Answer: The TP4056 is a CC/CV linear charger for one Li-ion cell: 4.2 V ±1 % float (4.158–4.242 V), charge current set by one resistor (I = 1200 / RPROG, up to 1 A), 4.0–8.0 V input, trickle charge below 2.9 V, and C/10 termination. TOPPWR lists two order codes, TP4056-42-ESOP8 and TP4056-42-EMSOP8, both marked “TP4056”. Pins: 1 TEMP, 2 PROG, 3 GND, 4 VCC, 5 BAT, 6 STDBY, 7 CHRG, 8 CE. (TP4056 REV_2.0, pp.2, 4, 5, 7.)
Key specifications
| Parameter | Value | Condition | Source |
|---|---|---|---|
| Input supply voltage VCC | 4.0 / 5 / 8.0 V | Full temperature range; absolute maximum −0.3 to 8 V | p.5 Electrical Characteristics; p.2 Absolute Maximum Ratings |
| Float voltage VFLOAT | 4.158 / 4.2 / 4.242 V | 0 °C ≤ TA ≤ 85 °C, IBAT = 40 mA | p.5 Electrical Characteristics |
| Charge current (current mode) | 450 / 500 / 550 mA at RPROG 2.4 kΩ; 950 / 1000 / 1050 mA at 1.2 kΩ | VBAT = 4.0 V, full temperature range for min | p.5 Electrical Characteristics |
| PROG pin voltage | 0.9 / 1.0 / 1.1 V | RPROG = 1.3 kΩ, current mode; 0.1 V in precharge | p.5 Electrical Characteristics; p.7 Pin Functions |
| Trickle threshold / current | 2.8 / 2.9 / 3.0 V; 120 / 130 / 140 mA | RPROG = 1.2 kΩ, VBAT rising; hysteresis 60 / 80 / 100 mV | p.5 Electrical Characteristics |
| C/10 termination threshold | 60 / 70 / 80 mA (2.4 kΩ); 120 / 130 / 140 mA (1.2 kΩ) | Filter time tTERM 0.8 / 1.8 / 4 ms | p.5 Electrical Characteristics |
| Recharge threshold ΔVRECHRG | 100 / 150 / 200 mV below VFLOAT | Recharge filter 0.8 / 1.8 / 4 ms | p.5 Electrical Characteristics |
| UVLO (VCC rising) / hysteresis | 3.5 / 3.7 / 3.9 V; 150 / 200 / 300 mV | Full temperature range | p.5 Electrical Characteristics |
| VCC − VBAT lockout | 60 / 100 / 140 mV rising; 5 / 30 / 50 mV falling | — | p.5 Electrical Characteristics |
| Supply current | 150 typ / 500 max µA charging; 55 typ / 100 max µA standby or shutdown | Charge mode at RPROG = 1.2 kΩ | p.5 Electrical Characteristics |
| BAT pin current, standby / sleep | 0 / −2.5 / −6 µA standby (VBAT = 4.2 V); −1 µA typ sleep (VCC = 0 V) | Negative = current out of the battery | p.5 Electrical Characteristics |
| TEMP trip thresholds | lower 43 min / 45 typ % VCC; upper 80 typ / 82 max % VCC | — | p.5 Electrical Characteristics |
| Thermal regulation TLIM | 145 °C | Junction temperature in constant-temperature mode | p.5 Electrical Characteristics |
| Power FET on-resistance RON | 650 mΩ typ | Between VCC and BAT | p.5 Electrical Characteristics |
| CHRG / STDBY output low | 0.3 typ / 0.6 max V | Sinking 5 mA | p.5 Electrical Characteristics |
| Operating ambient temperature | −40 to 85 °C | Maximum junction 145 °C | p.2 Features |
Pinout (ESOP8 and EMSOP8)
| Pin | Name | Function (p.7) |
|---|---|---|
| 1 | TEMP | NTC input. Charging is suspended below 45 % or above 80 % of VCC. Ground it to disable. |
| 2 | PROG | RPROG to GND sets the current; the pin voltage also reads it back: IBAT = VPROG / RPROG × 1200 |
| 3 | GND | Ground |
| 4 | VCC | Input supply. Within 30 mV of BAT, the chip shuts down and BAT draws under 2 µA |
| 5 | BAT | Battery positive, regulated to 4.2 V |
| 6 | STDBY | Open drain, pulled low when the charge cycle is complete |
| 7 | CHRG | Open drain, pulled low while charging |
| 8 | CE | Chip enable: high = normal, low = shutdown; TTL or CMOS levels |
| Pad | Exposed pad | Solder to PCB ground for the rated charge current (p.13) |
Status LEDs (p.10)
| State | CHRG (red) | STDBY (green) |
|---|---|---|
| Charging | On | Off |
| Charge complete | Off | On |
| Under-voltage, cell too hot or cold, or no battery (TEMP in use) | Off | Off |
| No battery, TEMP grounded, 10 µF on BAT | Flickers, T = 1–4 s | On |
If you don’t use an indicator, connect that pin to GND (p.10).
Design notes
Charge current. RPROG = 1200 / IBAT (p.9); 2.4 kΩ for 500 mA, 1.2 kΩ for 1 A. For resistor values, thermal checks and why the datasheet’s own table disagrees with its formula at 1.2 kΩ, use the TP4056 charge current calculator. Keep RPROG close to the chip and keep PROG capacitance small (p.13); if you filter PROG to read average current, TOPPWR adds a 10 kΩ series resistor for stability (p.11, Fig. 2).
NTC resistors. With R1 from VCC to TEMP and R2 from TEMP to GND in parallel with the cell’s NTC, TOPPWR gives (p.10–11, K1 = 0.45, K2 = 0.8):
- R1 = RTL·RTH·(K2 − K1) / ((RTL − RTH)·K1·K2)
- R2 = RTL·RTH·(K2 − K1) / (RTL·(K1 − K1·K2) − RTH·(K2 − K1·K2))
Example with an NTC of 30 kΩ at the cold limit and 4 kΩ at the hot limit (use your cell’s values): R1 = 4.49 kΩ, R2 = 44.7 kΩ. With E96 values 4.53 kΩ and 44.2 kΩ, TEMP sits at 79.8 % of VCC cold and 44.7 % hot, just inside the trip points. Because both limits are ratios of VCC, the window does not depend on supply voltage (p.11). If you only need over-temperature protection, leave R2 out.
Heat. Nearly all dissipation is in the pass FET: PD ≈ (VCC − VBAT) × IBAT (p.12). TOPPWR’s own example is 5 V in, 800 mA into a 3.75 V cell, θJA = 125 °C/W: PD = 1.0 W, so thermal regulation starts at an ambient of about 145 − 125 × 1.0 = 20 °C, and at 25 °C the current settles near (145 − 25) / (125 × 1.25) ≈ 0.77 A. The datasheet’s remedy is a resistor in series with VCC to move some of the heat off the chip (Fig. 3–4, p.12), provided the chip never drops into dropout.
Input capacitor. A ceramic input capacitor can ring when the charger is plugged into a live supply. TOPPWR suggests 1.5 Ω in series with it (p.13). Reverse-polarity protection takes a series diode or a P-channel MOSFET (p.13).
What it does not do. The datasheet describes charging only. There is no over-discharge, over-current or short-circuit protection for the cell, so pair it with a protection IC.
Where the datasheet disagrees with itself
| Item | One place | Another place |
|---|---|---|
| UVLO | 3.5 / 3.7 / 3.9 V (p.5) | “VDD < VUVLO (3.6 V)” in the state diagram (p.10) |
| Thermal regulation | 145 °C (pp.5, 8, 12) | ≈ 140 °C, zero current above 150 °C (p.10) |
| RPROG = 1.2 kΩ | 1000 mA typ (p.5) | 900 mA in the application table (p.9) |
| Package name | SOP8/MSOP8 (p.2 text) | ESOP8 / EMSOP8 with exposed pad (pp.4, 14–15) |
Design to the Electrical Characteristics table (p.5) and treat the other figures as approximate.
Pitfalls specific to TP4056
- Leaving the exposed pad unsoldered. TOPPWR says the rated charge current requires the back pad soldered to PCB ground (p.13). Without it, thermal regulation cuts the current early.
- Expecting the green LED to mean “battery full” with no cell. With TEMP grounded and no battery, STDBY is on and CHRG flickers (p.10).
- Floating CE. CE high enables charging (p.7). Tie it to VCC if you don’t drive it.
- Using a 9 V or 12 V adapter. 8 V is both the operating maximum and the absolute maximum (pp.2, 5).
- Floating TEMP. Without an NTC, ground it (p.7).
- Charging two cells in series. The float voltage is fixed at 4.2 V for a single cell (p.2); there is no pin to change it.
Part numbers (information only)
| Order code | Package | Marking | Source |
|---|---|---|---|
| TP4056-42-ESOP8 | ESOP8 (exposed pad) | TP4056 | p.4 Package/Order Information |
| TP4056-42-EMSOP8 | EMSOP8 (exposed pad) | TP4056 | p.4 |
Both share the same marking, so the top of the package does not tell you which it is. The datasheet gives no packing quantities.
FAQ
- What is the TP4056 pinout? 1 TEMP, 2 PROG, 3 GND, 4 VCC, 5 BAT, 6 STDBY, 7 CHRG, 8 CE, plus an exposed pad to ground (p.7).
- What do the TP4056 LEDs mean? Red (CHRG) on = charging; green (STDBY) on = complete; both off = fault or temperature out of range; red flickering with green on = no battery.
- What resistor sets 1 A on a TP4056? 1.2 kΩ by the formula (1200 / RPROG). The datasheet’s application table lists 1.1 kΩ for 1000 mA, so measure on your board.
- Can I disable the TP4056 temperature input? Yes. Ground the TEMP pin (p.7).
- What is the maximum input voltage of the TP4056? 8 V, both operating maximum and absolute maximum.
- What is the TP4056 order code? TP4056-42-ESOP8 or TP4056-42-EMSOP8, both marked “TP4056” (p.4).
Related (internal links)
Sources (retrieved 2026-10-26)
- NanJing Top Power ASIC Corp., TP4056 1A Linear Li-Ion Battery Charger, datasheet REV_2.0: https://www.toppwr.com/uploadfile/file/20230304/640301eae1260.pdf
Disclaimer
Values are copied from the TOPPWR TP4056 datasheet REV_2.0, read on 26 Oct 2026. The datasheet contradicts itself in places (listed above); this page follows the Electrical Characteristics table. Many “TP4056” modules use chips from other makers; check the actual part. Li-ion cells can catch fire if charged wrongly: always use cell protection.
Reviewed by: Jasper · Updated: 2026-10-26