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Allegro MicroSystems ARG81800KESJSR-1
- Part No.:
- ARG81800KESJSR-1
- Manufacturer:
- Allegro MicroSystems
- Package:
- 20-WFQFN Exposed Pad
- Datasheet:
-
ARG81800KESJSR-1.pdf
- Description:
- IC REG BUCK 0.8V 500MA 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:5,969
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Product details
Overview
ARG81800KESJSR-1 from Allegro MicroSystems is a 40 V, 500 mA synchronous buck regulator with ultralow quiescent current (8 µA in LP mode), ±1.5% output voltage accuracy over –40°C to 150°C, and programmable PWM frequency from 250 kHz to 2.4 MHz. It integrates SYNCIN/CLKOUT for EMI-reducing dithering and interleaving, supports pre-bias startup, and delivers robust protection including hiccup-mode OCP, thermal shutdown, and BOOT fault detection - deployed in automotive infotainment and ADAS power rails.
For engineers reviewing the ARG81800KESJSR-1 datasheet, ARG81800KESJSR-1 pinout, ARG81800KESJSR-1 application, or ARG81800KESJSR-1 equivalent, key selection criteria include its 500 mA rated output, wettable-flank 20-pin QFN package, 3.5–36 V input range with 40 V surge tolerance, adjustable soft-start, external compensation flexibility, and AEC-Q100 qualification for automotive systems.
Technical Context
The ARG81800KESJSR-1 implements current-mode PWM control with slope compensation and dual operating modes: forced PWM (via PWM/AUTO pin high) and AUTO mode enabling seamless transition to Low-Power (LP) mode at light loads. Its transconductance error amplifier (750 µA/V typ.) interfaces with external RC compensation on COMP to balance stability and transient response across wide fSW ranges.
It features integrated synchronization logic: SYNCIN accepts external clocks (0.25–2.5 MHz) to force synchronized PWM operation with dithering; CLKOUT provides phase-shifted, dithered clock output for downstream regulator interleaving. Frequency foldback during dropout extends duty cycle while maintaining regulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 500 mA continuous - optimized for compact PCB area in low-current automotive subsystems |
| Input Voltage Range | 3.5 V to 36 V - withstands 40 V load-dump surges per AEC-Q100, enabling direct battery connection |
| Quiescent Current | 8 µA in LP mode - enables "keepalive" supply operation with minimal battery drain during vehicle sleep |
| Output Accuracy | ±1.5% over –40°C to 150°C - ensures stable microcontroller or sensor rail under full automotive temperature range |
| Switching Frequency | 250 kHz to 2.4 MHz (programmable via FSET resistor) - balances efficiency, inductor size, and EMI performance |
| Protection Features | Pulse-by-pulse OCP, hiccup-mode short-circuit, BOOT open/short, UVLO, OVP, TSD - reduces need for external fault management circuitry |
| Package | 20-pin wettable flank QFN (4 mm × 4 mm) - supports automated optical inspection (AOI) and improves solder joint reliability |
Pinout & Package
ARG81800KESJSR-1 is housed in a 20-pin, 4 mm × 4 mm QFN package with exposed thermal pad (suffix "ES") and wettable flanks for enhanced solderability and thermal dissipation. The exposed pad must be connected to PCB ground plane via ≥6 vias.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 BOOT | High-side gate driver supply | Connects 100 nF ceramic capacitor to SW; no series resistor allowed - critical for reliable high-side MOSFET turn-on |
| 2,3 SW | Power switch node | Direct connection point to power inductor; requires short, wide PCB trace to minimize switching loop inductance and EMI |
| 4 SS | Soft-start timing control | Capacitor to GND sets startup ramp time and hiccup period - prevents inrush current into large output capacitors |
| 5 EN | Enable/shutdown control | Logic-high enables regulation; logic-low forces 1 µA shutdown with VOUT = 0 V - supports system-level power sequencing |
| 6 CLKOUT | Dithered master clock output | Provides phase-shifted, dithered clock for synchronizing downstream regulators - reduces input ripple and improves EMI signature |
| 7 SYNCIN | External clock input / mode select | High = internal fSW with 180° phase shift; low = CLKOUT disabled; external clock = forced sync + dither - enables multi-regulator coordination |
| 8 GND | Analog ground reference | Separate from PGND - must be star-connected to minimize noise coupling into feedback and error amplifier circuits |
| 9 FSET | Frequency programming | Resistor to GND sets fSW (e.g., 14.3 kΩ → 2.15 MHz); enables precise EMC tuning without component changes |
| 10 PWM/AUTO | Operating mode control | High = forced PWM; low = automatic PWM↔LP transition based on load - eliminates manual mode switching in dynamic systems |
| 11 COMP | Error amplifier output / compensation node | External RC network tunes loop dynamics - supports optimization for fast transient response or high phase margin |
| 12 PGOOD | Open-drain power-good indicator | Asserts after tdPG(SU) = 30 µs once VOUT reaches regulation - enables safe processor reset or downstream enable sequencing |
| 13 BIAS | Internal bias supply input | Connected to VOUT - powers internal circuitry when output is active, improving efficiency vs. VIN-derived bias |
| 14 FB | Feedback voltage sense | Resistor divider from VOUT sets output; 800 mV reference enables 3.3 V, 5.0 V, or custom voltages with ±1.5% accuracy |
| 15 VREG | Internal LDO bypass | 4.7 µF ceramic capacitor required - stabilizes internal 4.8 V regulator powering gate drivers and logic |
| 16,17 PGND | Power ground return | Low-impedance path for low-side MOSFET, BOOT charge circuit, and SW node - must be solid copper pour tied to exposed pad |
| 18 NC | No connection | Unbonded pin - must remain unconnected and unstubbed to avoid parasitic coupling |
| 19,20 VIN | Main power input | Bypassed to PGND with X7R/X8R ceramic capacitor - primary input for high-side MOSFET drain and control circuitry |
Key Features
| Feature | Design Value |
|---|---|
| Ultralow IQ LP mode | 8 µA input current at no load maintains 3.3 V or 5.0 V output - extends battery life in always-on automotive modules |
| Programmable fSW with dithering | 250 kHz–2.4 MHz range + ±5% frequency dither on CLKOUT - spreads spectral energy to meet CISPR 25 Class 5 EMI limits |
| Interleavable CLKOUT | Phase-shifted, dithered clock output enables synchronized switching of multiple downstream regulators - cuts input capacitor requirements by up to 50% |
| Pre-bias startup | Regulator starts cleanly even when output is pre-charged - avoids reverse current or system reset during hot-plug or brownout recovery |
| Robust fault coverage | Detects BOOT open/short, SW-to-GND short, pulse-by-pulse OCP, and thermal runaway - meets ASIL-B functional safety readiness |
| External compensation | COMP pin allows full loop tuning - accommodates diverse output capacitors (ceramic, polymer, hybrid) and load step profiles |
Applications
| Infotainment Power Rail | ADAS Camera Module Supply |
|---|---|
|
Use Scenario: Powers SoC, display interface, and audio codec in head-unit systems requiring low-noise, always-on 3.3 V or 5.0 V rails. IC Role / Device Role / Timing Role: Primary DC-DC converter delivering regulated output with <30 µs PGOOD assertion for safe SoC boot sequencing. Use Value: 8 µA LP mode minimizes overnight battery drain; SYNCIN/CLKOUT coordination reduces EMI in dense RF environments near cellular/WiFi antennas. |
Use Scenario: Supplies image sensor and ISP in forward-facing camera modules where thermal stress and vibration are severe. IC Role / Device Role / Timing Role: High-reliability buck regulator with AEC-Q100 Grade 0 rating and 150°C junction capability. Use Value: 40 V surge tolerance handles load dump; soft recovery from dropout prevents frame loss during engine cranking transients. |
| Instrument Cluster Display Backlight | Automotive Telematics Control Unit |
|
Use Scenario: Drives LED backlight strings in digital instrument clusters with dimming control via analog/PWM input. IC Role / Device Role / Timing Role: Constant-voltage source with adjustable soft-start to limit inrush into large output capacitance and EMI filters. Use Value: Programmable fSW allows optimization for lowest audible noise (<20 kHz) or best efficiency at partial load - critical for driver comfort. |
Use Scenario: Provides core 1.2 V and I/O 3.3 V supplies for LTE/C-V2X modems and GNSS receivers in telematics units. IC Role / Device Role / Timing Role: Synchronized regulator in multi-rail power tree, using CLKOUT to phase-align switching with other converters. Use Value: Interleaved operation reduces input ripple amplitude by √N, easing compliance with strict conducted emissions limits in cellular bands. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPQ4420AGL-A-Z | 3.3–36 V input, 2 A output, fixed 500 kHz fSW, no SYNCIN/CLKOUT, 17 µA IQ | Lacks dithering, interleaving, and AEC-Q100 qualification - suitable for non-automotive industrial use only | Select when higher output current is needed and EMI coordination is not required; requires layout redesign due to different pinout and package (12-pin QFN) |
| TPS54560QDGQRQ1 | 3.5–60 V input, 5 A output, 100–2500 kHz fSW, no LP mode, 14 µA IQ, AEC-Q100 | Higher current, wider VIN, but no ultralow-IQ LP mode or CLKOUT - cannot support keepalive operation | Choose for high-power ADAS ECUs needing >500 mA; not viable for battery-sensitive always-on functions like CAN wake-up receivers |
Compared with MPQ4420AGL-A-Z and TPS54560QDGQRQ1, the ARG81800KESJSR-1 uniquely combines AEC-Q100 qualification, 8 µA LP mode, and CLKOUT-based interleaving - making it the only option for space-constrained, EMI-sensitive automotive modules requiring both ultra-low standby power and coordinated multi-regulator timing.
Availability
ARG81800KESJSR-1 is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, and instrument cluster power supplies requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.
Supply support for ARG81800KESJSR-1 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
Allegro MicroSystems is a global leader in precision sensing and power ICs, specializing in magnetic sensors, motor drivers, and high-reliability power management solutions for automotive and industrial markets.
The ARG81800 product line was designed specifically for automotive power rails demanding ultralow quiescent current, robust fault protection, and EMI-aware synchronization - targeting infotainment, ADAS, and body electronics systems.
FAQ
What is the maximum input voltage the ARG81800KESJSR-1 can withstand during load dump events?
The ARG81800KESJSR-1 withstands 40 V surge voltages for load dump conditions, as specified in its absolute maximum ratings and validated per AEC-Q100 stress testing. This allows direct connection to automotive 12 V battery rails without external TVS clamping in most architectures. Its input voltage operating range remains 3.5 V to 36 V under normal conditions, with UVLO thresholds set at 3.55 V (turn-on) and 3.3 V (turn-off).
How does the ARG81800KESJSR-1 achieve 8 µA quiescent current in Low-Power mode?
The ARG81800KESJSR-1 achieves 8 µA quiescent current in Low-Power (LP) mode by dynamically disabling switching, entering burst-mode operation, and powering down non-essential circuitry while maintaining regulation via a dedicated low-power error amplifier path. This mode draws just 8 µA from VIN while sustaining 3.3 V or 5.0 V output - confirmed in electrical characteristics tables under ILP(3.3V) and ILP(5.0V) test conditions at TJ = 25°C.
Can the ARG81800KESJSR-1 synchronize to an external clock, and what is the supported frequency range?
Yes, the ARG81800KESJSR-1 supports external synchronization via its SYNCIN pin, accepting clock inputs from 0.25 MHz to 2.5 MHz. When driven by an external clock, it forces PWM mode, locks its switching frequency to the incoming signal, adds ±5% dithering, and outputs the dithered clock on CLKOUT with 180° phase shift - enabling precise timing coordination across multi-regulator power trees.
What protection features are integrated into the ARG81800KESJSR-1?
The ARG81800KESJSR-1 integrates pulse-by-pulse current limiting, hiccup-mode short-circuit protection, BOOT open/short detection, VIN undervoltage lockout (UVLO), VOUT overvoltage protection (OVP), thermal shutdown (TSD), and SW pin fault monitoring. These protections are documented in the Functional Description section and Electrical Characteristics table, with thresholds such as TTSD = 170°C (rising) and VFB(OV) = 880 mV ensuring robust fault coverage without external components.
Is the ARG81800KESJSR-1 pin-compatible with the 1 A version ARG81800KESJSR?
No, the ARG81800KESJSR-1 is not pin-compatible with the 1 A ARG81800KESJSR. While both share identical pin count, package outline, and pin functions, their internal power stages differ: ARG81800KESJSR-1 has gmPOWER2 = 1.0 A/V and lower current-limit thresholds (e.g., ILIMHS2 = 1.0 A typ.), whereas the 1 A variant uses gmPOWER1 = 2.0 A/V and ILIMHS1 = 2.0 A typ. Layout reuse is possible, but compensation and inductor selection must be re-validated for the 500 mA version.
ARG81800KESJSR-1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 20-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.5V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- -
- Current - Output:
- 500mA
- Frequency - Switching:
- 250kHz ~ 2.4MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 20-QFN (4x4)
ARG81800KESJSR-1 FAQ
1.How can I place an order for ARG81800KESJSR-1 through Aetrix?
Please submit a Request for Quotation (RFQ) for ARG81800KESJSR-1 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 ARG81800KESJSR-1 reliable?
The price and inventory of ARG81800KESJSR-1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ARG81800KESJSR-1 is usually 5 days.
3.What payment methods are accepted for ARG81800KESJSR-1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ARG81800KESJSR-1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ARG81800KESJSR-1?
ARG81800KESJSR-1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ARG81800KESJSR-1 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 ARG81800KESJSR-1?
For technical support, including ARG81800KESJSR-1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ARG81800KESJSR-1 requirements.
6.How does Aetrix verify that ARG81800KESJSR-1 is sourced from the original manufacturer or authorized distributors?
All ARG81800KESJSR-1 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 ARG81800KESJSR-1 meets industry standards.
7.What is the process for return or replacement of ARG81800KESJSR-1?
All ARG81800KESJSR-1 units undergo pre-shipment inspection (PSI). If there is an issue with ARG81800KESJSR-1, 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 ARG81800KESJSR-1 part is unused and in its original packaging.
Return procedure for ARG81800KESJSR-1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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