UC3845BN
Public Made by Adomby adom
STMicroelectronics AC-DC Controllers and Regulators, DIP-8. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.
UC3845BN
STMicroelectronics · AC-DC Controllers and Regulators · DIP-8
UC3845BN from STMicroelectronics, in a DIP-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | COMP | output | Error amplifier output made available for loop compensation. Typically an RC network is connected between this pin and VFB (pin 2) to shape the control-loop response. |
| 2 | VFB | input | Inverting input of the internal error amplifier. Normally connected to the switching power supply output through a resistor divider; the non-inverting input is internally tied to the 2.5 V reference. |
| 3 | ISENSE | input | Current-sense input. A voltage proportional to the primary/inductor current is applied here; the PWM comparator terminates the output switch conduction when this pin reaches the error-amp-derived threshold (max input signal ~1 V, gain 3 V/V). |
| 4 | RT/CT | passive | Oscillator timing pin. A resistor RT from this pin to VREF and a capacitor CT from this pin to GROUND set the oscillator frequency and the maximum output duty cycle. Operation up to 500 kHz is possible. |
| 5 | GROUND | power_in | Common control-circuitry and power-stage return. All voltages in the datasheet are referenced to this pin; timing and bypass capacitors must connect close to this pin in a single-point ground. |
| 6 | OUTPUT | output | High-current totem-pole gate-drive output for an external N-channel power MOSFET. Peak source/sink currents up to 1 A; typical rise/fall times ~50 ns into 1 nF. |
| 7 | VCC | power_in | Positive supply of the control IC (labeled Vi in the block diagram/absolute-maximum table). Max 30 V (self-limiting via internal ~36 V zener). UVLO turn-on 8.5 V typ, turn-off 7.9 V typ; operating supply current ~12 mA typ. |
| 8 | VREF | power_out | Buffered 5.0 V reference output (5 V, 50 mA capable). Provides charging current for the timing capacitor CT through the timing resistor RT and can bias external circuitry. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | DIP-8 |
| Category | PMIC |
| Pins | 8 |
Ordering variants
Same part, different packaging or reel option.
UC3845BNNUC3845BND1
CAD (KiCad official)
- Symbol:
UC3845BN - Footprint:
Package_DIP:DIP-8_W7.62mm - 3D model: DIP-8 (KiCad packages3D, STEP)
- 3D model files:
uc3845bn-etched.step/uc3845bn-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);uc3845bn.step/uc3845bn.glbare the bare package body.
3D model downloads
Two STEP files. Same geometry, different body top:
| File | Size | Use it when |
|---|---|---|
uc3845bn.step |
271 KB | You want the bare part, or you mark your own boards. |
uc3845bn-etched.step |
2.1 MB | You want the part with UC3845BN already on it. |
The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 502 faces against 148 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: STMicroelectronics datasheet (15 pp, sha256
62066370bcc6f048, retrieved 2026-08-17, tier: lcsc) - Extractor:
ds2sf(Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate. - CAD: KiCad official libraries (CC-BY-SA 4.0).