CTL503 Curve Tracer

£219.00 (excl. VAT)

+/-100V, 3A, 4 collector ranges, 4 base ranges
Curve traces NPN/PNP BJT, FET, MOSFET (N/P), diodes, etc.
Transistor Vbe matching and binning (EPIC 21.013 onwards)
Graph and CSV export function (EPIC21.013 onwards)

includes Free PC software (EPIC, download here)
includes USB 2.0 cable
includes Mains PSU (12V, 1.5A)
includes Calibration resistor token
includes SMT token (#CTL011)
includes 2 year warranty

Click here for USA sales

Availability: In stock (can be backordered)

SKU: CTL503 Category:

The CTL503 Curve Tracer is a low-cost transistor (BJT and FET) computer controller curve tracer. Unlike other simple curve tracing units the CTL503 is designed to measure devices to 100V and upto 3A.  Four collector resistors (relay selected) allow the user to test the smallest of BJT’s and FET’s as well as extracting meaningful curves from larger TO3/TO247 packaged devices.  Limits on both peak test voltage and peak test current can be easily set to prevent exceeding device parameters.

Pulse testing (80us/300us) is used to minimise device heating and to ensure the CTL503 can be powered via USB. This may be disabled for smaller parts.

Connected and powered via USB  and running our own free software (EPIC, download here) the CTL503 is easily configured using a built in wizard (for quick results), or the user can adjust every instrument parameter to suit. Works with EPIC 21.010 and above.
Users can save data from runs, as well simply grab images directly from EPIC.

Connections are made to the DUT (device-under-test) with the built-in colour coded test leads with crocodile clips.

Screen captures (EPIC21.010) show:
(i) Vds vs Id plot at different Vgs voltages (MOSFET).
(ii) XXXX
(iii) XXXXX

Features & Specifications

  • Step generator: 0 to 20 steps
  • Current mode: 1uA to 20mA (4 ranges)
  • Voltage mode: -10V to +10V (using 270R gate resistor)
  • Offset function for both current and voltage generation
  • Step generator can cross zero (e.g. start at -10V and sweep to +10V)
  • Collector sweep voltage: 0V to +100V (or -100V), adjustable peak voltage to limit chance of damage.
  • Collector resistance ranges: 12R, 270R, 2K45, 27K
  • Peak collector current: 3A
  • Acccuracy: >TBA
  • Powered via external (supplied) mains PSU, supplied with UK, EU, US and AU/NZ adaptors.
  • USB 2.0 connection to PC
  • Bright RED LED indicates HV generator is active, solid bright GREEN LED indicates unit is connected.


Each CTL503 calibrated and adjusted in-house as part of our standard production test procedure.  Calibration values are stored within the instrument.
If recalibration/adjustment is necessary it is simply done through the UTILITIES menu in EPIC (you will need a DMM with voltage and  current measurement ability).


1x CTL503 Curve Tracer
1x USB cable
1x Mains PSU (12V, 1.5V)
1x Pack of 4 measured calibration resistors
1x SMT token – included in UK shipped orders from 1/1/2022
please note: any test leads or devices shown are not supplied as standard.


2 year warranty against manufacturing defects.

Related Documents

Product Summary


User Manual



Weight 0.70 kg
Dimensions 30 × 20 × 15 cm
Collector voltage

+/-50V max.

Collector current

2A max.

Collector ranges

4 ranges, from 12R to 27Kohms

Step generator

0-20 steps, -10V to +10V (voltage mode), -20mA to +20mA (current mode – 4 ranges)

Power source

Via USB2.0, use high-quality cable.


PCB is 100mm x 80mm, height <25mm. 4x rubber feet on underside.

Scroll to Top