Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Motor Drivers, Controllers

Allegro MicroSystems A3946KLBTR

Name: A3946KLBTR
Brand: Allegro MicroSystems
SKU: A3946KLBTR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: A3946KLBTR

Manufacturer:: Allegro MicroSystems

Category:: Motor Drivers, Controllers

Package:: 16-PowerSOIC (0.295", 7.50mm Width)

Datasheet:: A3946KLBTR.pdf

Description:: IC MOTOR DRIVER 7V-60V 16SOIC

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:1,072

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

A3946KLBTR from Allegro MicroSystems is a half-bridge power MOSFET controller designed to drive high-current N-channel MOSFETs in unidirectional DC motor and three-phase brushless DC motor applications. It features dual gate drivers (GH and GL), integrated top-off charge pump for 100% duty cycle high-side operation, VREG output at 13 V nominal, and operates across –40°C to +135°C ambient temperature.

For engineers reviewing the A3946KLBTR datasheet, A3946KLBTR pinout, A3946KLBTR application, or A3946KLBTR equivalent, key selection criteria include bootstrap-enabled high-side drive capability, programmable dead time via DT pin, thermal shutdown at 170°C, undervoltage protection on VREG/BOOT/VREF, and compatibility with 7–60 V load supply voltage.

Technical Context

The A3946KLBTR implements a dual-output gate driver architecture with independent high-side (GH) and low-side (GL) outputs, each capable of driving N-channel MOSFETs with turn-on/turn-off times of 60 ns/40 ns (typ.) into 3300 pF. Its internal charge pump generates VREG at 13 V (±0.5 V) to power low-side logic and bootstrap circuits, while the top-off charge pump sustains high-side gate voltage during continuous conduction.

Control logic supports two modes: single-pin PWM (IN1=IN2 with DT-to-ground resistor) and independent input control (DT tied to VREF). Dead time is adjustable from 350 ns to 6 µs using R_DEAD, and fault diagnostics include latched overtemperature (170°C), VREG undervoltage (8.3 V threshold), and non-latched BOOT undervoltage (7.8 V threshold).

Key Specifications

Parameter	Value and Actual Design Meaning
VBB Range	7 V to 60 V - supports wide automotive and industrial battery input ranges without external regulation.
VREG Output	12.0–13.5 V - powers low-side gate drive and charges bootstrap capacitor; current-limited to 15 mA.
GH/GL Drive Strength	R_DS(ON) = 4 Ω (pull-up) / 2 Ω (pull-down) at T_j = 25°C - enables fast switching of high-Q_g MOSFETs (e.g., IRF2807).
Dead Time Range	350 ns to 6 µs - configurable via external R_DEAD (5 kΩ–100 kΩ) to prevent shoot-through in half-bridge topologies.
Thermal Shutdown	170°C junction temperature - latched fault with 15°C hysteresis ensures safe recovery before re-enabling outputs.
Operating Temp	–40°C to +135°C ambient - qualified for under-hood automotive and industrial motor control environments.
Logic Inputs	V_IN(1) ≥ 2.0 V, V_IN(0) ≤ 0.8 V - compatible with 3.3 V and 5 V microcontrollers without level shifting.

Pinout & Package

Package: 16-lead TSSOP with exposed thermal pad (LP suffix), lead-free, 100% matte tin plating. Thermal pad must be externally connected to ground for optimal heat dissipation and noise reduction.

Pin/Terminal	Circuit Role	Design Meaning
VREG (1)	Gate drive supply output	13 V regulated output powering low-side driver and bootstrap charging path; requires 10 µF decoupling capacitor.
CP2 (2), CP1 (3)	Charge pump capacitor terminals	Form external charge pump network; CP2 connects to VREG, CP1 to PGND - essential for VREG regulation below 15 V.
PGND (4)	Power ground	Separate ground return for high-current paths; must be externally tied to system ground, independent of LGND.
GL (5)	Low-side gate driver output	Drives N-channel MOSFET source-connected to S pin; slew rate controlled by external series gate resistor.
S (6)	Load terminal / bootstrap return	Direct connection to motor/load; serves as reference for high-side floating drive and negative terminal of C_BOOT.
GH (7)	High-side gate driver output	Drives N-channel MOSFET drain-connected to VBB; requires bootstrap capacitor (C_BOOT) referenced to S pin.
BOOT (8)	High-side bootstrap supply	Positive terminal of C_BOOT; supplies gate voltage > VBB to high-side MOSFET; monitored for UVLO (7.8 V threshold).
~FAULT (9)	Open-drain fault indicator	Asserts low for latched faults (overtemp, VREG UVLO) or transient faults (BOOT UVLO, VREF UVLO); requires external pull-up.
IN1, IN2 (10–11)	Digital control inputs	Define half-bridge state (H/L, L/H, both L, both H); support hysteresis (100–300 mV) for noise immunity.
RESET (12)	Global enable/disable	Pulling low forces sleep mode (<10 µA quiescent); 1–10 µs pulse clears latched faults.
LGND (13)	Logic ground	Separate ground for digital inputs and internal logic; must be externally tied to system ground, independent of PGND.
DT (14)	Dead time programming	Analog input setting delay between GH/GL turn-off and subsequent turn-on; open = 12 µs default, tied to VREF = disabled.
VREF (15)	Internal 5 V reference	Stable 4.5–5.5 V output for logic and external circuitry; max 4 mA sourcing; requires 0.1 µF decoupling.
VBB (16)	Main power supply input	7–60 V input powering charge pump, gate drivers, and internal regulators; quiescent current 3–6 mA (active).
PAD	Exposed thermal pad	Non-electrical thermal interface; must be soldered to PCB ground plane with thermal vias for R_θJA = 34°C/W (4-layer).

Key Features

Feature	Design Value
Top-off charge pump	Enables true 100% duty cycle high-side operation by replenishing gate charge lost to bias current during sustained ON state.
Programmable dead time	Adjustable 350 ns–6 µs delay prevents cross-conduction in half-bridge configurations using single external resistor (R_DEAD).
Dual independent gate drives	GH and GL outputs support both synchronous rectification (low-side FET as active switch) and braking (both FETs ON) modes.
Latched thermal protection	Shuts down outputs at 170°C junction temperature with 15°C hysteresis; fault cleared only by RESET pulse - prevents thermal runaway.
Multi-threshold undervoltage lockout	Independent UVLO on VREG (8.3 V), BOOT (7.8 V), and VREF (<4 V) disables outputs until all rails stabilize - ensures robust startup and fault recovery.

Applications

Automotive Power Window Control	Industrial Conveyor Motor Driver
Use Scenario: Bidirectional 12 V DC motor actuation for window lift/drop with soft-start and overcurrent detection. IC Role / Device Role / Timing Role: Half-bridge controller managing high-side and low-side N-channel MOSFETs; uses DT pin to set 500 ns dead time preventing shoot-through during direction reversal. Use Value: Integrated VREG and top-off charge pump eliminate need for external high-voltage gate driver ICs, reducing BOM count and PCB area by 30% vs discrete solutions.	Use Scenario: 24–48 V DC motor control in factory automation systems requiring continuous torque and thermal resilience. IC Role / Device Role / Timing Role: Gate driver enabling synchronous rectification in half-bridge topology; leverages 135°C ambient rating and thermal shutdown to sustain operation in enclosed enclosures. Use Value: 170°C thermal shutdown with hysteresis allows safe operation up to 125°C case temperature, extending service life in high-ambient industrial settings.
Brushless DC Fan Controller	Electric Power Steering Assist
Use Scenario: Three-phase BLDC fan commutation in HVAC systems with variable speed and stall detection. IC Role / Device Role / Timing Role: Paired A3946KLBTR units per phase providing independent high/low drive; VREF used for Hall sensor biasing and fault monitoring. Use Value: 5 V VREF output with 4 mA drive capability powers Hall sensors directly, eliminating external LDO and reducing component count.	Use Scenario: High-reliability assist motor control in 12 V automotive EPS modules with functional safety requirements. IC Role / Device Role / Timing Role: Safety-critical gate driver with latched fault reporting (~FAULT) and RESET-controlled recovery; meets ASIL-B diagnostic coverage needs. Use Value: Fault output distinguishes latched (overtemp, VREG UVLO) from transient (BOOT UVLO) conditions, enabling differentiated ECU response per ISO 26262.

Automotive Power Window Control

Industrial Conveyor Motor Driver

Use Scenario: Bidirectional 12 V DC motor actuation for window lift/drop with soft-start and overcurrent detection.

IC Role / Device Role / Timing Role: Half-bridge controller managing high-side and low-side N-channel MOSFETs; uses DT pin to set 500 ns dead time preventing shoot-through during direction reversal.

Use Value: Integrated VREG and top-off charge pump eliminate need for external high-voltage gate driver ICs, reducing BOM count and PCB area by 30% vs discrete solutions.

Use Scenario: 24–48 V DC motor control in factory automation systems requiring continuous torque and thermal resilience.

IC Role / Device Role / Timing Role: Gate driver enabling synchronous rectification in half-bridge topology; leverages 135°C ambient rating and thermal shutdown to sustain operation in enclosed enclosures.

Use Value: 170°C thermal shutdown with hysteresis allows safe operation up to 125°C case temperature, extending service life in high-ambient industrial settings.

Brushless DC Fan Controller

Electric Power Steering Assist

Use Scenario: Three-phase BLDC fan commutation in HVAC systems with variable speed and stall detection.

IC Role / Device Role / Timing Role: Paired A3946KLBTR units per phase providing independent high/low drive; VREF used for Hall sensor biasing and fault monitoring.

Use Value: 5 V VREF output with 4 mA drive capability powers Hall sensors directly, eliminating external LDO and reducing component count.

Use Scenario: High-reliability assist motor control in 12 V automotive EPS modules with functional safety requirements.

IC Role / Device Role / Timing Role: Safety-critical gate driver with latched fault reporting (~FAULT) and RESET-controlled recovery; meets ASIL-B diagnostic coverage needs.

Use Value: Fault output distinguishes latched (overtemp, VREG UVLO) from transient (BOOT UVLO) conditions, enabling differentiated ECU response per ISO 26262.

Equivalent & Alternatives

The following parts are listed as comparable options for similar half-bridge gate driver applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP6542GQ-Z	Integrated current sense amplifier; no top-off charge pump; max VBB = 45 V; 5 mm × 6 mm QFN package.	Preferred where inline current monitoring is required but 100% duty cycle high-side operation is not critical.	Select MP6542GQ-Z when closed-loop current control is needed and board space permits larger QFN footprint.
TBD62783AFWG,EL	High-side driver only (no low-side); built-in bootstrap diode; max VBB = 36 V; 16-pin HTSSOP with thermal pad.	Suitable for high-side-only loads like solenoids or LED strings, but cannot implement full half-bridge motor control.	Choose TBD62783AFWG,EL only for unidirectional high-side switching; not a functional replacement for A3946KLBTR's dual-drive capability.

Compared with MP6542GQ-Z and TBD62783AFWG,EL, the A3946KLBTR uniquely delivers 100% duty cycle high-side operation via top-off charge pump, supports 60 V VBB, and provides independent GH/GL control - making it the only option among the three qualified for automotive window lift and EPS assist applications requiring sustained high-side conduction.

Availability

A3946KLBTR is available at Aetrix Electronics and suitable for automotive power window systems, industrial conveyor motor controllers, brushless DC fan modules, and electric power steering assist designs requiring stable component supply and AEC-Q100-compliant performance.

Supply support for A3946KLBTR 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

Allegro MicroSystems is a U.S.-based designer and manufacturer of high-performance magnetic sensing and power ICs, specializing in motion control, energy-efficient power conversion, and automotive-grade semiconductor solutions.

The A3946 product line delivers robust half-bridge gate drivers optimized for high-power DC and BLDC motor control in automotive and industrial environments, emphasizing thermal resilience, integrated protection, and bootstrap-based high-side drive.

FAQ

What is the maximum VBB voltage rating for the A3946KLBTR?

The A3946KLBTR has an absolute maximum VBB rating of 60 V, with recommended operating range from 7 V to 60 V. This allows direct integration into 12 V, 24 V, and 48 V automotive and industrial power systems without external step-down regulation. Exceeding 60 V risks permanent damage to internal charge pump and gate driver circuitry.

Does the A3946KLBTR support 100% duty cycle high-side operation, and how is it achieved?

Yes, the A3946KLBTR supports true 100% duty cycle high-side operation via its internal top-off charge pump. Unlike basic bootstrap architectures that require periodic low-side conduction to recharge the bootstrap capacitor, the top-off pump continuously replenishes gate charge lost to bias current, sustaining GH output voltage even during indefinite high-side conduction - critical for applications like electric power steering assist.

How does the ~FAULT pin behave during different fault conditions on the A3946KLBTR?

The ~FAULT pin on the A3946KLBTR is an open-drain output that pulls low for all fault conditions. Latched faults (overtemperature at 170°C, VREG undervoltage) remain asserted until cleared by a 1–10 µs RESET pulse. Non-latched faults (BOOT undervoltage, VREF undervoltage) deassert automatically when the condition clears. The pin does not differentiate fault types - external logic must monitor VREG, BOOT, and die temperature to diagnose root cause.

What is the purpose of separate PGND and LGND pins on the A3946KLBTR, and how should they be connected?

The A3946KLBTR features isolated PGND (Pin 4) and LGND (Pin 13) to separate high-current power return paths from sensitive logic ground. PGND carries switching currents from GL/GH drivers and must connect directly to the power ground plane near the MOSFETs. LGND serves digital inputs (IN1/IN2/RESET/DT) and must connect to the microcontroller ground. Both pins must be externally tied to system ground at a single low-impedance point to prevent ground bounce and ensure noise-immune logic operation.

Can the A3946KLBTR drive both N-channel MOSFETs in a high-side/low-side configuration without external level-shifting components?

Yes, the A3946KLBTR is specifically designed to drive two N-channel MOSFETs in a half-bridge configuration without external level shifters. Its bootstrap architecture (BOOT/S pins) and integrated top-off charge pump generate the required gate voltage > VBB for the high-side MOSFET, while GL directly drives the low-side MOSFET referenced to PGND. This eliminates the need for P-channel high-side switches or dedicated high-voltage level-shift ICs.

A3946KLBTR Specifications

Product attributes: Attribute value

Manufacturer:: Allegro MicroSystems

Series:: -

Package/Case:: 16-PowerSOIC (0.295", 7.50mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Motor Type - Stepper:: -

Motor Type - AC, DC:: Brushless DC (BLDC)

Function:: Controller - Commutation, Direction Management

Output Configuration:: Pre-Driver - Half Bridge

Interface:: Parallel

Technology:: Power MOSFET

Step Resolution:: -

Applications:: General Purpose

Current - Output:: -

Voltage - Supply:: 7V ~ 60V

Voltage - Load:: -

Operating Temperature:: -40°C ~ 135°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 16-SOIC

A3946KLBTR FAQ

1.How can I place an order for A3946KLBTR through Aetrix?

Please submit a Request for Quotation (RFQ) for A3946KLBTR 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 A3946KLBTR reliable?

The price and inventory of A3946KLBTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A3946KLBTR is usually 5 days.

3.What payment methods are accepted for A3946KLBTR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A3946KLBTR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for A3946KLBTR?

A3946KLBTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your A3946KLBTR 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 A3946KLBTR?

For technical support, including A3946KLBTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A3946KLBTR requirements.

6.How does Aetrix verify that A3946KLBTR is sourced from the original manufacturer or authorized distributors?

All A3946KLBTR 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 A3946KLBTR meets industry standards.

7.What is the process for return or replacement of A3946KLBTR?

All A3946KLBTR units undergo pre-shipment inspection (PSI). If there is an issue with A3946KLBTR, 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 A3946KLBTR part is unused and in its original packaging.

Return procedure for A3946KLBTR:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…