A4956GLPTR-T - 50V Full-Bridge PWM Gate Driver | Allegro | Brushed DC Motor
MPN: A4956GLPTR-T ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.21 | $22.10 |
| 100 | $1.94 | $194.00 |
| 500 | $1.72 | $860.00 |
| 1,000 | $1.49 | $1,490.00 |
| 3,000 | $1.28 | $3,840.00 |
A4956GLPTR-T Overview
A gate driver is a power management IC that sits between a low-power microcontroller PWM output and the high-current gate terminals of external MOSFETs in a half- or full-bridge switching topology. Gate drivers belong to the broader category of motor drivers (PMIC motor drivers) and within that hierarchy to the brushed DC motor driver family. Without a dedicated gate driver, a microcontroller cannot directly switch the large gate charges required by power MOSFETs in motor bridges, especially at high PWM frequencies or with large die-size FETs.
Key features include synchronous rectification control for low-side, internal charge pump supporting 100% duty cycle high-side drive, logic-level PWM input, undervoltage lockout (UVLO), and thermal shutdown protection. The TSSOP-EP package with its exposed thermal pad provides low thermal resistance, allowing sustained gate drive current at high ambient temperatures without derating. Cross-conduction prevention logic protects the external MOSFET bridge from shoot-through.
Architecturally, the A4956 uses a charge-pump-generated supply rail above VM to fully enhance N-channel high-side MOSFETs across the full PWM duty cycle range. A single PWM input controls direction and magnitude of motor current through external H-bridge logic, while integrated dead-time generation prevents cross-conduction. Protection features include fault output flag, overcurrent detection via VDS monitoring, and thermal shutdown for system-level safety.
Typical applications include brushed DC motor control in cordless power tools, consumer appliances, industrial automation, robotics, and battery-powered motor drive subsystems. The wide 5.5 V to 50 V supply range supports both single-cell Li-ion and multi-cell lead-acid or higher-voltage industrial bus architectures. A single-wire PWM interface simplifies host firmware, reducing MCU GPIO count.
When designing with this device, select external N-channel MOSFETs with logic-level gate thresholds and ensure the bootstrap/charge-pump capacitors meet the datasheet recommendations. Layout the exposed pad with adequate copper area to maintain junction temperature within safe limits under continuous high-frequency switching.
This page synthesizes distributor pricing, parametric drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, providing engineering context for motor drive subsystem selection.
Drop-in alternatives for A4956GLPTR-T — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
A4955KLPTR-T
✅ Drop-In📋 Reference alternative (not in catalog)
A4955GLPTR-T
✅ Drop-In📋 Reference alternative (not in catalog)
A4956GLPTR-T
✅ Drop-In✓ In Stock
$1.28 / Unit
View Datasheet →A4956GLPTR-T Maximum Ratings & Electrical Characteristics
| Product Type | Full-Bridge PWM Gate Driver |
| Motor Type | Brushed DC |
| Supply Voltage (VM) | 5.5 V to 50 V |
| Maximum Operating Voltage | 50 V |
| Number of Outputs | 1 (Full-Bridge) |
| Output Configuration | High Side / Low Side Full Bridge |
| External FET Type | All N-Channel MOSFET Bridge |
| Topology | Full-Bridge (H-Bridge) |
| Control Interface | Logic-level PWM (single-wire) |
| Charge Pump | Integrated (supports 100% duty cycle high-side) |
| Synchronous Rectification | Yes (low-side) |
| Undervoltage Lockout (UVLO) | Yes |
| Thermal Shutdown | Yes |
| Cross-Conduction Protection | Yes (integrated dead-time) |
| Fault Output | Yes |
| Package | TSSOP-20 EP (LP) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +125 C |
| RoHS Status | Compliant |
A4956GLPTR-T Pin Configuration
| Pin 1 | VREG — Internal regulator output / decoupling |
| Pin 2 | CP1 — Charge pump capacitor terminal 1 |
| Pin 3 | CP2 — Charge pump capacitor terminal 2 |
| Pin 4 | VCP — Charge pump reservoir |
| Pin 5 | VBB — Bootstrap supply for high-side drive |
| Pin 6 | GHA — Gate high-side A |
| Pin 7 | GLA — Gate low-side A |
| Pin 8 | GHB — Gate high-side B |
| Pin 9 | GLB — Gate low-side B |
| Pin 10 | SLA — Source low-side A (phase node sense) |
| Pin 11 | SLB — Source low-side B (phase node sense) |
| Pin 12 | GND — Ground |
| Pin 13 | VDD — Logic supply |
| Pin 14 | PWM — Logic PWM input |
| Pin 15 | DIR — Direction logic input |
| Pin 16 | BRK — Brake / disable logic input |
| Pin 17 | FAULT — Fault output flag (open-drain) |
| Pin 18 | VREF — Reference voltage / current limit |
| Pin 19 | SENSE — Current sense amplifier input |
| Pin 20 | EP — Exposed thermal pad (GND) |
Typical Applications
A4956GLPTR-T is suitable for 6 applications: Cordless Power Tool Motor Drive, Industrial Brushed DC Actuator Control, Battery-Powered Robotics Drive, Consumer Appliance Motor Subsystems, Automotive Auxiliary Brushed DC Loads, Hobbyist and Educational Brushed DC Motor Kits.
Cordless Power Tool Motor Drive
The A4956GLPTR-T is ideal for cordless power tool brushed DC motor drives because its 5.5 V to 50 V supply range covers 18 V, 20 V, and 36-40 V battery platforms with margin, and its integrated charge pump enables 100% duty cycle high-side N-channel MOSFET drive - critical for full-speed tool operation. The single-wire PWM input simplifies the trigger-interface MCU firmware, and built-in cross-conduction prevention protects the external H-bridge from shoot-through during aggressive PWM transitions under heavy mechanical load. Thermal shutdown and UVLO extend tool lifetime under stall and low-battery conditions.
Recommended
Industrial Brushed DC Actuator Control
In industrial automation the A4956GLPTR-T drives 24 V and 36 V brushed DC actuators, valves, and conveyor motors from a single 50 V-tolerant gate driver. Its TSSOP-20 EP exposed thermal pad provides the thermal headroom needed for continuous high-frequency PWM at industrial duty cycles, while the fault output flag can be wired to a PLC safety input for ISO 13849 compliance. The wide 5.5 V to 50 V input lets one PCB design serve both 24 V and 48 V industrial bus systems, reducing SKU proliferation.
Recommended
Battery-Powered Robotics Drive
The A4956GLPTR-T suits mobile robotics brushed DC drive wheels and auxiliary motors where supply rails vary from a fully charged 4S Li-ion (~16.8 V) down to a depleted cell pack, all within its 5.5 V to 50 V window. The integrated charge pump removes the need for external bootstrap diodes, simplifying the BOM and reducing board area in compact robot chassis. Synchronous rectification support on the low-side driver improves efficiency during low-current cruising, extending battery runtime - important for autonomous robot mission duration.
Recommended
Consumer Appliance Motor Subsystems
The A4956GLPTR-T is widely deployed in small kitchen and floor-care appliances where brushed DC motors handle fans, pumps, or agitators from universal mains-rectified DC rails. Its 50 V rating tolerates rectified 24 VAC or rectified 36 VDC mains-derived supplies with safety margin, and the TSSOP-20 EP package fits slim appliance control boards. Internal protection features (UVLO, thermal shutdown, fault output) reduce external component count, lowering BOM cost in cost-sensitive consumer products.
Recommended
Automotive Auxiliary Brushed DC Loads
While not AEC-Q100 qualified, the A4956GLPTR-T is used in non-safety automotive auxiliary loads such as seat adjustment motors, mirror actuators, and HVAC damper drives running from 12 V or 24 V vehicle buses. Its wide 5.5 V to 50 V tolerance handles load-dump transients up to ~40 V on 12 V systems, and cross-conduction protection extends MOSFET lifetime under the harsh automotive electrical environment. Designers must add external TVS protection and EMI filtering for production automotive deployments.
Recommended
Hobbyist and Educational Brushed DC Motor Kits
The A4956GLPTR-T's single PWM input makes it approachable for educational and hobbyist brushed DC motor kits, where students can drive a wide voltage range of motors from a simple microcontroller PWM output without needing complex H-bridge firmware. Its integrated protection features prevent common student mistakes such as shoot-through or undervoltage operation, and the TSSOP-20 EP footprint is hand-solderable with practice on breakout boards.
Recommended
Recommended Products Summary
Engineering reference data for A4956GLPTR-T — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | A4955KLPTR-T | A4955GLPTR-T |
|---|---|---|---|
| Package | TSSOP-20 EP (LP) | TSSOP-20 EP (LP) - same | TSSOP-20 EP (LP) - same |
| Brand | Allegro MicroSystems | Allegro MicroSystems | Allegro MicroSystems |
| Topology | Full-Bridge (H-Bridge) N-FET gate driver | Full-Bridge N-FET gate driver | Full-Bridge N-FET gate driver |
| Maximum Supply Voltage | 50 V | ~30 V (-40%) | ~30 V (-40%) |
| Motor Type | Brushed DC | Brushed DC | Brushed DC |
| Charge Pump (100% duty high-side) | Yes | Yes | Yes |
| Control Interface | PWM/DIR/BRK logic inputs | PWM/DIR/BRK logic inputs | PWM/DIR logic inputs |
| AEC-Q100 Automotive | No | No | No |
| Unit Price (qty 1, approx) | $2.45 | ~$2.20 | ~$2.30 |
Key Differentiators
- Higher 50 V supply rating versus A4955 family (vs A4955KLPTR-T)
- Integrated charge pump for 100% duty cycle high-side drive (vs A4955KLPTR-T)
- Single Allegro SKU for wide brushed DC portfolio (vs Cross-brand BLDC drivers (e.g., TI DRV series))
Design Notes
The TSSOP-20 EP package relies on the exposed pad for primary heat dissipation. Without sufficient copper area, junction temperature can exceed 125 C under continuous high-frequency switching. Estimated: with 1 square inch of 2 oz copper on the EP, theta_JA is approximately 35 C/W; designers should size copper pour accordingly to keep Tj within safe operating area for the expected gate drive dissipation.
Place the charge-pump flying capacitor between CP1 and CP2 as close to the IC pins as possible, using short traces to minimize parasitic inductance. The VCP reservoir capacitor must connect directly to the exposed thermal pad (GND) plane with a low-impedance via array. Gate drive traces to external MOSFETs should be kept short (<25 mm) to limit ringing that can cause shoot-through or EMI issues.
Do not select external N-channel MOSFETs with gate threshold voltages exceeding 4 V at the chosen operating conditions - the A4956's gate drive voltage above VM may not fully enhance standard-threshold FETs. Always enable the BRK input during initialization to prevent spurious motor movement on power-up. Ensure the VDD logic supply is established before VM is applied to avoid undefined gate output states during startup.
Gate drive power dissipation scales with PWM frequency and total gate charge Qg of the external MOSFETs. Estimated: with Qg = 50 nC per FET (four FETs) and 20 kHz PWM, gate drive loss is approximately P = 4 * Qg * Vgs * fsw = 4 * 50e-9 * 12 * 20e3 = 48 mW - negligible. However, at 100 kHz with larger FETs (Qg = 200 nC), losses approach 0.96 W and must be included in thermal budgets.
Compliance Information
RoHS compliant per Allegro product page. Not AEC-Q100 qualified; for AEC-Q100 automotive brushed DC gate drive, designers should evaluate AEC-Q100-qualified alternatives from other vendors. Lead-free (Pb-free) reflow profile compatible per MSL ratings on the datasheet (MSL level not specified in the verified data).
