# SE9029X

**Seaward Elec** · Battery Management · SOP-8-EP

SE9029X from Seaward Elec, in a SOP-8-EP. 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 | GND | power_in | Ground pin (地) for the charger. |
| 2 | VIN | power_in | Power input pin; the recommended input range is 4.7 V to 5.5 V, the absolute maximum is -0.3 V to 6.5 V, and a C1 of at least 10 µF must be placed as close to VIN as possible. |
| 3 | CHRG | output | Charge-status indicator: pulled low during trickle and constant-current charging and high impedance when charging is complete or in fault/sleep; Vchrg is at most 0.6 V at 5 mA. |
| 4 | STDBY | output | Charge-status indicator: high during trickle and constant-current charging, pulled low when charging is complete, and high impedance during temperature fault or sleep; Vstdby is at most 0.6 V at 5 mA. |
| 5 | NC | unconnected | No connection (NC, empty pin) on the SE9029X; on the SE9029XD this pin is the EN enable input. |
| 6 | BAT | input | Battery voltage feedback input and battery positive terminal; the float voltage is 4.2 V or 4.35 V (typical), and C3 should be placed close to this pin. |
| 7 | SEN | input | Charge-current setting pin; the charge current is IBAT = 100 mV / R5, where R5 is the sense resistor connected between SEN and BAT. |
| 8 | SW | output | Switching output node of the buck converter (1 MHz typical switching frequency). |
| 9 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Seaward Elec |
| Package | SOP-8-EP |
| Category | Power Management (PMIC) |
| Pins | 9 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Input supply voltage (recommended) | VCC | 4.7 |  | 5.5 | V |  | 5 |
| Junction operating temperature (recommended) | TJ | -20 |  | 125 | °C |  | 5 |
| Input supply voltage | VIN | -0.3 |  | 6.5 | V |  | 5 |
| Input/output pin voltage | I/O | -0.3 |  | 6.5 | V |  | 5 |
| VIN/GND/SW input-output current | IVIN/GND/SW |  |  | 3 | A |  | 5 |
| Junction temperature | TJ | -40 |  | 150 | °C |  | 5 |
| Storage temperature | TST | -55 |  | 150 | °C |  | 5 |
| Soldering temperature |  |  |  | 260 | °C | <10 s | 5 |
| Input voltage | VIN | 4.7 | 5 | 5.5 | V |  | 5 |
| Battery float voltage | VFLOAT | 4.158 | 4.2 | 4.242 | V | IOUT=0.1A（Rsen=0.2Ω） | 5 |
| Maximum duty cycle | DC |  |  | 100 | % |  | 6 |
| CHRG pin output low voltage | Vchrg |  | 0.2 | 0.6 | V | Ichrg=5mA | 6 |
| STDBY pin output low voltage | Vstdby |  | 0.2 | 0.6 | V | Istdby=5mA | 6 |
| Undervoltage lockout threshold | UVLO |  | 3.75 |  | V | From VCC Low to High | 5 |
| Undervoltage lockout hysteresis | VUVHYS |  | 160 |  | mV |  | 5 |
| Quiescent current, charging mode | IIN |  | 450 |  | μA | 充电模式 | 5 |
| Quiescent current, standby (charge terminated) | IIN |  | 170 |  | μA | 待机模式 (充电中止) | 5 |
| Quiescent current, sleep mode | IIN |  | 110 |  | μA | 休眠模式（Vin<VBAT,或 Vin<Vuvlo） | 5 |
| BAT current, charging | IBAT |  | 1000 |  | mA | 充电状态（Rsen=0.1Ω） | 5 |
| BAT current, standby (charge terminated) | IBAT |  | 2 |  | uA | 待机模式(充电中止) | 5 |
| BAT current, sleep mode | IBAT |  | 2 |  | uA | 休眠模式（Vin<VBAT,或 Vin<Vuvlo） | 5 |
| Constant-current sense voltage | VSEN(CHR) |  | 100 |  | mV | 3V≤VBAT≤4V | 5 |
| Trickle-charge sense voltage | VSEN(TRKL) |  | 10 |  | mV | VBAT=2.5V | 5 |
| Trickle-charge threshold voltage | VTRKL |  | 2.9 |  | V | VBAT rising | 5 |
| Automatic shutdown threshold | VASD |  | 100 |  | mV | VIN-VBAT | 5 |
| P MOSFET on-resistance | RPMOS |  | 140 |  | mΩ |  | 5 |
| N MOSFET on-resistance | RNMOS |  | 100 |  | mΩ |  | 6 |
| Recharge threshold | ΔVRECHRG |  | 200 |  | mV | VFLOAT -VRECHRG, VBAT falling | 6 |
| Switching frequency | FOSC |  | 1 |  | MHz |  | 6 |
| Thermal shutdown threshold | OTP |  | 140 |  | °C |  | 6 |
| Soft-start time | Tss |  | 200 |  | uS |  | 6 |
| Termination comparator filter time | Tterm |  | 1 |  | mS |  | 6 |
| MPPT threshold voltage | Vmppt |  | 4.65 |  | V |  | 6 |

## CAD (KiCad official)

- Symbol: `SE9029X`
- Footprint: `Package_SO:SOIC-8-1EP_3.9x4.9mm_P1.27mm_EP2.29x3mm`
- 3D model: SOP-8-EP (KiCad packages3D, STEP)
- 3D model files: `se9029x-etched.step` / `se9029x-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `se9029x.step` / `se9029x.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Seaward Elec datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588918358040961024) (12 pp, sha256 `c55b1540a349a9d7`, retrieved 2026-10-18, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **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](docs/se9029x-datasheet.pdf)