Current Transducer LAH 25-NP

For the electronic measurement of currents: DC, AC, pulsed...,with galvanic separation between the primary circuit and the secondarycircuit.

IP N = 8-12-25 A

Electrical data
IP N Primary nominal RMS current		
IP M Primary current, measuring range 1)
RM Measuring resistance @ 2)		with ±12 V@ IP N [±At DC]		
@ IP N [At RMS] 3)with ±15 V@ IP N [±At DC]		
@ IP N [At RMS] 3)		@ IP < IP N 4)
IS N Secondary nominal RMS current		
NP/NS Turns ratio			UC Supply voltage (±5 %)			
ICCurrent consumption			

25		A0 … ±55
ATA = 70 °C TA = 85 °C
RM min RM max RM min RM max
02840280 Ω01820178 Ω67 39870394 Ω67 26370259 Ω25		1-2-3 : 1000
±12 … 1510 (@ ±15 V) + ISmAV
mA

Accuracy - Dynamic performance data
εtot Total error 5) @ IP N, TA = 25 °C		±0.3		εLLinearity error			< 0.2						TypMax
IO
Offset current referred to primary @ IP = 0, TA = 25 °C		±150
IO
Offset current referred to secondary @ IP = 0, TA = 25 °C		±0.15
IO M Magnetic offset current @ IP = 0, referred to secondaryand specified RM, after an overload of 5 × IP N
±0.20 ±0.25
IO T Temperature variation of IO, referred to secondary
0 °C … +70 °C ±0.10 ±0.60			
‒25 °C … +85 °C ±0.10 ±0.70
tD 10 Delay time to 10 % of the final output value for IP N step 6) < 200		
tD 90 Delay time to 90 % of the final output value for IP N step 6) < 500		
BW Frequency bandwidth (−1 dB)		
DC … 200%%mAmAmAmAmAnsnskHzGeneral dataTA Ambient operating temperature		‒25 … +85°C
TA st Ambient storage temperature			‒40 … +90°C
RS Resistance of secondary winding @ TA = 70 °C
72		Ω@ TA = 85 °C76
ΩmMass			20gStandards			
EN 50178: 1997
Notes: 1) During 10 s, with RM ≤ 109 Ω (UC = ±15 V)
2)
Calculation of RM min with the maximum power of the transistors = 0.307 W		 @ 70 °C and the maximum power of the transistors = 0.302 W @ 85 °C
3)Sinusoidal wave 50 Hz
4)
The minimum measuring resistance RM may be lower		 (see “LAH technical information” leaflet)5)
Without IO & IO M
6)For a di/dt = 100 A/µs.

● Closed loop (compensated) multirange current transducer using
the Hall effect● Printed circuit board mounting● Insulating plastic case recognizedaccording to UL 94-V0.

Advantages● Excellent accuracy● Very good linearity● Low temperature drift● Optimized delay time
● No insertion losses● High immunity to externalinterference● Current overload capability.

Applications● AC variable speed drives andservo motor drives● Static converters for DC motordrives● Battery supplied applications● Uninterruptible Power Supplies(UPS)● Switched Mode Power Supplies(SMPS)● Power supplies for welding
applications.

Application domain● Industrial.

Page 1/3

N° 97.34.19.000.023March2023/Version 12Features

LEM reserves the right to carry out modifications on its transducers,in order to improve them.

LEM International SA
Route du Nant-d’Avril, 152
1217 Meyrinwww.lem.com

Current Transducer LAH 25-NP
Insulation coordination
UdRMS voltage for AC insulation test, 50 Hz, 1 min5		kVUNiImpulse withstand voltage 1.2/50 μs

12		kVUt

Partial discharge RMS test voltage (qm< 10 pC)			

> 2		
MinkV

dCp

Creepage distance 1)			

12		mmdCIClearance 1)			

12		mmCTI

Comparative tracking index (group IIIa)

175

Note: 1) On PCB with soldering pattern UTEC93-703.

Applications examples
According to EN 50178 and IEC 61010-1 standards and following conditions:● Over voltage category OV 3
● Pollution degree PD2● Non-uniform field
EN 50178

IEC 61010-1

Rated insulation voltage

Nominal voltage

Basic insulation

1000 V

1000 V

Reinforced insulation

500 V

500 V

dCp, dCI, UNi

SafetyThis transducer must be used in limited-energy secondary circuits according toIEC 61010-1.

This transducer must be used in electric/electronic equipment with respect toapplicable standards and safety requirements in accordance with themanufacturer’s operating instructions.

Caution, risk of electrical shock
When operating the transducer, certain parts of the module can carry hazardous
voltage (e.g. primary busbar, power supply). Ignoring this warning can lead to injury
and/or cause serious damage.
This transducer is a build-in device, whose conducting parts must be inaccessible
after installation. A protective housing or additional shield could be used.
Main supply must be able to be disconnected.

Page 2/3
23March2023/Version 12

LEM reserves the right to carry out modifications on its transducers,in order to improve them.

LEM International SA
Route du Nant-d’Avril, 152
1217 Meyrinwww.lem.com

Dimensions LAH 25-NP (in mm)

ISIP

RM
UC
UC

dCp

dCIConnection
ISIP

RM
UC
UC

Number ofprimary turns

Primary current
nominal

IP N [ A ]Primary current Nominal output
maximum
current

Turns
ratio

IP [ A ]IS N [ mA ]NP /NS55

25

1 : 1000

PrimaryresistancePrimary insertion
inductance

0.180.012

RP [ mΩ ]Recommended
PCB connections

LP [ µH ]31225122724

2 : 1000

0.81

dCpdCIOUT

4OUT

423581824

3 : 1000

1.62● General tolerance● Fastening & connection of primary
Recommended PCB hole
● Fastening & connection of secondary
Recommended PCB hole

61IN

51IN

620.110OUT

Mechanical characteristics

2IN

0.054
3314

56Remarks● IS is positive when IP flows from terminals 1, 2, 3 (IN) to±0.2 mmterminals 6, 5, 4 (OUT).
6 pins 1 mm × 0.8 mm● The jumper temperature and PCB should not exceed
1.5 mm
100 °C.
3 pins 0.7 mm × 0.6 mm● This is a standard model. For different versions (supply1.2 mmvoltages, turns ratio, unidirectional measurements...),
please contact us.

Page 3/3
23March2023/Version 12

LEM reserves the right to carry out modifications on its transducers,in order to improve them.

LEM International SA
Route du Nant-d’Avril, 152
1217 Meyrinwww.lem.com