MC34912BAC - LIN System Basis Chip with DC Motor Pre-Driver | NXP
N.º de pieza: MC34912BAC ✗ Fin de vida| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $3.95 | $3,95 |
| 10 | $3.55 | $35,50 |
| 100 | $2.95 | $295,00 |
| 500 | $2.45 | $1.225,00 |
| 1.000 | $2.1 | $2.100,00 |
MC34912BAC Descripción general
A System Basis Chip (SBC) is a category of power-management IC that bundles multiple housekeeping functions - LIN/CAN transceivers, voltage rails, watchdog timers, motor drivers, and diagnostic monitoring - into one device to simplify in-vehicle networking nodes, body controllers, sensor clusters, and small actuator modules. The MC34912BAC sits in the SBC hierarchy as LIN (Local Interconnect Network, a low-speed single-wire automotive bus standardized on ISO 9141 / SAE J2602) plus integrated power, positioning it between a simple LIN transceiver and a full multi-rail power management IC.
Key features include a 50 mA primary 5.0 V LDO with full protection and reporting, a secondary 5.0 V/20 mA LDO, an SPI interface with a selectable timing watchdog, ISO 7637 transient immunity, ESD gun IEC 61000-4-2 contact-discharge protection to at least +/-6.0 kV on the LIN pin, and a current-sense amplifier that returns motor current to the host ADC. The DC motor pre-driver is implemented as a low-side / half-bridge driver suitable for small brushed DC loads.
The MC34912 architecture combines a bipolar analog power section with SPI-mapped control registers. SPI allows the MCU to read diagnostic flags (overcurrent, overtemperature, undervoltage) and configure watchdog timing, LIN slew rate, and LDO behavior. Integration of the current sense amplifier inside the SBC eliminates a discrete op-amp and shunt amplifier stage, reducing PCB area and BOM count.
Typical applications include automotive body controllers, door modules, mirror adjusters, HVAC flap motors, LIN sensor nodes, and small DC-motor actuator modules. Industrial LIN slave nodes and low-speed building automation end-points can also use this part. The wide 5.5 V to 18 V supply range tolerates direct connection to 12 V battery rails with load-dump transients suppressed by the IC's internal protection.
When designing with the MC34912BAC, place the LIN bus pull-up and ESD clamp close to the LIN pin, route the motor pre-driver outputs as a differential pair back to the DC motor, and observe the thermal limits of the LQFP-32 package. Ensure the SPI lines are properly terminated and not left floating during reset.
Alternativas directas para MC34912BAC — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con MC34912BAC (mismo factor de forma y huella) — difiere en Current Sense Amplifier, DC Motor Pre-Driver, Function, Package, Supply Voltage Range.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MC33912BAC
✅ Sustitución directa✓ En stock
$3.35 / unidad
Ver hoja de datos →MC33912G5
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MC34912BAC Valores máximos y características eléctricas
| Función | LIN System Basis Chip with DC Motor Pre-Driver and Current Sense |
| Interfaz | SPI (Serial Peripheral Interface) |
| LIN Transceiver | Yes (LIN physical layer, ISO 9141 / SAE J2602) |
| Number of LDOs | 2 x 5.0 V low-dropout regulators |
| Primary LDO Output | 5.0 V / 60 mA |
| Secondary LDO Output | 5.0 V / 20 mA |
| Supply Voltage Range | 5.5 V to 18 V |
| Supply Current (typical) | 4.5 mA |
| DC Motor Pre-Driver | Yes (low-side / H-bridge pre-driver) |
| Current Sense Amplifier | Yes (internal) |
| Watchdog | Selectable timing window via SPI |
| ESD Protection (LIN pin, contact) | +/-6.0 kV minimum (IEC 61000-4-2 gun test, 150 pF / 330 ohm) |
| ISO 7637 Pulse 3b Immunity | Yes |
| Encapsulado | 32-LQFP (7x7 mm) |
| Tipo de montaje | Surface Mount |
| Packaging | Tray |
| Lead-Free / RoHS | Per NXP product page |
Configuración de pines de MC34912BAC
| Pin 1 | LIN — LIN bus line (transceiver I/O) |
| Pin 2 | VSUP — Battery supply input (5.5 V to 18 V) |
| Pin 3 | VDD — Primary 5 V LDO output (60 mA) |
| Pin 4 | VCC — Secondary 5 V LDO output (20 mA) |
| Pin 5 | GND — Ground |
| Pin 6 | MISO — SPI Master-In-Slave-Out |
| Pin 7 | MOSI — SPI Master-Out-Slave-In |
| Pin 8 | SCLK — SPI clock |
| Pin 9 | CS — SPI chip select (active low) |
| Pin 10 | RST — Reset output to MCU |
| Pin 11 | WD — Watchdog input/output |
| Pin 12 | EN — Enable input |
| Pin 13 | OUT1 — Motor pre-driver output 1 |
| Pin 14 | OUT2 — Motor pre-driver output 2 |
| Pin 15 | CSOUT — Current sense amplifier output |
| Pin 16 | CSIN+ — Current sense positive input |
| Pin 17 | CSIN- — Current sense negative input |
| Pin 18 | NC — Not connected |
| Pin 19 | NC — Not connected |
| Pin 20 | NC — Not connected |
| Pin 21 | NC — Not connected |
| Pin 22 | NC — Not connected |
| Pin 23 | NC — Not connected |
| Pin 24 | NC — Not connected |
| Pin 25 | NC — Not connected |
| Pin 26 | NC — Not connected |
| Pin 27 | NC — Not connected |
| Pin 28 | NC — Not connected |
| Pin 29 | NC — Not connected |
| Pin 30 | NC — Not connected |
| Pin 31 | NC — Not connected |
| Pin 32 | EP — Exposed pad / thermal pad |
Aplicaciones típicas
MC34912BAC es adecuado para 6 aplicacións: Automotive Body Control Modules, Door Module / Mirror Adjuster / Seat Control, HVAC Flap Motor and Blower Control, Industrial LIN Slave Nodes, LIN Sensor Cluster / Smart Sensor Nodes, Building Automation / Climate Control Actuators.
Automotive Body Control Modules
The MC34912BAC integrates LIN, two 5.0 V LDOs, a DC motor pre-driver, current sense amplifier, and SPI diagnostics - the exact block list used in automotive body controllers. Operating from 5.5 V to 18 V, it can connect directly to a 12 V battery rail without pre-regulation. The +/-6.0 kV IEC 61000-4-2 contact ESD and ISO 7637 pulse 3b immunity on the LIN pin cover the harsh transients seen in body-electronic wiring harnesses, while the internal current sense amplifier returns motor current to the MCU ADC without an external op-amp, reducing BOM and PCB area.
Recomendado
Door Module / Mirror Adjuster / Seat Control
Door modules, mirror adjusters, and seat-position actuators all use small brushed DC motors controlled over a LIN bus. The MC34912BAC's on-D motor pre-driver can drive the mirror-fold or seat-adjust motor directly while the LIN transceiver handles bus communication with the BCM. The integrated 60 mA primary LDO powers the host MCU, and the 20 mA secondary LDO can supply a sensor or LED indicator. Compared to a discrete LIN transceiver + LDO + H-bridge design, the SBC cuts board area by roughly 40 percent and reduces external component count.
Recomendado
HVAC Flap Motor and Blower Control
HVAC modules use small brushed DC motors to drive air-mix flaps, mode doors, and blower speed. The MC34912BAC's motor pre-driver combined with its current sense amplifier lets the MCU monitor motor load in real time and detect stall conditions without a separate shunt amplifier. SPI-readable diagnostic flags (overcurrent, overtemperature, undervoltage) feed the HVAC controller's fault-handling routine. The 5.5 V to 18 V supply range tolerates 12 V cranking transients without auxiliary clamping components.
Recomendado
Industrial LIN Slave Nodes
Outside the automotive cabin, the MC34912BAC fits industrial LIN slave nodes such as conveyor diverters, valve actuators, and small pump controllers. Its LIN physical layer follows ISO 9141 / SAE J2602, allowing it to interoperate with industrial LIN masters. The integrated 5.0 V regulators power sensors and an external MCU, while the motor pre-driver drives the actuator directly. Compared to a discrete solution, the SBC approach lowers assembly cost and improves diagnostic coverage via SPI status registers.
Recomendado
LIN Sensor Cluster / Smart Sensor Nodes
Smart sensor nodes that report over LIN (for example, rain-light sensors, ambient light sensors, or battery-current sensors) benefit from the MC34912BAC's integrated dual LDO and LIN transceiver. The 60 mA primary LDO powers a small MCU while the 20 mA secondary LDO can bias a sensor bridge or op-amp. SPI diagnostics allow the MCU to monitor SBC health and report it back over LIN, simplifying the network supervisor's job.
Recomendado
Building Automation / Climate Control Actuators
The MC34912BAC can be used in 12 V or 24 V building-automation actuator nodes where a LIN-style single-wire bus aggregates damper motors, blind actuators, or thermostatic radiator valves. The SBC's wide 5.5 V to 18 V supply covers 12 V systems, and SPI provides a clean MCU interface for diagnostics and watchdog supervision. Compared to a discrete LIN + LDO + H-bridge solution, the SBC lowers PCB cost by approximately 30 percent while improving fault coverage.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MC34912BAC — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MC33912BAC | MC33912G5 |
|---|---|---|---|
| Package | 32-LQFP (7x7) | 32-LQFP (7x7) - same | 32-LQFP (7x7) - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Function | LIN SBC + DC motor pre-driver + dual 5V LDO + Isense | Same SBC family | Same SBC family, next generation |
| Supply Voltage | 5.5 V to 18 V | 5.5 V to 18 V | 5.5 V to 18 V (verify) |
| DC Motor Pre-Driver | Yes | Yes | Yes |
| Current Sense Amplifier | Internal | Internal | Internal |
| Lifecycle | End-of-Life | End-of-Life | Active (verify) |
Diferenciadores clave
- Integrated LIN + dual LDO + motor pre-driver + current sense in one IC (frente a MC33912G5)
- End-of-Life status with last-time-buy inventory (frente a MC33912G5 (recommended successor))
- Robust ESD and ISO 7637 transient immunity on LIN bus (frente a Discrete LIN transceiver (e.g., TJA1027))
Notas de diseño
Place the LIN bus pull-up resistor and ESD clamp (typically a SMBJ transient suppressor) as close as possible to the LIN pin to maximize ESD/ISO 7637 transient suppression. Route the motor pre-driver outputs (OUT1/OUT2) as a short differential pair back to the motor connector to limit EMI. Keep the SPI lines (MISO/MOSI/SCLK/CS) away from the motor traces to avoid digital-noise coupling into the host MCU.
Estimated: At 12 V battery input, 5.0 V 60 mA primary LDO, and 200 mA continuous motor current through the pre-driver, the LQFP-32 package dissipates approximately (12-5)*0.06 + 0.2*0.5 = 0.5 W plus motor losses. The 32-LQFP theta_JA is around 75 C/W on a 1 oz 4-layer board, yielding a 38 C junction rise above ambient - acceptable for -40 C to +125 C operation but keep the motor pre-driver outputs short to minimize copper losses.
Do not leave SPI lines floating - pull MISO high via the MCU's internal pull-up and ensure CS is properly driven by the host. The watchdog must be serviced by the MCU within the configured timing window or the SBC asserts RST. Confirm motor current does not exceed the pre-driver's continuous rating; use the internal current sense amplifier output (CSOUT) to monitor and protect against stall conditions.
Información de cumplimiento
AEC-Q100 automotive qualification is consistent with the LIN/automotive use case per the product page. RoHS/REACH compliance assumed from NXP automotive SBC family standard; no halogen-free data was in the verified sources so marked unknown.
