component
MCP7940NT-I
Public Made by Adomby adom
Microchip Real-time Clocks (RTC), SOIC-8. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.
main
Ray
page.json: drop the phantom "EP" pin. The datasheet package drawing is an 8-lead SOIC with 8 pads and no thermal pad, matching the shipped footprint exactly, so there is no exposed pad for this entry to describe and no symbol pin could ever resolve to it. Removed rather than "fixed" by adding a pad: putting copper under a part whose die has no thermal path would be the real defect.
ddbec00
1mo ago
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{
"schema": "adom.pads/1",
"slug": "mcp7940nt-i",
"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": "X1",
"type": "input",
"description": "Quartz crystal input / external oscillator input. Connects to one terminal of the 32.768 kHz tuning-fork crystal (optimized for 6-9 pF load capacitance) with its external load capacitor to VSS. Also usable as the external clock input when driving the device from an external oscillator.",
"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": "X2",
"type": "output",
"description": "Quartz crystal output. Connects to the second terminal of the 32.768 kHz crystal with its external load capacitor to VSS. Leave floating when using an external oscillator driving X1.",
"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": "VBAT",
"type": "power_in",
"description": "Battery backup supply input, 1.3 V to 5.5 V. Maintains RTCC and SRAM when VCC is lost; typical timekeeping backup current is 925 nA at 3.0 V. Tie to VSS if the battery backup feature is not used.",
"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": "VSS",
"type": "power_in",
"description": "Device ground (0 V) reference for VCC and VBAT rails and all logic signals.",
"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": "SDA",
"type": "bidirectional",
"description": "Bidirectional I2C serial data (open-drain). Requires an external pull-up resistor to VCC (typ. 10 kΩ at 100 kHz or 2 kΩ at 400 kHz). Data may change only while SCL is low; changes while SCL is high signal Start/Stop conditions.",
"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": "SCL",
"type": "input",
"description": "I2C serial clock input from the bus master, used to synchronize data transfer to/from the device. Supports clock rates up to 400 kHz. Schmitt-trigger input with 50 ns spike suppression; requires an external pull-up to VCC.",
"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": "MFP",
"type": "output",
"description": "Multifunction output (open-drain). Configurable as alarm output on an alarm match, as a selectable-frequency square-wave output, or as a general-purpose output driven by the OUT bit in the CONTROL register. Requires an external pull-up resistor to VCC (typ. 10 kΩ); leave floating if unused. VOL = 0.40 V at IOL = 3.0 mA (VCC = 4.5 V).",
"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": "VCC",
"type": "power_in",
"description": "Primary power supply, 1.8 V to 5.5 V. Typical timekeeping current 1.2 uA at 3.3 V; SRAM/RTCC register operating current is 300 uA (read) / 400 uA (write) at VCC = 5.5 V, SCL = 400 kHz. Power-fail switchover to VBAT occurs at VTRIP (1.3-1.7 V).",
"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"
}
}
]
}