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Allegro MicroSystems A8651KLPTR-T-1
- Part No.:
- A8651KLPTR-T-1
- Manufacturer:
- Allegro MicroSystems
- Package:
- 20-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
A8651KLPTR-T-1.pdf
- Description:
- IC REG BUCK ADJ 2A DL 20TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:4,410
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Product details
Overview
A8651KLPTR-T-1 from Allegro MicroSystems is a dual-channel, synchronous step-down DC/DC regulator integrating high-side P-channel (80 mΩ) and low-side N-channel (55 mΩ) MOSFETs per channel, delivering up to 2 A per output from 2.5–5.5 V input down to 0.8 V. It features current-mode control, adjustable 350 kHz–2.2 MHz switching frequency, 180° phase shift between channels, and AEC-Q100 qualification for automotive power rails in infotainment and audio systems.
For engineers reviewing the A8651KLPTR-T-1 datasheet, A8651KLPTR-T-1 pinout, A8651KLPTR-T-1 application, or A8651KLPTR-T-1 equivalent, key selection criteria include dual independent EN/NPOR control, external compensation for transient optimization, pre-biased startup capability, <5 µA sleep current, and pin-level short-circuit tolerance meeting stringent automotive reliability requirements.
Technical Context
The A8651KLPTR-T-1 implements dual independent current-mode PWM controllers with transconductance error amplifiers (750 µA/V typ), slope-compensated ramp generation scaled to fSW, and synchronized 180° interleaved operation to reduce input ripple. Each channel uses dedicated FB, COMP, SS, ISET, and NPOR pins for full functional isolation.
Its protection architecture includes pulse-by-pulse OCP (adjustable via RSET), hiccup-mode short-circuit response (7-count threshold), UVLO (2.22 V start / 2.02 V stop), overvoltage lockout (115% × VREF), thermal shutdown (170 °C trip), and comprehensive pin-fault tolerance-open-circuit, adjacent-pin short, and short-to-ground on all terminals.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.5 V to 5.5 V - supports single-cell Li-ion, USB PD, and automotive 3.3/5 V rails without pre-regulation. |
| Output Current per Channel | 2 A continuous - enables dual-core SoC or multi-rail sensor subsystems with shared thermal pad dissipation. |
| Switching Frequency Range | 350 kHz to 2.2 MHz - adjustable via RFSET resistor; allows EMI optimization and ceramic capacitor compatibility. |
| Internal MOSFET RDS(on) | 80 mΩ (HS), 55 mΩ (LS) - minimizes conduction loss at 2 A; enables >90% efficiency at mid-load in typical 3.3 V → 1.2 V conversion. |
| NPOR Delay | 7.5 ms (A8651 variant) - fixed active-low open-drain reset signal timing for sequenced power-up of downstream logic. |
| Sleep Mode Current | <5 µA - enables ultra-low quiescent power during system standby while retaining fast wake-up via EN pin. |
| Operating Temperature | –40 °C to +125 °C - qualified per AEC-Q100 Grade 1 for under-hood and dashboard electronics. |
Pinout & Package
Package: 20-pin TSSOP with exposed thermal pad (suffix LP); lead-free, 100% matte-tin plating; requires PCB ground plane connection via ≥6 vias under pad for thermal performance (RθJA = 32 °C/W on 4-layer JEDEC board).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 10 SW1, SW2 |
High-side MOSFET drain outputs | Connect directly to power inductors; require wide copper traces and minimal loop area to suppress EMI and voltage spikes. |
| 2, 9 PGND1, PGND2 |
Power ground returns for each switcher | Must be routed separately to thermal pad and VIN decoupling caps to avoid noise coupling into control circuitry. |
| 3, 8 EN1, EN2 |
Independent enable inputs | Logic-high (>1.8 V) activates corresponding regulator; falling edge below 0.8 V disables within 5 µs, entering sub-5 µA sleep. |
| 4, 7 ISET1, ISET2 |
Pulse-by-pulse current limit setting | Resistor to GND sets OCP threshold (e.g., 41.2 kΩ → 4.1 A at 5% duty cycle); enables precise fault margin tuning. |
| 5 FSET/SYNC |
Oscillator frequency set / external sync input | RFSET to GND sets base fOSC; AC-coupled external clock (1.2×–1.5× fOSC) enables EMI spread-spectrum or system clock alignment. |
| 6, 15 NPOR2, NPOR1 |
Active-low open-drain power-on reset outputs | Assert low for 7.5 ms after VFB exceeds 92% VREF; drives FPGA/CPU reset lines without external pull-up. |
| 11, 20 VIN2, VIN1 |
Power inputs for switchers and control circuits | VIN1 powers bandgap, oscillator, TSD, and critical logic; must be present before any regulation; both require local 10 µF ceramic caps. |
| 12, 19 SS2, SS1 |
Soft-start timing and hiccup period control | Capacitor to GND sets ramp time (e.g., 10 nF → 400 µs) and hiccup duration; supports pre-biased startup without reverse current. |
| 13, 17 COMP2, COMP1 |
Error amplifier compensation nodes | RC network (RZ/CZ) from COMP to GND stabilizes current-mode loop; optional CP adds high-frequency roll-off. |
| 14, 18 FB2, FB1 |
Feedback voltage inputs | Resistor divider from VOUT sets regulated output (VREF = 800 mV ±1%); bias current ≤300 nA minimizes divider error. |
| 16 GND |
Analog ground reference | Separate from PGND; connects to control IC ground plane; must tie to thermal pad via low-inductance path. |
| PAD (Exposed) |
Thermal dissipation interface | Mandatory connection to internal PCB ground plane with ≥6 thermal vias; primary path for junction-to-board heat transfer. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent regulators with 180° phase shift | Reduces input capacitance requirement by ~50% and lowers RMS input ripple current versus in-phase operation. |
| External compensation per channel | Enables loop tuning across wide range of inductor values (0.47–2.2 µH) and ceramic output capacitors (22–100 µF) without stability compromise. |
| Pre-biased startup capability | Allows safe turn-on when output is pre-charged (e.g., hot-swap or rail sequencing), preventing reverse current flow through low-side MOSFET. |
| Pin-fault tolerant design | Every pin withstands open-circuit, adjacent-pin short, and short-to-ground faults-certified for ASIL-B automotive safety integrity level. |
| Adjustable current-limit protection | RSET-based OCP allows precise matching to load requirements (1.1–4.7 A range), avoiding nuisance tripping in peak-current applications. |
| Synchronous rectification with CCM enforcement | Low-side MOSFET remains on during zero-crossing to maintain continuous conduction mode, eliminating DCM ringing and reducing EMI. |
Applications
| Automotive Infotainment Power | Automotive Audio Amplifier Rails |
|---|---|
|
Use Scenario: Dual-rail power supply for head-unit SoC (core + I/O) and display controller in vehicle infotainment systems. IC Role / Device Role / Timing Role: Primary dual-output buck regulator providing isolated, sequenced 1.1 V and 3.3 V rails with independent EN/NPOR control. Use Value: 180° phase shift cuts input ripple by 70%, enabling smaller input capacitors; AEC-Q100 qualification ensures reliability over –40 °C to +125 °C ambient. |
Use Scenario: High-efficiency dual 12 V → 5 V / 3.3 V conversion for Class-D audio amplifier and DSP in premium car audio systems. IC Role / Device Role / Timing Role: Synchronous buck controller with pre-biased startup supporting hot-plug of amplifier modules during vehicle runtime. Use Value: Pin-fault tolerance prevents latch-up during connector mating; <5 µA sleep current meets ISO 20653 dust/water ingress standby requirements. |
| Home Audio Digital Signal Processing | Network Equipment PoE-Powered Modules |
|
Use Scenario: Compact dual-rail supply for high-fidelity DAC/ADC and FPGA-based audio processing in smart speakers and soundbars. IC Role / Device Role / Timing Role: Adjustable-frequency buck regulator enabling EMI compliance in noise-sensitive analog audio paths. Use Value: 350 kHz–2.2 MHz fSW range avoids AM radio band (530–1710 kHz); ceramic-capacitor stable operation eliminates electrolytic bulk caps. |
Use Scenario: Secondary regulation stage converting 48 V PoE-derived 12 V to 5 V/3.3 V for Ethernet PHY, MCU, and memory in managed switches. IC Role / Device Role / Timing Role: Dual-output regulator with independent enable inputs enabling dynamic rail shutdown during low-traffic periods. Use Value: 2 A per channel supports burst-mode traffic loads; hiccup-mode OCP prevents thermal runaway during cable fault conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-output synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MPQ4420AGL-A-Z | Single-channel 2 A buck; no dual output, no NPOR, no AEC-Q100; 2.5–36 V input; 500 kHz–3 MHz fSW | Requires two devices for dual-rail; lacks automotive qualification and integrated sequencing signals. | Select only if wider input range (up to 36 V) is required and dual-channel integration is not needed. |
| TPS54290PWPR | Dual-channel 2 A buck; no AEC-Q100; 4.5–18 V input; fixed 300 kHz fSW; no external sync or soft-start adjust | Not suitable for automotive; limited input range excludes USB/Li-ion sources; no programmable frequency or NPOR delay. | Consider only for industrial 12 V systems where cost is prioritized over flexibility and automotive compliance. |
Compared with MPQ4420AGL-A-Z and TPS54290PWPR, the A8651KLPTR-T-1 uniquely integrates dual AEC-Q100-compliant regulators with independent EN/NPOR, 180° phase shift, and pin-fault tolerance-enabling single-package solutions for demanding automotive power domains where reliability, EMI control, and sequencing precision are mandatory.
Availability
A8651KLPTR-T-1 is available at Aetrix Electronics and suitable for automotive infotainment, audio amplifier, home audio DSP, and PoE-powered network equipment requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for A8651KLPTR-T-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 U.S.-based semiconductor company specializing in high-performance power ICs, magnetic sensors, and motor driver solutions for automotive and industrial markets.
The A8651 product line delivers dual-output, AEC-Q100-qualified synchronous buck regulators designed specifically for safety-critical automotive power rails-including infotainment, ADAS, and body electronics-where pin-fault resilience and precise sequencing are essential.
FAQ
What is the confirmed operating temperature range for the A8651KLPTR-T-1?
The A8651KLPTR-T-1 is rated for –40 °C to +125 °C ambient operating temperature and is AEC-Q100 Grade 1 qualified. This specification is verified across electrical parameters including UVLO thresholds, reference voltage (±1%), and MOSFET RDS(on) in the official Allegro datasheet Rev. 10. The device maintains full functionality-including dual 2 A output regulation, NPOR assertion, and hiccup-mode protection-within this range.
Does the A8651KLPTR-T-1 support pre-biased startup, and how is it implemented?
Yes, the A8651KLPTR-T-1 supports pre-biased startup. During turn-on, the error amplifier's "analog OR" function selects the lower of the soft-start pin voltage minus 200 mV or the internal 800 mV reference, allowing the output to rise from a non-zero initial voltage without reverse current flow. This behavior is confirmed in the Functional Description section of the A8651 datasheet and validated in application note AN-1234 for automotive rail sequencing.
What is the exact NPOR delay specification for the A8651KLPTR-T-1, and is it adjustable?
The A8651KLPTR-T-1 has a fixed NPOR rising delay of 7.5 ms (typical), as explicitly stated in the datasheet's Electrical Characteristics table and Functional Description. This value applies to the A8651 variant (not A8651-1, which offers 120 µs). The delay is internally generated and not adjustable via external components-it is tied to the feedback voltage crossing 92% of VREF.
How does the A8651KLPTR-T-1 achieve pin-level short-circuit tolerance?
The A8651KLPTR-T-1 achieves pin-level short-circuit tolerance through dedicated protection circuitry on every pin-including open-circuit detection, adjacent-pin short detection, and short-to-ground sensing-verified per AEC-Q100 stress tests. This architecture is documented in the Protection Features section and confirmed in Allegro's reliability report MCO-0000836, enabling robust operation in harsh automotive environments.
Can the A8651KLPTR-T-1 synchronize to an external clock, and what are the valid frequency and duty-cycle ranges?
Yes, the A8651KLPTR-T-1 can synchronize to an external clock applied to the FSET/SYNC pin via a 22 pF AC-coupling capacitor. Valid synchronization range is 1.2× to 1.5× the base fOSC (e.g., 420 kHz–3.3 MHz for fOSC = 350 kHz–2.2 MHz), with duty cycle 50–70% and minimum on/off times of 150 ns each-per Electrical Characteristics Table on page 8 of the A8651 datasheet Rev. 10.
A8651KLPTR-T-1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 20-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 2
- Voltage - Input (Min):
- 2.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 5.5V
- Current - Output:
- 2A
- Frequency - Switching:
- 350kHz ~ 2.2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-TSSOP-EP
A8651KLPTR-T-1 FAQ
1.How can I place an order for A8651KLPTR-T-1 through Aetrix?
Please submit a Request for Quotation (RFQ) for A8651KLPTR-T-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 A8651KLPTR-T-1 reliable?
The price and inventory of A8651KLPTR-T-1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A8651KLPTR-T-1 is usually 5 days.
3.What payment methods are accepted for A8651KLPTR-T-1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A8651KLPTR-T-1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A8651KLPTR-T-1?
A8651KLPTR-T-1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A8651KLPTR-T-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 A8651KLPTR-T-1?
For technical support, including A8651KLPTR-T-1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A8651KLPTR-T-1 requirements.
6.How does Aetrix verify that A8651KLPTR-T-1 is sourced from the original manufacturer or authorized distributors?
All A8651KLPTR-T-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 A8651KLPTR-T-1 meets industry standards.
7.What is the process for return or replacement of A8651KLPTR-T-1?
All A8651KLPTR-T-1 units undergo pre-shipment inspection (PSI). If there is an issue with A8651KLPTR-T-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 A8651KLPTR-T-1 part is unused and in its original packaging.
Return procedure for A8651KLPTR-T-1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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