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UC3842BP
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UTC Unisonic Tech DC-DC Converters, SOP-8. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
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UC3842BP
UTC Unisonic Tech · DC-DC Converters · SOP-8
UC3842BP from UTC Unisonic Tech, 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 | Compensation | output | Error amplifier output, made available for loop compensation. |
| 2 | VFB | input | Voltage feedback input is the inverting input of the error amplifier and is normally connected to the switching power supply output through a resistor divider. |
| 3 | ISENSE | input | Receives a voltage proportional to inductor current, which the PWM uses to terminate output switch conduction. |
| 4 | RT/CT | passive | Oscillator frequency and maximum output duty cycle are programmed by resistor RT to VREF and capacitor CT to ground, and operation to 1 MHz is possible. |
| 5 | GND | power_in | Power ground. |
| 6 | Output | output | Directly drives the gate of a power MOSFET, sourcing and sinking peak currents up to 1 A and switching at one-half the oscillator frequency. |
| 7 | VCC | power_in | Positive supply; absolute maximum is 30 V from a low-impedance source, and the supply is self-limiting when ICC is below 30 mA. |
| 8 | VREF | power_out | Reference output that provides charging current for capacitor CT through resistor RT; 4.9 V to 5.1 V at 1.0 mA and TJ = 25°C. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | UTC Unisonic Tech |
| Package | SOP-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 |
|---|---|---|---|---|---|---|---|
| Current Sense and Voltage Feedback Inputs | VIN | -0.3 | 5.5 | V | 4 | ||
| Supply Voltage (Low Impedance Source) | VCC | 30 | V | 4 | |||
| Error Amp Output Sink Current | ISINK | 10 | mA | 4 | |||
| Output Current, Source or Sink | IOUT | 1 | A | 4 | |||
| Output Energy (Capacitive Load per cycle) | W | 5 | μJ | 4 | |||
| Power Dissipation SOP-8 | PD | 800 | mW | 4 | |||
| Junction Temperature | TJ | 150 | °C | 4 | |||
| Operation Temperature | TOPR | 0 | 70 | °C | 4 | ||
| Storage Temperature | TSTG | -65 | 150 | °C | 4 | ||
| Reference Output Voltage | VREF | 4.9 | 5 | 5.1 | V | IOUT=1.0mA,TJ=25°C | 4 |
| Total Output Variation over Line, Load, Temperature | VREF | 4.82 | 5.18 | V | 4 | ||
| Line Regulation | △VOUT | 2 | 20 | mV | VCC=12V ~ 25V | 4 | |
| Load Regulation | △VOUT | 15 | 30 | mV | IOUT=1.0mA ~ 20mA | 4 | |
| Output Short Circuit Current | ISC | -50 | -155 | -280 | mA | 4 | |
| Frequency | fOSC | 47 | 52 | 57 | kHz | TJ=25°C | 4 |
| Frequency | fOSC | 46 | 60 | kHz | 0°C ≤ TA ≤ 70°C | 4 | |
| Frequency Change with Voltage | fOSC/V | 0.2 | 1 | % | VCC=12V ~ 25V | 4 | |
| Voltage Feedback Input | VFB | 2.42 | 2.5 | 2.58 | V | VOUT=2.5V | 4 |
| Output Voltage Swing High | VOH | 5 | 6.2 | V | RL=15k to ground, VFB=2.3V | 4 | |
| Output Voltage Swing Low | VOL | 0.8 | 1.1 | V | RL=15k to VREF, VFB=2.7V | 4 | |
| Output Current Sink | ISINK | 2 | 12 | mA | VOUT=1.6V, VFB=2.7V | 4 | |
| Output Current Source | ISOURCE | -0.5 | -1 | mA | VOUT=5.0V, VFB=2.3V | 4 | |
| Input Bias Current (error amplifier) | II(BIAS) | -0.1 | -2 | μA | VFB=2.7V | 4 | |
| Open Loop Voltage Gain | GVO | 65 | 90 | dB | VOUT=2.0V ~ 4.0V | 4 | |
| Power Supply Rejection Ratio (error amplifier) | PSRR | 60 | 70 | dB | VCC=12V ~ 25V | 4 | |
| Unity Gain Bandwidth | GBW | 0.7 | 1 | MHz | TJ=25°C | 4 | |
| Current Sense Input Voltage Gain | GV | 2.85 | 3 | 3.15 | V/V | 5 | |
| Maximum Current Sense Input Threshold | VI(THR) | 0.9 | 1 | 1.1 | V | 5 | |
| Input Bias Current (current sense) | II(BIAS) | -2 | -10 | μA | 5 | ||
| Propagation Delay | tPLH(IN/OUT) | 150 | 300 | ns | 5 | ||
| Output Voltage Low | VOL | 0.2 | 0.8 | V | ISINK=20mA | 5 | |
| Output Voltage Low | VOL | 1.6 | 2.2 | V | ISINK=200mA | 5 | |
| Output Voltage High | VOH | 11 | 13.5 | V | ISINK=20mA | 5 | |
| Output Voltage High | VOH | 11 | 13.4 | V | ISINK=200mA | 5 | |
| Output Voltage with UVLO Activated | VOL(UVLO) | 0.7 | 1.2 | V | VCC=6.0V, ISINK=1.0mA | 5 | |
| Output Voltage Rise Time | tR | 50 | 150 | ns | CL=1.0nF, TJ=25°C | 5 | |
| Output Voltage Fall Time | tF | 50 | 150 | ns | CL=1.0nF, TJ=25°C | 5 | |
| Startup Threshold (UC3842B) | VTHR | 14.5 | 16 | 17.5 | V | 5 | |
| Minimum Operating Voltage After Turn-On (UC3842B) | VCC(MIN) | 8.5 | 10 | 11.5 | V | 5 | |
| Duty Cycle MAX | DCMAX | 95 | 97 | 100 | % | 5 | |
| Duty Cycle MIN | DCMIN | 0 | % | 5 | |||
| Power Supply Zener Voltage | VZ | 30 | 34 | V | ICC=25mA | 5 | |
| Power Supply Current, Start Up | ICC | 0.25 | 0.5 | mA | 5 | ||
| Power Supply Current, Operating | ICC | 12 | 17 | mA | 5 | ||
| Temperature Stability | tS | 0.2 | mV/°C | 4 | |||
| Output Noise Voltage | eN | 50 | μV | f=10Hz ~ kHz, TJ=25°C | 4 | ||
| Long Term Stability | S | 5 | mV | TA=125°C for 1000 Hours | 4 | ||
| Oscillator Voltage Swing | VOSC | 1.6 | V | 4 | |||
| Discharge Current | IDSG | 10.8 | mA | VOSC=2.0V, TJ=25°C | 4 | ||
| Frequency Change with Temperature | fOSC/T | 5 | % | 0°C ≤ TA ≤ 70°C | 4 | ||
| Power Supply Rejection Ratio (current sense) | PSRR | 70 | dB | VCC=12V ~ 25V (Note 4) | 5 | ||
| Junction to Ambient (SOP-8) | θJA | 156 | °C/W | 4 |
CAD (KiCad official)
- Symbol:
UC3842BP - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files:
uc3842bp-etched.step/uc3842bp-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);uc3842bp.step/uc3842bp.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: UTC Unisonic Tech datasheet (7 pp, sha256
c6375cfcd27fb1e7, retrieved 2026-10-18, 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).
# UC3842BP
**UTC Unisonic Tech** · DC-DC Converters · SOP-8
UC3842BP from UTC Unisonic Tech, 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 | Compensation | output | Error amplifier output, made available for loop compensation. |
| 2 | VFB | input | Voltage feedback input is the inverting input of the error amplifier and is normally connected to the switching power supply output through a resistor divider. |
| 3 | ISENSE | input | Receives a voltage proportional to inductor current, which the PWM uses to terminate output switch conduction. |
| 4 | RT/CT | passive | Oscillator frequency and maximum output duty cycle are programmed by resistor RT to VREF and capacitor CT to ground, and operation to 1 MHz is possible. |
| 5 | GND | power_in | Power ground. |
| 6 | Output | output | Directly drives the gate of a power MOSFET, sourcing and sinking peak currents up to 1 A and switching at one-half the oscillator frequency. |
| 7 | VCC | power_in | Positive supply; absolute maximum is 30 V from a low-impedance source, and the supply is self-limiting when ICC is below 30 mA. |
| 8 | VREF | power_out | Reference output that provides charging current for capacitor CT through resistor RT; 4.9 V to 5.1 V at 1.0 mA and TJ = 25°C. |
## Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | UTC Unisonic Tech |
| Package | SOP-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 |
|---|---|---|---|---|---|---|---|
| Current Sense and Voltage Feedback Inputs | VIN | -0.3 | | 5.5 | V | | 4 |
| Supply Voltage (Low Impedance Source) | VCC | | | 30 | V | | 4 |
| Error Amp Output Sink Current | ISINK | | | 10 | mA | | 4 |
| Output Current, Source or Sink | IOUT | | | 1 | A | | 4 |
| Output Energy (Capacitive Load per cycle) | W | | | 5 | μJ | | 4 |
| Power Dissipation SOP-8 | PD | | | 800 | mW | | 4 |
| Junction Temperature | TJ | | | 150 | °C | | 4 |
| Operation Temperature | TOPR | 0 | | 70 | °C | | 4 |
| Storage Temperature | TSTG | -65 | | 150 | °C | | 4 |
| Reference Output Voltage | VREF | 4.9 | 5 | 5.1 | V | IOUT=1.0mA,TJ=25°C | 4 |
| Total Output Variation over Line, Load, Temperature | VREF | 4.82 | | 5.18 | V | | 4 |
| Line Regulation | △VOUT | 2 | | 20 | mV | VCC=12V ~ 25V | 4 |
| Load Regulation | △VOUT | 15 | | 30 | mV | IOUT=1.0mA ~ 20mA | 4 |
| Output Short Circuit Current | ISC | -50 | -155 | -280 | mA | | 4 |
| Frequency | fOSC | 47 | 52 | 57 | kHz | TJ=25°C | 4 |
| Frequency | fOSC | 46 | | 60 | kHz | 0°C ≤ TA ≤ 70°C | 4 |
| Frequency Change with Voltage | fOSC/V | 0.2 | | 1 | % | VCC=12V ~ 25V | 4 |
| Voltage Feedback Input | VFB | 2.42 | 2.5 | 2.58 | V | VOUT=2.5V | 4 |
| Output Voltage Swing High | VOH | 5 | | 6.2 | V | RL=15k to ground, VFB=2.3V | 4 |
| Output Voltage Swing Low | VOL | 0.8 | | 1.1 | V | RL=15k to VREF, VFB=2.7V | 4 |
| Output Current Sink | ISINK | 2 | | 12 | mA | VOUT=1.6V, VFB=2.7V | 4 |
| Output Current Source | ISOURCE | -0.5 | | -1 | mA | VOUT=5.0V, VFB=2.3V | 4 |
| Input Bias Current (error amplifier) | II(BIAS) | -0.1 | | -2 | μA | VFB=2.7V | 4 |
| Open Loop Voltage Gain | GVO | 65 | | 90 | dB | VOUT=2.0V ~ 4.0V | 4 |
| Power Supply Rejection Ratio (error amplifier) | PSRR | 60 | | 70 | dB | VCC=12V ~ 25V | 4 |
| Unity Gain Bandwidth | GBW | 0.7 | | 1 | MHz | TJ=25°C | 4 |
| Current Sense Input Voltage Gain | GV | 2.85 | 3 | 3.15 | V/V | | 5 |
| Maximum Current Sense Input Threshold | VI(THR) | 0.9 | 1 | 1.1 | V | | 5 |
| Input Bias Current (current sense) | II(BIAS) | -2 | | -10 | μA | | 5 |
| Propagation Delay | tPLH(IN/OUT) | 150 | | 300 | ns | | 5 |
| Output Voltage Low | VOL | 0.2 | | 0.8 | V | ISINK=20mA | 5 |
| Output Voltage Low | VOL | 1.6 | | 2.2 | V | ISINK=200mA | 5 |
| Output Voltage High | VOH | 11 | | 13.5 | V | ISINK=20mA | 5 |
| Output Voltage High | VOH | 11 | | 13.4 | V | ISINK=200mA | 5 |
| Output Voltage with UVLO Activated | VOL(UVLO) | 0.7 | | 1.2 | V | VCC=6.0V, ISINK=1.0mA | 5 |
| Output Voltage Rise Time | tR | 50 | | 150 | ns | CL=1.0nF, TJ=25°C | 5 |
| Output Voltage Fall Time | tF | 50 | | 150 | ns | CL=1.0nF, TJ=25°C | 5 |
| Startup Threshold (UC3842B) | VTHR | 14.5 | 16 | 17.5 | V | | 5 |
| Minimum Operating Voltage After Turn-On (UC3842B) | VCC(MIN) | 8.5 | 10 | 11.5 | V | | 5 |
| Duty Cycle MAX | DCMAX | 95 | 97 | 100 | % | | 5 |
| Duty Cycle MIN | DCMIN | 0 | | | % | | 5 |
| Power Supply Zener Voltage | VZ | 30 | | 34 | V | ICC=25mA | 5 |
| Power Supply Current, Start Up | ICC | 0.25 | | 0.5 | mA | | 5 |
| Power Supply Current, Operating | ICC | 12 | | 17 | mA | | 5 |
| Temperature Stability | tS | | 0.2 | | mV/°C | | 4 |
| Output Noise Voltage | eN | | 50 | | μV | f=10Hz ~ kHz, TJ=25°C | 4 |
| Long Term Stability | S | | 5 | | mV | TA=125°C for 1000 Hours | 4 |
| Oscillator Voltage Swing | VOSC | | 1.6 | | V | | 4 |
| Discharge Current | IDSG | | 10.8 | | mA | VOSC=2.0V, TJ=25°C | 4 |
| Frequency Change with Temperature | fOSC/T | | 5 | | % | 0°C ≤ TA ≤ 70°C | 4 |
| Power Supply Rejection Ratio (current sense) | PSRR | | 70 | | dB | VCC=12V ~ 25V (Note 4) | 5 |
| Junction to Ambient (SOP-8) | θJA | | 156 | | °C/W | | 4 |
## CAD (KiCad official)
- Symbol: `UC3842BP`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `uc3842bp-etched.step` / `uc3842bp-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `uc3842bp.step` / `uc3842bp.glb` are the bare package body.
## Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- **Datasheet:** [UTC Unisonic Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603078362260643840) (7 pp, sha256 `c6375cfcd27fb1e7`, retrieved 2026-10-18, tier: lcsc)
- **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/uc3842bp-datasheet.pdf)