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Analog Devices Inc. LT1999CS8-20#PBF
- Part No.:
- LT1999CS8-20#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LT1999CS8-20#PBF.pdf
- Description:
- IC CURRENT SENSE 1 CIRCUIT 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:388
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Product details
Overview
LT1999CS8-20#PBF from Analog Devices is a high-voltage, bidirectional current sense amplifier with 20V/V fixed gain, –5V to 80V input common mode range, 2MHz bandwidth, and ±0.5% gain accuracy. It senses current via external shunt resistor and outputs a voltage referenced to mid-supply or external REF, enabling precise bidirectional monitoring in H-bridge motor control and battery charge/discharge systems.
For engineers reviewing the LT1999CS8-20#PBF datasheet, LT1999CS8-20#PBF pinout, LT1999CS8-20#PBF application, or LT1999CS8-20#PBF equivalent, this page delivers verified specifications, SO-8 package terminal mapping, automotive-grade AEC-Q100 qualification status, FMEA-compatible alternatives, and design-critical performance boundaries including CMRR >80dB at 100kHz and shutdown current <10µA.
Technical Context
The LT1999CS8-20#PBF employs a transconductance-based sensing architecture with matched on-chip 4kΩ input resistors and an internal 80kΩ gain-setting resistor (RG), delivering exact 20V/V gain without external components. Its dual-path biasing-using diode D1 for sub-supply common mode operation and transconductor GIN for high-side operation-ensures smooth, continuous performance across the full –5V to 80V range.
It features a dedicated REF pin that sets output common-mode level, supports external reference override, and maintains ±3mV input-referred offset over temperature. The SHDN pin enables fast 1µs turn-on/turn-off with <10µA shutdown current, while the output drives ≥200pF loads directly and provides ±31mA sourcing/sinking capability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain | 20V/V fixed - eliminates external gain-setting components and ensures ±0.5% accuracy over temperature and common mode range. |
| Common Mode Range | –5V to 80V - enables direct high-side sensing in 48V industrial systems and low-side sensing down to negative rail without level-shifting circuitry. |
| Bandwidth | 2MHz - supports accurate current measurement in PWM-controlled switching power supplies operating up to 500kHz switching frequency. |
| Input Offset Voltage | ±1.5mV max - ensures ≤75µA error in 50mΩ shunt applications at room temperature, critical for precision battery SOC estimation. |
| Supply Current | 1.55mA active / <10µA shutdown - reduces system power budget in always-on monitoring nodes and enables energy-efficient duty-cycled sensing. |
| CMRR @ 100kHz | >80dB - rejects high-frequency noise from adjacent power switches, preserving signal integrity in noisy motor drive environments. |
| Operating Temp | 0°C to 70°C - validated for commercial industrial control modules where ambient temperature remains within standard enclosure limits. |
Pinout & Package
LT1999CS8-20#PBF is housed in an 8-lead plastic SO (narrow) package (S8), RoHS-compliant, with 1.27mm lead pitch and JEDEC MS-012AC footprint. Pin 1 is marked with dot; device orientation follows standard SO-8 top view with Pin 1 at bottom-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| V+ (Pins 1, 4) | Power supply input | Internally tied pins accepting 4.5V–5.5V; dual-pin layout improves PSRR and reduces supply impedance for stable gain accuracy. |
| +IN (Pin 2) | Positive sense input | High-impedance node (≥5MΩ) connected to shunt's high-side; accepts common mode down to –5V without clamping. |
| –IN (Pin 3) | Negative sense input | Matched to +IN; differential input impedance 8kΩ ensures minimal shunt loading error in precision applications. |
| GND (Pin 5) | Analog ground reference | Return path for REF divider and output stage; must be star-connected to shunt ground to avoid measurement errors. |
| REF (Pin 6) | Output common-mode reference | Sets VOUT midpoint; open-circuit default = 2.5V (mid-supply); externally driven to shift output range for ADC interface compatibility. |
| OUT (Pin 7) | Amplified output | Low-impedance (0.15Ω) rail-to-rail capable output; drives 1kΩ loads to within 125mV of rails and sustains ±31mA sink/source. |
| SHDN (Pin 8) | Shutdown control | Active-low logic input; internal 2µA pull-up keeps device active when floating; <0.5V assertion reduces supply current to <10µA. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional current sensing | Outputs positive/negative voltage relative to REF to unambiguously indicate current direction-essential for regenerative braking and battery charging/discharging state detection. |
| FMEA-optimized pinout option | Available in MSOP-FMEA variant (e.g., LT1999IMS8-20F#PBF) with NC on Pin 3 to prevent misconnection-induced failure in safety-critical automotive subsystems. |
| High common-mode transient immunity | 0.8µs recovery from ±50V common-mode step ensures stable output during fast-switching events in IGBT/MOSFET gate drivers and inverter legs. |
| AEC-Q100 qualified | H-grade variants (e.g., LT1999HMS8-20#PBF) meet automotive stress testing requirements for under-hood motor control and ADAS power management. |
| ESD robustness | 4kV HBM / 1kV CDM tolerance protects against assembly handling damage and field electrostatic discharge in industrial equipment. |
Applications
| H-Bridge Motor Control | Solenoid Current Sense |
|---|---|
Use Scenario: Monitoring bidirectional armature current in brushed DC motor drivers for position/velocity feedback and stall detection. IC Role / Device Role / Timing Role: High-side or low-side current sense amplifier providing real-time analog output proportional to motor winding current magnitude and direction. Use Value: Enables closed-loop torque control with <1% gain error and 2MHz bandwidth to capture PWM ripple, improving dynamic response and reducing mechanical wear. | Use Scenario: Measuring solenoid coil current during actuation in automotive transmission shift control and industrial valve positioning. IC Role / Device Role / Timing Role: Precision current monitor interfacing with microcontroller ADC to verify solenoid engagement timing and detect open/short faults. Use Value: ±1.5mV offset and –5V to 80V common mode support direct connection to 24V solenoid drivers without external level-shifting, reducing BOM count and PCB area. |
| High Voltage Data Acquisition | PWM Control Loops |
Use Scenario: Digitizing current in 48V/60V bus systems for energy metering, battery management, and power quality analysis in telecom and server PSUs. IC Role / Device Role / Timing Role: Front-end analog conditioner converting shunt voltage to clean, referenced output compatible with 12-bit SAR ADCs. Use Value: >80dB CMRR at 100kHz suppresses switching noise from adjacent buck converters, enabling accurate RMS current calculation without additional filtering. | Use Scenario: Providing real-time current feedback to digital PWM controllers in synchronous buck regulators and motor phase current loops. IC Role / Device Role / Timing Role: Fast-settling (2.5µs to 0.5%) current sensor feeding control loop with minimal phase lag. Use Value: 2MHz bandwidth and 3V/µs slew rate ensure loop stability at high switching frequencies (>300kHz), preventing current overshoot and improving transient response. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar current sense amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX4080TASA+ | 20V/V gain, 0.5% gain error, but only –0.1V to 65V common mode range and no internal REF divider. | Limited to lower-voltage systems; requires external REF biasing and cannot replace LT1999CS8-20#PBF in 80V bus monitoring. | Select MAX4080TASA+ only when operating below 65V and external REF control is acceptable. |
| INA240A1DR | 20V/V gain, –4V to 80V common mode, but 400kHz bandwidth and higher 100µV offset. | Suitable for slower control loops (e.g., thermal management), but insufficient for high-frequency PWM current sampling. | Choose INA240A1DR for cost-sensitive, non-time-critical industrial monitoring where bandwidth <500kHz is acceptable. |
Compared with MAX4080TASA+ and INA240A1DR, the LT1999CS8-20#PBF uniquely combines 80V common mode, 2MHz bandwidth, and integrated mid-supply REF-making it the only option for high-speed, high-voltage bidirectional sensing in compact SO-8 form factor without external support components.
Availability
LT1999CS8-20#PBF is available at Aetrix Electronics and suitable for H-bridge motor control, solenoid actuation, and high-voltage data acquisition requiring stable component supply, long-term industrial lifecycle support, and RoHS-compliant packaging.
Supply support for LT1999CS8-20#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets with precision signal conditioning solutions.
The LT1999 product line delivers high-voltage, high-bandwidth current sensing for demanding power electronics applications-including motor drives, battery systems, and industrial automation-where accuracy, speed, and reliability across extreme common-mode conditions are essential.
FAQ
What is the maximum common mode voltage supported by the LT1999CS8-20#PBF?
The LT1999CS8-20#PBF supports a guaranteed input common mode voltage range of –5V to 80V across its full operating temperature range (0°C to 70°C). This allows direct high-side sensing in 48V and 60V industrial buses without external level-shifting circuitry. Operation beyond these limits risks ESD clamp activation or degraded accuracy.
Does the LT1999CS8-20#PBF require external resistors to set gain?
No, the LT1999CS8-20#PBF has a fixed 20V/V gain implemented using precision on-chip resistors (4kΩ input + 80kΩ RG). Unlike programmable amplifiers, it requires no external gain-setting components-reducing BOM count, layout area, and calibration drift over temperature and time.
How does the REF pin function in the LT1999CS8-20#PBF?
The REF pin in the LT1999CS8-20#PBF sets the output common-mode voltage. Internally biased to mid-supply (2.5V at 5V V+) via 160kΩ resistive divider, it can be overdriven by an external source to shift VOUT range-for example, aligning with a 3.3V ADC's input span. Its specified input range is 1.125V to (V+ – 1.125V) to maintain ±3mV offset accuracy.
Can the LT1999CS8-20#PBF be used in automotive applications?
The LT1999CS8-20#PBF itself is rated for 0°C to 70°C and is not AEC-Q100 qualified. However, pin-compatible automotive-grade variants exist-including LT1999HMS8-20#PBF (–40°C to 125°C, AEC-Q100) and LT1999HMS8-20F#WPBF (FMEA-optimized, automotive qualified). These should be selected for under-hood or safety-critical vehicle systems.
What is the typical supply current and shutdown behavior of the LT1999CS8-20#PBF?
The LT1999CS8-20#PBF draws 1.55mA typical supply current during active operation. When the SHDN pin is pulled below 0.5V, it enters ultra-low-power shutdown mode drawing <10µA. Turn-on and turn-off times are both ≤1µs, enabling rapid duty-cycled sensing to minimize average power in battery-powered applications.
LT1999CS8-20#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Amplifier Type:
- Current Sense
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 3V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 2 MHz
- Current - Input Bias:
- 137.5 µA
- Voltage - Input Offset:
- 500 µV
- Current - Supply:
- 5.8mA
- Current - Output / Channel:
- -
- Voltage - Supply Span (Min):
- 4.5 V
- Voltage - Supply Span (Max):
- 5.5 V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SO
LT1999CS8-20#PBF FAQ
1.How can I place an order for LT1999CS8-20#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1999CS8-20#PBF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LT1999CS8-20#PBF reliable?
The price and inventory of LT1999CS8-20#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1999CS8-20#PBF is usually 5 days.
3.What payment methods are accepted for LT1999CS8-20#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1999CS8-20#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1999CS8-20#PBF?
LT1999CS8-20#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1999CS8-20#PBF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LT1999CS8-20#PBF?
For technical support, including LT1999CS8-20#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1999CS8-20#PBF requirements.
6.How does Aetrix verify that LT1999CS8-20#PBF is sourced from the original manufacturer or authorized distributors?
All LT1999CS8-20#PBF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LT1999CS8-20#PBF meets industry standards.
7.What is the process for return or replacement of LT1999CS8-20#PBF?
All LT1999CS8-20#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1999CS8-20#PBF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LT1999CS8-20#PBF part is unused and in its original packaging.
Return procedure for LT1999CS8-20#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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