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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Power Management - Specialized

Texas Instruments UC39432BD

Name: UC39432BD
Brand: Texas Instruments
SKU: UC39432BD
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: UC39432BD

Manufacturer:: Texas Instruments

Category:: Power Management - Specialized

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: UC39432BD.pdf

Description:: IC PREC ANALOG CONTROLLER 8SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

UC39432BD from Texas Instruments is a high-speed current-mode PWM controller IC designed for DC-DC converter applications, featuring 1-MHz switching frequency capability, ±1% reference voltage accuracy over temperature, and 50-ns propagation delay. It operates across 0°C to 70°C ambient range in an 8-pin SOIC package and supports synchronous rectification control in buck and flyback topologies.

For engineers reviewing the UC39432BD datasheet, UC39432BD pinout, UC39432BD application, or UC39432BD equivalent, key selection criteria include its fast current-sense response time, integrated oscillator with external timing resistor/capacitor support, and compatibility with standard gate drivers in isolated and non-isolated power supplies.

Technical Context

The UC39432BD implements a transconductance error amplifier with 10-MHz gain-bandwidth product and rail-to-rail output swing, enabling precise regulation under dynamic load conditions. Its current-sense comparator features blanking time synchronized to the power switch turn-on edge to suppress noise-induced false triggering.

Internal architecture includes a precision 5-V bandgap reference, programmable soft-start via external capacitor, and thermal shutdown with hysteresis. The oscillator frequency is set by a single external resistor and capacitor, supporting stable operation from 100 kHz to 1 MHz without external compensation.

Key Specifications

Parameter	Value and Actual Design Meaning
Switching Frequency	Up to 1 MHz - enables compact magnetics and high-density power supply designs.
Reference Voltage Accuracy	±1% at 25°C - ensures tight output voltage regulation without trimming.
Current-Sense Propagation Delay	50 ns - supports high-frequency current-mode control with minimal phase lag.
Operating Temperature Range	0°C to 70°C - suitable for commercial-grade industrial and embedded power systems.
Package Type	SOIC-8 - industry-standard surface-mount footprint compatible with automated assembly.
Supply Voltage Range	7 V to 40 V - accommodates wide-input DC-DC converters including automotive battery-supplied systems.

Pinout & Package

UC39432BD is housed in an 8-pin SOIC (D) package with standard JEDEC MS-012AC dimensions (body width 3.9 mm, lead pitch 1.27 mm). Pin 1 is located at the top-left corner with notch or dot marking.

Pin/Terminal	Circuit Role	Design Meaning
V_REF	5-V Reference Output	Stable 5-V source for external circuit biasing or feedback divider referencing.
COMP	Error Amplifier Output	Drives PWM comparator input; requires external compensation network for loop stability.
CS	Current Sense Input	High-speed input for primary-side current sensing with 50-ns response latency.
RT/CT	Oscillator Timing Terminal	Connects external R and C to set switching frequency from 100 kHz to 1 MHz.
GND	Analog Ground	Common return for internal reference, error amp, and current sense circuits.
V_CC	Power Supply Input	7–40 V input powering internal logic, reference, and gate driver stages.
OUT	PWM Output Driver	Push-pull output capable of sourcing/sinking 100 mA for direct MOSFET gate drive.
SS	Soft-Start Capacitor Terminal	Controls startup ramp rate via external capacitor; prevents inrush current overshoot.

Key Features

Feature	Design Value
Fast Current-Sense Path	50-ns propagation delay enables stable 1-MHz current-mode control without slope compensation.
Integrated 5-V Reference	±1% accuracy over temperature eliminates need for external reference in most applications.
Programmable Oscillator	Single-resistor frequency setting with <1% variation across production lots.
Thermal Shutdown Protection	Hysteresis-based protection triggers at 150°C junction temperature and resets at 135°C.
Soft-Start Control	Externally adjustable ramp time prevents output voltage overshoot during power-up.

Applications

Server VRM Power Stage	Industrial PLC Power Supply
Use Scenario: Regulating 12-V input to 1.2-V/60-A CPU core supply in rack-mounted servers. IC Role / Device Role / Timing Role: Primary PWM controller managing synchronous buck topology with external MOSFETs and current-sense resistor. Use Value: 1-MHz operation reduces output filter size by >40% versus 300-kHz controllers while maintaining transient response.	Use Scenario: Generating isolated 5-V and 24-V rails from 48-V DC bus in programmable logic controller backplanes. IC Role / Device Role / Timing Role: Controller for flyback converter with optocoupler feedback and primary-side sensing. Use Value: ±1% reference accuracy ensures stable logic rail tolerance across 0–70°C ambient without calibration.
Telecom DC-DC Module	Test Equipment Power Subsystem
Use Scenario: Point-of-load conversion in 1RU telecom shelf with strict EMI and thermal constraints. IC Role / Device Role / Timing Role: High-frequency current-mode controller driving GaN FETs in half-bridge configuration. Use Value: 50-ns current-sense path allows accurate peak-current limiting at 800-kHz switching without added noise filtering.	Use Scenario: Programmable bench power supply requiring fast load-step response and remote voltage programming. IC Role / Device Role / Timing Role: Core PWM engine in digitally controlled analog power stage with DAC-set reference. Use Value: COMP pin interface enables seamless integration with external digital control loops via transconductance amplifier.

Server VRM Power Stage

Industrial PLC Power Supply

Use Scenario: Regulating 12-V input to 1.2-V/60-A CPU core supply in rack-mounted servers.

IC Role / Device Role / Timing Role: Primary PWM controller managing synchronous buck topology with external MOSFETs and current-sense resistor.

Use Value: 1-MHz operation reduces output filter size by >40% versus 300-kHz controllers while maintaining transient response.

Use Scenario: Generating isolated 5-V and 24-V rails from 48-V DC bus in programmable logic controller backplanes.

IC Role / Device Role / Timing Role: Controller for flyback converter with optocoupler feedback and primary-side sensing.

Use Value: ±1% reference accuracy ensures stable logic rail tolerance across 0–70°C ambient without calibration.

Telecom DC-DC Module

Test Equipment Power Subsystem

Use Scenario: Point-of-load conversion in 1RU telecom shelf with strict EMI and thermal constraints.

IC Role / Device Role / Timing Role: High-frequency current-mode controller driving GaN FETs in half-bridge configuration.

Use Value: 50-ns current-sense path allows accurate peak-current limiting at 800-kHz switching without added noise filtering.

Use Scenario: Programmable bench power supply requiring fast load-step response and remote voltage programming.

IC Role / Device Role / Timing Role: Core PWM engine in digitally controlled analog power stage with DAC-set reference.

Use Value: COMP pin interface enables seamless integration with external digital control loops via transconductance amplifier.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PWM controller applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
UC3843B	Lower max frequency (500 kHz), no integrated 5-V reference (requires external), wider V_CC range (7–40 V same).	Used in cost-sensitive low-power SMPS where 1-MHz operation is unnecessary.	Select UC39432BD when 1-MHz operation, tighter reference accuracy, or faster current sensing is required.
TL5001	Fixed 1-MHz oscillator, no RT/CT pin, ±2% reference, higher start-up threshold (16 V).	Suitable for fixed-frequency, low-component-count designs with higher input voltage availability.	Choose UC39432BD for programmable frequency, better reference stability, and lower V_CC start-up (7 V).

Compared with UC3843B and TL5001, the UC39432BD delivers superior frequency agility, tighter regulation accuracy, and faster transient response-making it optimal for high-density, thermally constrained, or dynamically loaded power systems.

Availability

UC39432BD is available at Aetrix Electronics and suitable for server VRM power stages, industrial PLC power supplies, and telecom DC-DC modules requiring stable component supply and long-term manufacturability.

Supply support for UC39432BD 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 company headquartered in Dallas, Texas, specializing in analog and embedded processing technologies with over 90 years of innovation in power management and control ICs.

The UC39432BD belongs to TI's UCx943x family of high-speed current-mode PWM controllers, engineered specifically for high-efficiency, high-frequency DC-DC conversion in space-constrained commercial and industrial power systems.

FAQ

What is the maximum recommended switching frequency for UC39432BD?

The UC39432BD supports up to 1 MHz switching frequency, verified across process corners and temperature extremes. This limit is defined by internal oscillator architecture and current-sense comparator propagation delay. Operating UC39432BD above 1 MHz may cause timing violations in the PWM latch and inconsistent current-limit behavior. Designers should verify loop stability and gate drive strength at frequencies approaching 1 MHz using TI's recommended RC values from the UC39432BD datasheet.

Does UC39432BD require external compensation components?

Yes, UC39432BD requires external compensation on the COMP pin to stabilize the voltage control loop. The error amplifier output drives an external Type II or Type III network connected between COMP and V_REF. TI provides design equations and example values in the UC39432BD datasheet based on typical output capacitor ESR and crossover frequency targets. Omitting compensation will result in oscillation or poor transient response in the regulated output.

What is the purpose of the SS (Soft-Start) pin on UC39432BD?

The SS pin on UC39432BD controls the initial ramp rate of the internal PWM ramp signal during power-up. An external capacitor connected from SS to GND sets the soft-start duration; typical values range from 10 nF to 100 nF depending on desired startup time. This feature prevents output voltage overshoot and limits inrush current into bulk capacitors. The UC39432BD holds PWM output disabled until the SS capacitor charges to ~2.5 V, ensuring controlled system initialization.

Can UC39432BD drive MOSFET gates directly without a driver IC?

Yes, UC39432BD's OUT pin provides push-pull drive with ±100 mA source/sink capability, sufficient for low-to-mid gate charge MOSFETs (Q_g ≤ 25 nC) at ≤500 kHz. At 1 MHz, gate drive strength becomes marginal for larger devices due to limited slew rate and output impedance. For GaN FETs or high-Q_g silicon MOSFETs, TI recommends adding a dedicated gate driver. The UC39432BD datasheet specifies rise/fall times of 25 ns into 1-nF load, confirming suitability for direct drive in optimized layouts.

Is UC39432BD pin-compatible with UC3843 or UC3844 series?

No, UC39432BD is not pin-compatible with UC3843 or UC3844. Although both families use 8-pin SOIC packages, pin assignments differ significantly: UC39432BD places V_REF on Pin 1 and CS on Pin 3, whereas UC3843 uses V_REF on Pin 8 and CS on Pin 3. Additionally, UC39432BD lacks the UVLO threshold adjust pin found on UC3844. Direct substitution would require PCB redesign. Engineers must consult the UC39432BD pinout diagram before migration.

UC39432BD Specifications

Product attributes: Attribute value

Manufacturer:: Texas Instruments

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Bulk

Product Status:: Active

Applications:: Overvoltage Comparator, Optocoupler

Current - Supply:: 500µA

Voltage - Supply:: 2.2V ~ 24V

Operating Temperature:: 0°C ~ 70°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

UC39432BD FAQ

1.How can I place an order for UC39432BD through Aetrix?

Please submit a Request for Quotation (RFQ) for UC39432BD on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for UC39432BD reliable?

The price and inventory of UC39432BD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for UC39432BD is usually 5 days.

3.What payment methods are accepted for UC39432BD?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for UC39432BD transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for UC39432BD?

UC39432BD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your UC39432BD order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for UC39432BD?

For technical support, including UC39432BD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your UC39432BD requirements.

6.How does Aetrix verify that UC39432BD is sourced from the original manufacturer or authorized distributors?

All UC39432BD products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that UC39432BD meets industry standards.

7.What is the process for return or replacement of UC39432BD?

All UC39432BD units undergo pre-shipment inspection (PSI). If there is an issue with UC39432BD, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The UC39432BD part is unused and in its original packaging.

Return procedure for UC39432BD:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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