Specifications subject to change without notice.
Please check our website for latest information.
US
UK
Taiwan
China
Singapore
+1-847-639-6400 sales@coilcraft.com
+44-1236-730595 sales@coilcraft-europe.com
+886-2-2264 3646 sales@coilcraft.com.tw
+86-21-6218 8074 sales@coilcraft.com.cn
+ 65-6484 8412 sales@coilcraft.com.sg
© Coilcraft Inc. 2017
This product may not be used in medical or high
risk applications without prior Coilcraft appr
oval.
Specification subject to change without notice.
Please check web site for latest information.
Current Sense Transformers CST1, CST2
Document 385-1
Document 385-1 Revised 04/22/17
Turns DCR (Ohms) Frequency Volt-time Sensed Terminating
Part number1 (N) Inductance2 Pri Sec range product3 current Iin4 resistance RT5 Color
CST1 CST2 pri : sec min (µH) ref max (kHz) (V-µsec) max (A) (Ohms) dot
CST1-020L_ CST2-020L_ 1 : 20 81 0.0007 0.400 46 – 1000 10.8 20 1.0 Red
CST1-030L_ CST2-030L_ 1 : 30 180 0.0007 0.870 31 – 1000 16.2 20 1.5 Orange
CST1-040L_ CST2-040L_ 1 : 40 320 0.0007 1.14 23 – 1000 21.6 20 2.0 Yellow
CST1-050L_ CST2-050L_ 1 : 50 500 0.0007 1.50 19 – 1000 27.0 20 2.5 Green
CST1-060L_ CST2-060L_ 1 : 60 730 0.0007 1.98 15 – 1000 32.4 20 3.0 Blue
CST1-070L_ CST2-070L_ 1 : 70 980 0.0007 4.75 13 – 1000 37.8 20 3.5 Violet
CST1-100L_ CST2-100L_ 1 : 100 2000 0.0007 5.50 9 – 1000 54.0 20 5.0 Gray
CST1-125L_ CST2-125L_ 1 : 125 3000 0.0007 6.50 7 – 1000 67.5 20 6.3 Black
1. When ordering, please specify termination and packaging codes:
CSTX-125LC
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)
Special order: 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).
Packaging: C = 7″ machine-ready reel. EIA-481 embossed plastic
tape (250 parts per full reel).
B = Less than full reel. In tape, but not machine ready.
To have a leader and trailer added ($25 charge), use
code letter C instead.
D = 13″ machine-ready reel. EIA-481 embossed plastic
tape (1000 parts per full reel).
2. Inductance measured between secondary pins at 100 kHz, 0.1 Vrms.
3. Maximum volt-time product for the secondary, based on 2000 gauss.
4. Primary current of 20 A causes approximately 35°C temperature rise
from 25°C ambient. Higher current causes a greater temperature rise
(see Temperature Rise vs Current curve).
5. Terminating resistance (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 fol-
lowing equation: RT (Ohms) = Vout × Nsec / Iin.
6. Electrical specifications at 25°C.
Refer to Doc 362 “Soldering Surface Mount Components” before soldering.
Designer’s Kit C389 contains 2 each of each part
Core material Ferrite
Terminations See Note 1.
Weight 0.4 g
Ambient temperature –40°C to +125°C
Maximum part temperature 165°C (ambient + temp rise)
Storage temperature Component: –40°C to +165°C.
Tape and reel packaging: –40°C to +80°C
Resistance to soldering heat Max three 40 second reflows at
+260°C, parts cooled to room temperature between cycles
Moisture Sensitivity Level (MSL) 1 (unlimited floor life at <30°C /
85% relative humidity)
Failures in Time (FIT) / Mean Time Between Failures (MTBF)
38 per billion hours / 26,315,789 hours, calculated per Telcordia SR-332
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
PCB washing Tested to MIL-STD-202 Method 215 plus an additional
aqueous wash. See Doc787_PCB_Washing.pdf.
• For use up to 1 MHz
• AEC-Q200 Grade 1 qualified (–40°C to +125°C ambient)
• Two pinouts to meet the requirements of different applications.
• Low primary DC resistance
• 500 Vrms, one minute isolation (hipot) between windings.
Typical Circuits
CST1
CST2
8
Sec
(N turns)
Pri
(1 turn)
7
6+
4–
Vout
Iin RT
Iout
1
3
8
Sec
(N turns)
Pri
(1 turn)
7
Vout
Iin
+
–
RT
Iout
US
UK
Taiwan
China
Singapore
+1-847-639-6400 sales@coilcraft.com
+44-1236-730595 sales@coilcraft-europe.com
+886-2-2264 3646 sales@coilcraft.com.tw
+86-21-6218 8074 sales@coilcraft.com.cn
+ 65-6484 8412 sales@coilcraft.com.sg
© Coilcraft Inc. 2017
This product may not be used in medical or high
risk applications without prior Coilcraft appr
oval.
Specification subject to change without notice.
Please check web site for latest information.
CST Series Current Sense Transformers
Dimensions
Document 385-2
Document 385-2 Revised 04/22/17
Temperature Rise vs Current Pinouts
0.079 ±0.008
2,0 ±0,2
0.073 ±0.008
1,85 ±0,2
0.023 ±0.008
0,6 ±0,2
0.320
8,13
Color dot by
pin 1indicates
partnumber
max
0.004 / 0,10
0.047
1,2
0.118
3,0
0.051
1,3
0.051
1,3
0.063
1,6
0.098
2,5
0.106
2,7 0.073
1,85
Recommended Land Pattern
0.315
8,0
0.235
5,97 max max
0.245
6,22
0.209
5,3
max
max
40
35
30
25
20
15
10
0
5
Temperature rise (from 25°C)
Current (A rms)
420861210 16 1814 20
8
7
34
16
7
8
34
1
6
CST1
Bottom View Bottom View
CST2
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Coilcraft:
CST2-030LC CST2-125LB CST2-070LB CST1-125LC CST1-070LB CST2-040LC CST1-060LB CST2-040LB
CST2-020LB CST1-020LC CST1-050LC CST1-030LB CST1-040LC CST1-040LB CST1-100LC CST2-070LC
CST2-060LB CST1-100LB CST2-100LB CST2-050LC CST1-030LC CST1-050LB CST2-060LC CST2-125LC
CST1-060LC CST1-020LB CST1-070LC CST2-030LB CST2-020LC CST2-050LB CST2-100LC CST1-125LB
