My Inquiry
My Account
Allegro MicroSystems A3946KLP
- Part No.:
- A3946KLP
- Manufacturer:
- Allegro MicroSystems
- Category:
- Motor Drivers, Controllers
- Package:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
A3946KLP.pdf
- Description:
- IC MOTOR DRIVER 7V-60V 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,288
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
A3946KLP 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 A3946KLP datasheet, A3946KLP pinout, A3946KLP application, or A3946KLP equivalent, key selection considerations include bootstrap gate drive architecture, dead-time programmability 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 A3946KLP implements a dual-output gate driver architecture with independent high-side (GH) and low-side (GL) outputs, each capable of sourcing/sinking ≥2 A peak current. Its internal top-off charge pump enables sustained DC operation of the high-side N-MOSFET by replenishing bootstrap capacitor leakage without requiring switching transitions.
Control logic supports two modes: single-pin PWM (IN1=IN2 with DT-to-ground resistor) and independent input control (DT tied to VREF), with configurable dead time (350 ns to 6 µs) and latched fault reporting via open-drain ~FAULT pin. Protection includes VREG undervoltage lockout (8.3 V trip), BOOT undervoltage detection (7.8 V), and overtemperature shutdown at 170°C with 15°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBB Supply Range | 7 V to 60 V - supports wide-input automotive and industrial battery systems without external regulation |
| VREG Output | 13 V ±0.5 V at 15 mA - powers low-side gate drive and bootstraps high-side circuitry |
| Gate Drive Rise/Fall Time | 60 ns / 40 ns (typ.) into 3300 pF - enables fast switching of high-Qg MOSFETs up to 100 kHz PWM |
| Dead Time Range | 350 ns to 6 µs - adjustable via external RDEAD to prevent shoot-through in half-bridge configurations |
| Thermal Shutdown | 170°C junction temperature - protects device during overload or poor heatsinking conditions |
| Operating Ambient | –40°C to +135°C - qualified for under-hood automotive and industrial motor control environments |
| ESD Rating | 2000 V HBM - ensures robustness during PCB handling and assembly |
Pinout & Package
Package: 16-lead TSSOP with exposed thermal pad (LP suffix), lead-free, matte tin-plated leadframe. Thermal pad must be externally connected to ground for optimal thermal performance and noise reduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VREG (1) | Regulated gate drive supply | 13 V output powering GL driver and bootstrap charging path; requires 10 µF decoupling capacitor |
| CP2 (2), CP1 (3) | Charge pump capacitor terminals | Form external flying capacitor for VREG generation; CP2 positive, CP1 negative |
| PGND (4) | Power ground reference | Separate ground return for high-current gate drive paths; must be connected to system ground |
| GL (5) | Low-side gate driver output | Sinks/source up to 2 A to drive N-MOSFET gate; series resistor controls dv/dt at S pin |
| S (6) | Load connection node | Connects to motor phase or inductive load; serves as return for bootstrap capacitor and floating high-side supply |
| GH (7) | High-side gate driver output | Drives N-MOSFET source-connected to VBB; requires bootstrap capacitor between BOOT and S |
| BOOT (8) | Bootstrap capacitor positive terminal | Provides floating supply for GH driver; voltage must stay >7.8 V to avoid UVBOOT fault |
| ~FAULT (9) | Open-drain fault indicator | Pulled low during latched faults (VREG UV, OVERTEMP) or non-latched UVBOOT/VREF UV |
| IN1, IN2 (10–11) | Digital control inputs | Configure half-bridge state (H/L/both off); support logic-high threshold ≥2.0 V and hysteresis ≥100 mV |
| RESET (12) | Global enable/disable control | Low pulse ≥1 µs clears latched faults; held low forces sleep mode (<10 µA quiescent current) |
| LGND (13) | Logic ground reference | Separate ground for digital inputs and internal logic; must be connected to system ground independently of PGND |
| DT (14) | Dead time programming input | Analog input setting turn-on delay; 5 kΩ–100 kΩ to ground yields 350 ns–6 µs dead time |
| VREF (15) | Internal 5 V reference output | Decoupled with 0.1 µF capacitor; sources ≤4 mA for external circuitry or logic biasing |
| VBB (16) | Main power supply input | 7–60 V input powering charge pump, logic, and gate drivers; quiescent current 3–6 mA |
Key Features
| Feature | Design Value |
|---|---|
| Top-off charge pump | Enables true 100% duty cycle high-side N-MOSFET operation without requiring switching transitions to refresh BOOT voltage |
| Programmable dead time | Adjustable 350 ns–6 µs via single external resistor (DT pin), eliminating need for external timing ICs or complex layout |
| Dual independent control modes | Supports both single-pin PWM (IN1=IN2) and full 2-input logic control (DT=VREF), enabling flexible integration into diverse MCU interfaces |
| Latched fault management | ~FAULT pin asserts low for VREG UV and OVERTEMP faults; cleared only by RESET pulse - prevents unintended recovery during fault persistence |
| Thermal and supply robustness | Rated for –40°C to +135°C ambient and 7–60 V VBB range, meeting AEC-Q100 stress requirements for automotive motor control |
Applications
| Automotive HVAC Blower Control | Industrial Conveyor Motor Drive |
|---|---|
Use Scenario: Precise speed and direction control of 12–48 V DC blower motors in vehicle climate systems. IC Role / Device Role / Timing Role: Half-bridge gate driver controlling high-side and low-side N-MOSFETs; manages dead time to prevent shoot-through during PWM commutation. Use Value: Enables efficient unidirectional motor control with braking capability, leveraging VREG-regulated 13 V gate drive and thermal shutdown at 170°C for under-hood reliability. |
Use Scenario: High-reliability bidirectional control of 24–60 V DC conveyor belt motors in factory automation. IC Role / Device Role / Timing Role: Dual gate driver providing independent GH/GL control with programmable dead time and fault diagnostics via ~FAULT pin. Use Value: Supports long-term operation in hot industrial enclosures via –40°C to +135°C rating and 43°C/W thermal resistance on 2-layer PCB. |
| Brushless DC Fan Module | Electric Power Steering Assist |
Use Scenario: Compact, high-efficiency 3-phase BLDC fan modules for server cooling and telecom power supplies. IC Role / Device Role / Timing Role: Gate driver stage for external N-MOSFET half-bridges; uses top-off charge pump to sustain high-side conduction during stall or low-speed conditions. Use Value: Eliminates need for external high-voltage gate driver ICs or isolated supplies, reducing BOM count and board space in space-constrained modules. |
Use Scenario: Redundant or auxiliary assist motor control in EPS systems requiring functional safety-aware gate driving. IC Role / Device Role / Timing Role: Safety-critical half-bridge driver with latched fault reporting (~FAULT), VREG/BOOT undervoltage detection, and thermal shutdown at 170°C. Use Value: Provides deterministic fault response and diagnostic visibility required for ASIL-B decomposition, while operating across full automotive temperature range. |
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 |
|---|---|---|---|
| MP6612DQ | Integrated 12 V gate driver with internal bootstrap diode; no top-off charge pump; max VBB = 36 V | Lacks 100% duty cycle support and automotive temperature range; suited for consumer-grade 24 V systems | Select when cost-sensitive designs accept reduced duty cycle headroom and lower thermal rating |
| TBD62783AFG | High-side/low-side driver with built-in level shifters; no internal charge pump; requires external 12 V supply | Needs external gate supply rail; lacks integrated VREG and BOOT UVLO; rated to +125°C only | Choose where board space allows separate gate supply and ambient stays below 125°C |
Compared with MP6612DQ and TBD62783AFG, the A3946KLP uniquely delivers 100% duty cycle capability via top-off charge pump, full automotive temperature range (–40°C to +135°C), and integrated 13 V VREG regulator - making it the only option among the three qualified for demanding high-reliability motor control where sustained high-side conduction and thermal resilience are mandatory.
Availability
A3946KLP is available at Aetrix Electronics and suitable for automotive HVAC systems, industrial conveyor drives, BLDC fan modules, and electric power steering assist applications requiring stable component supply, long lifecycle support, and AEC-Q100-aligned reliability.
Supply support for A3946KLP 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 semiconductor company specializing in magnetic sensing, power ICs, and motor control solutions, with design centers in North America, Europe, and Asia.
The A3946KLP belongs to Allegro's high-current gate driver product line, engineered specifically for robust, high-efficiency control of N-channel MOSFET half-bridges in automotive and industrial motor systems.
FAQ
What is the maximum duty cycle supported by the A3946KLP?
The A3946KLP supports true 100% duty cycle operation on the high-side output (GH) due to its integrated top-off charge pump, which continuously replenishes the bootstrap capacitor charge during sustained conduction - unlike conventional bootstrap drivers that require periodic low-side switching to recharge.
How does the A3946KLP handle fault conditions like overtemperature or undervoltage?
The A3946KLP asserts the open-drain ~FAULT pin low during latched faults (VREG undervoltage, junction temperature >170°C) and non-latched faults (BOOT undervoltage, VREF undervoltage). Latched faults require a 1–10 µs low pulse on RESET to clear; non-latched faults self-clear when the condition resolves.
Can the A3946KLP drive both high-side and low-side N-channel MOSFETs without external level-shifting circuitry?
Yes - the A3946KLP integrates a charge pump (VREG) and top-off circuit to generate the floating high-side gate drive voltage, eliminating the need for external level shifters or P-channel devices. The GH output directly drives N-MOSFET gates referenced to the S node, while GL drives low-side N-MOSFETs referenced to LGND/PGND.
What is the recommended dead time resistor value for typical 12 V automotive motor control using the A3946KLP?
For 12 V systems, a 15.8 kΩ resistor from DT to LGND yields ~1 µs dead time - sufficient to prevent shoot-through while minimizing conduction loss. This value is explicitly used in Allegro's Application Diagram A and aligns with typical MOSFET switching speeds and layout parasitics in automotive harnesses.
Does the A3946KLP require separate connections for PGND and LGND, and why?
Yes - PGND (pin 4) and LGND (pin 13) are internally isolated grounds. PGND carries high di/dt return currents from GL/GH drivers, while LGND serves digital logic and reference circuits. Separating them prevents noise coupling and ensures stable VREF and input thresholds, especially critical in noisy motor drive environments.
A3946KLP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tube
- 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-eTSSOP-EP
A3946KLP FAQ
1.How can I place an order for A3946KLP through Aetrix?
Please submit a Request for Quotation (RFQ) for A3946KLP 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 A3946KLP reliable?
The price and inventory of A3946KLP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A3946KLP is usually 5 days.
3.What payment methods are accepted for A3946KLP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A3946KLP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A3946KLP?
A3946KLP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A3946KLP 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 A3946KLP?
For technical support, including A3946KLP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A3946KLP requirements.
6.How does Aetrix verify that A3946KLP is sourced from the original manufacturer or authorized distributors?
All A3946KLP 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 A3946KLP meets industry standards.
7.What is the process for return or replacement of A3946KLP?
All A3946KLP units undergo pre-shipment inspection (PSI). If there is an issue with A3946KLP, 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 A3946KLP part is unused and in its original packaging.
Return procedure for A3946KLP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A3946KLP Tags
-
DRV2603RUNR
Texas Instruments
-
DRV8837CDSGR
Texas Instruments
-
DRV8837DSGR
Texas Instruments
-
DRV8838DSGR
Texas Instruments
-
DRV8839DSSR
Texas Instruments
-
EMC2301-1-ACZL-TR
Microchip Technology
-
DRV8231ADSGR
Texas Instruments
-
EMC2302-2-AIZL-TR
Microchip Technology
-
DRV8800PWPR
Texas Instruments
-
DRV8835DSSR
Texas Instruments
-
EMC2303-1-KP-TR
Microchip Technology
-
DRV8876PWPR
Texas Instruments
Tech Hub
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
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.
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.
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…
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…
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…
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 …
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…
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…
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…
