IHLP-4040DZ-01 is a shielded surface-mount power inductor series designed for high-current DC-DC converters, point-of-load (POL) regulators and distributed power systems. Available in inductance values from 0.19µH to 22µH, the series combines high saturation current capability with compact, low-profile construction.

For engineers, selecting the correct IHLP-4040DZ-01 variant requires more than choosing an inductance value. Saturation current, temperature-rise current, DC resistance (DCR), switching current ripple and PCB thermal performance must all be considered. Buyers should also verify the complete Vishay ordering number rather than using the series name alone.

IHLP-4040DZ-01 Key Specifications

Note: The maximum 90A typical saturation current applies only to the 0.19µH version. Electrical current ratings vary with inductance and operating conditions.

Inductance, DCR and Current Rating Comparison

Values are taken from Vishay datasheet 34193. Heat rating current is based on approximately 40°C temperature rise, while saturation current corresponds to approximately 20% reduction in initial inductance. These are different selection criteria.

Saturation Current vs Temperature-Rise Current

One important distinction when selecting an IHLP-4040DZ-01 inductor is the difference between saturation current and heat rating current.

Saturation current (Isat) is the DC current at which the inductance decreases by approximately 20% from its initial value. This indicates magnetic performance under increasing DC bias.

Heat rating current is the DC current causing approximately 40°C temperature rise under the manufacturer's reference conditions. It reflects thermal performance rather than magnetic saturation.

For example, the 1.0µH variant has a typical saturation current of 36A, but its heat rating current is only 17.5A. Selecting this inductor for continuous 30A operation solely because Isat is 36A would overlook its thermal limitations.

Engineers must verify both the maximum instantaneous current and the continuous RMS current in the intended application.

DC Resistance and Power Loss

Winding resistance generates conduction loss in a power inductor. As a first approximation, DC copper loss can be estimated using:

P = I² × DCR

For example, a 1.0µH IHLP-4040DZ-01 variant has 3.70mΩ typical DCR at 25°C. At 10A RMS current, the estimated DC resistance loss is:

P = 10² × 0.0037 = 0.37W

This is an illustrative calculation at the stated reference resistance. Actual losses can increase with temperature and also include AC winding and core losses.

DC Bias and Inductance Selection

In a buck converter, the inductor current includes both a DC component and switching ripple. Peak inductor current must be evaluated against the inductance-versus-current characteristics, not simply the nominal inductance printed in the product description.

When selecting the appropriate value:

• Calculate the inductance required for the converter's switching frequency and ripple current target.

• Check inductance reduction at the expected DC bias current.

• Compare peak current against the saturation characteristics.

• Calculate RMS current and evaluate temperature rise.

• Include DCR, core loss, PCB heat spreading and ambient temperature in the thermal assessment.

Vishay provides performance curves showing inductance and temperature rise versus DC current for the different IHLP-4040DZ-01 values.

Package, PCB Layout and Thermal Checks

The IHLP-4040DZ-01 is a low-profile surface-mount inductor with magnetically shielded construction and a maximum height of 4.0mm.

The manufacturer's datasheet provides different typical pad layouts for inductance values of 0.56µH and below versus 1.0µH and above. Engineers should therefore verify the footprint associated with the selected value before PCB fabrication.

The total component temperature, including ambient temperature and self-heating, must remain within the specified +125°C limit.

For high-current PCB designs, trace width, copper thickness, airflow and nearby heat-generating components can affect actual temperature rise.

IHLP-4040DZ-01 Ordering Part Numbers

The Vishay global part number identifies the IHLP product family, package code, inductance value, tolerance and series designation.

The EK, EE, ER and EP package codes indicate different tape-and-reel configurations. The EP code includes polarity marking, which may help control magnetic field orientation in EMI-sensitive PCB layouts.

For purchasing, confirm the exact complete part number, inductance value, package code, quantity and available inventory.

Typical Applications

• High-current point-of-load DC-DC converters

• Server and computing power supplies

• FPGA core voltage regulators

• Distributed power systems

• Low-profile high-current switching regulators

Related Inductor Series and Manufacturer Resources

For applications requiring different DCR or saturation performance, engineers may compare the IHLP-4040DZ-01 high-saturation series with Vishay's IHLP-4040DZ-11 low-DCR series.

The two series do not necessarily provide equivalent current handling or identical PCB footprints at the same inductance value. Detailed specification checks are required before replacement.

• Vishay IHLP-4040DZ-01 Official Product Page

• IHLP-4040DZ-01 Datasheet PDF

• IHLP-4040DZ-11 Low-DCR Series Datasheet

IHLP-4040DZ-01 Pricing and RFQ

Looking for Vishay IHLP-4040DZ-01 inductors, complete ordering part numbers or alternative high-current power inductors?

Contact DataStorageIC with your required inductance, target DC current, operating temperature, full part number and quantity. Our team can assist with sourcing, quotation requests and specification confirmation.