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MP9942AGJ-Z
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Monolithic Power Systems DC-DC Converters, TSOT-23-8. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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Contents
README
markdownMP9942AGJ-Z
Monolithic Power Systems · DC-DC Converters · TSOT-23-8
MP9942AGJ-Z from Monolithic Power Systems, in a TSOT-23-8. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | PG | output | Power Good open-drain output that goes high when the output voltage exceeds 90% of the nominal voltage and should be pulled up through a resistor (e.g. 100kΩ) to VCC or another voltage source. |
| 2 | IN | power_in | Supply voltage input for a 4V to 30V input rail, decoupled with C1 and connected with a wide PCB trace. |
| 3 | SW | output | Switch output node that must be connected with a wide PCB trace; the absolute maximum VSW rating is -0.3V to 41V. |
| 4 | GND | power_in | System ground and reference for the regulated output voltage, to be connected to GND with copper traces and vias. |
| 5 | BST | passive | Bootstrap pin that requires a capacitor between SW and BST to form the floating high-side driver supply, with a 20Ω resistor in series strongly recommended to reduce SW spike voltage. |
| 6 | EN/SYNC | input | Enable/synchronize input where high enables the regulator and an external clock of 200kHz to 2.2MHz applied here changes the switching frequency. |
| 7 | VCC | power_out | Internal bias supply output that must be decoupled with a 0.1μF to 0.22μF capacitor, not exceeding 0.22μF. |
| 8 | FB | input | Feedback input connected to the tap of the external output resistor divider; the frequency fold-back comparator lowers the oscillator frequency when FB is below 660mV. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Monolithic Power Systems |
| Package | TSOT-23-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Input voltage (VIN) absolute maximum | VIN | -0.3 | 40 | V | 3 | ||
| Switch voltage (VSW) absolute maximum | VSW | -0.3 | 41 | V | 3 | ||
| All other pins absolute maximum | -0.3 | 6 | V | All other pins; see note 2 for EN pin | 3 | ||
| Continuous power dissipation TSOT23-8 | 1.25 | W | TA = +25°C | 3 | |||
| Junction temperature absolute maximum | 150 | °C | 3 | ||||
| Lead temperature absolute maximum | 260 | °C | 3 | ||||
| Storage temperature | -65 | 150 | °C | 3 | |||
| Continuous supply voltage VIN | VIN | 4 | 30 | V | 3 | ||
| Output voltage VOUT | VOUT | 0.8 | V | Upper limit printed as VIN*DMAX (not numeric) | 3 | ||
| Operating junction temperature | TJ | -40 | 125 | °C | 3 | ||
| Supply current (shutdown) | ISHDN | 8 | μA | VEN = 0V | 4 | ||
| Supply current (quiescent) | IQ | 0.5 | 0.7 | mA | VEN = 2V, VFB = 1V | 4 | |
| HS switch-ON resistance | RON_HS | 90 | 155 | mΩ | VBST-SW=5V | 4 | |
| LS switch-ON resistance | RON_LS | 55 | 105 | mΩ | VCC =5V | 4 | |
| Switch leakage | ILKG_SW | 1 | μA | VEN = 0V, VSW =12V | 4 | ||
| Current limit | ILIMIT | 3.5 | 5 | 7 | A | Under 40% Duty Cycle | 4 |
| Oscillator frequency | fSW | 320 | 410 | 500 | kHz | VFB=750mV | 4 |
| Fold-back frequency | fFB | 70 | 100 | 130 | kHz | VFB<400mV | 4 |
| Maximum duty cycle | DMAX | 92 | 95 | % | VFB=750mV, 410kHz | 4 | |
| Minimum ON time | tON_MIN | 70 | ns | 4 | |||
| Sync frequency range | fSYNC | 0.2 | 2.4 | MHz | 4 | ||
| Feedback voltage | VFB | 780 | 792 | 804 | mV | 4 | |
| Feedback current | IFB | 10 | 100 | nA | VFB=820mV | 4 | |
| EN rising threshold | VEN_RISING | 1.15 | 1.4 | 1.65 | V | 4 | |
| EN falling threshold | VEN_FALLING | 1.05 | 1.25 | 1.45 | V | 4 | |
| EN input current | IEN | 4 | 6 | μA | VEN=2V | 4 | |
| EN input current | IEN | 0 | 0.2 | μA | VEN=0 | 4 | |
| VIN UVLO threshold rising | INUVRISING | 3.3 | 3.5 | 3.7 | V | 4 | |
| VIN UVLO threshold falling | INUVFALLING | 3.1 | 3.3 | 3.5 | V | 4 | |
| VCC regulator | VCC | 4.6 | 4.9 | 5.2 | V | ICC=0mA | 4 |
| VCC load regulation | 1.5 | 4 | % | ICC=5mA | 4 | ||
| Soft-start period | tSS | 0.55 | 1.45 | 2.45 | ms | VOUT from 10% to 90% | 4 |
| Thermal shutdown | TSD | 150 | 170 | °C | 4 | ||
| PG rising threshold | PGVth_RISING | 86.5 | 90 | 93.5 | % | as percentage of VFB | 4 |
| PG falling threshold | PGVth FALLING | 80.5 | 84 | 87.5 | % | as percentage of VFB | 4 |
| PG rising delay | PGTd_RISING | 40 | 90 | 160 | μs | 5 | |
| PG falling delay | PGTd_FALLING | 30 | 55 | 95 | μs | 5 | |
| PG sink current capability | VPG Sink | 0.1 | 0.3 | V | 4mA | 5 | |
| PG leakage current | ILKG_PG | 10 | 100 | nA | 5 | ||
| VIN UVLO threshold hysteresis | INUVHYS | 200 | mV | 4 | |||
| EN threshold hysteresis | VEN_HYS | 150 | mV | 4 | |||
| Thermal hysteresis | TSD_HYS | 30 | °C | 4 | |||
| PG threshold hysteresis | PGVth_HYS | 6 | % | as percentage of VFB | 5 | ||
| Thermal resistance junction-to-ambient | θJA | 100 | °C/W | Measured on JESD51-7, 4-layer PCB | 3 | ||
| Thermal resistance junction-to-case | θJC | 55 | °C/W | Measured on JESD51-7, 4-layer PCB | 3 |
Materials and finish
As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).
| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | copper | 4 GND System Ground. This pin is the reference ground of the regulated output voltage, and PCB layout requires special care. For best results, connect to GND with copper traces and vias. | 6 |
CAD (KiCad official)
- Symbol:
MP9942AGJ-Z - Footprint:
Package_TO_SOT_SMD:TSOT-23-8 - 3D model: TSOT-23-8 (KiCad packages3D, STEP)
- 3D model files:
mp9942agj-z-etched.step/mp9942agj-z-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);mp9942agj-z.step/mp9942agj-z.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Monolithic Power Systems datasheet (21 pp, sha256
4966796d66d7efc3, retrieved 2026-10-20, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusclaude-sonnet-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).