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Contents

README

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MCP73871-2CAI

MICROCHIP TECHNOLOGY · Global Sourcing Parts · QFN-20(4x4)

MCP73871-2CAI from MICROCHIP TECHNOLOGY, in a QFN-20(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 OUT power_out System output terminal that powers the system while the battery is charged independently; bypass to VSS with a minimum of 4.7 µF is recommended.
2 VPCC input Voltage proportional charge control input; supplying 1.23V or greater enables the feature, and connecting it to IN disables the feature.
3 SEL input Input source type selection: low for a USB port input, high for an AC-DC adapter input.
4 PROG2 input USB port input current limit selection when SEL is low: low = 100 mA, high = 500 mA.
5 THERM bidirectional Thermistor monitoring input and bias current for the battery cell temperature monitor.
6 PG output Power Good status output (open-drain); low when the input is above the UVLO threshold and greater than the battery voltage.
7 STAT2 output Charge Status Output 2 (open-drain) for an LED or a pull-up resistor to a host microcontroller.
8 STAT1/LBO output Charge Status Output 1 (open-drain); functions as the low battery output indicator when VBAT > VIN.
9 TE input Timer Enable input; enables the safety timer when active-low.
10 VSS power_in Battery management 0V reference, connected to the negative terminal of the battery, system load and input supply.
11 VSS power_in Battery management 0V reference, connected to the negative terminal of the battery, system load and input supply.
12 PROG3 bidirectional Termination set point for both AC-DC adapter and USB port.
13 PROG1 bidirectional Fast charge current regulation setting with SEL high and preconditioning set point for both USB port and AC-DC adapter; maximum constant charge current is set by a resistor from PROG1 to VSS.
14 VBAT power_in Battery positive input and output connection; bypass to VSS with a minimum of 4.7 µF to ensure loop stability when the battery is disconnected.
15 VBAT power_in Battery positive input and output connection; bypass to VSS with a minimum of 4.7 µF to ensure loop stability when the battery is disconnected.
16 VBAT_SENSE bidirectional Battery voltage sense; connect to the positive battery terminal, where a precision internal sense regulates the final voltage to VREG.
17 CE input Device Charge Enable input; charging is enabled when CE is high.
18 IN power_in Power supply input; a supply of VREG + 0.3V to 6V is recommended, bypassed to VSS with a minimum of 4.7 µF.
19 IN power_in Power supply input; a supply of VREG + 0.3V to 6V is recommended, bypassed to VSS with a minimum of 4.7 µF.
20 OUT power_out System output terminal that powers the system while the battery is charged independently; bypass to VSS with a minimum of 4.7 µF is recommended.
21 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter Value
Manufacturer MICROCHIP TECHNOLOGY
Package QFN-20(4x4)
Category Global Sourcing Parts
Pins 21

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
Storage Temperature Range TA -65 150 °C 4
Specified Temperature Range TA -40 85 °C 8
Operating Temperature Range TJ -40 125 °C 8
Supply Voltage (absolute maximum) VIN 7 V 4
All Inputs and Outputs w.r.t. VSS -0.3 V w.r.t. VSS; VDD = VIN or VBAT 4
Supply Voltage VIN 6 V 4
Supply Current - Charging ISS 2500 3750 µA Charging 4
Supply Current - Charge Complete ISS 260 350 µA Charge Complete 4
Supply Current - Standby ISS 180 300 µA Standby 4
Supply Current - Shutdown ISS 28 50 µA (VDD < VBAT, 100 mV or VDD < VSTOP) 4
Regulated Charge Voltage Tolerance VRTOL -0.5 0.5 % TA = +25°C 4
Regulated Charge Voltage Tolerance VRTOL -0.75 0.75 % TA = -5°C to +55°C 4
Line Regulation 0.08 0.2 %/V VDD = [VREG(typical) + 1V] to 6V, IOUT = 10 mA 4
Load Regulation 0.08 0.18 % IOUT = 10 mA to 150 mA, VDD = [VREG(typical) + 1V] 4
AC-Adapter Fast Charge Current IREG 90 100 110 mA PROG1 = 10 kΩ, TA = -5°C to +55°C, SEL = High 5
AC-Adapter Fast Charge Current IREG 900 1000 1100 mA PROG1 = 1 kΩ, TA = -5°C to +55°C, SEL = High 5
USB Fast Charge Current IREG 80 90 100 mA PROG2 = Low, SEL = Low, (Note 2), TA = -5°C to +55°C 5
USB Fast Charge Current IREG 400 450 500 mA PROG2 = High, SEL = Low, (Note 2), TA = -5°C to +55°C 5
USB-Port Supply Current Limit ILIMIT_USB 80 90 100 mA PROG2 = Low, SEL = Low, TA = -5°C to +55°C 5
USB-Port Supply Current Limit ILIMIT_USB 400 450 500 mA PROG2 = High, SEL = Low, TA = -5°C to +55°C 5
AC-DC Adapter Current Limit ILIMIT_AC 1500 1650 1800 mA SEL = High, TA = -5°C to +55°C 5
VPCC Input Threshold Tolerance VRTOL -3 3 % 5
Input Leakage Current (VPCC) ILK 0.01 1 µA VVPCC = VDD 5
Precondition Current Ratio IPREG/IREG 7.5 10 12.5 % PROG1 = 1.0 kΩ to 10 kΩ, TA = -5°C to +55°C 5
Precondition Current Threshold Ratio VPTH/VREG 69 72 75 % VBAT Low-to-High 5
Charge Termination Current Ratio ITERM 75 100 125 mA PROG3 = 10 kΩ, TA = -5°C to +55°C 5
Charge Termination Current Ratio ITERM 7.5 10 12.5 mA PROG3 = 100 kΩ, TA = -5°C to +55°C 5
Output Reverse Leakage Current IDISCHARGE 30 40 µA Shutdown (VBAT < VDD < VUVLO) 6
Output Reverse Leakage Current IDISCHARGE -6 -13 µA Charge Complete 6
Sink Current ISINK 16 35 mA 6
Low Output Voltage VOL 0.4 1 V ISINK = 4 mA 6
Input Leakage Current (Status Indicators) ILK 0.01 1 µA High Impedance, VDD on pin 6
PROG1 Charge Impedance Range RPROG 1 20 kΩ 6
PROG3 Termination Impedance Range RPROG 5 100 kΩ 6
PROG2 Input High Voltage Level VIH 1.8 V 6
PROG2 Input Low Voltage Level VIL 0.8 V 6
PROG2 Input Leakage Current ILK 0.01 1 µA VPROG2 = VDD 6
Timer Enable (TE) Input High Voltage Level VIH 1.8 V Note 1 6
Timer Enable (TE) Input Low Voltage Level VIL 0.8 V Note 1 6
Chip Enable (CE) Input High Voltage Level VIH 1.8 V 7
Chip Enable (CE) Input Low Voltage Level VIL 0.8 V 7
Input Source Selection (SEL) Input High Voltage Level VIH 1.8 V 7
Input Source Selection (SEL) Input Low Voltage Level VIL 0.8 V 7
Thermistor Current Source ITHERM 47 50 53 µA 2 kΩ < RTHERM < 50 kΩ 7
Upper Trip Threshold VT1 1.2 1.24 1.26 V VT1 Low-to-High 7
Lower Trip Threshold VT2 0.23 0.25 0.27 V VT2 High-to-Low 7
UVLO Start Delay tSTART 5 ms VDD Low-to-High 8
Transition Time Out of Precondition tDELAY 10 ms VBAT < VPTH to VBAT > VPTH 8
Current Rise Time Out of Precondition tRISE 10 ms IOUT Rising to 90% of IREG 8
Precondition Comparator Filter Time tPRECON 0.4 1.3 3.2 ms Average VBAT Rise/Fall 8
Termination Comparator Filter Time tTERM 0.4 1.3 3.2 ms Average IOUT Falling 8
Charge Comparator Filter Time tCHARGE 0.4 1.3 3.2 ms Average VBAT Falling 8
Thermistor Comparator Filter Time tTHERM 0.4 1.3 3.2 ms Average THERM Rise/Fall 8
Elapsed Timer Period (6-hour option, code C) tELAPSED 5.4 6 6.6 Hours 8
ESD Human Body Model 4 kV Human Body Model (1.5 kΩ in series with 100 pF) 4
ESD Machine Model 300 V Machine Model (200 pF, no series resistance) 4
Thermal Resistance, 20LD-QFN 4x4 JA 50 °C/W 4-Layer JC51-7 Standard Board, Natural Convection 8
Thermal Resistance, 20LD-QFN 4x4 (junction-to-case) JC 8 °C/W 8

CAD (KiCad official)

  • Symbol: MCP73871-2CAI
  • Footprint: Package_DFN_QFN:QFN-20-1EP_4x4mm_P0.5mm_EP2.5x2.5mm
  • 3D model: QFN-20(4x4) (KiCad packages3D, STEP)
  • 3D model files: mcp73871-2cai-etched.step / mcp73871-2cai-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); mcp73871-2cai.step / mcp73871-2cai.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: MICROCHIP TECHNOLOGY datasheet (36 pp, sha256 56654f56a8ac83ad, retrieved 2026-10-29, tier: manufacturer)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF