A4950

@@ -0,0 +1,52 @@+# A4950++**Allegro MicroSystems** · Brushed DC motor driver · SOIC-8-EP++Full-bridge (H-bridge) driver for one brushed DC motor from an 8 to 40 V supply, delivering up to 3.5 A peak. Two logic inputs (IN1, IN2) set forward, reverse, brake, and coast, and a fixed off-time current-limit circuit set by VREF and a low-side sense resistor (LSS) regulates the winding current for torque control. Internal undervoltage, overcurrent, and thermal protection guard the bridge, and the exposed pad carries heat into the board. A rugged mid-voltage single-motor driver.++## Pinout++| Pin | Name | Type | Function |+|---|---|---|---|+| 1 | GND | power_in | Device ground return. Should tie to the PCB star ground located directly under the exposed thermal pad. |+| 2 | IN2 | input | Logic input 2 for the full bridge. VIN(1) ≥ 2.0 V, VIN(0) ≤ 0.8 V, with internal ~50 kΩ pull-down. Combined with IN1 selects forward, reverse, brake, or coast/standby per the PWM Control Truth Table. |+| 3 | IN1 | input | Logic input 1 for the full bridge. VIN(1) ≥ 2.0 V, VIN(0) ≤ 0.8 V, with internal ~50 kΩ pull-down. Both inputs low for >1 ms enters Low Power Standby mode. |+| 4 | VREF | input | Analog reference input that sets the PWM current-limit threshold. Valid range 0 to 5 V; peak trip current is ITripMAX = VREF / (10 × RS), where RS is the sense resistor on LSS. |+| 5 | VBB | power_in | Load supply voltage input, 8 to 40 V operating range (40 V absolute max). Should be decoupled with a bulk electrolytic (~100 µF) in parallel with a ceramic (~0.22 µF) close to the pin. |+| 6 | OUT1 | output | DMOS full-bridge output 1 driving one side of the motor winding. Rated for up to ±3.5 A continuous (6 A transient <500 ns); absolute output voltage range −2 to 42 V. |+| 7 | LSS | passive | Low-side source / sense-resistor return. External current-sense resistor RS is connected from LSS to ground for PWM current regulation. Sense voltage limit ±500 mV. |+| 8 | OUT2 | output | DMOS full-bridge output 2 driving the other side of the motor winding. Rated for up to ±3.5 A continuous (6 A transient <500 ns); absolute output voltage range −2 to 42 V. |+| 9 | PAD | passive | Exposed thermal pad on the underside of the package. Solder to the PCB copper ground plane for enhanced thermal dissipation; typically connected to GND at the star ground point. |++## Key specifications++| Parameter | Value |+|---|---|+| Type | Full-bridge brushed DC motor driver |+| Supply (VBB) | 8-40 V |+| Peak current | 3.5 A |+| Control | IN1 / IN2 (PWM) |+| Current limit | Fixed off-time (VREF + LSS sense) |+| Protection | UVLO, OCP, thermal |+| Package | SOIC-8 with exposed pad |++## Ordering variants++- `A4950ELJTR-T (SOIC-8 EP)`+- `A4950KLJTR-T (extended temp)`++## CAD (KiCad official)++- Symbol: `Driver_Motor:A4950E (KiCad official)`+- Footprint: `Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.41x3.3mm`+- 3D model: SOIC-8 exposed-pad (KiCad packages3D, STEP)++## Provenance++Data extracted from the manufacturer datasheet, not a distributor listing:++- **Datasheet:** [Allegro MicroSystems datasheet](https://www.allegromicro.com/-/media/files/datasheets/a4950-datasheet.pdf) (9 pp, sha256 `9878d992aa310a27`, retrieved 2026-08-17, tier: manufacturer)+- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.+- **CAD:** KiCad official libraries (CC-BY-SA 4.0).++[Datasheet PDF](docs/a4950-datasheet.pdf)

@@ -0,0 +1,38 @@+{+  "slug": "a4950",+  "version": "0.1.0",+  "type": "component",+  "description": "Allegro full-bridge brushed DC motor driver, SOIC-8 with exposed pad. 8-40 V, 3.5 A peak, current limit. Datasheet-verified.",+  "tags": [+    "component",+    "driver",+    "motor-driver",+    "h-bridge",+    "brushed-dc",+    "soic-8",+    "allegro"+  ],+  "dependencies": {},+  "hero": {+    "type": "image",+    "path": "docs/hero.png"+  },+  "files": [+    "page.json",+    "README.md",+    "a4950.kicad_sym",+    "a4950.kicad_mod",+    "a4950.glb",+    "a4950.step",+    "a4950.lbr",+    "docs/hero.png",+    "docs/a4950-datasheet.pdf",+    "viewers/symbol.html",+    "viewers/footprint.html"+  ],+  "visibility": "public",+  "author": {+    "name": "Ray",+    "email": "[email protected]"+  }+}\ No newline at end of file