Texas Instruments LMR23625CDDA

Overview

LMR23625CDDA from Texas Instruments is a 36-V, 2.5-A synchronous step-down DC-DC converter in an 8-pin HSOIC package with PowerPAD™. It delivers regulated output from 4 V to 36 V input, supports 2.1-MHz fixed-frequency operation with PFM/FPWM mode selection, and integrates high- and low-side MOSFETs (R_DS(on) = 185 mΩ / 105 mΩ). It enables compact industrial power supplies for PLC CPU and HVAC control.

For engineers reviewing the LMR23625CDDA datasheet, LMR23625CDDA pinout, LMR23625CDDA application, or LMR23625CDDA equivalent, key selection considerations include its 75-µA quiescent current in PFM mode, 60-ns minimum on-time, precision enable input with 1.55-V typical threshold, and internal compensation eliminating external loop components.

Technical Context

The LMR23625CDDA employs peak-current-mode control with a fixed 2.1-MHz switching frequency (PFM/FPWM selectable), internal voltage reference (1.0 V ±1%), and integrated synchronous rectification. Its control architecture uses cycle-by-cycle current limiting and hiccup-mode short-circuit protection triggered after 64 cycles of valley current limit violation.

It features dual undervoltage lockout thresholds (VIN UVLO rising: 3.7 V typ; falling: 3.3 V typ) and thermal shutdown at 170°C with 15°C hysteresis. The device supports synchronization to external clocks from 200 kHz to 2.2 MHz via the EN/SYNC pin, and includes an internal LDO (4.1 V output) powering internal circuitry with 2.8–3.6 V UVLO.

Key Specifications

Pinout & Package

LMR23625CDDA is housed in an 8-pin HSOIC (4.89 mm × 3.90 mm) package with exposed thermal pad (PowerPAD™) for enhanced thermal dissipation. The package supports ≤42.0°C/W junction-to-ambient thermal resistance under standard PCB layout conditions.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down converter applications.

Compared with LMR23625CFDDA, the LMR23625CDDA offers PFM/FPWM flexibility for optimal light-load efficiency, while LMR23630CDDA provides 20% higher output current within identical board space-enabling scalable power design without changing layout or thermal strategy.

Availability

LMR23625CDDA is available at Aetrix Electronics and suitable for factory automation systems, building HVAC controllers, and GSM/GPRS telematics requiring stable component supply, long-term industrial lifecycle support, and consistent parametric performance across production batches.

Supply support for LMR23625CDDA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management ICs, with decades of expertise in industrial-grade power conversion solutions.

The LMR23625CDDA belongs to TI's SIMPLE SWITCHER® family-designed specifically for rugged, easy-to-deploy DC-DC conversion in harsh industrial environments where reliability, wide input range, and minimal external components are critical.

FAQ

What is the maximum input voltage rating for the LMR23625CDDA?

The LMR23625CDDA has an absolute maximum input voltage rating of 42 V across the VIN-to-PGND terminals. Its recommended operating input range is 4 V to 36 V, making it suitable for 24-V industrial buses and automotive-derived supplies. Operation above 36 V is not guaranteed and may trigger internal UVLO or cause reliability degradation.

Does the LMR23625CDDA support output voltage synchronization to an external clock?

No-the LMR23625CDDA does not support output voltage synchronization. However, its switching frequency can be synchronized to an external clock signal applied to the EN/SYNC pin, covering 200 kHz to 2.2 MHz. This maintains constant f_SW across multiple converters to reduce beat frequencies and simplify EMI filtering.

Can the LMR23625CDDA operate with a 3.3-V output from a 36-V input?

Yes-the LMR23625CDDA supports high-duty-cycle operation with a minimum on-time of 60 ns. At 2.1 MHz, this enables a minimum duty cycle of ~12.6%, allowing stable 3.3-V output regulation from a 36-V input (D ≈ 9.2%). Verified in TI's dropout curves (Figure 6-8) and supported by internal slope compensation.

Is the thermal pad of the LMR23625CDDA electrically connected?

Yes-the exposed thermal pad on the LMR23625CDDA (HSOIC-8 package) is internally connected to AGND. It must be soldered to a dedicated AGND copper pour on the PCB to ensure both thermal performance (R_θJA = 42.0°C/W) and low-noise analog grounding. Floating or isolated pads degrade thermal and electrical performance.

What protection features are built into the LMR23625CDDA?

The LMR23625CDDA includes cycle-by-cycle overcurrent protection, hiccup-mode short-circuit response (after 64 current-limit cycles), thermal shutdown at 170°C with 15°C hysteresis, VIN undervoltage lockout (3.7 V rising threshold), and VCC undervoltage lockout (3.2 V rising threshold). These features collectively prevent damage during overload, overtemperature, or input brownout conditions.