My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX9918ASA+
- Part No.:
- MAX9918ASA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Datasheet:
-
MAX9918ASA+.pdf
- Description:
- IC CURRENT SENSE 1 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:377
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX9918ASA+ from Maxim Integrated is a single-supply, high-accuracy current-sense amplifier with -20V to +75V input common-mode range, adjustable gain via external resistors (30–90V/V), ±0.6% max gain error, and 400µV max input offset voltage. It supports unidirectional (VREFIN = GND) or bidirectional (VREFIN = VCC/2) operation and is used for precision motor/solenoid current monitoring in automotive H-bridge systems.
For engineers reviewing the MAX9918ASA+ datasheet, MAX9918ASA+ pinout, MAX9918ASA+ application, or MAX9918ASA+ equivalent, this device delivers AEC-Q100 qualified performance in an 8-pin SOIC-EP package with rail-to-rail output, 75kHz bandwidth, and support for high-side/low-side sensing of inductive loads under reverse-battery or inductive-kickback conditions.
Technical Context
The MAX9918ASA+ employs dual-level-shifting input architecture to maintain accuracy across its full -20V to +75V common-mode range: one stage handles +2V to +75V, another handles -20V to +2V. Its instrumentation amplifier core enables precise differential sensing with indirect feedback for external gain control via R1/R2 on FB and REFIN pins.
It operates from a single 4.5V–5.5V supply, features shutdown mode (≤10µA ICC_SHDN), and uses BiCMOS process technology. Output is rail-to-rail, referenced either to GND (unidirectional) or VCC/2 (bidirectional), with guaranteed performance over -40°C to +125°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Common-Mode Range | -20V to +75V - enables sensing during reverse-battery events and inductive kickback in automotive motor drives |
| Gain Accuracy Error | ±0.6% (max) - ensures <1% total current measurement error when combined with 1% sense resistor |
| Input Offset Voltage | ±400µV (max) - supports accurate low-current detection down to ~5mA with 50mΩ sense resistor |
| Small-Signal Bandwidth | 75kHz (-3dB) - sufficient for PWM-based motor control up to ~15kHz switching frequency |
| Supply Voltage Range | 4.5V to 5.5V - compatible with standard automotive 5V LDO rails and immune to battery transients |
| Operating Temperature | -40°C to +125°C - fully specified for under-hood automotive applications per AEC-Q100 Grade 1 |
| Shutdown Current | ≤10µA - enables power-gating in always-on vehicle subsystems without measurable quiescent drain |
Pinout & Package
Package: 8-pin SOIC with exposed pad (SO-EP), RoHS-compliant, thermal resistance θJA = 41°C/W (4-layer board).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 RS+ | Positive current-sense input | Connects to high-side of sense resistor; withstands -30V to +80V vs. GND at VCC = 5V |
| 2 RS- | Negative current-sense input | Connects to low-side of sense resistor; forms differential pair with RS+ for VSENSE measurement |
| 3 SHDN | Active-high shutdown control | Pull high (>2.0V) to disable amplifier and reduce ICC to ≤10µA; tie to GND for normal operation |
| 4 GND | Analog/digital ground reference | Primary return path; must be connected to solid ground plane; EP must also connect to same ground |
| 5 OUT | Current-sense output | Rail-to-rail voltage output proportional to VSENSE × gain; requires ≥100mV headroom from rails for full accuracy |
| 6 FB | Feedback input for gain setting | Connects to external R1/R2 divider; sets gain as G = 1 + R2/R1 (MAX9918); unused on MAX9919 |
| 7 REFIN | Bidirectional reference input | Set to GND for unidirectional output (0–VCC); set to VCC/2 for bidirectional output (VCC/2 ± ΔV) |
| 8 VCC | Positive supply input | 4.5V–5.5V single supply; bypass to GND with 0.1µF ceramic capacitor adjacent to pin |
Key Features
| Feature | Design Value |
|---|---|
| Dual-level-shifting input stage | Enables seamless operation across -20V to +75V common-mode range without external level translators |
| Adjustable gain architecture | Supports 30V/V to 90V/V via external R1/R2; minimum stable gain of 30V/V prevents instability at low settings |
| AEC-Q100 qualification | Qualified for automotive Grade 1 (-40°C to +125°C), including stress testing for humidity, temperature cycling, and ESD |
| Rail-to-rail output with 100mV margin | Ensures full gain accuracy by maintaining ≥100mV separation from VCC or GND rails under load |
| Exposed thermal pad (EP) | Reduces junction-to-ambient thermal resistance to 41°C/W; requires direct connection to large contiguous ground plane |
Applications
| Motor Control Feedback | Solenoid Actuation Monitoring |
|---|---|
Use Scenario: Real-time phase current measurement in 12V/24V automotive H-bridge motor drivers for torque regulation and fault detection. IC Role / Device Role / Timing Role: High-side or low-side current-sense amplifier converting mV-level RSENSE voltage into amplified analog signal for MCU ADC input. Use Value: Enables closed-loop current control with <1% error across -40°C to +125°C, supporting ASIL-B functional safety requirements. | Use Scenario: Monitoring coil current during energization/de-energization of 12V solenoids in transmission shift actuators or fuel injectors. IC Role / Device Role / Timing Role: Bidirectional current amplifier (VREFIN = VCC/2) capturing both pull-in and release current profiles for diagnostics. Use Value: Detects open-circuit, short-circuit, and degraded coil conditions using ±50mV full-scale sensing and 120µs 1% settling time. |
| Super-Capacitor Management | Automotive Battery Protection |
Use Scenario: Charge/discharge current monitoring in 48V mild-hybrid energy storage systems with supercapacitor banks. IC Role / Device Role / Timing Role: Precision unidirectional amplifier (VREFIN = GND) measuring bidirectional current flow via two dedicated devices per bank. Use Value: Supports accurate Coulomb counting with ±0.6% gain error and 400µV offset, enabling >99% state-of-charge estimation accuracy. | Use Scenario: High-side current sensing in battery disconnect units (BDUs) to detect overcurrent, short-circuit, and leakage faults. IC Role / Device Role / Timing Role: Low-offset, high-CMRR amplifier operating from -20V (reverse-battery) to +75V (load-dump) common-mode range. Use Value: Eliminates need for external clamping diodes by tolerating -20V inputs, reducing BOM count and PCB area. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar current-sense amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX9919FASA+ | Fixed 45V/V gain; no external resistors required; 250kHz bandwidth; ±0.45% gain error (typ) | Optimized for higher-speed PWM sensing where gain stability outweighs flexibility | Select when fixed gain suffices and faster transient response is needed over programmability |
| INA240A1QDRQ1 | TI AEC-Q100 Grade 1 device; 80V common-mode; 20V/V fixed gain; 4V/V to 500V/V variants available | Wider supply range (2.7V–5.5V); integrated EMI filtering; different pinout (SO-8, no EP) | Select when needing lower supply voltage operation or enhanced EMC robustness in noisy environments |
Compared with MAX9919FASA+, the MAX9918ASA+ trades higher bandwidth for gain adjustability and tighter offset drift; compared with INA240A1QDRQ1, it offers superior thermal performance via EP and higher CMRR at DC but lacks integrated EMI filtering.
Availability
The MAX9918ASA+ is available at Aetrix Electronics and suitable for automotive motor control, solenoid actuation, and battery protection systems requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.
Supply support for MAX9918ASA+ 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
Maxim Integrated (now part of Analog Devices) designs precision analog and mixed-signal ICs for automotive, industrial, and communications markets, emphasizing high reliability and extended temperature operation.
The MAX9918 series belongs to Maxim's high-voltage current-sense amplifier product line, engineered specifically for automotive-grade inductive load monitoring under harsh electrical conditions including reverse battery and load dump.
FAQ
What is the maximum differential input voltage the MAX9918ASA+ can handle?
The MAX9918ASA+ supports a continuous differential input voltage (VRS+ – VRS-) of ±15V. This rating allows safe operation with sense resistors up to 300mΩ at 50A full-scale current while maintaining accuracy and avoiding internal saturation or damage.
Does the MAX9918ASA+ require external components for basic operation?
Yes - the MAX9918ASA+ requires a 0.1µF bypass capacitor between VCC and GND, and external R1/R2 resistors on the FB pin to set gain. For unidirectional use, REFIN must be tied to GND; for bidirectional, REFIN must be driven by a low-impedance VCC/2 source. The exposed pad must connect to a solid ground plane.
How does the MAX9918ASA+ achieve operation down to -20V common-mode voltage?
The MAX9918ASA+ uses a dual-level-shifting input architecture: one stage handles +2V to +75V common-mode, and a second stage activates below +2V to accommodate -20V to +2V. This eliminates need for external level translators and maintains 96dB CMRR across the full range.
Can the MAX9918ASA+ be used in bidirectional current sensing without external op-amps?
Yes - the MAX9918ASA+ natively supports bidirectional sensing by applying a stable VCC/2 reference to the REFIN pin. The output then centers at VCC/2 and swings ±(G × VSENSE), enabling direct interface with single-supply ADCs without additional signal conditioning circuitry.
Is the MAX9918ASA+ pin-compatible with other devices in the MAX9918/MAX9919/MAX9920 family?
Yes - all devices in the MAX9918/MAX9919/MAX9920 family share identical 8-pin SO-EP pinout and footprint. However, FB must be left unconnected on MAX9919 variants, and REFIN voltage range differs slightly between MAX9918/MAX9919 (0V to VCC–1.9V) and MAX9920 (0V to VCC–2.4V).
MAX9918ASA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Amplifier Type:
- Current Sense
- Number of Circuits:
- 1
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 0.6V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 75 kHz
- Current - Input Bias:
- 175 µA
- Voltage - Input Offset:
- 400 µV
- Current - Supply:
- 1mA
- Current - Output / Channel:
- -
- Voltage - Supply Span (Min):
- 4.5 V
- Voltage - Supply Span (Max):
- 5.5 V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC-EP
MAX9918ASA+ FAQ
1.How can I place an order for MAX9918ASA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX9918ASA+ 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 MAX9918ASA+ reliable?
The price and inventory of MAX9918ASA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX9918ASA+ is usually 5 days.
3.What payment methods are accepted for MAX9918ASA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX9918ASA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX9918ASA+?
MAX9918ASA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX9918ASA+ 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 MAX9918ASA+?
For technical support, including MAX9918ASA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX9918ASA+ requirements.
6.How does Aetrix verify that MAX9918ASA+ is sourced from the original manufacturer or authorized distributors?
All MAX9918ASA+ 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 MAX9918ASA+ meets industry standards.
7.What is the process for return or replacement of MAX9918ASA+?
All MAX9918ASA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX9918ASA+, 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 MAX9918ASA+ part is unused and in its original packaging.
Return procedure for MAX9918ASA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX9918ASA+ Tags
-
LM358DT
STMicroelectronics
-
LM358DR
Texas Instruments
-
LM2904DR
Texas Instruments
-
LM358ADR
Texas Instruments
-
LM2904DGKR
Texas Instruments
-
LM324DR
Texas Instruments
-
MCP6006T-E/OT
Microchip Technology
-
MCP6006UT-E/OT
Microchip Technology
-
LM324PWR
Texas Instruments
-
LM2902PWR
Texas Instruments
-
LM2902DR
Texas Instruments
-
LM358P
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
