component
A3977SLPTR-T
Public Made by Adomby adom
Allegro MicroSystems, LLC Motor Driver ICs, TSSOP-28-EP. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
main
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{
"slug": "a3977slptr-t",
"version": "0.1.0",
"type": "component",
"description": "Allegro MicroSystems, LLC Motor Driver ICs, TSSOP-28-EP. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
"tags": [
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"power management ics",
"a3977slptr-t",
"factory-2.0.0",
"extractor-text"
],
"dependencies": {},
"hero": {
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"path": "docs/hero.png"
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"a3977slptr-t.step",
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"component": {
"mpn": "A3977SLPTR-T",
"manufacturer": "Allegro MicroSystems, LLC",
"package": "TSSOP-28-EP",
"pin_count": 29,
"category": "Power Management ICs",
"subcategory": "Motor Driver ICs",
"datasheet": "https://datasheet.lcsc.com/datasheet/pdf/0494da4f1ef374b762cf49539b466b97.pdf",
"parts": {
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"footprint": "a3977slptr-t.kicad_mod",
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"model_3d_step": "a3977slptr-t-etched.step",
"model_3d_step_plain": "a3977slptr-t.step",
"lbr": "a3977slptr-t.lbr"
},
"distributor_links": {
"lcsc": "C163514",
"digikey": "620-1147-2-ND",
"mouser": "250-A3977SLPTR-T"
},
"distributor_check": {
"checked_at": "2026-11-05T01:00:24Z",
"source": "Component Ocean /api/assign-pns",
"digikey": {
"pn": "620-1147-2-ND",
"status": "found"
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},
"pins": [
{
"number": "1",
"name": "SENSE1",
"type": "passive",
"description": "Sense resistor connection for bridge 1; the SENSE terminal maximum rating is 0.5 V (DC)."
},
{
"number": "2",
"name": "HOME",
"type": "output",
"description": "Logic output indicating the translator's initial home state; it goes low during RESET and at home state."
},
{
"number": "3",
"name": "DIR",
"type": "input",
"description": "Direction input that sets the direction of motor rotation."
},
{
"number": "4",
"name": "OUT1A",
"type": "output",
"description": "DMOS H bridge 1 output A, rated for ±2.5 A and 35 V."
},
{
"number": "5",
"name": "PFD",
"type": "input",
"description": "Mixed decay setting input; above 0.6 × VDD selects slow decay and below 0.21 × VDD selects fast decay, with a 0.1 µF decoupling capacitor recommended."
},
{
"number": "6",
"name": "RC1",
"type": "passive",
"description": "Analog input for the fixed off-time timing network of bridge 1, connected to RT and CT to ground."
},
{
"number": "7",
"name": "AGND",
"type": "power_in",
"description": "Analog ground that must be connected externally to PGND (pin 21) on the TSSOP package."
},
{
"number": "8",
"name": "REF",
"type": "input",
"description": "Gm reference input; the reference voltage range is 0 to VDD and sets the current limit via ITRIPmax = VREF / 8 × RS."
},
{
"number": "9",
"name": "RC2",
"type": "passive",
"description": "Analog input for the fixed off-time timing network of bridge 2, connected to RT and CT to ground."
},
{
"number": "10",
"name": "VDD",
"type": "power_in",
"description": "Logic supply voltage, operating range 3.0 to 5.5 V."
},
{
"number": "11",
"name": "OUT2A",
"type": "output",
"description": "DMOS H bridge 2 output A, rated for ±2.5 A and 35 V."
},
{
"number": "12",
"name": "MS2",
"type": "input",
"description": "Logic input that selects the microstep resolution together with MS1 per Table 1."
},
{
"number": "13",
"name": "MS1",
"type": "input",
"description": "Logic input that selects the microstep resolution together with MS2 per Table 1."
},
{
"number": "14",
"name": "SENSE2",
"type": "passive",
"description": "Sense resistor connection for bridge 2; the SENSE terminal maximum rating is 0.5 V (DC)."
},
{
"number": "15",
"name": "VBB2",
"type": "power_in",
"description": "Load supply for bridge 2, operating range 8.0 to 35 V."
},
{
"number": "16",
"name": "SR",
"type": "input",
"description": "Logic input that selects synchronous rectification: logic low enables active mode and logic high disables it."
},
{
"number": "17",
"name": "RESET",
"type": "input",
"description": "Active-low logic input that sets the translator to the home state and turns off all DMOS outputs."
},
{
"number": "18",
"name": "OUT2B",
"type": "output",
"description": "DMOS H bridge 2 output B, rated for ±2.5 A and 35 V."
},
{
"number": "19",
"name": "STEP",
"type": "input",
"description": "Logic input where a low-to-high transition advances the motor one microstep increment; maximum STEP frequency is 500 kHz."
},
{
"number": "20",
"name": "VREG",
"type": "passive",
"description": "Internally generated regulator voltage for the sink-side DMOS outputs, to be decoupled with a 0.22 µF capacitor to ground."
},
{
"number": "21",
"name": "PGND",
"type": "power_in",
"description": "Power ground that must be connected externally to AGND (pin 7) on the TSSOP package."
},
{
"number": "22",
"name": "VCP",
"type": "passive",
"description": "Charge pump reservoir capacitor node, requiring a 0.22 µF ceramic capacitor between VCP and VBB."
},
{
"number": "23",
"name": "CP1",
"type": "passive",
"description": "Charge pump capacitor terminal, requiring a 0.22 µF ceramic capacitor between CP1 and CP2."
},
{
"number": "24",
"name": "CP2",
"type": "passive",
"description": "Charge pump capacitor terminal, requiring a 0.22 µF ceramic capacitor between CP1 and CP2."
},
{
"number": "25",
"name": "OUT1B",
"type": "output",
"description": "DMOS H bridge 1 output B, rated for ±2.5 A and 35 V."
},
{
"number": "26",
"name": "ENABLE",
"type": "input",
"description": "Active-low logic input that enables all DMOS outputs; when logic high the outputs are disabled."
},
{
"number": "27",
"name": "SLEEP",
"type": "input",
"description": "Active-low logic input that minimizes power consumption by disabling the output DMOS, regulator and charge pump; a 1 ms wake-up time applies."
},
{
"number": "28",
"name": "VBB1",
"type": "power_in",
"description": "Load supply for bridge 1, operating range 8.0 to 35 V."
},
{
"number": "29",
"name": "EP",
"type": "passive",
"description": "Exposed pad (from the footprint; not named in the datasheet pin table)."
}
],
"provenance": {
"extractor": "extract_pins 0.3",
"factory_chain": {
"factory": "2.0.0",
"extractor": "extract_pins 0.3",
"primary_model": "claude-haiku-5-5",
"primary_mode": "text",
"consensus_model": "claude-sonnet-5-5",
"consensus": "agreed",
"guards": "pin_guards 0.1: passed",
"guard_notes": [
"extractor flagged: Pin 10 text in the terminal table reads 'LOGIC SUPPLYNC'; it is mapped to VDD (logic supply) from th; The datasheet's terminal table is for the LP (28-pin TSSOP with exposed thermal pad) package, which "
],
"pages_sent": 17,
"cost_usd": 0.0281,
"at": "2026-11-05T01:00:17"
},
"datasheet": {
"url": "https://datasheet.lcsc.com/datasheet/pdf/0494da4f1ef374b762cf49539b466b97.pdf",
"pages": 17,
"sha256": "d5b5c7b7d14cbc27",
"source_tier": "lcsc"
},
"cad": "KiCad official (CC-BY-SA 4.0)",
"pins": {
"total": 29,
"described": 29,
"cites_pages": true,
"refuses_to_fabricate": true
}
},
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}