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Cx Family Common Mode Chokes
0402CT Low Profile Chip Inductors
XAL7050 High-inductance Shielded Power Inductors
XGL4020 Ultra-low DCR Power Inductors

CST1, CST2 – High Frequency

SMT Current Sense Transformers

RoHS compliant AEC-Q flag
  • Senses current up to 20 Amps
  • Designed for up to 1 MHz and above
  • Eight different turns ratios to meet variety of requirements
  • Two pin-out configurations for different applications
  • AEC-Q200 Grade 1 (−40°C to +125°C)
  • Two samples of each value are available in Coilcraft Designer's Kit C389

Buy Now:
Count Unit price
1 $1.92
250 $1.64
500 $1.39
1000 $1.14
2500 $0.99
5000 $0.92

For high volume or non-stock items, request a quote.

. in stock, ready to ship today.
Request a Sample:
Designer's Kit:
Kit Values Price
C389 16 (2 of each) $50.00

Specifications

Electrical specifications at 25°C.

Part number 1
(Hover for schematics)
Inductance
min (µH) 2
DCR max (Ω) 3 Turns Ratio Volt-time
product (V-µs) 4
Frequency (kHz) 5 Current (A) 6 Terminating
resistance RT (Ω) 7
Isolation
Voltage (Vrms) 8
Color dot
Pri Sec Pri : Sec
CST1-020L_ 81 0.0007 0.40 1 : 20 10.8 46 >1000 20.0 1.0 500 Red
CST2-020L_ 81 0.0007 0.40 1 : 20 10.8 46 >1000 20.0 1.0 500 Red
CST1-030L_ 180 0.0007 0.87 1 : 30 16.2 31 >1000 20.0 1.5 500 Orange
CST2-030L_ 180 0.0007 0.87 1 : 30 16.2 31 >1000 20.0 1.5 500 Orange
CST1-040L_ 320 0.0007 1.1 1 : 40 21.6 23 >1000 20.0 2.0 500 Yellow
CST2-040L_ 320 0.0007 1.1 1 : 40 21.6 23 >1000 20.0 2.0 500 Yellow
CST1-050L_ 500 0.0007 1.5 1 : 50 27 19 >1000 20.0 2.5 500 Green
CST2-050L_ 500 0.0007 1.5 1 : 50 27 19 >1000 20.0 2.5 500 Green
CST1-060L_ 730 0.0007 2.0 1 : 60 32.4 15 >1000 20.0 3.0 500 Blue
CST2-060L_ 730 0.0007 2.0 1 : 60 32.4 15 >1000 20.0 3.0 500 Blue
CST1-070L_ 980 0.0007 4.8 1 : 70 37.8 13 >1000 20.0 3.5 500 Violet
CST2-070L_ 980 0.0007 4.8 1 : 70 37.8 13 >1000 20.0 3.5 500 Violet
CST1-100L_ 2000 0.0007 5.5 1 : 100 54 9 >1000 20.0 5.0 500 Gray
CST2-100L_ 2000 0.0007 5.5 1 : 100 54 9 >1000 20.0 5.0 500 Gray
CST1-125L_ 3000 0.0007 6.5 1 : 125 67.5 7 >1000 20.0 6.3 500 Black
CST2-125L_ 3000 0.0007 6.5 1 : 125 67.5 7 >1000 20.0 6.3 500 Black
Notes
  1. When ordering, please specify termination and packaging codes: e.g. CST1-125LC or CST2-125LC
  2. Inductance measured across secondary at 100 kHz, 0.1 Vrms.
  3. DCR at 25°C. For other operating temperatures, use this DCR at Temperature calculator.
  4. Volt-time product is for the secondary, between pin 6 and 4 for CST1 and between pin 1 and 3 for CST2.
  5. For specific questions regarding frequency range, please contact us at [email protected].
  6. Primary current of 20 A causes approximately 40°C temperature rise from 25°C ambient. Higher current causes a greater temperature rise. (see Temperature Rise vs Current curve).
  7. Terminating resistor value is based on 1 Volt output with 20 Amps flowing through the primary. Varying terminating resistance increases or decreases output Voltage/Ampere according to the following equation:
    RT (Ohms) = Vout × Nsec / Iin.
  8. 500 Vrms, one minute isolation (hipot) winding to winding.

Termination:

  • L = RoHS compliant tin-silver over tin over nickel over phos bronze (pins 1 – 6); RoHS compliant Matte tin over nickel over copper (pins 7 – 8).
  • S = non-RoHS tin-lead (63/37) over tin over nickel over phos bronze (pins 1 – 6); non-RoHS tin-lead over gold over nickel over copper (pins 7 – 8). (Special order, added cost)

Packaging:

  • C = 7″ machine-ready reel. EIA-481 embossed plastic tape (250 parts per full reel). Quantities less than full reel available: in tape (not machine ready) or with leader and trailer ($25 charge).
  • D = 13″ machine-ready reel. EIA-481 embossed plastic tape. Factory order only, not stocked (1000 parts per full reel).
  • B = Less than full reel. In an effort to simplify our part numbering system, Coilcraft is eliminating the need for multiple packaging codes. When ordering, simply change the last letter of your part number from B to C.
Environmental
Environmental:
RoHS compliant
Ambient temperature range:
−40°C to +125°C
Storage temperature range:
Component: −40°C to +165°C
Tape and reel packaging: −40°C to +80°C
Maximum part temperature:
+165°C (ambient + temp rise)
Failures in Time (FIT) / Mean Time Between Failures (MTBF):

Performance curves

Temperature vs. Current

Schematics

CST1 Series
cst1schematic.gif
Terminating resistor (RT)value is based on 1 Volt output with 20 Amps flowing through the primary. Varying terminating resistance increases or decreases output Voltage/Ampere according to the following equation: RT (Ohms) = Vout × Nsec / Iin.

CST2 Series
cst2schematic.gif

Terminating resistor (RT) value is based on 1 Volt output with 20 Amps flowing through the primary. Varying terminating resistance increases or decreases output Voltage/Ampere according to the following equation: RT (Ohms) = Vout × Nsec / Iin.

Physical characteristics

cstdimensions.gif

dims_inches_mm.gif

 

Pinouts

cst_pinouts.gif

Tape and Reel specification

csttapeandreel.gif

 
Parts per reel Reel dimensions (mm) Tape dimensions (mm) Orientation
7" (178 mm) 13" (330 mm) A B C D E W P Po P1 H T cstorientation.gif
250 1000* 178/330 60/100 13 22,4 16,4 16 12 4 2 5,6 0,35

General specification

Core Material:
Ferrite
Weight:
0.4 g
Packaging:
250/7″reel;1000/13″ reel; Plastic tape: 16 mm wide, 0.35 mm thick, 12 mm pocket spacing, 5.6 mm pocket depth

Soldering/Washing

Moisture Sensitivity Level (MSL):
1 (unlimited floor life at <30°C / 85% relative humidity)
Resistance to soldering heat:
Three reflows at >217°C for 90 seconds (+260°C ±5°C for 20 – 40 seconds), allowing parts to cool to room temperature between.
Refer to Soldering Coilcraft Components before soldering.
PCB Washing:
Tested to MIL-STD-202 Method 215 plus an additional aqueous wash. More info.

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