LT1933IDCB - 600mA 500kHz Step-Down Regulator | Analog Devices
MPN: LT1933IDCB ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.28 | $3.28 |
| 10 | $3.28 | $32.80 |
| 100 | $3.28 | $328.00 |
| 500 | $3.28 | $1,640.00 |
| 1,000 | $3.28 | $3,280.00 |
LT1933IDCB Overview
A step-down DC/DC converter, also called a buck converter, reduces a higher input voltage to a regulated lower voltage using an internal switching element, inductor, capacitor, and control loop. The LT1933 belongs to the switching-regulator family within the broader DC/DC converter and power-management semiconductor hierarchy. Its current-mode PWM architecture provides a practical solution for generating local rails from automotive, industrial, or distributed power systems.
The LT1933 uses an internal 0.75 A power switch and is specified for a 600 mA output configuration. Its 500 kHz switching frequency supports a compact implementation with external passive components. The 6-lead DFN package reduces board area, while the exposed pad provides a thermal connection when copper area and heat dissipation are adequate. The adjustable output allows the design to select the required feedback divider rather than using a fixed-voltage version.
The verified distributor data identifies the part as a positive adjustable buck regulator with a 1.245 V reference and a 600 mA output rating. The manufacturer search result describes the LT1933 family as a current-mode PWM step-down converter with an internal 0.75 A switch and a wide 3.6 V to 36 V input range. Additional electrical values, including efficiency curves, switching specifications, current-limit behavior, thermal resistance, and inductor recommendations, should be confirmed in the manufacturer datasheet before production release.
Typical applications include point-of-load regulation, industrial control systems, automotive electronics, battery-powered equipment, and portable electronics. In these systems, the converter can create a lower, stable rail for sensors, communications circuitry, analog sections, or embedded controllers. Because a switching regulator introduces ripple and switching-node energy, layout and component selection are as important as the nominal voltage and current ratings.
Use the exposed pad as a thermal and electrical connection according to the package land pattern, and keep the switching node compact and away from sensitive signal paths. Verify the maximum input voltage, duty-cycle limits, output-voltage accuracy, current-limit behavior, and capacitor ratings in the official datasheet. This page combines distributor data, manufacturer information, and practical design guidance for engineers evaluating a compact 600 mA buck regulator.
Drop-in alternatives for LT1933IDCB — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LT1933IDCB (same form factor and footprint) — differing in Package, Topology.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LT1933IDCB#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT1933IDCB Maximum Ratings & Electrical Characteristics
| Product Type | Step-Down Switching Regulator |
| Topology | Current-Mode PWM Buck Converter |
| Rated Output Current | 600 mA |
| Input Voltage Range | 3.6 V to 36 V |
| Switching Frequency | 500 kHz |
| Internal Power Switch | 0.75 A |
| Output Type | Positive Adjustable |
| Reference Voltage | 1.245 V |
| Output Voltage | 1.245 V to 31.68 V |
| Package | 6-WFDFN Exposed Pad |
| Package Lead Count | 6 |
| Mounting Type | Surface Mount |
| Temperature Grade | Automotive |
| Switching Control | Current-Mode PWM |
LT1933IDCB 6 Pin Configuration Guide
Pin configuration for LT1933IDCB (6 package). This power device features gate, drain, and source terminals. For non-polarized packages, refer to the manufacturer datasheet for exact pin 1 orientation and footprint details. Common applications include power supply design, motor driving, and load switching.
No detailed pinout data available for LT1933IDCB.
Refer to the datasheet for full pin configuration.
Typical Applications
LT1933IDCB is suitable for 6 applications: Industrial Point-of-Load Regulation, Automotive Electronic Control Units, Battery-Powered Portable Equipment, RF and Communications Module Rails, Sensor and Analog Front-End Power, LED and Display Backlight Control.
Industrial Point-of-Load Regulation
The LT1933IDCB is suitable for creating a local regulated rail from a higher industrial supply. Its 3.6 V to 36 V input range covers many nominal bus-derived systems, while the 500 kHz switching frequency allows a compact power stage. The 600 mA rating is useful for controller, sensor, communications, and logic loads. The exposed-pad DFN package helps transfer heat when the board provides adequate copper. The main design checks are available duty-cycle margin, inductor ripple, capacitor ESR, startup behavior, and thermal rise. Feedback routing should be kept short and away from the switching node to preserve regulation accuracy.
Recommended
Automotive Electronic Control Units
The wide 3.6 V to 36 V input capability makes the LT1933IDCB a candidate for automotive electronics when the exact qualification and transient requirements are satisfied. The 500 kHz PWM stage can generate lower auxiliary rails for sensors, interfaces, and control logic. Its 600 mA output rating supports moderate-load subrails rather than high-current actuators. Automotive implementation requires careful review of load dump, reverse battery, temperature, EMI, and startup behavior beyond the basic operating range. The exposed pad should be tied to the recommended thermal land pattern, and the final design should use the manufacturer’s automotive qualification documentation for the exact suffix.
Recommended
Battery-Powered Portable Equipment
A buck regulator can reduce battery-system voltage to a stable logic or analog rail with better efficiency than a linear regulator when the voltage step-down is large. The LT1933IDCB provides a 3.6 V minimum input, 36 V maximum input, and 600 mA rated output, making it applicable to battery-derived systems whose input remains within that range. Its small 6-WFDFN footprint supports space-constrained boards, while the 500 kHz frequency permits compact filtering. Designers must calculate battery droop, startup sequencing, light-load behavior, quiescent current, and thermal dissipation. The selected inductor must maintain current above the load requirement while limiting saturation and ripple.
Recommended
RF and Communications Module Rails
The LT1933IDCB can provide a compact local supply for communications modules, RF front ends, or mixed-signal sections that require a regulated rail derived from a higher input. The 500 kHz switching frequency supports a small implementation, and the 600 mA rating can serve moderate-current digital and analog loads. Switching converters can add conducted and radiated noise, so the design should use short current loops, controlled switching-node copper, shielded or carefully placed inductors, and filtered feedback. The final ripple and sensitivity requirements must be checked against the communications equipment specification. A linear post-regulator may be preferable when the load is exceptionally noise-sensitive.
Recommended
Sensor and Analog Front-End Power
The LT1933IDCB can supply a lower regulated rail for sensors, amplifiers, converters, and data-acquisition front ends. A buck topology reduces the required external headroom compared with a linear regulator when the input-to-output voltage difference is significant. The 500 kHz operating frequency permits reasonably small magnetic components, while the exposed-pad package supports compact placement. Designers should still account for ripple reaching sensitive analog nodes and may add filtering or a low-noise post-regulator where required. The feedback divider tolerance and reference accuracy determine output precision. Place the feedback network close to the device and avoid routing it beside the inductor or switching node.
Recommended
LED and Display Backlight Control
The LT1933IDCB may be evaluated for auxiliary power in LED, display, or backlight systems where a regulated lower rail is needed for driver logic or control electronics. Its 600 mA current rating is appropriate for moderate-load control and analog sections, but it is not intended by itself to replace a high-current LED constant-current driver. The wide input range can support multiple nominal supply sources, and the 6-WFDFN package leaves room for compact power routing. The designer must verify LED driver topology, ripple tolerance, dimming compatibility, and the voltage headroom available at the lowest input. If the LED string requires direct current regulation, use a dedicated LED driver and consider this device for its control rail.
Recommended
Recommended Products Summary
Engineering reference data for LT1933IDCB — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LT1933ES6 | LT1933IDCB#TRPBF |
|---|---|---|---|
| Package | 6-WFDFN Exposed Pad | SOT-23-6 — not same package | 6-WFDFN Exposed Pad — same package family |
| Brand | Analog Devices | Analog Devices | Analog Devices |
Key Differentiators
- Wide input range for compact buck conversion (vs LT1933ES6)
- Exposed-pad package supports compact thermal integration (vs LT1933ES6)
- Adjustable positive output referenced to 1.245 V (vs LT1933IDCB#TRPBF)
Design Notes
Use the manufacturer’s recommended land pattern for the 6-WFDFN exposed-pad package and connect the exposed pad to the specified thermal and ground copper. Keep the input capacitor, switching node, inductor, and output capacitor in a compact current-loop arrangement. Do not route feedback traces beneath or parallel to the switching node, because induced ripple can degrade output regulation.
Thermal performance depends on copper area, board construction, ambient temperature, switching loss, and the input-to-output voltage ratio. The exposed pad is not a substitute for a thermal-analysis result. Verify the package land pattern, maximum junction temperature, and application-specific dissipation in the datasheet and thermal simulation before production.
The 500 kHz switching regulator can radiate or conduct switching noise. Keep the switching node physically small, minimize high-dv/dt copper, place the inductor and input capacitor close to the device, and follow the manufacturer’s recommended output filtering. For sensitive analog or RF circuits, compare the measured output ripple with the maximum noise specification and consider a linear post-regulator.
Select the inductor and capacitors using the actual input voltage, output voltage, 600 mA load target, allowed ripple, switching frequency, and startup requirements. Check inductor saturation current, DC resistance, capacitor voltage rating, ripple-current rating, ESR, and effective capacitance. The verified data does not provide the recommended passive values, so do not infer them without the official datasheet.
Compliance Information
The supplied data identifies an automotive temperature grade but does not explicitly state AEC-Q100 qualification, RoHS, REACH, lead-free, halogen-free, or conflict-minerals status for the exact LT1933IDCB orderable part. Confirm these declarations with Analog Devices and the exact suffix.
