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STMicroelectronics ST1PS02A1QTR
- Part No.:
- ST1PS02A1QTR
- Manufacturer:
- STMicroelectronics
- Package:
- 12-UFQFN
- Datasheet:
-
ST1PS02A1QTR.pdf
- Description:
- IC REG BUCK ADJ 400MA 12TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,000
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Product details
Overview
ST1PS02A1QTR from STMicroelectronics is a nano-quiescent (500 nA), synchronous step-down DC-DC converter in TQFN12 package, delivering up to 400 mA output current with 1.8–5.5 V input and digitally selectable output voltages from 1.40 V to 1.75 V. It integrates Power Good flag, auxiliary load switch (Vout2), and 100% duty cycle mode for ultra-low-power wearable systems powered by single-cell Li-ion batteries.
For engineers reviewing the ST1PS02A1QTR datasheet, ST1PS02A1QTR pinout, ST1PS02A1QTR application, or ST1PS02A1QTR equivalent, this device supports dynamic voltage scaling, sub-µA shutdown current, ±1.5% output accuracy at 25 °C, and seamless PFM/PWM transition - critical for energy harvesting sensors and Bluetooth® Low Energy peripherals requiring stable rail generation under microampere loads.
Technical Context
The ST1PS02A1QTR employs peak current control (PCC) architecture with hysteretic switching to maintain constant inductor ripple across load and input conditions, enabling high efficiency down to 10 µA loads. Its digital voltage selection (D0–D2) configures eight fixed VOUT levels without external resistors, and the embedded soft-start limits inrush current during startup.
It features dual regulation paths: main output (VOUT) with feedback sensing and auxiliary output (Vout2) controlled via AUX pin, sharing the same regulated rail but with integrated 100 mA OCP and 0.75 Ω typical on-resistance. The 100% duty cycle mode activates when VIN approaches VOUT, directly connecting input to output through the high-side MOSFET to minimize dropout loss.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Quiescent Current | 500 nA typical at VIN = 3.6 V, non-switching - enables multi-year battery life in always-on wearables |
| Output Voltage Range | 1.40 V to 1.75 V in 50 mV steps via D0/D1/D2 - eliminates need for external resistor divider |
| Max Output Current | 400 mA continuous - sufficient for MCU + BLE radio + sensor subsystems from single Li-ion cell |
| Efficiency | 92% typical at 10 mA, VIN = 3.6 V, VOUT = 2.5 V - minimizes thermal rise in sealed enclosures |
| Input Voltage Range | 1.8 V to 5.5 V - supports full discharge curve of 3.0–4.2 V Li-ion cells plus 3.3 V/5 V system rails |
| UVLO Threshold | 1.57 V (VIN falling, typ.) - prevents brownout operation during deep battery discharge |
| PGOOD Accuracy | 97.5% of selected VOUT - ensures reliable power sequencing for downstream logic |
| Package | TQFN12 (2.0 × 1.7 × 0.55 mm) - enables < 4 mm² PCB footprint for compact wearables |
Pinout & Package
TQFN12 (2.0 mm × 1.7 mm × 0.55 mm) thermally enhanced plastic package with exposed pad for improved heat dissipation and low-profile mounting in space-constrained applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| AUX | Auxiliary output enable | High-level activation enables Vout2 rail; tied low disables auxiliary switch to prevent leakage |
| VIN | Main input supply | Accepts 1.8–5.5 V; requires 10 µF low-ESR ceramic bypass capacitor for stable regulation |
| SW | Switch node | Connects to 2.2 µH inductor; carries high di/dt switching current - must be routed with minimal loop area |
| GND | Power and signal ground | Common reference for all analog/digital blocks; connects to exposed thermal pad for thermal management |
| VOUT | Feedback sense input | Direct connection to inductor output terminal ensures accurate regulation; no external divider needed |
| Vout2 | Auxiliary regulated output | Provides same VOUT level minus ~75 mV drop (at 100 mA); includes internal discharge path when disabled |
| PGOOD | Open-drain Power Good flag | High-impedance when VOUT ≥ 97.5% target; requires external pull-up for host processor monitoring |
| CL | Current limit threshold | Grounded for default 850 mA switch current limit; resistor to GND reduces limit for smaller inductors |
| D0–D2 | Digital voltage select inputs | Three-bit code sets one of eight fixed outputs (1.40–1.75 V); dynamically reconfigurable during operation |
| EN | Enable control | Active-high logic; must not float - ties to system controller for precise power sequencing |
Key Features
| Feature | Design Value |
|---|---|
| Nano-quiescent operation | 500 nA IQ enables >10-year battery life in personal trackers with 200 mAh coin cells |
| Digital voltage selection | Eight factory-trimmed VOUT options (1.40–1.75 V) via D0/D1/D2 - eliminates BOM cost and layout error of resistor dividers |
| Integrated auxiliary load switch | Vout2 delivers same regulated rail with 100 mA OCP and 0.75 Ω RON - powers secondary sensors without extra regulator |
| 100% duty cycle mode | Eliminates switching loss when VIN ≤ VOUT + 300 mV - extends runtime near battery EOD |
| Embedded soft-start | 1.7 ms fixed ramp time limits inrush current to <280 mA - protects weak sources like energy harvesters |
| Power Good flag with hysteresis | 97.5% trip point + 3.5% hysteresis ensures clean power sequencing for MCUs and RF ICs |
Applications
| Wearable Fitness Monitor | Bluetooth® LE Sensor Node |
|---|---|
|
Use Scenario: Continuous heart-rate and motion sensing in wrist-worn band with 200 mAh Li-ion battery. IC Role / Device Role / Timing Role: Primary power rail generator for ARM Cortex-M0+ MCU, optical sensor, and BLE transceiver. Use Value: 500 nA quiescent current extends battery life to 18 months; dynamic VOUT scaling reduces active power by 22% during sleep mode. |
Use Scenario: Self-powered environmental sensor node harvesting ambient light, transmitting data every 5 minutes via BLE. IC Role / Device Role / Timing Role: Ultra-low-power buck converter supplying 1.65 V to MCU and 1.65 V to humidity/temperature sensor via Vout2. Use Value: 92% efficiency at 10 µA load preserves harvested energy; PGOOD enables precise wake-up timing for transmission bursts. |
| Smartwatch Display Backlight | Industrial Wireless Sensor |
|
Use Scenario: Driving OLED display backlight from single-cell Li-ion in ultra-thin smartwatch chassis. IC Role / Device Role / Timing Role: High-efficiency step-down regulator with fast transient response to support pulsed LED current demands. Use Value: Seamless PFM/PWM transition maintains <15 mV output ripple during backlight dimming; TQFN12 fits <0.55 mm height constraint. |
Use Scenario: Remote vibration sensor in predictive maintenance system, operating unattended for 5+ years on primary cell. IC Role / Device Role / Timing Role: Main power source for low-power MCU, MEMS accelerometer, and LoRa transceiver with cold-temperature operation. Use Value: -40 °C to +85 °C rating ensures reliability; 1.57 V UVLO prevents malfunction below 2.4 V battery voltage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar nano-quiescent buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS62840DRVR | 400 nA IQ, 1.8–5.5 V IN, but fixed 1.8 V output only; no auxiliary switch or digital VOUT selection | Suitable for static-rail designs without voltage scaling or secondary load control | Select when VOUT stability > flexibility; lacks D0–D2 and Vout2, limiting multi-rail integration |
| MAX77650EWL+T | 2.5 µA IQ (higher than ST1PS02A1QTR), integrates charger + LDO + buck; 300 mA max buck output | Better for battery-charged systems needing PMIC integration, not pure ultra-low-IQ standalone buck | Choose if system requires charging and multiple rails; trades 5× higher IQ for feature consolidation |
Compared with TPS62840DRVR and MAX77650EWL+T, ST1PS02A1QTR uniquely combines nano-quiescent operation, digital voltage scaling, and an auxiliary load switch in a 2.0 × 1.7 mm package - making it optimal for space- and energy-constrained wearables where rail flexibility and secondary load control are essential.
Availability
ST1PS02A1QTR is available at Aetrix Electronics and suitable for wearable fitness monitors, Bluetooth® LE sensor nodes, and industrial wireless sensors requiring stable component supply with guaranteed long-term availability and traceable sourcing.
Supply support for ST1PS02A1QTR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.
ST1PS02 belongs to ST's nano-power DC-DC converter product line, engineered specifically for battery-operated wearables and IoT edge nodes where PCB area, thickness, and multi-year battery life are non-negotiable design constraints.
FAQ
What is the minimum input voltage required for ST1PS02A1QTR to start switching?
The device begins switching when VIN rises above the undervoltage lockout (UVLO) threshold of 1.63 V (typical). Below this, internal circuitry remains disabled to prevent unstable operation. Once VIN exceeds 1.63 V, EN must be high and D0–D2 configured to initiate regulation. Startup delay is 1.7 ms from EN assertion to VOUT reaching 90% of target.
Can ST1PS02A1QTR support dynamic voltage scaling during system operation?
Yes - D0, D1, and D2 pins accept standard logic-level inputs and can be reconfigured in real time without interrupting regulation. For example, changing from 1.50 V to 1.65 V while powering an MCU allows adaptive core voltage adjustment during performance vs. sleep transitions, verified in Figure 10 of DS13206.
How does the auxiliary output (Vout2) behave when AUX pin is left floating?
The AUX pin has no internal pull-up or pull-down; leaving it floating causes undefined behavior and potential shoot-through or leakage. STMicroelectronics explicitly requires AUX to be actively driven high (to enable Vout2) or tied to GND (to disable). Floating AUX may result in partial turn-on of the auxiliary switch and uncontrolled current draw.
Is output discharge functionality available on ST1PS02A1QTR?
No - ST1PS02A1QTR is the "no output discharge" variant per Table 9 of DS13206. Only ST1PS02AQTR (not A1QTR) includes the internal discharge MOSFET. When EN is pulled low on ST1PS02A1QTR, VOUT and Vout2 remain active until external discharge paths dissipate stored energy in C2/C3 capacitors.
ST1PS02A1QTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 12-UFQFN
- 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):
- 1.8V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 1.4V
- Voltage - Output (Max):
- 1.75V
- Current - Output:
- 400mA
- Frequency - Switching:
- 2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 12-TQFN (1.7x2)
ST1PS02A1QTR FAQ
1.How can I place an order for ST1PS02A1QTR through Aetrix?
Please submit a Request for Quotation (RFQ) for ST1PS02A1QTR 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 ST1PS02A1QTR reliable?
The price and inventory of ST1PS02A1QTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST1PS02A1QTR is usually 5 days.
3.What payment methods are accepted for ST1PS02A1QTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST1PS02A1QTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST1PS02A1QTR?
ST1PS02A1QTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST1PS02A1QTR 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 ST1PS02A1QTR?
For technical support, including ST1PS02A1QTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST1PS02A1QTR requirements.
6.How does Aetrix verify that ST1PS02A1QTR is sourced from the original manufacturer or authorized distributors?
All ST1PS02A1QTR 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 ST1PS02A1QTR meets industry standards.
7.What is the process for return or replacement of ST1PS02A1QTR?
All ST1PS02A1QTR units undergo pre-shipment inspection (PSI). If there is an issue with ST1PS02A1QTR, 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 ST1PS02A1QTR part is unused and in its original packaging.
Return procedure for ST1PS02A1QTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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