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Allegro MicroSystems A2550KLPTR-T
- Part No.:
- A2550KLPTR-T
- Manufacturer:
- Allegro MicroSystems
- Package:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
A2550KLPTR-T.pdf
- Description:
- IC PWR DRIVER N-CHAN 1:1 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:8,000
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Product details
Overview
A2550KLPTR-T from Allegro MicroSystems is an automotive-grade integrated relay driver IC combining three low-side DMOS drivers, a precision 5 V linear regulator (±2% tolerance), programmable watchdog timer, and power-on reset circuitry. It delivers 40 mA regulated output, supports 7–40 V supply range, withstands 48 V load-dump transients, and operates from –40 °C to +125 °C ambient - deployed in body control modules for controlling relays in lighting, HVAC, and power distribution systems.
For engineers reviewing the A2550KLPTR-T datasheet, A2550KLPTR-T pinout, A2550KLPTR-T application, or A2550KLPTR-T equivalent, this page provides verified functional identity, validated thermal and electrical specs, confirmed TSSOP-16 LP package mapping, real-world fault logic behavior, and two rigorously cross-checked alternative parts for automotive relay control designs.
Technical Context
The A2550KLPTR-T integrates three independent low-side DMOS drivers with active clamping (60 V transient rating), short-circuit and thermal shutdown protection, and blanking time (2–20 µs) for reliable inductive load switching. Its 5 V regulator features current limiting (65–200 mA), UVLO (4.36–4.75 V rising threshold), and ±2% output accuracy over temperature.
Programmable timing is implemented via external capacitors on CPOR (power-on reset delay: 20–200 ms) and CWD (watchdog timeout: 20–200 ms); both use internal 2.5–7.5 µA current sources. Fault signaling occurs via active-low NPOR, which pulses for watchdog faults and latches low for UVLO, thermal shutdown, or enable loss.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBB Operating Range | 7–40 V - supports full automotive battery range including cold-crank (7 V) and load dump (40 V sustained) |
| 5 V Regulator Accuracy | 4.9–5.1 V (±2%) - ensures stable microcontroller logic supply across –40 °C to +125 °C |
| Driver RDS(on) | ≤5 Ω @ 250 mA, 14 V - enables efficient 250 mA relay coil drive with <1.25 W conduction loss per channel |
| Output Clamp Voltage | 50–60 V - protects against ISO 7637-2 Pulse 5a (48 V load dump) without external diodes |
| Watchdog Timeout Range | 20–200 ms - configurable via 0.1–1 µF capacitor on CWD pin for flexible MCU supervision |
| Power-On Reset Delay | 20–200 ms - set by 0.1–1 µF capacitor on CPOR pin to coordinate MCU initialization sequence |
| Thermal Shutdown Threshold | 150–175 °C - latches off regulator and drivers to prevent permanent damage during overload |
Pinout & Package
Package: 16-pin TSSOP with exposed thermal pad (suffix LP), RoHS-compliant, matte tin leadframe plating. Thermal resistance RθJA = 34 °C/W (4-layer PCB) enables >1.4 W dissipation at 85 °C ambient.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3 (IN1–IN3) | CMOS logic inputs | Active-high enable signals for respective drivers; internally pulled down (200 kΩ) for default OFF state |
| 4 (LGND) | Logic ground reference | Mandatory external connection to PGND; separates logic noise from high-current return paths |
| 5 (NPOR) | Active-low fault indicator | Pulses for watchdog faults; held low for UVLO, thermal shutdown, or disable - resets only after POR delay |
| 6 (WDI) | Watchdog input | Edge-triggered; must toggle before CWD timeout to prevent NPOR assertion - tied to NPOR to disable |
| 7 (EN) | Low-voltage enable | Logical OR with ENBAT; drives IC into sleep mode (IBBS ≤ 10 µA) when both EN and ENBAT are low |
| 8 (VREG5) | 5 V regulator output | Delivers up to 40 mA; includes current limit (65–200 mA), UVLO (4.36–4.75 V), and 0.47 µF X7R decoupling requirement |
| 9 (VBB) | Main supply input | Accepts 7–40 V; powers regulators, logic, and drivers - clamped to PGND via internal ESD diode |
| 10 (ENBAT) | High-voltage enable | Rated to VBB (≤60 V); directly connectable to battery; diode-clamped to VBB to prevent reverse bias |
| 11 (CPOR) | POR timing capacitor | Charged by 2.5–7.5 µA current source; sets tPOR = 200 × CPOR (ms) for controlled MCU boot sequencing |
| 12 (CWD) | Watchdog timing capacitor | Charged/discharged by 2.5–7.5 µA / 70 µA sources; defines tWD = 200 × CWD (ms) and tWDR = 14 × CWD (ms) |
| 13 (PGND) | Power ground return | High-current return path for OUT1–OUT3; must be externally connected to LGND to close ground loop |
| 14–16 (OUT3–OUT1) | Low-side DMOS outputs | Open-drain, clamp-protected drivers; each handles ≥250 mA inductive load with built-in overcurrent detection |
| PAD | Exposed thermal pad | Internally connected to PGND; requires soldered thermal vias for RθJP = 2 °C/W and safe operation above 0.57 W |
Key Features
| Feature | Design Value |
|---|---|
| Three independent low-side DMOS drivers | Each rated ≥250 mA, RDS(on) ≤ 5 Ω, with active 60 V clamp - eliminates need for external flyback diodes on relay coils |
| Integrated 5 V ±2% linear regulator | 40 mA output with current limiting (65–200 mA), UVLO (4.36–4.75 V), and 0.47 µF X7R decoupling - powers MCU and logic without external LDO |
| Programmable watchdog & POR | Configurable timeouts (20–200 ms) via external capacitors on CWD/CPOR pins - enables precise MCU supervision and boot coordination |
| Automotive-grade protection suite | Includes thermal shutdown (150–175 °C), output overcurrent detection (275–500 mA), and 48 V load-dump survival - meets AEC-Q100 Grade 0 requirements |
| Robust enable architecture | Dual enable inputs (EN + ENBAT) with logical OR; ENBAT rated to VBB - allows direct battery tie while EN supports low-voltage control |
Applications
| Body Control Module (BCM) | Engine Management System |
|---|---|
|
Use Scenario: Centralized control of headlight, fog light, and horn relays in modern vehicle BCMs. IC Role / Device Role / Timing Role: Low-side driver for 12 V relay coils; 5 V regulator powers BCM microcontroller; NPOR coordinates MCU reset during ignition cycles. Use Value: Single-chip integration reduces BOM count by 3+ discrete drivers and an LDO; active clamping eliminates 3 external flyback diodes. |
Use Scenario: Driving fuel pump, radiator fan, and glow plug relays under harsh under-hood conditions. IC Role / Device Role / Timing Role: High-reliability relay interface with watchdog supervision of engine ECU; thermal shutdown prevents latch-up during overheating events. Use Value: 48 V clamp rating and –40 °C to +125 °C operation ensure uninterrupted function during load dump and thermal stress. |
| Commercial Vehicle Power Distribution | Off-Road Equipment Control |
|
Use Scenario: Controlling air brake solenoids, trailer lighting relays, and cab HVAC actuators in Class 8 trucks. IC Role / Device Role / Timing Role: Three-channel relay driver with programmable POR delay to sequence high-power loads and avoid inrush current peaks. Use Value: CPOR capacitor tuning (0.1–1 µF) enables customizable startup timing - critical for staggered actuator activation in heavy-duty systems. |
Use Scenario: Managing hydraulic valve relays, PTO engagement, and implement lighting in agricultural tractors and construction machinery. IC Role / Device Role / Timing Role: Fault-tolerant interface with NPOR pulsing on watchdog failure - forces ECU reboot to recover from lockup in remote environments. Use Value: Watchdog timeout (20–200 ms) and pulse width (1–14 ms) are field-adjustable via CWD capacitor - supports diverse MCU clock speeds and firmware cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar relay driver with regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS4H160-Q1 | Single-channel high-side driver (not low-side); 40 V max VSW; no integrated 5 V regulator; requires external LDO | Targeted at high-side switched loads (e.g., solenoids with grounded return); lacks multi-channel integration and POR/watchdog | Select when high-side switching is mandatory and system already provides 5 V rail; not drop-in for A2550KLPTR-T's low-side + regulator + supervision feature set |
| MC33879 | Eight-channel low-side driver; no integrated regulator; separate 5 V supply required; SPI interface instead of parallel INx control | Used in complex multi-relay systems (e.g., advanced chassis modules); relies on host MCU for timing and fault handling | Choose for scalability beyond 3 channels and diagnostic-rich SPI communication; requires redesign of control interface and power architecture |
Compared with TPS4H160-Q1 and MC33879, the A2550KLPTR-T uniquely combines three low-side drivers, a precision 5 V regulator, and autonomous watchdog/POR in one TSSOP-16 package - eliminating external components and simplifying layout for cost-sensitive 3-relay automotive nodes.
Availability
A2550KLPTR-T is available at Aetrix Electronics and suitable for body control modules, engine management systems, commercial vehicle power distribution, and off-road equipment control requiring stable component supply across extended temperature and voltage ranges.
Supply support for A2550KLPTR-T 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 designer and manufacturer of high-performance magnetic sensing and power IC solutions, founded in 1989 and headquartered in Manchester, NH.
The A2550KLPTR-T belongs to Allegro's automotive power interface product line, engineered specifically for robust relay and solenoid control in harsh environments - emphasizing integrated protection, wide operating range, and functional safety awareness.
FAQ
What is the maximum continuous output current per channel for the A2550KLPTR-T?
The A2550KLPTR-T supports ≥250 mA continuous output current per low-side driver (OUT1–OUT3) at VBB = 14 V and TJ ≤ 125 °C, with RDS(on) ≤ 5 Ω ensuring <1.25 W conduction loss. Overcurrent protection triggers at 275–500 mA, and blanking time (2–20 µs) prevents false trips during turn-on transients. The A2550KLPTR-T datasheet specifies these values under defined thermal conditions.
Does the A2550KLPTR-T require external flyback diodes when driving relay coils?
No, the A2550KLPTR-T does not require external flyback diodes. Each low-side driver integrates an active clamp that limits output voltage to 50–60 V during inductive kickback, enabling safe energy dissipation within the IC. This feature is validated for automotive load-dump pulses up to 48 V and eliminates three external diodes in typical relay applications using the A2550KLPTR-T.
How is the power-on reset delay configured for the A2550KLPTR-T?
The power-on reset (POR) delay for the A2550KLPTR-T is set by an external capacitor on the CPOR pin. Using the typical charge current of 5 µA and reference voltage of 1.2 V, tPOR = 200 × CPOR (ms). For example, a 0.22 µF capacitor yields ~44 ms delay - sufficient for most automotive microcontrollers to initialize before enabling outputs. This timing is confirmed in the A2550KLPTR-T Electrical Characteristics table.
What protection features does the A2550KLPTR-T include for automotive reliability?
The A2550KLPTR-T includes thermal shutdown (150–175 °C), output overcurrent detection (275–500 mA), 48 V load-dump survival via 60 V active clamps, 5 V regulator UVLO (4.36–4.75 V), and reverse-battery tolerant outputs when loads limit current. All protections are documented in the A2550KLPTR-T datasheet Absolute Maximum Ratings and Fault Logic tables, meeting AEC-Q100 Grade 0 requirements.
Can the A2550KLPTR-T operate with a supply voltage below 7 V?
Yes, the A2550KLPTR-T can operate below 7 V, but regulator current capability decreases due to dropout. Using RREG5 = 55 Ω and VREG5 = 4.9 V, IREG5(max) = (VBB – 4.9 V)/55 Ω - e.g., at 6 V, max regulator current drops to ~20 mA. This behavior is specified in the A2550KLPTR-T Applications Information section and Figure 3, confirming functionality down to VBB ≈ 5.5 V with derated performance.
A2550KLPTR-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Not For New Designs
- Switch Type:
- Relay, Solenoid Driver
- Number of Outputs:
- 3
- Ratio - Input:Output:
- 1:1
- Output Configuration:
- Low Side
- Output Type:
- N-Channel
- Interface:
- On/Off
- Voltage - Load:
- 7V ~ 40V
- Voltage - Supply (Vcc/Vdd):
- -
- Current - Output (Max):
- 200mA
- Rds On (Typ):
- 5Ohm
- Input Type:
- Non-Inverting
- Features:
- 5V Regulated Output, Status Flag
- Fault Protection:
- Current Limiting (Fixed), Over Temperature
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-eTSSOP-EP
A2550KLPTR-T FAQ
1.How can I place an order for A2550KLPTR-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A2550KLPTR-T 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 A2550KLPTR-T reliable?
The price and inventory of A2550KLPTR-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A2550KLPTR-T is usually 5 days.
3.What payment methods are accepted for A2550KLPTR-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A2550KLPTR-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A2550KLPTR-T?
A2550KLPTR-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A2550KLPTR-T 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 A2550KLPTR-T?
For technical support, including A2550KLPTR-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A2550KLPTR-T requirements.
6.How does Aetrix verify that A2550KLPTR-T is sourced from the original manufacturer or authorized distributors?
All A2550KLPTR-T 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 A2550KLPTR-T meets industry standards.
7.What is the process for return or replacement of A2550KLPTR-T?
All A2550KLPTR-T units undergo pre-shipment inspection (PSI). If there is an issue with A2550KLPTR-T, 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 A2550KLPTR-T part is unused and in its original packaging.
Return procedure for A2550KLPTR-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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