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UC3845B-HXY
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HXY MOSFET AC-DC Controllers & Regulators, SOP-8. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownUC3845B-HXY
HXY MOSFET · AC-DC Controllers & Regulators · SOP-8
UC3845B-HXY from HXY MOSFET, in a SOP-8. 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 | COMP | output | Output of the error amplifier, which can be used for loop compensation. |
| 2 | VFB | input | Inverting input of the error amplifier, normally driven through a resistor divider from the switching power supply output. |
| 3 | SENSE | input | Input for a voltage proportional to the sensor current, which the PWM uses to terminate output switch conduction; absolute maximum range is -0.3 V to 5.5 V. |
| 4 | RT/CT | passive | Timing pin where RT connected to Vref and CT connected to ground set the oscillator frequency and maximum output duty cycle, with operation up to 1.0 MHz. |
| 5 | GND | power_in | Ground reference pin for the controller. |
| 6 | OUTPUT | output | Directly drives the power MOSFET gate with up to 1.0 A peak source and sink current, at half the oscillator frequency. |
| 7 | VCC | power_in | Positive supply pin for the control IC; absolute maximum supply voltage is 30 V. |
| 8 | VREF | power_out | 5.0 V reference output that supplies the charging current through RT to CT and can source more than 20 mA to external circuits. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | HXY MOSFET |
| Package | SOP-8 |
| Category | Power Supply Chip |
| Pins | 8 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Supply voltage | Vcc | 30 | V | Absolute maximum, Tamb=25℃ unless otherwise specified | 3 | ||
| Output current source or sink | Io | -1 | 1 | A | Note 1 | 3 | |
| Current sense and voltage feedback input voltage | Vin | -0.3 | 5.5 | V | 3 | ||
| Error amplifier output sink current | Io | 10 | mA | 3 | |||
| Output energy per cycle with capacitive load | W | 5 | uJ | 3 | |||
| Operating junction temperature | Tj | 150 | ℃ | 3 | |||
| Power dissipation | PD | 1 | W | 3 | |||
| Operating ambient temperature | Tamb | 0 | 70 | ℃ | 3 | ||
| Storage temperature | Tstg | -65 | 150 | ℃ | 3 | ||
| Reference output voltage | Vref | 4.9 | 5 | 5.1 | V | Tj=25℃ Io=1mA | 3 |
| Reference line regulation | ΔVref | 2 | 20 | mV | 12V≤Vi≤25V | 3 | |
| Reference load regulation | ΔVref | 3 | 25 | mV | 1mA≤Vi≤20mA | 3 | |
| Reference short-circuit output current | Isc | -30 | -85 | -180 | mA | Ta=25℃ | 3 |
| Oscillation frequency | fosc | 47 | 52 | 57 | kHz | Ta=25℃ | 3 |
| Oscillator frequency voltage variation | Δfosc/ΔV | 0.2 | 1 | % | Vcc=12V to 25V | 3 | |
| Error amplifier input voltage | Vfb | 2.42 | 2.5 | 2.58 | V | Vo=2.5V | 3 |
| Error amplifier input bias current | Iib | -0.1 | -2 | μA | Vfb=2.7V | 3 | |
| Error amplifier open-loop voltage gain | Gvol | 65 | 90 | dB | 2V≤Vo≤4V | 3 | |
| Error amplifier unity gain bandwidth | BW | 0.7 | 1 | MHz | Tj=25℃ | 3 | |
| Error amplifier power supply rejection ratio | PSRR | 60 | 70 | dB | 12V≤Vi≤25V | 3 | |
| Error amplifier output sink current | Isink | 2 | 6 | mA | Vfb=2.7V，Vo=1.1V | 3 | |
| Error amplifier output source current | Isource | -0.5 | -1 | mA | Vfb=2.3V，Vo=5V | 3 | |
| Error amplifier output high level | VOH | 6 | 7 | V | Vfb=2.3V，Rl=15kΩ to Ground | 3 | |
| Error amplifier output low level | VOL | 0.8 | 1.1 | V | Vo=2.7V，Rl=15kΩ to Vref | 4 | |
| Voltage sense input voltage gain | Av | 2.85 | 3 | 3.15 | V/V | 注4 & 5 | 4 |
| Maximum current sense input threshold | Vth | 0.9 | 1 | 1.1 | V | 注4 | 4 |
| Current sense power supply rejection ratio | PSRR | 70 | dB | 12V≤Vcc≤25V 注4 | 4 | ||
| Current sense input bias current | Iib | -2 | -10 | μA | 4 | ||
| Current sense input to output propagation delay | TPLH(in/off) | 150 | 300 | ns | 4 | ||
| Output low level | VOL | 0.1 | 0.4 | V | Isink=20mA | 4 | |
| Output low level | VOL | 1.8 | 2.2 | V | Isink=200mA | 4 | |
| Output high level | VOH | 13 | 13.5 | V | Isource=20mA | 4 | |
| Output high level | VOH | 12 | 13.4 | V | Isource=200mA | 4 | |
| Output voltage under UVLO | Vol(uvlo) | 0.1 | 1.1 | V | Vcc=6V，Isink=1mA | 4 | |
| Output voltage rise time | tr | 50 | 150 | ns | Tj=25℃ Cl=1nF | 4 | |
| Output voltage fall time | tf | 50 | 150 | ns | Tj=25℃ Cl=1nF | 4 | |
| Undervoltage lockout start threshold | Vth | 7.8 | 8.2 | 9 | V | 4 | |
| Undervoltage lockout minimum operating voltage | Vcc(min) | 7 | 7.6 | 8.2 | V | 4 | |
| Maximum duty cycle | DCmax | 47 | 48 | 50 | % | 4 | |
| Minimum duty cycle | DCmin | 0 | % | 4 | |||
| Start-up current | Istart | 0.12 | 1 | mA | Vcc=6.5V | 4 | |
| Operating supply current | Icc | 11 | 17 | mA | Vcc=15V (注2) | 4 | |
| Supply Zener voltage | Vz | 30 | 36 | V | Icc=25mA | 4 | |
| Oscillator temperature characteristic | Δfosc/ΔT | 5 | % | Ta=Tlow to Thigh | 3 | ||
| Oscillator peak-to-peak amplitude | Vosc | 1.6 | V | peak to peak | 3 | ||
| Oscillator discharge current | Idischg | 10.8 | mA | Vosc=2V，Tj=25℃ | 3 | ||
| Reference output noise voltage | Vn | 50 | μV | 10Hz≤f≤10kHz | 3 |
CAD (KiCad official)
- Symbol:
UC3845B-HXY - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files:
uc3845b-hxy-etched.step/uc3845b-hxy-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);uc3845b-hxy.step/uc3845b-hxy.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: HXY MOSFET datasheet (12 pp, sha256
e1410c549d244d35, retrieved 2026-10-27, 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, primaryclaude-haiku-5-5(text), consensusoff(skipped (clean text read)), 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).