component
UC3845B
Public Made by Adomby adom
UMW AC-DC Controllers and Regulators, SOP-8. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.
main
Ray
pin 1: carry the footprint's marker into the .lbr, the viewer and page.json (silk-marker, drawn, top-left)
eebaca6
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{
"schema": "adom.pads/1",
"slug": "uc3845b",
"footprint": "SOIC-8_3.9x4.9mm_P1.27mm",
"generated_from": {
"footprint": "SOIC-8_3.9x4.9mm_P1.27mm@sha256:074ecb2092b24fa4",
"pins": "page.json:component.pins",
"overrides": null
},
"pin1": {
"pad": "1",
"at": [
-2.475,
-1.905
],
"corner": "top-left",
"source": "silk-marker",
"derived_from": "SOIC-8_3.9x4.9mm_P1.27mm@sha256:074ecb2092b24fa4"
},
"pad_count": 8,
"symbol_pins": [
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8"
],
"paste_apertures": 0,
"issues": [],
"pads": [
{
"pad": "1",
"kind": "smd",
"shape": "roundrect",
"at": [
-2.475,
-1.905
],
"rot": 0.0,
"size": [
1.95,
0.6
],
"layers": [
"F.Cu",
"F.Mask",
"F.Paste"
],
"thermal": false,
"pin": "1",
"name": "COMP",
"type": "output",
"description": "Error Amplifier output pin, used for external loop compensation. Typical high output voltage 5-6 V, low output 0.8-1.1 V (with 15 kΩ load).",
"is_pin1": true,
"source": {
"geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
"meaning": "page.json:component.pins",
"correspondence": "kicad: symbol pin number == pad name"
}
},
{
"pad": "2",
"kind": "smd",
"shape": "roundrect",
"at": [
-2.475,
-0.635
],
"rot": 0.0,
"size": [
1.95,
0.6
],
"layers": [
"F.Cu",
"F.Mask",
"F.Paste"
],
"thermal": false,
"pin": "2",
"name": "VFB",
"type": "input",
"description": "Inverting input of the Error Amplifier. Normally connected to the switching power supply output through a resistor divider; internal reference at 2.5 V (typ). Input bias current -0.1 µA typ.",
"is_pin1": false,
"source": {
"geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
"meaning": "page.json:component.pins",
"correspondence": "kicad: symbol pin number == pad name"
}
},
{
"pad": "3",
"kind": "smd",
"shape": "roundrect",
"at": [
-2.475,
0.635
],
"rot": 0.0,
"size": [
1.95,
0.6
],
"layers": [
"F.Cu",
"F.Mask",
"F.Paste"
],
"thermal": false,
"pin": "3",
"name": "ISENSE",
"type": "input",
"description": "Current sense input. A voltage proportional to the inductor current (up to ~1 V max) is applied here; the PWM comparator uses this to terminate output switch conduction each cycle. Input voltage range -0.3 to 5.5 V max.",
"is_pin1": false,
"source": {
"geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
"meaning": "page.json:component.pins",
"correspondence": "kicad: symbol pin number == pad name"
}
},
{
"pad": "4",
"kind": "smd",
"shape": "roundrect",
"at": [
-2.475,
1.905
],
"rot": 0.0,
"size": [
1.95,
0.6
],
"layers": [
"F.Cu",
"F.Mask",
"F.Paste"
],
"thermal": false,
"pin": "4",
"name": "RT/CT",
"type": "passive",
"description": "Oscillator timing pin. Oscillator frequency and maximum output duty cycle are set by connecting a timing resistor RT from VREF to this pin and a timing capacitor CT from this pin to ground. Operating frequency up to 500 kHz.",
"is_pin1": false,
"source": {
"geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
"meaning": "page.json:component.pins",
"correspondence": "kicad: symbol pin number == pad name"
}
},
{
"pad": "5",
"kind": "smd",
"shape": "roundrect",
"at": [
2.475,
1.905
],
"rot": 0.0,
"size": [
1.95,
0.6
],
"layers": [
"F.Cu",
"F.Mask",
"F.Paste"
],
"thermal": false,
"pin": "5",
"name": "GND",
"type": "power_in",
"description": "Combined control circuitry and power ground return for the IC.",
"is_pin1": false,
"source": {
"geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
"meaning": "page.json:component.pins",
"correspondence": "kicad: symbol pin number == pad name"
}
},
{
"pad": "6",
"kind": "smd",
"shape": "roundrect",
"at": [
2.475,
0.635
],
"rot": 0.0,
"size": [
1.95,
0.6
],
"layers": [
"F.Cu",
"F.Mask",
"F.Paste"
],
"thermal": false,
"pin": "6",
"name": "OUT",
"type": "output",
"description": "Totem-pole gate drive output for an external power MOSFET. Sources/sinks peak currents up to 1 A. VOH ≈ 13-13.5 V, VOL ≈ 0.08-1.4 V depending on load; rise/fall time ~35-45 ns into 1 nF.",
"is_pin1": false,
"source": {
"geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
"meaning": "page.json:component.pins",
"correspondence": "kicad: symbol pin number == pad name"
}
},
{
"pad": "7",
"kind": "smd",
"shape": "roundrect",
"at": [
2.475,
-0.635
],
"rot": 0.0,
"size": [
1.95,
0.6
],
"layers": [
"F.Cu",
"F.Mask",
"F.Paste"
],
"thermal": false,
"pin": "7",
"name": "VCC",
"type": "power_in",
"description": "Positive supply for the IC. UVLO start threshold 8.4 V typ (7.8-9 V), min operating 7.6 V typ (7-8.2 V) after turn-on. Absolute max 30 V; zener clamp ≈ 30-38 V at 25 mA. Operating supply current 13 mA typ; start-up current 0.5 mA typ.",
"is_pin1": false,
"source": {
"geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
"meaning": "page.json:component.pins",
"correspondence": "kicad: symbol pin number == pad name"
}
},
{
"pad": "8",
"kind": "smd",
"shape": "roundrect",
"at": [
2.475,
-1.905
],
"rot": 0.0,
"size": [
1.95,
0.6
],
"layers": [
"F.Cu",
"F.Mask",
"F.Paste"
],
"thermal": false,
"pin": "8",
"name": "VREF",
"type": "power_out",
"description": "Internal 5 V reference output (4.9-5.1 V), used to charge timing capacitor CT through timing resistor RT and to bias external circuitry. Short-circuit current typically -100 mA (limited to -180 mA max). Load current 1-20 mA.",
"is_pin1": false,
"source": {
"geometry": "SOIC-8_3.9x4.9mm_P1.27mm.kicad_mod",
"meaning": "page.json:component.pins",
"correspondence": "kicad: symbol pin number == pad name"
}
}
]
}