My Inquiry
My Account
Monolithic Power Systems Inc. MP9942GJ-P
- Part No.:
- MP9942GJ-P
- Manufacturer:
- Monolithic Power Systems Inc.
- Package:
- SOT-23-8 Thin, TSOT-23-8
- Datasheet:
-
MP9942GJ-P.pdf
- Description:
- IC REG BUCK ADJ 2A TSOT23-8
- Quantity:
- Payment:
- Shipping:
Inventory:474
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MP9942GJ-P from Monolithic Power Systems is a synchronous step-down DC/DC converter IC with integrated 90mΩ/55mΩ MOSFETs, delivering 2A continuous output current across a 4V–36V input range. It operates at 410kHz fixed frequency (synchronizable to 200kHz–2.2MHz), features power-good indication, internal soft-start, and thermal shutdown-designed for automotive cold-crank and industrial power rail regulation.
For engineers reviewing the MP9942GJ-P datasheet, MP9942GJ-P pinout, MP9942GJ-P application, or MP9942GJ-P equivalent, key selection criteria include its wide VIN range, PG threshold accuracy (±3.5% of VFB), hiccup-mode over-current protection, and TSOT23-8 footprint compatibility with space-constrained PCB layouts.
Technical Context
The MP9942GJ-P uses peak-current-mode control with internal compensation, enabling stable loop response without external type-II/III networks. Its AAM (Advanced Asynchronous Modulation) power-save mode dynamically transitions between PWM and PFM based on load, maintaining >85% efficiency at 10mA while supporting full 2A output.
It integrates a bootstrap driver with 2.2V UVLO and supports external BST diode enhancement for high-duty-cycle operation (>65%). The EN/SYNC pin serves dual function: digital enable control with 1.4V rising threshold and external clock synchronization up to 2.2MHz with <2μs pulse width tolerance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4V to 36V continuous - supports automotive battery transients including cold-crank down to 4.5V |
| Output Current | 2A continuous - sustained without derating at TA ≤ 85°C with proper PCB copper area |
| Switching Frequency | 410kHz typical - enables compact magnetics; synchronizable to 200kHz–2.2MHz for EMI tuning |
| Feedback Reference | 792mV ±1.5% - sets output voltage via resistor divider; enables 0.8V minimum VOUT |
| Power Good Threshold | 90% of VFB rising / 84% falling - provides accurate rail-valid signaling with 90μs delay |
| Thermal Shutdown | 170°C activation / 140°C hysteresis - protects die during overload or poor heatsinking |
| Current Limit | 4.2A typical - cycle-by-cycle protection prevents inductor saturation during short-circuit |
Pinout & Package
MP9942GJ-P is housed in an 8-pin TSOT23 package (2.9mm × 1.6mm × 0.85mm), optimized for high-density layout with exposed thermal pad (not electrically connected). Pin 1 is bottom-left when top marking is read left-to-right.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - PG | Open-drain power-good output | Pulled low until VOUT reaches 90% of target; asserts after 90μs delay; pulled low on EN disable or thermal shutdown |
| 2 - IN | Main input supply connection | Accepts 4V–36V; requires local 22μF + 0.1μF ceramic decoupling; routed with wide trace to minimize impedance |
| 3 - SW | Switch node | Connects to inductor; carries high di/dt; must be kept short and away from FB/EN to avoid noise coupling |
| 4 - GND | System ground reference | Primary return path for power and feedback; requires direct low-inductance connection to PCB ground plane |
| 5 - BST | Bootstrap supply for high-side gate driver | Requires 0.1μF capacitor to SW; 20Ω series resistor recommended to suppress ringing |
| 6 - EN/SYNC | Enable input / external clock sync | 1.4V rising threshold; 500kΩ internal pulldown; accepts 200kHz–2.2MHz square wave for frequency locking |
| 7 - VCC | Bias supply output | Regulated ~4.9V output; powers internal circuitry; requires 0.1–0.22μF ceramic decoupling |
| 8 - FB | Feedback input | Compares against 792mV reference; connects to resistor divider tap; sensitive to noise-must be routed short and shielded |
Key Features
| Feature | Design Value |
|---|---|
| Integrated MOSFETs | 90mΩ HS / 55mΩ LS RDS(ON) - eliminates external FETs and gate drivers, reducing BOM count and layout complexity |
| Internal Soft-Start | 1.45ms ramp time - prevents output overshoot and inrush current during startup |
| Power-Good Indicator | Accurate 90%/84% VFB thresholds with 90μs delay - enables reliable system sequencing and fault detection |
| Hiccup-Mode OCP | Enters periodic restart on sustained over-current - limits average power dissipation during output short |
| AAM Light-Load Mode | Automatic transition to PFM below ~200mA - maintains >85% efficiency at 10mA without external control |
Applications
| Automotive Body Control Module | Industrial PLC I/O Power |
|---|---|
Use Scenario: Regulating 3.3V or 5V rails from 12V/24V vehicle battery under cold-crank (down to 4.5V) and load-dump conditions. IC Role / Device Role / Timing Role: Primary buck regulator providing stable logic supply; handles wide VIN transients without dropout. Use Value: High duty-cycle capability (95%) and 36V absolute max rating ensure uninterrupted operation during battery dips and surges. | Use Scenario: Generating isolated 5V or 12V auxiliary supplies for sensor interfaces and communication modules in programmable logic controllers. IC Role / Device Role / Timing Role: Local point-of-load converter with PG signal used for watchdog reset and system health monitoring. Use Value: Power-good accuracy (±3.5% of VFB) and hiccup-mode OCP prevent false resets and enable safe recovery from field-induced shorts. |
| Distributed Telecom Power | Medical Diagnostic Equipment |
Use Scenario: Providing 3.3V/2A bias for FPGA configuration, Ethernet PHYs, and ADCs in remote radio units and baseband boards. IC Role / Device Role / Timing Role: Compact, high-efficiency buck stage minimizing heat in air-cooled enclosures; synchronized to system clock to reduce EMI peaks. Use Value: 410kHz base frequency + external sync capability allows EMI spread-spectrum alignment with other switching regulators. | Use Scenario: Supplying regulated 5V for microcontroller, display, and analog front-end circuits in portable ultrasound and patient monitors. IC Role / Device Role / Timing Role: Safety-critical power stage with thermal shutdown and PG reporting integrated into system-level fault tree analysis. Use Value: 150°C max junction temperature and 30°C thermal hysteresis ensure predictable shutdown/recovery behavior under ambient drift. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2451DT-LF-Z | 36V input, 0.6A output, no PG pin, 2MHz fixed frequency | Limited to lower current loads; lacks power-good signaling and hiccup-mode OCP | Select only for space-constrained, low-power applications where PG and robust fault handling are not required |
| LM61480RQRR | 36V input, 8A output, 2.1MHz sync, integrated PG with adjustable threshold | Higher current, larger QFN package (3mm × 4mm), higher quiescent current (15μA vs. 0.7mA) | Choose when scaling to >3A loads or requiring tighter PG threshold adjustability; accept larger footprint and higher IQ |
Compared with MP9942GJ-P, MP2451DT-LF-Z sacrifices current capability and fault diagnostics for smaller size and higher frequency, while LM61480RQRR trades board area and quiescent power for scalability and precision PG control-making MP9942GJ-P optimal for 2A automotive/industrial designs needing PG assurance in minimal TSOT23-8 area.
Availability
MP9942GJ-P is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, and distributed telecom systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MP9942GJ-P 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
Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.
The MP9942 belongs to MPS's high-voltage synchronous buck converter product line, engineered for ruggedized operation in automotive, industrial, and telecom environments where input transients, thermal stress, and reliability under continuous load are critical.
FAQ
What is the maximum allowable input voltage for MP9942GJ-P, and what happens above that limit?
The absolute maximum input voltage is 40V. Exceeding this risks permanent damage to the internal MOSFETs and control circuitry due to oxide breakdown or junction overvoltage. Operation above 36V is outside the specified operating range and may cause erratic behavior, reduced lifetime, or immediate failure-even if within the 40V absolute max rating.
Can MP9942GJ-P operate with an input voltage below 4V, and what is the functional limit?
No-4V is the guaranteed minimum operating input. Below 4V, the internal VCC regulator cannot sustain sufficient bias voltage, causing the error amplifier, oscillator, and gate drivers to cease functioning. The UVLO threshold is 3.5V rising, so the device remains disabled until VIN exceeds that level.
How does the Power Good (PG) pin behave during startup and fault conditions?
At power-on, PG is pulled low until VOUT reaches 90% of the target (e.g., 2.97V for 3.3V output), then goes high after a 90μs delay. It pulls low again if VOUT drops to 84% of target, EN is deasserted, or thermal shutdown activates-providing unambiguous rail-status signaling for system sequencing and fault isolation.
Is an external bootstrap diode required, and when does it improve performance?
An external bootstrap diode (e.g., 1N4148) is optional but recommended for duty cycles >65% or VIN < 5V, where internal bootstrap charging becomes insufficient. It improves high-side gate drive strength, reduces switching losses, and stabilizes BST voltage during light-load PFM operation-boosting efficiency by up to 3% in high-VIN, high-duty scenarios.
What is the purpose of the T-type feedback network, and when should it be used?
The T-type network (R1, R2, RT) replaces the standard two-resistor divider to improve loop stability at low output voltages (<5V). RT adds phase margin by shaping the compensation zero; it's mandatory for 3.3V outputs to maintain ≥45° phase margin at 410kHz switching frequency and prevent oscillation under transient load steps.
Does MP9942GJ-P support forced PWM mode, or is it limited to automatic PFM/PWM transition?
MP9942GJ-P operates exclusively in automatic AAM (asynchronous modulation) mode-no pin or register control exists to force continuous PWM. The transition between PWM and PFM is fully internal and load-dependent, beginning below ~200mA. This simplifies design but precludes deterministic low-noise operation at light loads.
What is the recommended minimum BST capacitor value, and why is the 20Ω series resistor advised?
A 0.1μF ceramic capacitor is the minimum recommended BST value. The 20Ω resistor between SW and BST dampens ringing caused by parasitic inductance in the bootstrap loop, reducing voltage spikes that could exceed the 6V BST rating and degrade gate drive integrity-especially critical in high-frequency, high-dV/dt applications.
MP9942GJ-P Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Monolithic Power Systems Inc.
- Series:
- -
- Package/Case:
- SOT-23-8 Thin, TSOT-23-8
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 30V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 28.5V
- Current - Output:
- 2A
- Frequency - Switching:
- 410kHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-8
MP9942GJ-P FAQ
1.How can I place an order for MP9942GJ-P through Aetrix?
Please submit a Request for Quotation (RFQ) for MP9942GJ-P 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 MP9942GJ-P reliable?
The price and inventory of MP9942GJ-P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP9942GJ-P is usually 5 days.
3.What payment methods are accepted for MP9942GJ-P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP9942GJ-P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MP9942GJ-P?
MP9942GJ-P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MP9942GJ-P 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 MP9942GJ-P?
For technical support, including MP9942GJ-P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP9942GJ-P requirements.
6.How does Aetrix verify that MP9942GJ-P is sourced from the original manufacturer or authorized distributors?
All MP9942GJ-P 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 MP9942GJ-P meets industry standards.
7.What is the process for return or replacement of MP9942GJ-P?
All MP9942GJ-P units undergo pre-shipment inspection (PSI). If there is an issue with MP9942GJ-P, 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 MP9942GJ-P part is unused and in its original packaging.
Return procedure for MP9942GJ-P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MP9942GJ-P Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
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…
