component
UC3844BVD1R2G
Public Made by Adomby adom
onsemi AC-DC Controllers And Regulators, SOIC-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
markdownUC3844BVD1R2G
onsemi · AC-DC Controllers And Regulators · SOIC-8
UC3844BVD1R2G from onsemi, in a SOIC-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 | Compensation | output | This pin is the error amplifier output, made available for loop compensation, and the output voltage is offset by two diode drops (about 1.4 V) and divided by three before it reaches the current sense comparator. |
| 2 | Voltage Feedback | input | This is the inverting input of the error amplifier, normally connected to the switching power supply output through a resistor divider, with a maximum input bias current of -2.0 µA. |
| 3 | Current Sense | input | A voltage proportional to inductor current is connected to this input, which the PWM uses to terminate output switch conduction; the input range is -0.3 V to +5.5 V. |
| 4 | RT/CT | passive | Resistor RT connects to Vref and capacitor CT to ground to program the oscillator frequency and maximum output duty cycle, with oscillator operation to 1.0 kHz possible. |
| 5 | GND | power_in | This pin is the combined control circuitry and power ground. |
| 6 | Output | output | This output directly drives the gate of a power MOSFET, sourcing and sinking peak currents up to 1.0 A, and switches at one-half the oscillator frequency. |
| 7 | VCC | power_in | This pin is the positive supply of the control IC, with VCC rated up to 36 V in the maximum ratings. |
| 8 | Vref | power_out | This is the reference output, nominally 5.0 V, that provides charging current for capacitor CT through resistor RT. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | SOIC-8 |
| Category | Power Management (PMIC) |
| 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 |
|---|---|---|---|---|---|---|---|
| Bias and Driver Voltages (VCC, VC) | VCC, VC | 36 | V | Zero series impedance (Note 1) | 2 | ||
| Total Power Supply and Zener Current | 30 | mA | 2 | ||||
| Output Current, Source or Sink | IO | 1 | A | Note 2 | 2 | ||
| Output Energy (Capacitive Load per Cycle) | W | 5 | J | 2 | |||
| Current Sense and Voltage Feedback Inputs | Vin | -0.3 | 5.5 | V | 2 | ||
| Error Amp Output Sink Current | IO | 10 | mA | 2 | |||
| Operating Junction Temperature | TJ | 150 | °C | 2 | |||
| Operating Ambient Temperature (UC384xBV) | TA | -40 | 105 | °C | UC384xBV | 2 | |
| Storage Temperature Range | Tstg | -65 | 150 | °C | 2 | ||
| Maximum Power Dissipation, SOIC-8 (D1 suffix) | PD | 702 | mW | TA = 25°C | 2 | ||
| Thermal Resistance, Junction-to-Air, SOIC-8 (D1 suffix) | RJA | 178 | °C/W | 2 | |||
| Reference Output Voltage | Vref | 4.9 | 5 | 5.1 | V | IO = 1.0 mA, TJ = 25°C | 2 |
| Line Regulation | Regline | 2 | 20 | mV | VCC = 12 V to 25 V | 2 | |
| Load Regulation | Regload | 3 | 25 | mV | IO = 1.0 mA to 20 mA | 2 | |
| Total Output Variation over Line, Load, & Temperature | Vref | 4.82 | 5.18 | V | 2 | ||
| Output Short Circuit Current | ISC | -30 | -85 | -180 | mA | 2 | |
| Frequency (TJ = 25°C) | fOSC | 49 | 52 | 55 | kHz | TJ = 25°C | 2 |
| Frequency (TA = Tlow to Thigh) | fOSC | 48 | 56 | kHz | TA = Tlow to Thigh | 2 | |
| Frequency (RT/CT test point) | fOSC | 225 | 250 | 275 | kHz | TJ = 25°C (RT = 6.2 k, CT = 1.0 nF) | 2 |
| Frequency Change with Voltage | fOSC/V | 0.2 | 1 | % | VCC = 12 V to 25 V | 2 | |
| Discharge Current (TJ = 25°C) | Idischg | 7.8 | 8.3 | 8.8 | mA | VOSC = 2.0 V, TJ = 25°C | 3 |
| Discharge Current (TA = Tlow to Thigh, UC384XBV) | Idischg | 7.2 | 8.8 | mA | VOSC = 2.0 V, TA = Tlow to Thigh (UC384XBV) | 3 | |
| Voltage Feedback Input | VFB | 2.42 | 2.5 | 2.58 | V | VO = 2.5 V | 3 |
| Input Bias Current | IIB | -0.1 | -2 | µA | VFB = 5.0 V | 3 | |
| Open Loop Voltage Gain | AVOL | 65 | 90 | dB | VO = 2.0 V to 4.0 V | 3 | |
| Unity Gain Bandwidth | BW | 0.7 | 1 | MHz | TJ = 25°C | 3 | |
| Power Supply Rejection Ratio (Error Amp) | PSRR | 60 | 70 | dB | VCC = 12 V to 25 V | 3 | |
| Output Current - Sink | ISink | 2 | 12 | mA | VO = 1.1 V, VFB = 2.7 V | 3 | |
| Output Current - Source | ISource | -0.5 | -1 | mA | VO = 5.0 V, VFB = 2.3 V | 3 | |
| Output Voltage Swing High State | VOH | 5 | V | RL = 15 k to ground, VFB = 2.3 V | 3 | ||
| Output Voltage Swing Low State (UC384XBV) | VOL | 1.2 | V | RL = 15 k to Vref, VFB = 2.7 V | 3 | ||
| Current Sense Input Voltage Gain | AV | 2.85 | 3 | 3.25 | V/V | Notes 9 & 10 | 3 |
| Maximum Current Sense Input Threshold | Vth | 0.85 | 1 | 1.1 | V | Note 9 | 3 |
| Current Sense Input Bias Current | IIB | -2 | -10 | µA | 3 | ||
| Propagation Delay (Current Sense Input to Output) | tPLH(In/Out) | 150 | 300 | ns | 3 | ||
| Output Voltage Low State | VOL | 0.1 | 0.4 | V | ISink = 20 mA | 3 | |
| Output Voltage Low State (UC384XBV) | VOL | 1.6 | 2.3 | V | ISink = 200 mA (UC384XBV) | 3 | |
| Output Voltage High State (UC384XBV) | VOH | 12.9 | V | ISource = 20 mA (UC384XBV) | 3 | ||
| Output Voltage High State | VOH | 12 | 13.4 | V | ISource = 200 mA | 3 | |
| Output Voltage with UVLO Activated | VOL(UVLO) | 0.1 | 1.1 | V | VCC = 6.0 V, ISink = 1.0 mA | 3 | |
| Output Voltage Rise Time | tr | 50 | 150 | ns | CL = 1.0 nF, TJ = 25°C | 3 | |
| Output Voltage Fall Time | tf | 50 | 150 | ns | CL = 1.0 nF, TJ = 25°C | 3 | |
| Startup Threshold (UCX844B, BV) | Vth | 14.5 | 16 | 17.5 | V | 3 | |
| Minimum Operating Voltage After Turn-On (UCX844B, BV) | VCC(min) | 8.5 | 10 | 11.5 | V | 3 | |
| Maximum Duty Cycle (UC384XBV) | DC(max) | 46 | 48 | 50 | % | Maximum (UC384XBV) | 4 |
| Minimum Duty Cycle | DC(min) | 0 | % | Minimum | 4 | ||
| Startup Supply Current (UCX844B, BV) | ICC | 0.3 | 0.5 | mA | VCC = 14 V for UCX844B, BV | 4 | |
| Operating Supply Current | ICC | 12 | 17 | mA | Note 11 | 4 | |
| Power Supply Zener Voltage | VZ | 30 | 36 | V | ICC = 25 mA | 4 |
CAD (KiCad official)
- Symbol:
UC3844BVD1R2G - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files:
uc3844bvd1r2g-etched.step/uc3844bvd1r2g-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);uc3844bvd1r2g.step/uc3844bvd1r2g.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: onsemi datasheet (22 pp, sha256
37535ea3c79885e8, retrieved 2026-10-17, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusclaude-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).