ACS760ELFTR-20B-T(2013) データシートの表示（PDF） - Allegro MicroSystems

部品番号

コンポーネント説明

メーカー

ACS760ELFTR-20B-T
(Rev.:2013)

12 V High-Side Hot-Swap Hall Effect Based Current Monitor IC

Allegro MicroSystems 

ACS760ELF-20B 12 V High-Side Hot-Swap Hall Effect Based Current Monitor IC

Soft Start and Fault Characteristics

Gate turn on rise time, tGR. Set by external capacitance, CG, on

the CG pin, such that CG = 7.5 × tGR , where CG is in F and tGR

is rise time in seconds. For example, a 3.9 F capacitor connected

from the CG pin to GND (without an output load) will yield a

rise time of approximately 500 ms: CG  7.5 × 0.5 s = 3.75 F,

 3.9 F (a common capacitor value).

When the CG pin is kept open, the ACS760 has a minimum tGR

of 1 ms typical.

IPF fault signal delay, tIPF. This is the delay from high current

level fault sense to the start of turn-off of the external MOSFET

S1 turn-off. Set by external capacitance, COCD, on the OCDLY

pin, such that COCD = 5.17 × trOCD ; where COCD is in F and

trOCD is rise time in seconds.

When the OCDLY pin is kept open, the IC has a minimum fault

delay, tIPFLmax, of 8 s maximum.

Load power fault signal delay, tPFL. This is the delay from

maximum power level fault, PF(th), sense to the start of external

MOSFET S1 turn-off. Set by external capacitance, COPD, on the

OPDLY pin, such that COPD = 5.17 × trOPD ; where COPD is in F

and trOPD is rise time in seconds.

The IC has a minimum fault delay when the OPDLY pin kept

open of 10 s typical.

IPF fault current setting, IPF. The IPF upper trip level may be

set by using a resistor between the ISET pin and GND, such that

RSET = 104 (0.4 + 0.065 × IPF), where IPF is in A and RSET in .

Accuracy Characteristics

Sensitivity, Sens. The change in device output in response to a

1 A change through the primary conductor. Sens is the product of

the magnetic circuit sensitivity (G/A) and the linear IC amplifier

gain (mV/G). The linear IC amplifier gain is trimmed at Allegro

final test to optimize the sensitivity (mV/A) for the full-scale cur-

rent range of the device.

Noise, VNOISE(PP). The product of the linear IC amplifier gain

(mV/G) and the noise floor for the Allegro Hall effect linear IC.

Dividing the noise (mV) by the sensitivity (mV/A) provides the

smallest current that the device is able to resolve.

Nonlinearity, ELIN. The linearity of the VIOUT signal is the

degree to which the voltage output from the device varies in

direct proportion to the primary sensed current, up to 20 A.

Nonlinearity reveals the maximum deviation in the slope of the

device transfer function compared to the slope of the ideal trans-

fer curve for this transducer. The following equation is used to

derive the linearity:

{ [ (VIOUT_full-scale amperes – VIOUT(Q))

100 1–

2 (VIOUT_half-scale amperes – VIOUT(Q))

,

where full-scale current is 20 A, and half-scale current is 10 A.

Zero Current Output Voltage, VIOUT(Q). The output of the

device when the primary current, IP, is 0 A. Variation in VIOUT(Q)

can be attributed to the resolution of the Allegro linear IC quies-

cent voltage trim and thermal drift.

VIOUT Total Error, ETOT. The maximum percentage deviation of

the actual output from its ideal value, based on an ideal sensitiv-

ity of 65.7 mV/A at 25°C and 64.3 mV/A at 85°C.

Dynamic Response Characteristics

Propagation delay, tPROP. The time required for the device

output to reflect a change in the primary current signal. Propaga-

tion delay is attributed to inductive loading within the linear IC

package, as well as in the inductive loop formed by the primary

conductor geometry. Propagation delay can be considered as a

fixed time offset and may be compensated.

I (%)

90

Primary Current

Transducer Output

0

t

Propagation Time, tPROP

Response time, tRESPONSE. The time interval between a) when

the primary current signal reaches 90% of its final value, and b)

when the device reaches 90% of its output corresponding to the

applied current.

I (%)

Primary Current

90

Transducer Output

0

t

Response Time, tRESPONSE

Rise time (tr). The time interval between a) when the device

reaches 10% of its full scale value, and b) when it reaches 90%

of its full scale value. The rise time to a step response is used to

derive the bandwidth of the device, in which ƒ(–3 dB) = 0.35 / tr.

Both tr and tRESPONSE are detrimentally affected by eddy current

losses observed in the conductive IC ground plane.

I (%)

Primary Current

90

Transducer Output

10

0

t

Rise Time, tr

Allegro MicroSystems, LLC

7

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Share Link: