My Inquiry
My Account
STMicroelectronics L9781TR
- Part No.:
- L9781TR
- Manufacturer:
- STMicroelectronics
- Package:
- 64-LQFP
- Datasheet:
-
L9781TR.pdf
- Description:
- IC PWR DRVR N-CH 1:32 64LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:3,829
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
L9781TR from STMicroelectronics is an AEC-Q100 qualified automotive multi-valve pre-driver IC for diesel and gasoline direct injection systems. It integrates one DC/DC step-up controller (up to 80 V VTank), two independent bank controllers (A and B) for inductive load driving, and one dedicated fuel pump peak-and-hold controller - all supporting up to 11 external N-channel logic-level MOSFETs. Key confirmed parameters: 32-bit SPI interface (8 MHz max), programmable peak current thresholds via on-chip DACs, differential current sensing with programmable gain, and hardware-based short-circuit protection per channel.
For engineers reviewing the L9781TR datasheet, L9781TR pinout, L9781TR application in direct fuel injection, or L9781TR equivalent for high-side/low-side pre-driving in automotive powertrain systems, this page delivers verified functional architecture, validated pin roles, real-world load control behavior, and precise alternative selection guidance based on documented bank configuration and fault management capabilities.
Technical Context
The L9781TR implements three independent pre-driver control domains: a DC/DC converter controller for VTank generation (with push-pull N-MOSFET pre-driver, current sense block, and VTank voltage comparator); dual bank controllers (Bank A & B), each with VTank/VBat high-side and dual low-side N-MOSFET pre-drivers, differential amplifiers, DAC-set peak current thresholds, and HW protection FSMs; plus a dedicated fuel pump controller with identical signal chain structure.
All current sensing paths use differential amplifiers with programmable gain and analog inputs referenced to dedicated RSP/RSN pins. Load actuation is managed by internal configurable Finite State Machines triggered via CMD_A/CMD_B/CMD_C digital inputs, enabling microcontroller offload of timing-critical peak-and-hold sequencing while retaining full diagnostic visibility through IRQ and SPI-read registers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | VCCD: 4.5–5.5 V; VCCI: 3.3 V or 5 V; VTANK up to 80 V - enables direct integration with 12 V/24 V automotive battery and boosted injector rail |
| SPI Interface Speed | Up to 8 MHz - supports real-time parameter update and diagnosis readback without CPU bottleneck in fast-cycling injection events |
| Current Sensing Architecture | Differential amplifier with programmable gain per bank + fuel pump - allows accurate peak current detection across varying shunt resistor values and temperature drift |
| Peak Current Threshold Setting | 8-bit DAC per channel - provides 256-step resolution for fine-tuned actuation current limits in multi-injector configurations |
| Protection Coverage | Hardware-based short-circuit detection per output channel with automatic shutdown and IRQ assertion - eliminates software latency in fault response |
| Operating Temperature | −40 °C to +150 °C ambient - meets under-hood requirements for gasoline/diesel direct injection ECUs |
| AEC-Q100 Grade | Grade 0 (−40 °C to +150 °C) - qualified for safety-critical powertrain applications with zero defects at qualification stress levels |
Pinout & Package
L9781TR is housed in a 64-pin LQFP package (10 × 10 mm, 0.5 mm pitch), RoHS-compliant and ECOPACK® certified, with exposed thermal pad for enhanced power dissipation in high-duty-cycle valve driving.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GHSB_A / GHSB_B | Vbat high-side N-MOSFET pre-driver output | Push-pull driver stage for Vbat-referenced high-side switches in Bank A/B - enables direct drive of logic-level N-MOSFETs without external level shifters |
| GHST_A / GHST_B | VTank high-side N-MOSFET pre-driver output | Push-pull driver stage referenced to VTank rail - supports high-voltage injector switching with precise timing and shoot-through prevention |
| GLS_Ax / GLS_Ay / GLS_Bx / GLS_By / GLS_P | Low-side N-MOSFET pre-driver output | Push-pull outputs for low-side injector/fuel pump MOSFETs - each independently controllable via FSM and protected against overcurrent |
| RSP_A / RSN_A / RSP_B / RSN_B / RSP_P / RSN_P | Differential current sense inputs | High-impedance analog inputs for shunt-based current measurement - paired per bank and fuel pump to enable real-time peak detection and closed-loop hold current regulation |
| DAOUT_A / DAOUT_B / DAOUT_P | Analog current feedback outputs | Buffered, scaled representations of sensed current per bank/fuel pump - used for external monitoring or redundant MCU validation |
| CS / SCK / DIN / DOUT | 4-wire SPI interface | Full-duplex serial interface with chip select - supports daisy-chaining, register read/write, and diagnostic status polling at up to 8 MHz |
| IRQ | Open-drain interrupt output | Asserts on hardware fault (short circuit, overtemperature, undervoltage) - enables immediate system-level response without polling overhead |
| ENB | Global pre-driver enable input | Asynchronous active-low enable controlling all pre-driver stages - used for safe power-up sequencing and emergency shutdown |
Key Features
| Feature | Design Value |
|---|---|
| Configurable FSM-based peak-and-hold control | Eliminates MCU timing burden by autonomously executing injector actuation sequences (peak duration, hold level, decay) upon CMD input assertion |
| Per-channel hardware short-circuit protection | Detects external MOSFET short within <1 µs and disables affected output while asserting IRQ - no firmware dependency for critical fault response |
| Programmable DAC-set current thresholds | 8-bit resolution per channel enables precise adaptation to injector coil variance, aging, and temperature drift without recalibration |
| Differential current sensing with gain control | Reduces noise susceptibility and improves accuracy vs. single-ended sensing - essential for reliable current limiting in noisy engine compartments |
| VTank DC/DC controller integration | On-chip push-pull pre-driver and voltage comparator simplify boost converter design for 60–80 V injector rails - reduces external component count by ≥4 |
Applications
| Gasoline Direct Injection (GDI) | Heavy-Duty Diesel Common Rail |
|---|---|
|
Use Scenario: High-pressure fuel injection in turbocharged gasoline engines requiring precise multi-pulse injection events per combustion cycle. IC Role / Device Role / Timing Role: Pre-driver for up to 4 injectors per bank with independent peak-and-hold control, VTank rail generation, and real-time current feedback. Use Value: Enables sub-millisecond pulse width resolution and adaptive current profiling to meet Euro 6d particulate number limits and transient torque response targets. |
Use Scenario: Multi-injector control in commercial vehicle diesel engines with dual-bank cylinder layouts and high VTank requirements (>70 V). IC Role / Device Role / Timing Role: Dual-bank pre-driver with synchronized CMD_A/CMD_B triggering and shared VTANK generation for compact ECU packaging. Use Value: Reduces PCB area by consolidating two independent pre-driver ICs into one LQFP64 device while maintaining channel-level diagnostics and fault isolation. |
| Fuel Pump Control Module | Engine Control Unit (ECU) Safety Subsystem |
|
Use Scenario: High-current brushless DC fuel pump actuation in 48 V mild-hybrid architectures with variable flow demand. IC Role / Device Role / Timing Role: Dedicated peak-and-hold controller (CMD_C path) with independent current sensing, DAC threshold, and HW protection for fuel pump MOSFETs. Use Value: Guarantees consistent pump start-up torque and smooth speed ramping across battery voltage sag (down to 6 V) using regulated VTANK and adaptive current profiling. |
Use Scenario: Fault-tolerant injector driver supervision in ASIL-B compliant ECUs requiring dual-channel redundancy and hardware-enforced safe states. IC Role / Device Role / Timing Role: Primary pre-driver with IRQ-linked fault reporting, ENB-controlled fail-safe disable, and SPI-accessible diagnostic registers for ISO 26262 FMEDA compliance. Use Value: Provides measurable FIT rate reduction via integrated hardware protection - eliminates need for external watchdog or current monitor ICs in safety-critical paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multi-valve pre-driving applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPIC2603DQPWRQ1 | Single-bank 6-channel pre-driver with fixed 12 V gate drive; no VTank generation or DAC-based current threshold | Supports only low-voltage (≤20 V) injector rails; requires external boost converter and separate current sense ICs | Select when cost-sensitive designs use 12 V injectors and can accept reduced integration and diagnostic depth |
| MC33816AEKR2 | 8-channel pre-driver with integrated VTank controller but no dedicated fuel pump controller or per-bank DACs | Lacks independent CMD_C path and fuel pump-specific protection FSM - requires MCU-managed pump timing | Select when fuel pump control is handled externally and bank-level current threshold tuning is not required |
Compared with TPIC2603DQPWRQ1 and MC33816AEKR2, the L9781TR uniquely combines triple-domain control (DC/DC + dual bank + fuel pump), per-channel DAC-set current limits, and hardware FSMs - delivering highest integration for ASIL-B-compliant GDI and diesel ECU platforms needing minimal external components and deterministic fault response.
Availability
L9781TR is available at Aetrix Electronics and suitable for gasoline direct injection, heavy-duty diesel common rail, and 48 V fuel pump control modules requiring stable component supply, long-term automotive lifecycle support, and traceable sourcing.
Supply support for L9781TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.
The L9781TR belongs to ST's Automotive Powertrain Pre-Driver IC product line, engineered specifically for high-reliability, high-precision control of solenoid and piezo injectors in modern internal combustion engines - emphasizing hardware-based safety, thermal robustness, and SPI-configurable flexibility.
FAQ
What is the maximum VTank voltage supported by the L9781TR DC/DC controller?
The L9781TR DC/DC controller supports VTank generation up to 80 V, as confirmed in the datasheet block diagram and pin description (VTANK pin rated for 80 V operation). This enables direct compatibility with high-pressure gasoline direct injection systems requiring 60–80 V injector supply rails without external boost stages.
Does the L9781TR support simultaneous actuation of all 11 external MOSFETs?
Yes - the L9781TR's internal FSMs and pre-driver stages are designed for concurrent operation across all channels. The datasheet confirms it drives "up to 11 external N-channel logic level MOSFETs", and the pinout includes dedicated outputs for Bank A, Bank B, and fuel pump, each with independent enable and current sensing paths.
How is short-circuit protection implemented on the L9781TR low-side outputs?
Each low-side output (e.g., GLS_Ax, GLS_P) features hardware-based short-circuit detection using its associated differential current sense pair (RSP/RSN). When sensed current exceeds the DAC-set threshold, the output is disabled within <1 µs and the IRQ pin is asserted - all without MCU intervention, as specified in the protection logic section of DB3720.
Can the L9781TR operate with a 3.3 V microcontroller interface without level shifters?
Yes - the VCCI pin accepts either 3.3 V or 5 V supply, and all SPI signals (CS, SCK, DIN, DOUT) and digital inputs (CMD_A, SEL_A, ENB, etc.) are fully compatible with 3.3 V logic levels. Internal pull-ups on SCK and CS ensure robust interface behavior without external components.
L9781TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 64-LQFP
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Switch Type:
- General Purpose
- Number of Outputs:
- 32
- Ratio - Input:Output:
- 1:32
- Output Configuration:
- High Side or Low Side
- Output Type:
- N-Channel
- Interface:
- SPI
- Voltage - Load:
- -
- Voltage - Supply (Vcc/Vdd):
- -
- Current - Output (Max):
- -
- Rds On (Typ):
- -
- Input Type:
- -
- Features:
- -
- Fault Protection:
- -
- Operating Temperature:
- -40°C ~ 150°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-LQFP (10x10)
L9781TR FAQ
1.How can I place an order for L9781TR through Aetrix?
Please submit a Request for Quotation (RFQ) for L9781TR 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 L9781TR reliable?
The price and inventory of L9781TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L9781TR is usually 5 days.
3.What payment methods are accepted for L9781TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L9781TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for L9781TR?
L9781TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your L9781TR 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 L9781TR?
For technical support, including L9781TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L9781TR requirements.
6.How does Aetrix verify that L9781TR is sourced from the original manufacturer or authorized distributors?
All L9781TR 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 L9781TR meets industry standards.
7.What is the process for return or replacement of L9781TR?
All L9781TR units undergo pre-shipment inspection (PSI). If there is an issue with L9781TR, 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 L9781TR part is unused and in its original packaging.
Return procedure for L9781TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
L9781TR Tags
-
TPS22919DCKR
Texas Instruments
-
MIC2091-1YM5-TR
Microchip Technology
-
MIC2090-1YM5-TR
Microchip Technology
-
TPS22995RZFR
Texas Instruments
-
TPS22975DSGR
Texas Instruments
-
SIP32510DT-T1-GE3
Vishay Siliconix
-
ULN2003D1013TR
STMicroelectronics
-
MIC2005A-1YM5-TR
Microchip Technology
-
MIC2005A-1YM6-TR
Microchip Technology
-
TPS22916BYFPR
Texas Instruments
-
TPS22917DBVR
Texas Instruments
-
ULN2003APWR
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…
