The UNI-T UDP4303S is a 4-channel, 297W precision programmable linear DC power supply with fully isolated outputs: two 0–32V/3A channels, one 0–15V/3A channel, and one 0–6V/10A channel.

The linear topology delivers exceptionally clean output with ripple under 350 µVrms — critical for sensitive analog circuits, precision sensor development, and any application where switching noise is unacceptable.

With 8 kSa/s output sampling across all four channels, 1 µA current resolution, 1 ms programming time resolution, and a built-in waveform display, the UDP4303S provides real-time visibility into transient load behavior that competing supplies simply cannot match. Series/parallel/tracking modes, a controllable bleeder circuit, and comprehensive OVP/OCP/OTP protection round out a professional-grade instrument (3 years standard + 2 with free registration = 5 years total).

Across the Design. Debug. Deploy.™ Lifecycle

Across the design-debug-deploy lifecycle, the UDP4303S earns its bench position: Design. Four isolated channels source the rails and biases that an analog or precision-sensor design needs from first prototype, with linear topology that doesn’t inject switching noise into the measurement. Debug. 8 kSa/s output sampling and 1 µA current resolution expose transients and sleep-mode draws that lower-bandwidth supplies average away. Deploy. List-mode profiles and SCPI/LXI automation drive production characterization runs from the same instrument. Affordability meets precision — design, debug, deploy.

• 4-Channel Fully Isolated Linear Output (297W) — CH1 & CH2: 0–32V/3A, CH3: 0–15V/3A, CH4: 0–6V/10A. Complete electrical isolation between all channels eliminates crosstalk.
• Ultra-Low Ripple & Noise — <350 µVrms/2 mVpp output ripple (20 Hz–20 MHz). Linear topology means zero switching artifacts in the output.
• 1 µA Current Resolution — Low-current measurement mode across all four channels resolves down to 1 µA for precision IoT, sensor, and battery drain testing.
• 8 kSa/s Output Sampling — Real-time voltage/current/power waveform display on all channels captures transient load behavior and power-up sequences.
• 1 ms Programming Time Resolution — Generate precise arbitrary waveforms with 512-group list output. Built-in waveform templates (sine, ramp, pulse) for fast setup.
• Series/Parallel/Tracking Modes — One-touch CH1+CH2 combination: up to 64V in series or 6A in parallel with no external wiring. Tracking mode synchronizes channels automatically.
• Controllable Bleeder Circuit — Active discharge pulls output to zero rapidly when disabled. Turn off for battery testing to prevent unintended discharge.
• Configurable OCP Response (<3 ms) — Adjustable over-current protection delay from 0–10 seconds with fastest response under 3 ms. "Setting Change" mode prevents false triggers at power-on.
• 4-Wire Remote Sense (All Channels) — Compensates for voltage drop in test leads on all four channels, with built-in sense protection.
• USB, LAN, RS-232, Digital I/O — SCPI remote control, web browser interface, and digital trigger I/O for automated test integration.

Precision That Sets It Apart

• Four Independent Channels (CH1 & CH2: 32V/3A, CH3: 15V/3A, CH4: 6V/10A)
  Power multi-rail embedded designs from a single instrument — digital core, analog front-end, I/O, and sensor power simultaneously. No external wiring needed for series/parallel combinations.
• 1 µA Resolution Across All Channels
  The low-current measurement mode samples down to 20 mA with 1 µA resolution on all four channels — measure sleep-mode current draw, standby leakage, and IoT sensor consumption directly from the power supply.
• 8 kSa/s Waveform Capture
  See exactly what your load is doing in real time. The built-in waveform display captures voltage, current, and power transients across all channels simultaneously — no external oscilloscope needed for power behavior analysis.

Real-Time Output Waveform Display

The UDP4303S puts a built-in waveform analyzer on every channel. At 8 kSa/s across all four channels, you can observe voltage, current, and power behavior in real time — capturing inrush currents, transient load steps, and power-up sequences without connecting a separate oscilloscope. The waveform view displays min/max/offset values and supports adjustable time/div and amplitude/div scaling for detailed analysis.

1 ms Arbitrary Waveform Programming

Program up to 512 voltage/current/time groups with 1 ms dwell time resolution — 100× finer than previous-generation supplies. Built-in waveform templates (sine, ramp, triangle, pulse, and more) let you create complex output profiles in seconds. Every channel, including series and parallel modes, supports list output for automated test sequences, battery charge simulation, and device stress testing.

Protect Your DUT with Configurable OCP

The UDP4303S provides adjustable over-current protection with the fastest response time under 3 ms — fast enough to protect sensitive components from damage. The configurable OCP delay (0–10 seconds) prevents false triggers during power-on inrush. "Setting Change" mode detects overcurrent events only after the programmed delay, while "Anyway" mode monitors continuously. Combined with OVP and OTP, every channel is fully protected.

Six Display Styles

The 4.3-inch color LCD offers six distinct display layouts — from a four-channel overview showing voltage, current, and power simultaneously, to a single-channel focused view with large digits for across-the-room readability. Choose the view that matches your workflow and switch between them instantly.

Series & Parallel in One Touch

Combine CH1 and CH2 through the front-panel menu — no external wiring needed. Series mode delivers up to 64V, parallel mode provides up to 6A, all with the same regulation performance and protection features as independent operation. Channel tracking keeps CH1 and CH2 synchronized automatically when you need matched outputs.

Controllable Bleeder Circuit

When you turn off a channel output, the controllable bleeder circuit rapidly discharges the output to zero — preventing residual voltage from reaching sensitive DUTs. For battery testing, turn the bleeder off to prevent the supply from draining the battery when the output is disabled. This flexibility makes the UDP4303S equally suited for both powered-circuit development and battery characterization.

Full-Channel Remote Sense with Protection

All four channels support 4-wire remote sensing through rear-panel terminals, compensating for voltage drop in test leads to ensure the DUT sees exactly the programmed voltage. Unlike competing supplies, the UDP4303S includes sense line protection on all channels — guarding against reverse connection and overvoltage on the sense terminal.

Complete Data Management

The built-in recorder captures voltage, current, and power data from all channels (including series and parallel modes) to a USB flash drive. Store up to 10 status files, 10 list files, and 10 delayer files locally, plus 5 quick-access presets for your most common configurations. Export everything via USB for analysis on your PC

Full Channel Isolation

Applications

Analog & Mixed-Signal Development

Linear output with sub-350 µVrms ripple for op-amp circuits, precision ADC/DAC testing, and low-noise signal chain development. Four isolated channels power multi-rail designs from one instrument — digital core, analog front-end, I/O, and sensor rails simultaneously.

IoT & Battery Drain Analysis

1 µA current resolution on all channels measures sleep-mode consumption, standby leakage, and active-mode transitions. 8 kSa/s sampling captures fast wake-up current spikes. The controllable bleeder circuit prevents unintended battery discharge during characterization.

Embedded System Prototyping

Independent isolated channels provide separate power rails with 1 ms programming resolution for power-up sequencing tests. 8 kSa/s waveform monitoring shows real-time transient current demands during boot and operational state changes.

Automated Production Test

SCPI over USB/LAN/RS-232 integrates into automated test systems. 512-group list output with 1 ms timing runs complex test profiles. Digital I/O trigger input/output coordinates with external equipment. Web server enables remote monitoring.

Specifications

Options & Accessories

Included in box:

• Power cord
• English download guide
• multi-language safety manual
• calibration report (COC)

FAQ's

Why choose a linear power supply over switching?

Linear supplies produce fundamentally cleaner output — no switching frequency harmonics, no EMI, and significantly lower ripple. For precision analog circuits, sensitive sensors, audio applications, and any measurement where µV-level noise matters, the difference is measurable. The tradeoff is lower efficiency and more heat, but for bench power at these power levels, that's typically acceptable.

How does the 8 kSa/s sampling compare to other bench supplies?

Most bench power supplies sample at 4 Sa/s or less — you see averaged readings with no visibility into transients. At 8 kSa/s across all four channels, the UDP4303S captures fast current spikes, inrush events, and load transients in real time on the built-in display. This is 2,000× faster than previous-generation supplies and eliminates the need for an external oscilloscope in many power characterization tasks.

Can I use the UDP4303S for battery drain testing?

Yes — this is one of its strongest applications. The 1 µA current resolution on all channels captures sleep-mode consumption accurately. The controllable bleeder circuit is key: turn it off during battery testing so the supply doesn't drain the battery when the output is disabled. The 8 kSa/s sampling captures fast wake-up transients that lower-speed supplies miss entirely.

What interfaces does the UDP4303S support for remote control?

USB Device, LAN (with built-in web server), RS-232, and a 4-line Digital I/O port for trigger input/output. All interfaces support SCPI commands. The web server provides browser-based control from any device on your network without installing dedicated software.

What's included with the UDP4303S?

The UDP4303S ships with the instrument, power cord, USB data cable, 5-pin plug (3.81mm), two 8-pin plugs (5.08mm), factory calibration report Ships from authorized US dealer.