TPS38700C03NRGERQ1 - Automotive 12-CH Sequencer + Watchdog QFN-24
MPN: TPS38700C03NRGERQ1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.62 | $46.20 |
| 100 | $3.95 | $395.00 |
| 500 | $3.46 | $1,730.00 |
| 1,000 | $3.1 | $3,100.00 |
| 3,000 | $2.78 | $8,340.00 |
TPS38700C03NRGERQ1 Overview
What is a power-supply sequencer? A power-supply sequencer is a controller IC that turns multiple voltage rails on and off in a defined order and timing rather than providing regulation itself. It sits between the system PMIC rails (or discrete regulators) and the digital load. The sequencer hierarchy is: voltage sequencer -> power management controller -> power management IC (PMIC) -> semiconductor. Sequencers are essential whenever downstream devices require a specific rail order for proper initialization (e.g., core before I/O before analog) or to prevent latch-up, inrush-induced brown-outs, or device damage during power transitions.
Key features include support for up to 12 sequenced channels via an external cascade, OTP-default timing windows that load automatically on power-up, I2C-configurable threshold, delay, and watchdog timeout, and an integrated window watchdog for the host MCU. The device operates from a wide supply range and provides active-high enables to external regulators, along with a fault-output (nRST/WDO) that asserts when any monitored rail is out of tolerance or the watchdog window is violated.
Architecturally, the TPS38700-Q1 combines a precision internal reference, twelve programmable threshold comparators via external resistor dividers, I2C control logic, and a window watchdog timer. The OTP banks store the default rail configuration and timing, so production boards boot deterministically even before firmware reprograms the device. The 24-pin VQFN (4x4) thermal pad delivers low junction-to-PCB thermal resistance, enabling high-channel-count designs on a compact footprint suitable for automotive ECU modules.
Typical applications include automotive ADAS domain controllers, advanced driver-assistance ECUs, infotainment head units, zonal/zonal-architecture compute modules, and industrial multi-rail FPGA/ASIC platforms. The wide operating range and AEC-Q100 grade make it a strong fit for any high-reliability multi-rail board.
When designing with this device, leave margin for OTP timing drift across temperature and validate the watchdog window against the slowest legitimate service routine. Cascade multiple TPS38700-Q1 parts when sequencing more than the local channel budget allows, tying their fault lines together so the system does not partial-power in a faulted state.
Drop-in alternatives for TPS38700C03NRGERQ1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
TPS38700C02NRGERQ1
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
TPS38700C04NRGERQ1
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
TPS38700C05NRGERQ1
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
TPS38700-Q1
✅ Drop-In📋 Reference alternative (not in catalog)
TPS38700C03NRGERQ1 Specifications
| Function | Multichannel power-supply sequencer with window watchdog |
| Number of Sequenced Channels | Up to 12 (cascade expansion) |
| Interface | I2C (programmable thresholds, delays, watchdog) |
| Watchdog Type | Window watchdog (upper and lower bounds) |
| Default Configuration | OTP-programmed at factory |
| Output Type | Active-high enable drivers to external rails + open-drain nRST/WDO |
| Operating Temperature Range | -40 C to +125 C (automotive grade 1) |
| Package | 24-pin VQFN (RGE) 4 mm x 4 mm with thermal pad |
| Mounting Type | Surface Mount |
| AEC-Q100 Qualification | Yes (automotive grade) |
| RoHS Status | Compliant |
TPS38700C03NRGERQ1 Pin Configuration
| Pin 1 | GND — Ground return |
| Pin 2 | EN1 — Active-high enable to rail 1 |
| Pin 3 | EN2 — Active-high enable to rail 2 |
| Pin 4 | EN3 — Active-high enable to rail 3 |
| Pin 5 | EN4 — Active-high enable to rail 4 |
| Pin 6 | EN5 — Active-high enable to rail 5 |
| Pin 7 | EN6 — Active-high enable to rail 6 |
| Pin 8 | EN7 — Active-high enable to rail 7 |
| Pin 9 | EN8 — Active-high enable to rail 8 |
| Pin 10 | EN9 — Active-high enable to rail 9 |
| Pin 11 | EN10 — Active-high enable to rail 10 |
| Pin 12 | EN11 — Active-high enable to rail 11 |
| Pin 13 | EN12 — Active-high enable to rail 12 |
| Pin 14 | WDO — Open-drain watchdog fault output |
| Pin 15 | nRST — Open-drain reset output |
| Pin 16 | WD_EN — Watchdog enable input |
| Pin 17 | SCL — I2C clock |
| Pin 18 | SDA — I2C data |
| Pin 19 | ADDR — I2C address select |
| Pin 20 | MR — Manual reset input |
| Pin 21 | CASCADE_IN — Cascade input from upstream TPS38700-Q1 |
| Pin 22 | CASCADE_OUT — Cascade output to downstream TPS38700-Q1 |
| Pin 23 | VDD — Supply input |
| Pin 24 | NC — Not connected (per datasheet) |
Typical Applications
TPS38700C03NRGERQ1 is suitable for 7 applications: Automotive ADAS Domain Controller, Infotainment Head Unit, Industrial Multi-Rail FPGA Platform, Zonal Architecture ECU, Server and Datacenter Add-In Cards, Aerospace Flight-Computing Modules, Solid-State LiDAR Sensor.
Automotive ADAS Domain Controller
The TPS38700C03NRGERQ1 sequences the SoC core, GPU, NPU, DDR, image-sensor PHY, and Ethernet PHY rails of an ADAS domain controller in OTP-defined order so the radar/lidar processor boots safely. Its AEC-Q100 grade-1 (-40 C to +125 C) qualification lets it sit beside the MPU on the same thermal stack, and its window watchdog protects the system MCU from missed service routines in a safety-critical loop. Cascaded parts extend sequencing beyond 12 rails for higher-channel ADAS compute boards.
Recommended
Infotainment Head Unit
In an infotainment head unit the TPS38700C03NRGERQ1 brings up the application processor, the DDR memory, the touchscreen controller, and the audio DSP in a deterministic sequence to prevent bus contention and back-power during boot. Its open-drain nRST/WDO fault pin can hold the application processor in reset if any rail breaches tolerance, preventing boot-loop states. I2C retiming enables late-stage firmware updates to delay or skip rails during diagnostic states without re-spinning the PCB.
Recommended
Industrial Multi-Rail FPGA Platform
FPGA platforms typically require core, GT/Transceiver, auxiliary, and I/O rails to come up in a strict order to avoid in-rush damage and latch-up on the transceivers. The TPS38700C03NRGERQ1 controls external point-of-load regulators via its active-high enable pins so each rail starts only after the prior rail is valid. The integrated window watchdog monitors the FPGA soft-core housekeeping loop, important for functional-safety system integrators.
Recommended
Zonal Architecture ECU
Zonal ECUs consolidate power management for an entire vehicle zone (body, chassis, powertrain) and require sequenced rail-up of the MCU, CAN-FD transceivers, sensor rails, and actuators. The TPS38700C03NRGERQ1's OTP defaults ensure deterministic boot even when the zonal MCU's flash is empty or corrupted, and its window watchdog supports ASIL-B safety-system goals. Its 4 mm x 4 mm VQFN fits the constrained PCB area near connector pins.
Recommended
Server and Datacenter Add-In Cards
PCIe add-in cards, NVMe storage controllers, and accelerator cards require deterministic multi-rail sequencing for hot-plug safety and in-rush control. The TPS38700C03NRGERQ1's I2C interface allows the host BMC to override timing windows during service or firmware-update states. Industrial-grade operating range and OTP defaults are useful in unattended, high-altitude compute cabinets.
Recommended
Aerospace Flight-Computing Modules
Avionics flight computers must bring up several SoCs, FPGAs, and DDR banks in a strict sequence to comply with DO-254/DO-178C objectives, and any lost watchdog service routine indicates a faulted task. The TPS38700C03NRGERQ1's window watchdog enforces independent upper and lower bounds on watchdog service, making it easier to distinguish legitimate variable-time tasks from a hung process. AEC-Q100 qualification is a strong proxy for high-reliability flight platforms where source-control is paramount.
Recommended
Solid-State LiDAR Sensor
Solid-state LiDAR sensors require the laser-driver rails to come up only after the FPGA image-processing rails are stable, and to shut down in a defined order when the sensor is decommissioned. The TPS38700C03NRGERQ1 sequences the FPGA core, ADC rails, and laser-driver rails, and its open-drain fault output simultaneously clamps the laser-driver enable during a sequencing fault - critical for eye-safety interlocks.
Recommended
Recommended Products Summary
Engineering reference data for TPS38700C03NRGERQ1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | TPS38700C02NRGERQ1 | TPS38700C04NRGERQ1 | TPS38700C05NRGERQ1 | TPS38700-Q1 (generic family) |
|---|---|---|---|---|---|
| Package | VQFN-24 (RGE) 4x4 mm | VQFN-24 (RGE) 4x4 mm | VQFN-24 (RGE) 4x4 mm | VQFN-24 (RGE) 4x4 mm | VQFN-24 (RGE) 4x4 mm |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Function | 12-CH sequencer + window watchdog | 12-CH sequencer + window watchdog | 12-CH sequencer + window watchdog | 12-CH sequencer + window watchdog | 12-CH sequencer + window watchdog |
| Channel Count | 12 (cascade expandable) | 12 | 12 | 12 | 12 (cascade expandable) |
| AEC-Q100 | Yes (grade 1) | Yes | Yes | Yes | Yes |
| OTP Timing Profile | C03 (factory-programmed) | C02 | C04 | C05 | User-selected OTP |
| Interface | I2C + OTP defaults | I2C + OTP defaults | I2C + OTP defaults | I2C + OTP defaults | I2C + OTP defaults |
| Watchdog | Window (upper + lower) | Window | Window | Window | Window |
Key Differentiators
- OTP-default boot without firmware (vs TPS3898 array)
- Window watchdog with independent upper/lower bounds (vs Time-out watchdog in typical competitor sequencers)
- AEC-Q100 grade-1 in 4x4 VQFN (vs Larger QFP 32-pin legacy TI sequencers)
Design Notes
Wire the TPS38700-Q1's VDD pin to a clean 3.3 V or 5 V rail sourced from the same upstream protection circuit that drives the rest of the housekeeping logic. Place a 1 uF X7R ceramic bypass capacitor directly at the VDD pin and a 100 nF capacitor at the exposed thermal pad ground to keep the OTP-default boot deterministic against large downstream load transients from FPGA configuration writes or radio PA bursts.
Although the TPS38700-Q1 dissipates little power (it drives only logic-level enable signals), keep the exposed thermal pad soldered to a copper pour stitched with at least four thermal vias to inner ground planes. This keeps junction temperature well below the 125 C AEC-Q100 limit, even in sealed automotive enclosures where ambient can exceed 85 C. Estimated: at 50 mA VDD load and 5 V supply the IC power dissipation is around 250 mW, well within thermal limits when the thermal pad is properly stitched.
Do not assume the OTP timing will match your board's startup budget across temperature: the C03 OTP loads default thresholds and delay values, but the silicon timing still varies by a few percent at the AEC-Q100 temperature extremes. Always characterize the worst-case sequencing window in a thermal chamber before locking the BOM, and verify that downstream regulators' enable-to-valid times are well below the TPS38700's fault-debounce window.
Route the I2C SCL/SDA traces short and symmetric; place a 4.7 kohm pull-up to VDD (use VDD, not a downstream rail, so the bus never powers up before the sequencer). Keep the CASCADE_OUT trace away from switching-regulator switch nodes to avoid crosstalk into the next sequencer's house-keeping logic; if you must route near a switcher, place a guard ground between the two.
Compliance Information
RoHS-compliant and lead-free per TI product page. AEC-Q100 grade-1 qualified for automotive. REACH status and halogen-free status were not surfaced in verified web data; confirm with the TI compliance declaration before import to regions requiring those attestations.
