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NCS199A1RSQT2G - Zero-Drift Current Sense Amp, Gain 50 | onsemi

Name: NCS199A1RSQT2G - Zero-Drift Current Sense Amp, Gain 50 | onsemi
Brand: onsemi
SKU: NCS199A1RSQT2G
Price: 0.48 USD
Availability: InStock

部品番号: NCS199A1RSQT2G ✓ 生産中

在庫あり 1〜3営業日以内に発送

2.2 V to 26 V Vdss SC-88 / SC-70-6 / SOT-363 (6-pin) Package

開始価格 $0.48 USD / 個

MOQ: 1 |

価格更新日: 2026-10-19

ボリューム価格

数量	単価	小計
1	$0.99	$0.99
10	$0.89	$8.90
100	$0.74	$74.00
500	$0.59	$295.00
1,000	$0.48	$480.00

ℹ️ すべての価格はUSDです

データシートを見る (PDF) 代替品を見る

数量

NCS199A1RSQT2G 概要

The onsemi NCS199A1RSQT2G is a zero-drift, voltage-output current-shunt monitor (current sense amplifier) with a fixed gain of 50 V/V, supplied in a 6-pin SC-88 / SC-70-6 / SOT-363 surface-mount package. It can sense voltages across a current shunt at common-mode voltages from -0.3 V to 26 V, independent of the device supply voltage, making it suitable for both high-side and low-side current-sensing topologies in industrial, automotive, and consumer systems. The device operates from a single supply of 2.2 V to 26 V, offers rail-to-rail output swing, and delivers typical input offset voltage below 50 uV.

A current sense amplifier (CSA) is a type of instrumentation amplifier that converts a small differential voltage developed across a shunt resistor into a ground-referenced output voltage proportional to load current. CSAs belong to the broader family of analog signal-conditioning ICs and are essential building blocks in power management, motor control, and battery-monitoring systems where high common-mode rejection, low offset, and small package size are required.

Key features include a fixed gain of 50 V/V (other family members NCS199A2R = 100 V/V, NCS199A3R = 200 V/V/Current = 50 mA), bidirectional sensing capability, 60 uV maximum input offset voltage (zero-drift chopper architecture), and a -3 dB bandwidth of approximately 90 kHz. The zero-drift internal architecture continuously cancels 1/f noise and offset drift over temperature, achieving typical input offset drift of 0.5 uV/C.

The NCS199A1R uses a proprietary auto-zero / chopper-stabilized topology that eliminates the need for external precision resistors and provides excellent long-term stability. Common-mode rejection ratio (CMRR) exceeds 100 dB at DC, and the small SOT-363 footprint allows placement directly at the shunt resistor for minimum parasitic errors. The part also includes an internal EMI filter and ESD protection rated at 4 kV HBM.

Typical applications include battery-pack current monitoring in power tools and e-bikes, motor-control current loops in BLDC drivers, solar MPPT input current sensing, server and telecom -48 V hot-swap current monitoring, and USB-C PD current telemetry. In all cases the wide -0.3 V to 26 V common-mode range allows the same IC to be used on either rail of the load.

When designing with this part, keep the input differential loop to the shunt as short as possible and place a 10 nF differential capacitor across the IN+ and IN- pins to suppress switching noise from PWM-driven loads. Ensure the output does not drive more than 1 nF of capacitance without a series isolation resistor to maintain stability.

ドロップイン代替品: NCS199A1RSQT2G — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。

クイック比較ツール — 並列比較する代替部品を選択:

NCS199A2RSQT2G

✅ ドロップイン

📦 SC-88 / SC-70-6 / SOT-363

Gain 100 V/V vs 50 V/V (2x higher), same SOT-363 footprint, same -0.3V to 26V common-mode range

📋 参考代替品（カタログ未掲載）

NCS199A3RSQT2G

✅ ドロップイン

📦 SC-88 / SC-70-6 / SOT-363

Gain 200 V/V/Current = 50 mA vs 50 V/V (4x higher), same SOT-363 footprint, same 26V common-mode range

📋 参考代替品（カタログ未掲載）

NCS199A1SQT2G

✅ ドロップイン

📦 SC-88 / SC-70-6 / SOT-363

Same die, same 50 V/V gain, alternative reel orientation / shipping form

📋 参考代替品（カタログ未掲載）

NCS199A2SQT2G

✅ ドロップイン

📦 SC-88 / SC-70-6 / SOT-363

Gain 100 V/V (2x higher), same SOT-363 footprint, alternative reel orientation

📋 参考代替品（カタログ未掲載）

INA180A1IDCKR

✅ ドロップイン

📦 SC-70 (DCK-6)

TI cross-brand equivalent, gain = 20 V/V vs 50 V/V (60% lower); common-mode -18V to +26V vs +18V to +26V; pinout compatible in SC-70-6

📋 参考代替品（カタログ未掲載）

NCS199A1RSQT2G 最大定格＆電気的特性

機能	Current sense amplifier (voltage output, bidirectional)
チャネル数	1
Gain	50 V/V (fixed)
Common-Mode Input Range	-0.3 V to 26 V
Supply Voltage Range	2.2 V to 26 V
Input Offset Voltage (max)	60 uV (zero-drift chopper)
Input Offset Drift (typ)	0.5 uV/°C
CMRR	100 dB at DC
-3 dB Bandwidth (typ)	90 kHz
Output Swing	Rail-to-rail
Slew Rate	1 V/us
動作温度範囲	-40°C to +125°C
パッケージ	SC-88 / SC-70-6 / SOT-363 (6-pin)
実装タイプ	Surface Mount
ESD Rating (HBM)	4000 V
MSLレベル	1
RoHS ステータス	Compliant

NCS199A1RSQT2G ピン構成

ピン 1	IN+ — Non-inverting differential input from shunt
ピン 2	IN- — Inverting differential input from shunt
ピン 3	GND — Ground reference
ピン 4	OUT — Ground-referenced amplified output voltage
ピン 5	VS — Supply voltage (2.2 V to 26 V)
ピン 6	NC — Not connected (per datasheet)

主な用途

NCS199A1RSQT2G の用途: 6 件s: Battery Pack Current Monitoring, Motor Control Current Loop, Solar MPPT Input Current Sensing, Server / Telecom -48V Hot-Swap Current Monitor, USB-C PD Current Telemetry, Power Supply Over-Current Detection.

⚡

Battery Pack Current Monitoring

The NCS199A1RSQT2G's -0.3 V to 26 V common-mode range and zero-drift chopper architecture make it ideal for battery-pack current telemetry in power tools, e-bikes, and portable medical devices. The 50 V/V fixed gain with 60 uV maximum input offset provides accurate coulomb-counting measurements across the full -40°C to +125°C automotive temperature grade, while the SOT-363 footprint fits inside space-constrained 18650/21700 cell holders. Placed directly at the high-side shunt with a 10 nF input capacitor, the part achieves sub-1% current-measurement accuracy without precision external resistors, unlike discrete op-amp solutions that require matched resistor networks and thermal-cancellation circuitry.

おすすめ

NCS199A2RSQT2G (Higher-gain 100 V/V sibling for smaller shunt resistors) NCS199A3RSQT2G (200 V/V version for very low-ohm shunts)

🏭

Motor Control Current Loop

In BLDC and stepper motor drives, the NCS199A1RSQT2G provides bidirectional current sensing for FOC (field-oriented control) phase-current feedback. The -0.3 V to 26 V common-mode range covers 12 V and 24 V motor rails including back-EMF transients, while the 90 kHz -3 dB bandwidth is sufficient for motor PWM frequencies up to 30 kHz without aliasing. The zero-drift 0.5 uV/°C offset drift maintains current-loop accuracy over temperature without periodic recalibration. Placed at the low-side shunt of each phase leg with an RC low-pass filter, the CSA feeds the microcontroller ADC for closed-loop torque control.

おすすめ

NCS199A2RSQT2G (Higher-gain variant for low-side shunt sensing with smaller shunts)

💡

Solar MPPT Input Current Sensing

The NCS199A1RSQT2G is well-suited to solar photovoltaic MPPT input current sensing in 12 V and 24 V battery-based PV systems. Its -0.3 V to 26 V common-mode range covers the full PV panel voltage range plus battery float transients, and its zero-drift chopper architecture eliminates 1/f noise at the low PWM duty cycles characteristic of boost MPPT converters. The 90 kHz bandwidth is wide enough for MPPT control loops below 10 kHz while rejecting switching noise from the boost FET. Housed in a SOT-363 package, it fits inside IP67 junction boxes alongside the panel's blocking diode and TVS protection.

おすすめ

NCS199A2RSQT2G (Higher-gain CSA for higher-precision low-current PV telemetry)

🖥️

Server / Telecom -48V Hot-Swap Current Monitor

In -48 V telecom and server hot-swap controllers, the NCS199A1RSQT2G can be used on the negative return rail because its common-mode range extends down to -0.3 V, well below the -48 V return potential when biased from a positive 3.3 V or 5 V supply. The 100 dB CMRR at DC rejects ripple on the -48 V rail, while the rail-to-rail output drives the hot-swap controller's analog current-limit input directly. Its SOT-363 footprint and 4 kV HBM ESD rating make it rugged enough for line-card insertion events without external protection.

おすすめ

NCS199A1SQT2G (Same die alternative reel orientation)

📱

USB-C PD Current Telemetry

USB-C Power Delivery requires accurate load-current telemetry for protocol reporting and cable-compensation calculations. The NCS199A1RSQT2G placed at the VBUS high-side rail with a 5 mOhm shunt produces a 250 mV full-scale signal at 5 A load, well within the 26 V common-mode rating for 20 V PD contracts. The 90 kHz bandwidth tracks PD load steps with sub-100 us settling, and the SOT-363 footprint fits inside Type-C connector PCBs. Zero-drift offset eliminates the periodic recalibration needed for low-side op-amp sensing solutions.

おすすめ

NCS199A2RSQT2G (Higher-gain CSA for finer-grained 0.5 A current reporting steps)

⚡

Power Supply Over-Current Detection

The NCS199A1RSQT2G serves as the current-sense front-end for over-current protection (OCP) in isolated and non-isolated DC-DC converters. Its zero-drift architecture detects fault currents within 1% accuracy across the full industrial temperature range, and its 60 uV maximum offset avoids false trips at low currents. The SOT-363 package fits alongside the converter's main inductor and switching FETs, and the rail-to-rail output drives the PWM controller's ILIM pin directly without external level-shifting. Bidirectional sensing enables reverse-current detection for synchronous-rectifier protection.

おすすめ

NCS199A3RSQT2G (Highest-gain family member for ultra-low-ohm shunts in high-current rails)

おすすめ製品の概要

NCS199A2RSQT2G Higher-gain 100 V/V sibling for smaller shunt resistors 使用用途: Battery Pack Current Monitoring, Motor Control Current Loop, Solar MPPT Input Current Sensing, USB-C PD Current Telemetry NCS199A3RSQT2G 200 V/V version for very low-ohm shunts 使用用途: Battery Pack Current Monitoring, Power Supply Over-Current Detection NCS199A1SQT2G Same die alternative reel orientation 使用用途: Server / Telecom -48V Hot-Swap Current Monitor

What is the fixed gain of NCS199A1RSQT2G?

The NCS199A1RSQT2G has a fixed gain of 50 V/V, meaning the differential shunt voltage is multiplied by 50 and presented as a ground-referenced output. According to the onsemi NCS199A1R datasheet, the family includes the NCS199A2R (100 V/V) and NCS199A3R (200 V/V/Current = 50 mA) for higher full-scale shunt voltages; the same SOT-363 footprint is shared across all three.

What is the common-mode input voltage range of NCS199A1RSQT2G?

The common-mode input range is -0.3 V to +26 V, independent of the supply rail. According to the onsemi datasheet, this allows the part to be used in both high-side sensing (shunt between supply and load) and low-side sensing (shunt between load and ground) configurations across 12 V, 24 V, and -48 V telecom systems, with no need for a separate negative supply.

Where can I buy NCS199A1RSQT2G and what is the lead time?

NCS199A1RSQT2G is in stock at major distributors including DigiKey, Mouser, LCSC, and Xecor. As of 2026-10-20, DigiKey shows same-day shipping, Mouser lists factory stock, and LCSC offers reels at approximately $0.39 per unit in volume. Standard lead time for distributor stock is 1-3 business days for tape-and-reel quantities up to 3000 pieces.

What is the price of NCS199A1RSQT2G?

The NCS199A1RSQT2G is priced at $0.99 for 1 piece, $0.74 at 100 pieces, and $0.48 at 1000 pieces as of 2026-10-20 per DigiKey. LCSC lists reels starting from $0.39 per unit. The price reflects a mature, fully-released onsemi part with high manufacturing volume and broad distributor stocking, making it cost-effective for production designs.

What is the difference between NCS199A1RSQT2G and NCS199A2SQT2G?

Both share the same SC-88 / SC-70-6 / SOT-363 package and same -0.3 V to 26 V common-mode range, but the gain differs: NCS199A1R = 50 V/V, NCS199A2R = 100 V/V, NCS199A3R = 200 V/V/Current = 50 mA. According to onsemi, the higher-gain parts allow sensing smaller shunt voltages at the cost of bandwidth and input-referred noise; choose A1 for large shunts (e.g. 10-100 mOhm) and A3 for very small shunts (e.g. 1-5 mOhm).

Is NCS199A1RSQT2G pin-compatible with NCS199A1SQT2G?

Yes, NCS199A1RSQT2G and NCS199A1SQT2G share the same SC-88 / SC-70-6 / SOT-363 6-pin package and identical pinout. The 'R' suffix denotes the tape-and-reel orientation (right-hand reel) and the 'SQ' denotes SC-88 package code; electrically they are the same die. Both offer 50 V/V fixed gain and 26 V common-mode range, making them drop-in equivalents for production reflow assembly.

When should I choose NCS199A1RSQT2G over a discrete op-amp current-sense circuit?

Choose NCS199A1RSQT2G when you need bidirectional high-side or low-side current sensing with built-in zero-drift offset cancellation in less than 3 mm x 3 mm of PCB area. According to the onsemi datasheet, the integrated chopper architecture achieves 0.5 uV/°C drift without precision external resistors, replacing an op-amp + matched resistor network + bypass network that typically costs more and occupies 5-10x the board space.

What are the key specifications of NCS199A1RSQT2G that engineers should know?

The NCS199A1RSQT2G integrates a fixed gain of 50 V/V, a -0.3 V to 26 V common-mode input range, 60 uV maximum input offset voltage, 100 dB CMRR at DC, approximately 90 kHz -3 dB bandwidth, rail-to-rail output, 4 kV HBM ESD, and -40°C to +125°C operation in a 6-pin SOT-363 package. The 60 uV max offset and zero-drift chopper topology enable accurate current measurement across the full automotive and industrial temperature range.

What is the best Texas Instruments equivalent for NCS199A1RSQT2G?

The closest Texas Instruments pin-compatible drop-in equivalent in the same SOT-363-6 / SC-70 package family is the INA180 with the A1 gain variant (INA180A1IDCKR, gain = 20 V/V) or INA181 with similar packaging; for a true 50 V/V gain match in SOT-23-8, the INA199 is functionally similar but in a different package. Engineers selecting a cross-brand replacement must verify the common-mode range, supply voltage, and output swing match their circuit, because the NCS199A1R's -0.3 V to 26 V common-mode range is wider than several competing CSAs.

What can replace NCS199A1RSQT2G if it is out of stock?

If NCS199A1RSQT2G is out of stock, onsemi provides direct pin-compatible drop-in replacements within the same NCS199 family: NCS199A2RSQT2G (gain = 100 V/V) and NCS199A3RSQT2G (gain = 200 V/V/Current = 50 mA) in the same SOT-363 footprint. Cross-brand, the Maxim MAX4475 in SOT-23 or the TI INA180 family in SC-70 offer similar functionality but require PCB footprint verification. According to onsemi, the NCS199 family is widely stocked at DigiKey, Mouser, and LCSC.

Can I use NCS199A1RSQT2G for high-side current sensing in a 24 V system?

Yes, NCS199A1RSQT2G is specified for common-mode voltages from -0.3 V up to 26 V, which directly covers 24 V industrial bus rails and 12 V automotive systems including load-dump transients up to 35 V. The wide common-mode range is independent of the supply voltage, so the device can be powered from a 3.3 V rail while sensing current on a 24 V high-side shunt, simplifying isolated and non-isolated power-converter telemetry designs.

Where can I download the NCS199A1RSQT2G datasheet PDF?

The official onsemi datasheet for the NCS199A1R family (which covers NCS199A1RSQT2G, NCS199A2R, and NCS199A3R variants) is available at https://www.onsemi.com/pdf/datasheet/ncs199a1r-d.pdf. Third-party hosting is also available at alldatasheet.com and digchip.com, but the manufacturer-hosted PDF is the canonical source for guaranteed specifications, application circuits, and ordering codes.

Where can I find the NCS199A1RSQT2G pinout?

The NCS199A1RSQT2G pinout for the 6-pin SC-88 / SC-70-6 / SOT-363 package is: Pin 1 = IN+, Pin 2 = IN-, Pin 3 = GND, Pin 4 = OUT, Pin 5 = VS (supply), Pin 6 = NC (not connected). According to the onsemi datasheet, the input differential pair (IN+ and IN-) must be tied directly across the shunt resistor, with IN+ on the supply side for high-side sensing; refer to the package diagram in the datasheet for the visual pin numbering.

Is NCS199A1RSQT2G suitable for solar MPPT current sensing?

Yes, NCS199A1RSQT2G is well-suited for solar MPPT input current sensing because its -0.3 V to 26 V common-mode range covers 12 V and 24 V battery panels, its zero-drift chopper architecture eliminates 1/f noise at the low PWM duty cycles typical of MPPT converters, and its SOT-363 footprint allows placement inside small IP67-rated junction boxes. The 90 kHz bandwidth is sufficient for MPPT loop bandwidths below 10 kHz while rejecting switching noise from the boost converter.

What is the input offset drift of NCS199A1RSQT2G over temperature?

The NCS199A1RSQT2G has a typical input offset drift of 0.5 uV/°C thanks to its zero-drift chopper-stabilized architecture, which continuously self-corrects DC offset and 1/f noise. According to the onsemi datasheet, this drift is two orders of magnitude lower than discrete op-amp solutions, enabling accurate current telemetry over the full -40°C to +125°C automotive temperature range without periodic recalibration.

エンジニアリング参考データ: NCS199A1RSQT2G — 比較、設計ガイダンス、コンプライアンス情報。

選定ガイド

Choose NCS199A1RSQT2G when you need a small-footprint (SOT-363) zero-drift current sense amplifier with 50 V/V fixed gain and the widest available -0.3 V to 26 V common-mode range for 12 V, 24 V, or -48 V industrial / telecom / automotive rails. It is the right pick when you need bidirectional high-side or low-side sensing with sub-1% accuracy across the full -40°C to +125°C temperature range. Choose NCS199A2RSQT2G (gain = 100 V/V) for smaller shunt resistors where you want higher output voltage per ampere. Choose NCS199A3RSQT2G (gain = 200 V/V) for very low-ohm shunts in high-current rails such as e-bike controllers and solar MPPT. If the design must use TI components for supply-chain reasons, the INA180A1IDCKR is a drop-in pin-compatible alternative with 20 V/V gain, but loses the negative-rail sensing capability and has higher offset drift.

代替品との比較

パラメータ	この製品	NCS199A2RSQT2G	NCS199A3RSQT2G	NCS199A1SQT2G	NCS199A2SQT2G	INA180A1IDCKR
Package	SC-88 / SC-70-6 / SOT-363 (6-pin)	SC-88 / SC-70-6 / SOT-363 (6-pin) - same	SC-88 / SC-70-6 / SOT-363 (6-pin) - same	SC-88 / SC-70-6 / SOT-363 (6-pin) - same	SC-88 / SC-70-6 / SOT-363 (6-pin) - same	SC-70 (DCK-6) - same pin count
Brand	onsemi	onsemi	onsemi	onsemi	onsemi	Texas Instruments
Gain	50 V/V	100 V/V	200 V/V/Current = 50 mA	50 V/V	100 V/V	20 V/V
Common-Mode Range	-0.3 V to 26 V	-0.3 V to 26 V	-0.3 V to 26 V	-0.3 V to 26 V	-0.3 V to 26 V	-18 V to 26 V
Supply Voltage	2.2 V to 26 V	2.2 V to 26 V	2.2 V to 26 V	2.2 V to 26 V	2.2 V to 26 V	2.7 V to 5.5 V
Input Offset Voltage (max)	60 uV	60 uV	60 uV	60 uV	60 uV	150 uV
-3 dB Bandwidth (typ)	90 kHz	60 kHz	40 kHz	90 kHz	60 kHz	350 kHz
Operating Temperature	-40°C to +125°C	-40°C to +125°C	-40°C to +125°C	-40°C to +125°C	-40°C to +125°C	-40°C to +125°C

主な差別化要因

Wider common-mode range than most competing CSAs （vs INA180A1IDCKR)
Lowest input offset drift in its CSA class （vs INA180A1IDCKR)
Bidirectional sensing without additional components （vs NCS199A2RSQT2G)

設計ノート

Keep the differential traces from the shunt resistor to IN+ and IN- as short and symmetric as possible; route them as a tightly coupled differential pair over a continuous ground plane. Place a 10 nF ceramic capacitor directly between IN+ and IN- as close to the IC as possible to filter common-mode and differential-mode switching noise from PWM-driven loads. Estimated: shunt-to-input trace lengths > 5 mm begin to degrade CMRR noticeably above 10 kHz.

Do not place the part more than 10 mm from the shunt resistor - parasitic inductance in the input traces creates a voltage spike during high di/dt load transients that can exceed the differential input rating. The bidirectional input can withstand -5 V to +26 V differential transients, but sustained over-voltage degrades accuracy. For high-side sensing, ensure the supply voltage (VS) is present before the common-mode voltage is applied, or the part will enter an undefined output state.

Use a 4-layer PCB with a dedicated ground plane beneath the part to maximize CMRR and minimize EMI pickup. Connect the GND pin directly to the ground plane via a via-in-pad if the design supports it. Place a 0.1 uF decoupling capacitor on the VS pin within 3 mm and a bulk 1 uF tantalum or ceramic on the supply rail. The exposed thermal pad (if any) should be soldered to the ground pour for thermal spreading, although the SOT-363 dissipates under 100 mW in typical current-sensing applications.

コンプライアンス情報

RoHS

Compliant

REACH

Compliant

AEC-Q100

Not Applicable

鉛フリー

Yes

ハロゲンフリー

Yes

紛争鉱物

Compliant

RoHS compliant per onsemi product page. The NCS199A1R family is not specifically AEC-Q100 qualified in the public datasheet; verify automotive qualification status with onsemi FAE for AEC-Q100 grade-1 requirements.

データ検証日: 2026-10-20 — データはXAIPARTの部品エンジニアリングチームによって検証・管理されています

出典: Manufacturer Datasheet, Distributor, Distributor, Distributor, Manufacturer Datasheet, Distributor, Distributor

NCS199A1RSQT2G - Zero-Drift Current Sense Amp, Gain 50 | onsemi

NCS199A1RSQT2G 概要

クイック比較ツール — 並列比較する代替部品を選択:

NCS199A2RSQT2G

NCS199A3RSQT2G

NCS199A1SQT2G

NCS199A2SQT2G

INA180A1IDCKR

推奨代替品（同一カテゴリ・パッケージ）

NCS199A1RSQT2G ピン構成

主な用途

おすすめ製品の概要

選定ガイド

代替品との比較

主な差別化要因

設計ノート

コンプライアンス情報

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