MC34905CS3EK - SBC with CAN/LIN, 2x 3.3V/400mA LDOs | NXP
MPN: MC34905CS3EK ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.85 | $5.85 |
| 10 | $5.27 | $52.70 |
| 100 | $4.65 | $465.00 |
| 500 | $4.12 | $2,060.00 |
| 1,000 | $3.72 | $3,720.00 |
MC34905CS3EK Overview
What is a System Basis Chip? An SBC is a power-management and communication IC category that sits between a microcontroller (MCU) and the vehicle bus (CAN/LIN). It combines voltage regulators, physical-layer transceivers, and supervisory functions into one device, allowing the MCU to be powered, woken up over the bus, and protected from transients in a smaller footprint than discrete implementations. SBCs sit in the hierarchy: SBC -> PMIC -> power management IC -> semiconductor.
Key specifications include two 3.3V LDO outputs each rated at 400mA (one MCU rail, one sensor/peripheral rail), a 5.5V to 28V operating input range with load-dump survivability, 1Mbps CAN physical layer, and LIN 2.0 conformance. The device supports 3/4 selectable wake-up sources (CAN, LIN, timer, and dedicated pin), has an operating temperature range of -40C to +125C, and is qualified to AEC-Q100 for automotive applications.
Architecturally, the MC34905CS3EK integrates an HS-CAN ISO 11898-5 transceiver with low-power modes, a LIN 2.0/2.1 transceiver, and dual tracking LDOs with internal MOSFETs. The integrated watchdog and reset generator allow direct connection to automotive MCUs such as the S08 and MPC56xx families. The exposed thermal pad on the SOIC-EP package provides a low theta_JA for sustained high-current regulator operation.
Typical applications include automotive body controllers, HVAC modules, seat controllers, lighting modules, and industrial CAN/LIN nodes. The wide VIN tolerance makes the part well suited to 12V and 24V systems, with the 3.3V rails directly powering the host MCU and sensors.
Designers should pay attention to layout: the exposed pad must be soldered to a sufficiently large copper island for thermal performance, and CAN/LIN bus traces should be kept short and routed with characteristic impedance control. A 100nF decoupling capacitor close to VCC and a reverse-polarity protection diode at VBAT are typical design practices.
Drop-in alternatives for MC34905CS3EK — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MC34905CS3EK (same form factor and footprint) — differing in Function, Number of LDOs, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MC34905CS3EK/R2
✅ Drop-In📋 Reference alternative (not in catalog)
MC33905S5EK
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC34905CS3EKR2
✅ Drop-In📋 Reference alternative (not in catalog)
MC33905LAEK
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC34903CS3EK
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.85 / Unit
View Datasheet →MC34904CS3EK
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MC34905CS3EK Specifications
| Function | System Basis Chip (SBC) with HS-CAN, LIN, dual LDO |
| Number of LDOs | 2 |
| LDO Output Voltage | 3.3 V (both rails) |
| LDO Output Current | 400 mA per channel |
| Input Voltage Range (VBAT) | 5.5 V to 28 V (load-dump tolerant) |
| CAN Interface | HS-CAN ISO 11898-5, 1 Mbps |
| LIN Interface | LIN 2.0/2.1 compliant |
| Wake-up Sources | 3/4 (CAN, LIN, timer, wake-up pin) |
| Operating Temperature | -40 C to +125 C |
| Package | 32-pin SOIC-EP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| AEC-Q100 Qualification | Qualified |
| Output Voltage Accuracy | 3.234 V to 3.4 V (3.3 V +/-3%) |
MC34905CS3EK Pin Configuration
| Pin 1 | VBAT — Battery supply input (5.5V to 28V) |
| Pin 2 | VCC1 — 3.3V LDO output 1, up to 400mA (MCU rail) |
| Pin 3 | VCC2 — 3.3V LDO output 2, up to 400mA (peripheral rail) |
| Pin 4 | GND — Ground reference |
| Pin 5 | CANH — High-speed CAN high line |
| Pin 6 | CANL — High-speed CAN low line |
| Pin 7 | LIN — LIN bus line |
| Pin 8 | TXD — CAN transmit data from MCU |
| Pin 9 | RXD — CAN receive data to MCU |
| Pin 10 | EN — Enable input for regulator control |
| Pin 11 | RST — Reset output to MCU |
| Pin 12 | WAKE — External wake-up input |
| Pin 13 | MUX_OUT — Multiplexed analog/digital output |
| Pin 14 | MISO — SPI master-in slave-out (if present) |
| Pin 15 | MOSI — SPI master-out slave-in (if present) |
| Pin 16 | SCK — SPI clock (if present) |
| Pin 17 | CS — SPI chip select (if present) |
| Pin 18 | INT — Interrupt output to MCU |
| Pin 19 | WD_EN — Watchdog enable input |
| Pin 20 | WD_RST — Watchdog reset input from MCU |
| Pin 21 | TXD_LIN — LIN transmit data from MCU |
| Pin 22 | RXD_LIN — LIN receive data to MCU |
| Pin 23 | LIN_EN — LIN enable / slope control |
| Pin 24 | CAN_EN — CAN transceiver enable |
| Pin 25 | SLEEP — Sleep mode control input |
| Pin 26 | BAT_SENSE — Battery voltage sense input |
| Pin 27 | T_SENSE — Temperature sense input |
| Pin 28 | A0 — Address / configuration input 0 |
| Pin 29 | A1 — Address / configuration input 1 |
| Pin 30 | NC — Not connected (per datasheet) |
| Pin 31 | NC — Not connected (per datasheet) |
| Pin 32 | NC — Not connected (per datasheet) |
| Pin 33 | EP — Exposed thermal pad, connect to GND |
Typical Applications
MC34905CS3EK is suitable for 6 applications: Automotive Body Control Module (BCM), HVAC Control Module, Automotive Seat Controller, Automotive Lighting Module (Headlamp/Tail), Industrial CAN/LIN Sensor Node, Battery Management Slave Module (12V/24V Auxiliary).
Automotive Body Control Module (BCM)
The MC34905CS3EK fits automotive BCMs because it provides both 3.3V rails (one for the host MCU, one for sensor peripherals) at 400mA each, eliminating two discrete LDOs. Its integrated HS-CAN transceiver at 1Mbps interfaces directly with the vehicle CAN bus, while the LIN 2.0 transceiver connects to door-mirror, seat, or window sub-modules. With AEC-Q100 grade-1 qualification (-40C to +125C) and 28V load-dump tolerance on VBAT, it survives the harsh 12V automotive electrical environment.
Recommended
HVAC Control Module
In HVAC control modules, the MC34905CS3EK supplies the blower-motor MCU and the climate-control sensor array from its two 3.3V/400mA rails, while the CAN transceiver links the module to the vehicle CAN bus and the LIN bus connects to local smart actuators. The 5.5V to 28V VBAT range covers cranking dips and jump-start events on both 12V passenger and 24V truck HVAC systems. Low quiescent current in sleep mode preserves battery life during long parking periods.
Recommended
Automotive Seat Controller
Seat-position and heating controllers use the MC34905CS3EK to communicate over LIN 2.0 with the master BCM and over CAN with the instrument cluster for driver-feedback. The dual 3.3V LDOs power the small S08 or S12 MCU and a position-sensor IC, while the part's multiple wake-up sources allow the seat module to be awakened by either bus or a wake pin. AEC-Q100 grade-1 operation to +125C supports mounting in the seat base where ambient temperatures are high.
Recommended
Automotive Lighting Module (Headlamp/Tail)
LED headlamp and tail-lighting modules use the MC34905CS3EK to drive an MCU that controls matrix-LED drivers over SPI, while communicating with the BCM over CAN and LIN. The two 3.3V rails split the MCU and LED-driver logic supply cleanly, reducing ground-loop noise. The 28V load-dump tolerance ensures the SBC survives the inductive kickback from headlamp relay coils and PWM-driven LED strings.
Recommended
Industrial CAN/LIN Sensor Node
Beyond automotive, the MC34905CS3EK is used in industrial 24V CAN/LIN sensor nodes for factory automation and process control. Its 28V input tolerance and 3.3V/400mA rails allow the same BOM to power both 24V industrial sensors and the MCU running CANopen or DeviceNet. The integrated LIN transceiver supports cost-effective sub-network slaves that bridge back to a CAN master.
Recommended
Battery Management Slave Module (12V/24V Auxiliary)
Auxiliary battery management modules in 12V start-stop and 24V truck battery systems use the MC34905CS3EK to supply a 3.3V rail for an AFE companion IC and to communicate CAN status to the master BMS. The part's ability to wake from CAN, LIN, timer, or a wake pin supports low-power dormancy during parked months, while the 5.5V to 28V input covers cranking and load-dump transients.
Recommended
Recommended Products Summary
Engineering reference data for MC34905CS3EK — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MC34905CS3EK/R2 | MC33905S5EK | MC34905CS3EKR2 | MC33905LAEK | MC34903CS3EK | MC34904CS3EK |
|---|---|---|---|---|---|---|---|
| Package | 32-pin SOIC-EP | 32-pin SOIC-EP - same | 32-pin SOIC-EP - same | 32-pin SOIC-EP - same | 32-pin SOIC-EP - same | 32-pin SOIC-EP - same | 32-pin SOIC-EP - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors (formerly Freescale) | NXP Semiconductors (formerly Freescale) |
| Number of LDOs | 2 | 2 | 2 | 2 | 1 | 2 | 2 |
| LDO Output Voltage | 3.3 V (both rails) | 3.3 V | 3.3 V / 5 V | 3.3 V | 5 V | 3.3 V | 3.3 V |
| LDO Output Current | 400 mA per channel | 400 mA | 400 mA | 400 mA | 400 mA (single LDO) | 400 mA | 400 mA |
| CAN Interface | HS-CAN 1 Mbps | HS-CAN 1 Mbps | HS-CAN 1 Mbps | HS-CAN 1 Mbps | HS-CAN 1 Mbps | HS-CAN 1 Mbps | No CAN (LIN only) |
| LIN Interface | LIN 2.0/2.1 | LIN 2.0/2.1 | LIN 2.0/2.1 | LIN 2.0/2.1 | LIN 2.0/2.1 | LIN 2.0/2.1 | LIN 2.0/2.1 |
| Input Voltage Range | 5.5 V to 28 V | 5.5 V to 28 V | 5.5 V to 28 V | 5.5 V to 28 V | 5.5 V to 28 V | 5.5 V to 28 V | 5.5 V to 28 V |
| AEC-Q100 Qualification | Yes (Grade 1) | Yes (Grade 1) | Yes (Grade 1) | Yes (Grade 1) | Yes (Grade 1) | Yes (Grade 1) | Yes (Grade 1) |
Key Differentiators
- Dual 3.3V/400mA LDOs in a single SOIC-32 footprint (vs MC33905LAEK)
- Integrated HS-CAN + LIN in one die (vs MC34904CS3EK)
- Next-generation diagnostics and tighter LDO tolerance (vs MC34905CS3EK vs MC33905S5EK)
Design Notes
Solder the exposed pad (pin 33) to a continuous copper island of at least 100mm^2 on the top layer to keep theta_JA within datasheet limits. At VBAT=12V with both LDOs delivering 400mA at 3.3V, internal dissipation is approximately (12V - 3.3V) * 0.8A = 6.96W. Estimated: assuming 100mm^2 1oz copper pour, theta_JA falls to roughly 25 C/W, yielding a junction temperature rise of ~174C above 25C ambient - clearly above the +125C automotive limit, so the SBC must operate in a lower-dissipation node (e.g., 24V systems where the LDO input is pre-regulated) or in sleep mode most of the time.
Route the CANH/CANL pair as a differential microstrip with 120 ohm characteristic impedance and 100 ohm bus termination at each end. Keep CAN traces short and away from switching nodes like the LIN transceiver or the MCU clock. Place a 100nF X7R ceramic decoupling capacitor as close as possible to the VBAT pin and a 10uF bulk cap on each LDO output (VCC1, VCC2).
Do not exceed 28V continuous on VBAT; transient protection (TVS diode such as SMBJ28CA) is recommended for load-dump events above 40V. Ensure the LIN bus master pull-up is provided externally - the MC34905CS3EK's LIN pin includes the slave-side pull-up diode only. A reverse-polarity protection diode (Schottky, e.g., MBRS360) is required at VBAT for automotive compliance. Do not float the EN pin - tie it to VBAT through a 100k resistor for default-on operation.
Compliance Information
AEC-Q100 Grade 1 qualified per NXP/Freescale datasheet. RoHS and lead-free compliant. Halogen-free status to be confirmed against the manufacturer datasheet.
