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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Motor Drivers, Controllers

STMicroelectronics L9903

Name: L9903
Brand: STMicroelectronics
SKU: L9903
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: L9903

Manufacturer:: STMicroelectronics

Category:: Motor Drivers, Controllers

Package:: 20-SOIC (0.295", 7.50mm Width)

Datasheet:: L9903.pdf

Description:: IC MOTOR DRIVER 8V-20V 20SO

Quantity:: RFQ Add To RFQ list

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Product details

Overview

L9903 from STMicroelectronics is an automotive H-bridge motor bridge controller IC with ISO 9141 bus interface, designed to drive four external N-channel MOSFETs in dual half-bridge configuration. It operates from 8V–20V supply (extendable to 6V via integrated step-up converter), features real-time diagnostic output (DG), programmable cross-conduction protection, and integrated charge pump for reverse battery protection. Used in DC motor control for automotive body electronics such as window lifters and seat adjusters.

For engineers reviewing the L9903 datasheet, L9903 pinout, L9903 application, or L9903 equivalent, this page delivers verified technical context on ISO 9141 timing, bootstrap capacitor sizing, gate driver propagation delays (≤1.3 µs including tCCP), thermal shutdown behavior (TJSD = 150°C), and PWM frequency support up to 30 kHz - all critical for functional safety-compliant motor control design.

Technical Context

The L9903 implements a dual half-bridge control architecture with independent high-side (GH1/GH2) and low-side (GL1/GL2) gate drivers, each supporting bootstrap operation via CB1/CB2 capacitors and internal charge pump (CP pin). Its ISO 9141 interface uses open-drain K-line (pin 9) with bidirectional communication, 60–100 kHz transmission frequency, and short-circuit detection at K-pin via IKSC (40–130 mA).

Protection logic includes overvoltage disable threshold (22 V typ), undervoltage disable (7 V typ), thermal shutdown (150°C ±15°C hysteresis), and per-half-bridge short-circuit detection (VS1TH/VS2TH = 4 V, tSCd = 5–15 µs). Cross-conduction prevention is implemented via PR-pin programmable RC network (tCCP = 0.69·RPR·CPR), with propagation delays measured at ≤1.3 µs including protection latency.

Key Specifications

Parameter	Value and Actual Design Meaning
Supply Voltage Range	8–20 V operating; extends to 6 V using ST pin step-up converter (fST = 50–149 kHz)
ISO 9141 Interface	K-line bidirectional communication with 60–100 kHz fK; supports VBAT/GND-compatible signaling
Gate Driver Outputs	GH1/GH2 high-side drivers (VGHxH = VS + 6.5–14 V); GL1/GL2 low-side drivers (VGLxH = 7–14 V)
Short-Circuit Detection	Per-half-bridge sensing at S1/S2 pins; VS1TH/VS2TH = 4 V threshold; tSCd = 5–15 µs response
Thermal Protection	Junction shutdown at TJSD = 150°C; hysteresis = 15°C; DG pin asserts LOW during fault
PWM Frequency Support	Up to 30 kHz; dynamic supply current scales as Idyn = 2·fPWM·QGate (e.g., 6.4 mA @ 20 kHz, QGate = 160 nC)
Quiescent Current	<50 µA in standby mode (VEN = LOW); 5.8–13 mA in active PWM/dc modes

Pinout & Package

Package: SO20 (Small Outline, 20-pin, 12.6 × 7.5 mm, 1.27 mm pitch), per mechanical drawing 0016022 D.

Pin/Terminal	Circuit Role	Design Meaning
1 ST	Open-drain step-up converter switch	Drives external inductor/diode to boost supply below 8 V; fST = 50–149 kHz
2 DG	Open-drain diagnostic output	Asserts LOW on thermal/overvoltage/undervoltage/short-circuit faults; internal 10–40 kΩ pull-up
3 PWM	H-bridge PWM control input	CMOS-level input (VIL = 1.5 V, VIH = 3.5 V); internal 16–100 kΩ pull-up
4 EN	Enable input	Active-HIGH enable; floating or LOW forces standby mode (<50 µA IQ)
5 DIR	Direction select input	CMOS-level direction control; internal 16–100 kΩ pull-up; defines motor polarity
6 PR	Cross-conduction protection timing	RC network (RPR/CPR) sets tCCP = 0.69·RPR·CPR; VPRL/VPRH ratio = 2
7 RX	ISO 9141 receiver output	Open-drain monitor of K-line; internal 5–20 kΩ pull-up; tRXH/tRXL = 0.5 µs
8 TX	ISO 9141 transmitter input	Drives K-line via open-drain; internal 10–40 kΩ pull-up; VTXL/VTXH = 1.5/3.5 V
9 K	ISO 9141 bidirectional K-line	VBAT/GND-tolerant; IKSC = 40–130 mA; tKr/tKf = 2–6 µs; VKL/VKH = 0.45·VVS / 0.55·VVS
10 VS	Main supply input	8–20 V nominal; absolute max 40 V; OVH = 22 V, UVH = 7 V
11 CP	Charge pump output	Drives gate of external N-MOS for reverse battery protection; VCP = VS + 7–14 V
12 GH1	Half-bridge 1 high-side gate driver	Sources/sinks ≥50 mA; RGH1L = 10 Ω (25°C); VGH1H = VS + 6.5–14 V
13 CB1	Bootstrap capacitor 1 connection	Charges when GL1 is ON; supplies GH1 gate drive above VS; min C = 100 pF
14 S1	Half-bridge 1 source/drain node	Monitored for short-to-ground/battery; VS1TH = 4 V; RS1 = 10–100 kΩ discharge path
15 GH2	Half-bridge 2 high-side gate driver	Identical specs to GH1; independent control via DIR/PWM logic
16 CB2	Bootstrap capacitor 2 connection	Same function as CB1 for GH2; decouples gate drive from VS rail ripple
17 S2	Half-bridge 2 source/drain node	Independent short-circuit detection (VS2TH = 4 V); RS2 = 10–100 kΩ
18 GL2	Half-bridge 2 low-side gate driver	Sinks ≥50 mA; RGL2L = 10 Ω (25°C); VGL2H = 7–14 V
19 GL1	Half-bridge 1 low-side gate driver	Identical specs to GL2; complements GH1 in half-bridge 1 switching
20 GND	Power and signal ground reference	Common return for VS, logic, drivers, and ISO interface; requires low-impedance layout

Key Features

Feature	Design Value
Integrated step-up converter	Extends operational range to 6 V via ST pin; eliminates need for external buck-boost IC in low-battery scenarios
Programmable cross-conduction protection	tCCP set by external RPR/CPR (100 pF–1 nF, >7 kΩ); prevents shoot-through in half-bridges without fixed delay logic
Real-time diagnostic output (DG)	Single open-drain pin reports thermal, overvoltage, undervoltage, and short-circuit faults - simplifies system-level error handling
ISO 9141 K-line interface	Native single-wire automotive diagnostics interface; no external transceiver required; supports 60–100 kHz baud rates
Reverse battery protection charge pump	CP pin drives external N-MOS gate above VS; bypasses drain-bulk diode to reduce conduction loss vs. discrete diode solution
Per-half-bridge short-circuit detection	Independent VS1TH/VS2TH comparators with 4 V threshold and 5–15 µs response; isolates fault to affected bridge only

Applications

Power Window Control

Automotive Seat Adjustment

Use Scenario: Bidirectional DC motor driving for glass lift/lower motion with soft-start and stall detection.

IC Role / Device Role / Timing Role: L9903 acts as H-bridge gate driver controller, interpreting PWM/DIR commands from body ECU while managing bootstrap timing, cross-conduction delay, and K-line diagnostics.

Use Value: Integrated short-circuit detection at S1/S2 pins enables immediate motor stall response; DG pin signals fault to ECU without additional monitoring circuitry.

Use Scenario: Precise position control of multi-motor seat systems (fore/aft, recline, lumbar) requiring coordinated direction and duty-cycle modulation.

IC Role / Device Role / Timing Role: Dual half-bridge control (GH1/GL1 + GH2/GL2) allows independent motor actuation; PR-pin programmability tailors tCCP to motor inductance and switching speed.

Use Value: Charge pump (CP) drives reverse-battery MOS, eliminating 0.7 V diode drop and reducing heat dissipation in compact seat modules.

Roof Sunshade Actuator

Trunk Lid Release Mechanism

Use Scenario: Low-duty-cycle, intermittent DC motor operation for sunshade extension/retraction with battery voltage variation (6–16 V).

IC Role / Device Role / Timing Role: ST pin step-up converter maintains stable internal VCC down to 6 V; ISO 9141 K-line enables direct ECU diagnostics without CAN gateway.

Use Value: Quiescent current <50 µA in standby reduces parasitic drain on vehicle battery during long parking periods.

Use Scenario: High-reliability solenoid or small DC motor actuation for trunk release, requiring fail-safe fault reporting and overtemperature protection.

IC Role / Device Role / Timing Role: Thermal shutdown (TJSD = 150°C) and DG pin provide hardware-level fault indication to body controller; EN pin enables controlled power-down sequence.

Use Value: Undervoltage lockout (UVH = 7 V) prevents erratic operation during cranking; DG assertion ensures ECU logs fault before power collapse.

Equivalent & Alternatives

The following parts are listed as comparable options for similar H-bridge motor controller applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
TLE9201SG	Integrated high-side/low-side drivers (no external MOS required); 40 V abs max; no ISO 9141 interface	Eliminates external MOSFETs and bootstrap components but lacks native K-line diagnostics	Select when board space is constrained and ISO diagnostics are handled externally or via CAN
VNQ7050AJ	Dual-channel high-side driver only; no low-side or H-bridge logic; includes SPI interface instead of ISO 9141	Requires external low-side switches and MCU-based direction/PWM logic; no integrated cross-conduction protection	Select for simpler unidirectional loads where full H-bridge control and K-line are not needed

Compared with TLE9201SG and VNQ7050AJ, the L9903 uniquely combines ISO 9141 diagnostics, programmable cross-conduction protection, and external MOS flexibility - making it optimal for cost-sensitive, diagnostics-enabled automotive body motors where gate drive customization and legacy bus compatibility are required.

Availability

L9903 is available at Aetrix Electronics and suitable for automotive body electronics, DC motor control modules, and ISO 9141-based diagnostic subsystems requiring stable component supply across extended temperature and voltage ranges.

Supply support for L9903 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, specializing in automotive, industrial, and power management ICs with broad AEC-Q100 qualification coverage.

The L9903 belongs to ST's automotive motor driver portfolio, engineered specifically for ISO 9141-compliant DC motor control in body electronics - emphasizing integration of protection, diagnostics, and legacy bus interface without sacrificing external MOSFET flexibility.

FAQ

What is the minimum bootstrap capacitor value required for reliable GH1/GH2 operation?

The L9903 datasheet specifies CPR values between 100 pF and 1 nF for cross-conduction protection, but bootstrap capacitors CB1/CB2 must be sized based on gate charge (QGate) and PWM frequency. For standard power MOSFETs (10 V VGS), ST recommends ≥100 nF ceramic capacitors placed close to GH1/GL1 and GH2/GL2 pins to maintain sufficient gate voltage during high-duty-cycle operation and minimize voltage droop.

How does the L9903 handle reverse battery conditions?

The L9903 itself is not reverse-battery tolerant on VS, but its CP pin drives the gate of an external N-channel MOSFET configured as an ideal diode. When battery polarity is reversed, the MOSFET remains off, blocking current flow. The CP output provides gate voltage up to VS + 14 V, ensuring full enhancement of the MOSFET and minimizing conduction loss compared to a series Schottky diode solution.

Can the L9903 operate without an external microcontroller?

No - the L9903 is a gate driver controller, not a standalone motor controller. It requires external PWM and DIR signals for H-bridge control, and its ISO 9141 interface expects command frames from a host microcontroller. It has no internal motor control algorithm, position feedback interface, or closed-loop regulation capability.

What happens during thermal shutdown, and how is recovery managed?

When junction temperature exceeds 150°C, all gate drivers (GH1/GL1/GH2/GL2) force sink-state (LOW), K-line output disables, and DG pin pulls LOW. Recovery occurs automatically when temperature falls below 135°C (15°C hysteresis); no reset pulse or EN toggle is required. The device resumes normal operation once thermal equilibrium is restored and EN remains HIGH.

L9903 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 20-SOIC (0.295", 7.50mm Width)

Packaging:: Tube

Product Status:: Active

Motor Type - Stepper:: -

Motor Type - AC, DC:: Brushed DC

Function:: Controller - Commutation, Direction Management

Output Configuration:: Pre-Driver - Half Bridge (2)

Interface:: Serial

Technology:: Power MOSFET

Step Resolution:: -

Applications:: General Purpose

Current - Output:: -

Voltage - Supply:: 8V ~ 20V

Voltage - Load:: -

Operating Temperature:: -40°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-SO

L9903 FAQ

1.How can I place an order for L9903 through Aetrix?

Please submit a Request for Quotation (RFQ) for L9903 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 L9903 reliable?

The price and inventory of L9903 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L9903 is usually 5 days.

3.What payment methods are accepted for L9903?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L9903 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for L9903?

L9903 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your L9903 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 L9903?

For technical support, including L9903 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L9903 requirements.

6.How does Aetrix verify that L9903 is sourced from the original manufacturer or authorized distributors?

All L9903 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 L9903 meets industry standards.

7.What is the process for return or replacement of L9903?

All L9903 units undergo pre-shipment inspection (PSI). If there is an issue with L9903, 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 L9903 part is unused and in its original packaging.

Return procedure for L9903:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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