UNI-T UDP3303C Programmable DC Power Supply, product image 1

UNI-T UDP3303C Programmable DC Power Supply, product image 2

UNI-T UDP3303C Programmable DC Power Supply, product image 3

UNI-T

UNI-T UDP3303C Programmable DC Power Supply — 3 Channels, 195W

$364.99

Availability notice: This model is currently out of stock with our distributor. Restock timing is unconfirmed. Please contact us to confirm availability before ordering.

The UNI-T UDP3303C is a three-channel linear bench power supply for electronics development and automated testing. Two adjustable channels deliver up to 30V and 3A each; USB-Device and RS-232 provide SCPI control.

Browse UNI-T instruments and test and measurement equipment. Check the selected variant's availability before ordering.

Overview

The UDP3303C is the SCPI-programmable counterpart to the UDP3303A — same 195W three-channel linear hardware, same CH3 logic-rail selector cycling 1.8V / 2.5V / 3.3V / 5V at 3.2A, same ≤1 mVrms ripple — with a back-panel USB-Device port and RS-232 added for full SCPI control. CH1 and CH2 deliver 0–30V at 0–3A; series and parallel modes extend that to 60V or 6A.

Programming accuracy holds inside ≤0.1% + 30 mV on voltage and ≤0.5% + 2 mA on current — fine enough for sleep-mode current characterization on IoT prototypes, battery-charge cut-off testing, and any automated sweep that needs the setpoint to land exactly where you asked it. Five preset storage groups (M1–M5), shutdown memory, OVP / OCP / OTP per channel, and a Digital I/O hardware ON/OFF pin pair round out a programmable supply built for benches that have to behave the same way every time. For 5A per adjustable channel, see the UDP3305C; for the knob-only manual variant, see the UDP3303A.

Key Features

Three Channels, 195W Total — SCPI Programmable — CH1 and CH2: 0–30V / 0–3A adjustable. CH3: switchable 1.8V / 2.5V / 3.3V / 5V at 3.2A. SCPI control over USB-Device or RS-232.
USB-Device + RS-232 with SCPI — Back-panel data interfaces for PC connection. Standard accessories include both a USB cable (UT-D14) and RS-232 communication line — pick the bus your test rig already uses.
Programming Accuracy ≤0.1% + 30 mV — Voltage programming accuracy ≤0.1% + 30 mV; current programming accuracy ≤0.5% + 2 mA. Set value matches output value across the full range.
CH3 Logic-Rail Selector — Single front-panel button cycles CH3 through 1.8V / 2.5V / 3.3V / 5V at 3.2A. CMOS, microcontroller cores, legacy TTL, USB-class — covered without sacrificing CH1/CH2.
Linear Topology, ≤1 mVrms Ripple — Clean DC output for low-noise analog work. Load regulation ≤0.01% + 3 mV in CV mode.
10 mV / 1 mA Resolution — Four-digit voltage and current display per channel on EBTN LCD.
Series, Parallel, and Tracking Modes — Combine CH1+CH2 for up to 60V series or 6A parallel from the front panel. SCPI exposes the same modes for automated test integration.
OVP / OCP / OTP Protection — Configurable per-channel thresholds, plus over-temperature shutdown and keypad lock.
Five Preset Storage Groups — M1–M5 store full instrument states for fast bench setup. Shutdown memory restores last settings on power-up.
Front-Panel 5V/2A USB Charging Port (CH4) — Independent 5V/2A USB-A charging output. Charging output only — the data interfaces are USB-Device and RS-232 on the back panel.
Hardware Output Disable via Digital I/O — Two-pin Digital I/O terminal for emergency cutoff and external interlock circuits.

Detailed Features

CH3 Logic-Rail Selector — One Button, Four Voltages

Most three-channel bench supplies give you two adjustable channels and a fixed 5V rail you'll resent the moment you need 3.3V. The UDP3303C's CH3 cycles between 1.8V, 2.5V, 3.3V, and 5V at 3.2A — covering CMOS logic, modern microcontroller cores, legacy TTL, and USB-class devices — at a single front-panel button press. CH1 and CH2 stay free for the analog work the linear topology is genuinely good at — op-amp rails, sensor bias, charge-pump references, audio circuits — while CH3 handles whatever digital subsystem the project also needs powered. One supply, two adjustable analog rails, one switchable digital rail, all labeled, all protected, all SCPI-controllable.

UNI-T UDP3303C — ch3 logic-rail selector

SCPI Programmable for Repeatable Bench Work

The UDP3303C is the programmable counterpart to the UDP3303A — same hardware, same protection, same CH3 logic-rail selector — with a back-panel USB-Device port and RS-232 added for SCPI control. Script the rails over USB or RS-232, capture readbacks, document the run, and repeat it tomorrow morning the same way. Programming accuracy holds inside ≤0.1% + 30 mV on voltage and ≤0.5% + 2 mA on current — fine enough for IoT sleep-mode current characterization, battery-charge cut-off testing, and any sweep that needs the setpoint to land where you asked it to. Five preset storage groups (M1–M5) and a Digital I/O hardware ON/OFF pin pair round out a programmable supply built for benches that have to behave the same way every time.

Applications

R&D Bench & Prototyping

Three rails (two adjustable, one switchable digital) with SCPI control script the bench setup directly from your test framework. Linear topology and ≤1 mVrms ripple keep supply noise out of measurement on op-amp characterization, ADC reference rails, and sensor-bridge excitation work.

Automated Test Lab Integration

SCPI over USB-Device or RS-232 integrates with LabVIEW, Python-VISA, and shell-driven test frameworks. Five preset storage groups keep frequently used test setups one command away. Programming accuracy ≤0.1% + 30 mV keeps automated sweeps repeatable across runs.

Teaching Labs & Automated Lab Exercises

For curricula that introduce instrument automation alongside instrument operation, the UDP3303C lets a class go from manual front-panel work to scripted SCPI control without changing the instrument.

Mixed-Signal Development

CH1 and CH2 power analog rails at low ripple; CH3 cycles through digital-side voltages without retuning. SCPI lets the test script raise or lower the digital rail while CH1/CH2 hold the analog supplies steady — useful for power-sequencing and sleep-mode characterization on mixed-signal prototypes.

Frequently Asked Questions

What's the difference between the UDP3303A and the UDP3303C?

The UDP3303C adds SCPI programmability over USB-Device and RS-232. Hardware (channels, voltage, current, power, CH3 logic-rail selector, protection, display, dimensions) is otherwise identical. Choose the UDP3303A if your bench is knob-only; choose the UDP3303C if you need automated test integration. For 5A per adjustable channel instead of 3A, step up to the UDP3305C.

Does the UDP3303C have LAN?

No. The UDP3303C's data interfaces are USB-Device (back-panel SCPI port for PC connection) and RS-232. If your workflow needs LAN with LXI/web interface, the UDP3000S series adds it on the same linear-PSU platform. The Digital I/O pin pair on the back panel handles hardware ON/OFF — useful for external interlocks but not for data communication.

What is the front-panel USB port for?

It's a 5V/2A USB-A charging output (CH4) — for charging a phone or powering a USB-powered demo board. It is explicitly not a data interface. The SCPI data ports are on the back panel: USB-Device and RS-232.

Can the UDP3303C run automated voltage/current sweeps?

Yes — SCPI control over USB-Device or RS-232 supports remote voltage and current setpoint commands plus readbacks, and the five preset storage groups (M1–M5) keep frequently used configurations available for fast recall. For complex programmable waveform output (list/delayer functions), the UDP3000S series adds those capabilities on the same linear platform.

Why a linear supply instead of switching for SCPI work?

Linear topology produces fundamentally cleaner output — no switching frequency, no harmonic spurs, ripple under 1 mVrms. SCPI control gives you automation; linear regulation keeps the output clean enough for the precision measurements that automated test usually exists to take in the first place. The trade-off is lower efficiency and more heat, which at 195W bench-supply scale is not a meaningful constraint.

What's included with the UDP3303C?

The UDP3303C ships with the instrument, power cord, USB communication cable (UT-D14), RS-232 communication line, alligator clip test leads, English user manual Ships from authorized US dealer.

Specifications

Model	UDP3303C
Channels	3 programmable (CH1, CH2 adjustable; CH3 selectable) + CH4 USB charging output
CH1, CH2 Output Voltage	0–30V
CH1, CH2 Output Current	0–3A
CH3 Output Voltage	1.8V / 2.5V / 3.3V / 5V (±3%, fine-tunable)
CH3 Output Current	3.2A
Total Output Power	195W
CH4 USB Charging Output	5V / 2A (front-panel USB charging output)
Voltage Resolution	10 mV
Current Resolution	1 mA
Load Regulation (CV)	≤0.01% + 3 mV
Load Regulation (CC)	≤0.2% + 3 mA
Programming Accuracy (Voltage)	≤0.1% + 30 mV
Programming Accuracy (Current)	≤0.5% + 2 mA
Ripple & Noise (Voltage)	≤1 mVrms (20Hz–20MHz)
Ripple & Noise (Current)	≤3 mArms
Temperature Coefficient	≤300 ppm/°C (V/I)
Series Mode (CH1+CH2)	Up to 60V (CH1+CH2)
Parallel Mode (CH1+CH2)	Up to 6A (CH1+CH2)
Display	EBTN LCD, 4-digit voltage + current per channel
Programmable	Yes — SCPI over USB-Device or RS-232
Interfaces	USB-Device, RS-232, Digital I/O
Memory	5 preset storage groups (M1–M5)
Protection	OVP, OCP (per-channel, configurable), OTP, keypad lock, shutdown memory
AC Input	100 / 120 / 220 / 230V ±10%, 50/60 Hz
Dimensions (W × H × D)	240 × 168 × 347 mm
Weight	8.8 kg
Certifications	CE

Documentation

UDP3303C Datasheet, User Manual, and Software/Firmware Downloads

Options & Accessories

Included in box:

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

Shipping policy

Last updated: October 27, 2026

Where we ship and shipping charges

Shipping availability depends on the product, supplier, and delivery address. Enter your address at checkout to see the available shipping options and final shipping charge before payment. If no shipping option is offered for your address, we cannot ship that combination of items to that destination. A shipping zone does not mean every product is available in every location.

Fulfillment through our partners

Apex Technica works with fulfillment partners, including suppliers through Shopify Collective, who ship products directly to customers. An order containing products from different suppliers may ship in separate packages. Shipping charges may be combined across packages; review the total at checkout.

Processing and delivery estimates

Order handling generally takes 3–5 business days before dispatch, but varies by supplier and product. Business days are Monday through Friday, excluding holidays. Carrier transit time is additional to handling time. Contact hello@apextechnica.com before ordering if you need an item-specific dispatch estimate or delivery by a particular date. For Collective products, available shipping rates and carrier transit estimates are calculated at checkout. Carrier transit estimates describe time in transit after dispatch, not a guaranteed order-to-delivery date. Weekends, holidays, carrier disruptions, and customs processing can affect delivery.

Tracking and separate shipments

We send shipping confirmation and tracking details when they become available from the fulfillment partner. Separate shipments may have different tracking numbers and arrive on different days. Tracking can take time to show the carrier's first scan.

Address changes, delays, and delivery problems

Check your address before placing an order. Contact Apex Technica promptly to request a correction or cancellation; changes may be unavailable once processing begins. If a shipment is delayed, missing, damaged, or incorrect, contact us with your order number so we can investigate with the supplier or carrier. Do not send an item back without return instructions. See our return and refund policy.

Contact

Apex Technica
Email: hello@apextechnica.com
Phone: 760-525-6460

Refund policy

Last updated: October 27, 2026

30-day returns — exception for Collective supplier fulfillment

Apex Technica accepts return requests for products fulfilled by Apex Technica within 30 calendar days after delivery. This standard 30-day return window does not apply to products fulfilled by our Shopify Collective suppliers. Collective-fulfilled products are subject to the applicable supplier's return eligibility, return window, condition requirements, and fees, which may differ from our standard policy.

Products fulfilled by Collective suppliers

Review any supplier-specific return terms shown on the product page before purchasing. If those terms are not shown, contact hello@apextechnica.com before placing your order to confirm the applicable return window, eligibility, shipping costs, and any restocking fee. The exception does not mean that every Collective product is non-returnable. Apex Technica remains your contact for return requests and will coordinate with the supplier. Do not send products directly to a supplier without our return instructions.

Condition for standard Apex returns

For products covered by our standard 30-day policy, items must be unused, in their original packaging, and include all accessories and proof of purchase. This condition requirement does not prevent you from reporting a damaged, defective, or incorrect product.

How to request a return

Email hello@apextechnica.com with your order number, the item you want to return, and the reason for the request. Include photos if the item arrived damaged, defective, or incorrect. We will review the request and provide authorization, the correct return address, and shipping instructions. Returns are made by mail; items from different suppliers may require separate return shipments. Please retain tracking and proof of shipment.

Return costs

For standard Apex returns due to a change of mind, the customer pays return shipping and original shipping charges are not refundable. We do not charge a restocking fee for eligible standard Apex returns. For damaged, defective, or incorrect items, contact us so we can arrange the appropriate return or other resolution without charging you return shipping. For Collective-fulfilled change-of-mind returns, supplier-specific shipping and restocking terms apply.

Refunds and exchanges

After the authorized return is received and inspected, we will notify you of the outcome. Approved refunds are issued to the original payment method within 10 business days after receipt and inspection. Your bank or payment provider may require additional time to post the credit. Any applicable, previously disclosed return charges will be explained. For exchanges, contact us to arrange a return and a separate new order; replacement availability is not guaranteed.

Damaged, defective, incorrect, or missing items

Contact Apex Technica promptly if your order arrives damaged or incorrect, has a defect, or does not arrive. We will investigate with the supplier or carrier and explain the available resolution. Manufacturer warranty coverage is separate from this return policy. Nothing in this policy or a supplier exception limits rights that cannot be excluded under applicable law.