BETASelected charge voltage4.20 V · -2 option
Single-cell linear charge controller
MCP73831 Specifications
Review MCP73831 electrical specifications, operating conditions and package details.
Package view
Key specifications
Current is held near its programmed value until the cell reaches the regulation voltage. The charger then holds voltage while current tapers, terminating when the selected threshold is reached.
Programmable fast charge15–500 mA nominal range
Specified ambient−40–85 °C
Example program resistor10 kΩ → 100 mA nominal
Package details
MCP73831T-2ACI/OT · SOT-23-5
| Property | Details |
|---|---|
| Manufacturer | Microchip Technology |
| Part number | MCP73831T-2ACI/OT |
| Package | SOT-23-5 |
| Connections | 5 pins |
| Mounting | SMD |
| Lead pitch | 0.95 mm |
| Package code | OT |
| Thermal reference | −40–85°C specified ambient; board-dependent cooling |
Supply and regulation
Selected MCP73831-2AC · conditions retained
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input operating range | 3.75–6 V | Allow adequate headroom above the battery |
| Recommended input for -2 option | 4.50–6 V | Pin description: VREG + 0.3 V minimum |
| Reference test supply | 5.2 V | VREG + 1 V; example uses the same value |
| Regulated battery voltage | 4.168 / 4.200 / 4.232 V | Minimum / typical / maximum; -5–55°C, 10 mA output, 5.2 V input |
| Line regulation | 0.09%/V typical; 0.30%/V maximum | 5.2–6 V input; 10 mA output |
| Load regulation | 0.05% typical; 0.30% maximum | 10–50 mA; 5.2 V input |
| Specified ambient / operating junction | −40–85°C / −40–125°C | Do not extend narrower table conditions implicitly |
No specifications match. Try a parameter name or a unit.
Unless a row states otherwise, source limits use VREG + 1 V to 6 V and −40–85°C ambient; typical values use 25°C.
Set the charge current
IREG[mA] = 1000 / RPROG[kΩ]
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Programming resistor range | 2–67 kΩ | Source operating impedance range |
| 10 kΩ example | 100 mA nominal | 90–110 mA source limits at −5–55°C |
| 2 kΩ example | 500 mA by design equation | Source table gives 505 mA typical, 450–550 mA limits; design-assured |
| 67 kΩ example | About 15 mA nominal | Source table: 12.5 / 14.5 / 16.5 mA |
| Disable charging | Float PROG | Charge current stops; STAT becomes high impedance |
| Cell-current selection | Follow the specific cell manufacturer | Capacity alone is insufficient to choose a safe charge rate |
| RPROG tolerance | Adds to programmed-current error | Use a suitable precision resistor |
No specifications match. Try a parameter name or a unit.
Do not infer that every cell accepts the charger’s maximum programmed current.
The selected -2AC sequence
Factory options are not runtime settings
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Regulation voltage | 4.20 V | The -2 voltage code |
| Precharge current | 10% of fast-charge current | 7.5–12.5% source limits at −5–55°C |
| Precharge transition | 66.5% of VREG nominal | 64–69% limits; nominal 2.793 V for 4.20 V |
| Termination current | 7.5% of fast-charge current | 5.6–9.4% limits at −5–55°C |
| Automatic recharge | 96.5% of VREG nominal | 94–99% limits; nominal 4.053 V |
| 100 mA example thresholds | 10 mA precharge; 7.5 mA termination | Nominal values before tolerances |
| Other options | Different voltage, precharge or termination settings | Read the exact suffix; do not substitute family values |
No specifications match. Try a parameter name or a unit.
Charge time depends on the cell, starting state, current taper and thermal regulation.
Read STAT correctly
MCP73831 three-state output
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Preconditioning | LOW | Charging indicator LED can be on |
| Constant-current fast charge | LOW | Not a percentage-of-charge indication |
| Constant-voltage phase | LOW | Current tapers while regulation holds |
| Charge complete / standby | HIGH | This is driven HIGH on MCP73831 |
| Shutdown or no battery | High impedance | An unlit single LED cannot distinguish these from complete |
| Source / sink logic test | About 0.4 V typical drop at 4 mA | Use the full electrical limits for logic interfacing |
| Microcontroller connection | Observe output voltage and logic compatibility | Do not connect a 5 V STAT signal to a non-tolerant 3.3 V input |
No specifications match. Try a parameter name or a unit.
MCP73832 has an open-drain status output and a different complete-state indication.
A nominal 100 mA charger
SOT-23-5 example · one compatible cell
Manufacturer specifications 8 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input supply | Regulated 5.2 V | VDD4 with common return at VSS2 |
| CIN and COUT | At least 4.7 µF each | Local low-ESR ceramic; account for DC-bias derating |
| RPROG | 10 kΩ to ground | PROG5; 100 mA nominal fast charge |
| Charge indicator | Input → 2.2 kΩ → LED anode; cathode → STAT1 | Lights while STAT is LOW |
| Cell positive / negative | VBAT3 / common ground | Single cell specified for 4.20 V termination |
| Cell nominal voltage | Typically described as 3.7 V | Nominal label is not the full-charge setting |
| Pass-stage heat at 3.0 V cell | (5.2 − 3.0) × 0.1 = 0.22 W | Before bias-current losses; constant-current phase |
| Attached load | Not shown in this charger-only example | A system load can affect termination; use appropriate power-path design |
No specifications match. Try a parameter name or a unit.
This IC is not a complete protected battery pack or a power-path controller.
Thermal behavior and protection
Heat can reduce the actual charge current
Manufacturer specifications 8 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| SOT-23 θJA reference | 230°C/W | Four-layer standard board; larger copper can improve it |
| DFN θJA reference | 76°C/W | Source minimum-copper condition on four-layer board |
| Thermal regulation | Reduces charge current as the die heats | Do not assume programmed current is maintained continuously |
| Thermal shutdown | 150°C typical | About 10°C hysteresis |
| Input absolute maximum | 7 V | Stress limit, not the 6 V operating maximum |
| Battery reverse leakage | 2 µA maximum in specified disabled conditions | No input / below UVLO / PROG floating |
| Cell temperature | No dedicated thermistor input | External supervision is needed where required by the cell or application |
| Battery fault protection | Not a substitute for a pack protection circuit | Provide required over-discharge, short-circuit and cell safeguards |
No specifications match. Try a parameter name or a unit.
At 0.22 W and 230°C/W, a simple reference estimate gives about 51°C rise; actual board conditions and regulation change the result.
Physical package mapping
MCP73831T-2ACI/OT · SOT-23-5
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| SOT-23-5 pins | 1 STAT; 2 VSS; 3 VBAT; 4 VDD; 5 PROG | Five external leads; no separate exposed pad |
| DFN-8 pins | 1/2 VDD; 3/4 VBAT; 5 STAT; 6 VSS; 7 NC; 8 PROG | Connect both contacts of each power node |
| DFN contact 9 | Exposed pad, internally VSS | Must connect to the ground plane |
| SOT body / pitch | 1.60 × 2.90 mm / 0.95 mm | Shown rotated into left/right pin banks |
| DFN body / pitch | 2 × 3 × 0.9 mm nominal / 0.50 mm | Shown rotated clockwise; bottom pad identified separately |
| SOT marking family | KD + trace code for selected -2AC option | Illustration labels identify the order rather than reproduce a lot code |
| DFN marking family | AAE + trace codes for selected -2AC option | See manufacturer marking table |
No specifications match. Try a parameter name or a unit.
Original reviewed footprints are assembly starting points; check the purchased package and production design rules.
Connections by function
Select a pin for its function, connection guidance and electrical notes.