TDK-Lambda Americas Blog
Introducing TDK-Lambda’s i9C series – the next generation of DC-DC converters with “PHEPT” - Programmable High Efficiency Pass-Through.
Tuesday, June 30, 2026
Figure 1: i9C DC-DC converter
Overview
A key factor in selecting a DC-DC converter is its operating efficiency. This extends battery life and reduces the required time between the recharging.
The i9C converter has an operating efficiency of up to 99% in PHEPT mode and supports input ranges of 9–80 V or 9–40 V and provides outputs of 9.6–60 V at up to 30 A or 5–36 V at up to 50 A, for battery applications. It can also deliver up to 1500 W for 12 V, 24 V, 48 V, and 60 V bus architectures.
The i9C has a buck-boost topology enabling it to step the output voltage up or down (see Figure 2).
A conventional buck-boost DC-DC converter will incur switching and conversion losses and will dissipate energy during the step up (boost) and step down (buck) modes.
Figure 2: Step-up-Step-down diagram
PHEPT
The patented Programmable High Efficiency Pass‑Through enables FETs S1 and S4 to turn on when the output voltage (Vout) is within the user‑programmed pass‑through window, while S2 and S3 remain off (see Figures 3 and 4). In PHEPT mode, the module bypasses regulation and directly connects the input to the output, eliminating switching and conversion losses. Users can choose to operate the i9C in either fully regulated mode (typical buck‑boost) or in PHEPT mode.
Figure 3: Pass-Through States
Figure 4: Programmable High Efficiency Pass-Through Diagram
Other features of the i9C include a flanged (-0C3-R suffix) and non-flanged (-NC3-R suffix) baseplate for mounting flexibility and to support manufacturing processes needed for various cooling approaches.
The user-configurable sleep mode programs the power module into a low-power dissipation state during idle or light-load conditions.
The adjustable overcurrent protection reduces stress on both the power module and the load helping engineers reduce or eliminate external circuitry.
Figure 4 shows the i9C application circuit, including the trim terminals, on/off and DC power good.
Figure 5: Application circuit
Figure 6: Evaluation Board
For full technical details please click here
https://product.tdk.com/en/power/i9c
For more assistance on TDK-Lambda’s extensive DC-DC and AC-DC converters and power supplies please contact our technical support at 800-LAMBDA-4 (800-526-2324) or tla.powersolutions@tdk.com
Power Guy
