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STMicroelectronics ST1PS02AQTR
- Part No.:
- ST1PS02AQTR
- Manufacturer:
- STMicroelectronics
- Package:
- 12-UFQFN
- Datasheet:
-
ST1PS02AQTR.pdf
- Description:
- IC REG BUCK ADJ 400MA 12TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,990
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Product details
Overview
ST1PS02AQTR from STMicroelectronics is a nano-quiescent (500 nA) synchronous step-down converter in TQFN12 package, delivering up to 400 mA output current with 1.8–5.5 V input range and digitally selectable output voltages from 1.40 V to 1.75 V in 50 mV steps. It integrates Power Good flag, auxiliary load switch (Vout2), and 100% duty cycle operation-optimized for single-cell Li-ion wearable systems requiring ultra-low standby power and minimal PCB footprint.
For engineers reviewing the ST1PS02AQTR datasheet, ST1PS02AQTR pinout, ST1PS02AQTR application, or ST1PS02AQTR equivalent, key selection criteria include its 500 nA quiescent current at 3.6 V, ±1.5% output voltage accuracy at 25 °C, dynamic D0/D1/D2 voltage selection, embedded soft-start, and AUX-controlled 100 mA auxiliary rail-critical for energy-constrained personal tracking monitors and Bluetooth® Low Energy sensors.
Technical Context
The ST1PS02AQTR employs peak current control (PCC) architecture with seamless PFM/PWM mode transition, enabling high efficiency down to microampere loads while maintaining low output ripple. Its hysteretic comparator senses coil ripple current to sustain constant ripple across load and input variations.
It supports 100% duty cycle operation when VIN approaches VOUT, directly connecting input to output via the high-side MOSFET; UVLO triggers at 1.57 V (VIN falling, typ.) and includes fast output discharge during shutdown. The auxiliary Vout2 rail mirrors VOUT with 0.5–0.95 Ω on-resistance and controlled rise time (300–650 µs).
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 external resistor divider and supports dynamic voltage scaling |
| Max Output Current | 400 mA continuous - sufficient for MCU + sensor + BLE subsystems powered from single Li-ion cell |
| Input Voltage Range | 1.8 V to 5.5 V - compatible with discharged to fully charged single-cell Li-ion (2.7–4.2 V) plus margin |
| Efficiency | 92% typical at 10 mA, VIN = 3.6 V, VOUT = 2.5 V - minimizes thermal rise in sealed enclosures |
| Power Good Threshold | 97.5% of selected VOUT - provides reliable system reset signaling without external monitoring circuitry |
| Current Limit | 850 mA typical (CL = GND) - protects against short-circuit while allowing safe inrush during soft-start |
Pinout & Package
TQFN12 (2.0 × 1.7 × 0.55 mm) package with 0.4 mm pitch, exposed thermal pad, RoHS-compliant and ECOPACK® certified.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| AUX | Auxiliary output enable | Logic-high activates Vout2 rail; tied low disables auxiliary switch - enables selective subsystem power gating |
| VIN | Main input supply | Accepts 1.8–5.5 V; requires 10 µF low-ESR ceramic bypass capacitor - ensures stable regulation under pulsed loads |
| SW | Switch node | Connects to 2.2 µH inductor; internal PMOS/NMOS switching node - defines layout critical path for EMI control |
| GND | Power and signal ground | Common reference for all analog/digital blocks and thermal pad connection - mandatory low-impedance plane tie |
| VOUT | Feedback sense input | Direct connection to inductor output node - enables accurate regulation without resistive divider errors |
| Vout2 | Auxiliary regulated output | Provides same VOUT level minus switch drop (max 100 mA); requires separate 10 µF capacitor - powers secondary sensors or radios |
| PGOOD | Open-drain Power Good flag | High-impedance when VOUT ≥ 97.5% target - used for processor reset or sequencer handoff without pull-up dependency |
| CL | Current limit threshold | Pull-down resistor adjusts switch current limit (e.g., 650 mA typ. with 1 MΩ) - enables precise OCP tuning per subsystem |
| D0–D2 | Digital voltage select inputs | 3-bit binary code sets VOUT (e.g., 000 = 1.40 V); dynamically reconfigurable - supports adaptive power modes |
| EN | Enable control | Active-high logic; must not float - allows system-level sleep/wake coordination with <200 nA shutdown current |
Key Features
| Feature | Design Value |
|---|---|
| Nano-quiescent operation | 500 nA IQ enables >10-year battery life in 20 µA average-load wearables (e.g., fitness trackers) |
| Digital output voltage selection | Eight fixed VOUT options (1.40–1.75 V) via D0/D1/D2 - removes trimming components and simplifies firmware control |
| Integrated auxiliary load switch | Vout2 delivers same regulated voltage as VOUT with 0.75 Ω typical RAUX - powers BLE radio or display backlight independently |
| 100% duty cycle mode | Automatic transition when VIN ≤ VOUT + 300 mV - maintains output during battery brownout without dropout or reset |
| Embedded soft-start | Fixed ~1.7 ms ramp time with 280 mA initial current limit - prevents inrush into weak sources like energy harvesters |
Applications
| Personal Tracking Monitors | Smart Sport Bands |
|---|---|
|
Use Scenario: Continuous heart-rate and motion sensing using optical and accelerometer ICs powered by coin-cell or thin Li-ion. IC Role / Device Role / Timing Role: Primary power regulator supplying 1.5 V to ultra-low-power MCU and analog front-end; PGOOD signals stable rail to enable sensor sampling. Use Value: 500 nA quiescent current extends battery life to 18+ months; 1.5 V output matches optimal core voltage for ARM Cortex-M0+ MCUs. |
Use Scenario: Multi-sport activity tracker with OLED display, GPS assist, and BLE connectivity in sub-12 mm profile. IC Role / Device Role / Timing Role: Main DC/DC converter (VOUT) powers SoC; AUX-enabled Vout2 drives display backlight only during UI interaction. Use Value: Dynamic D0/D1/D2 reconfiguration lowers VOUT to 1.4 V during sleep, reducing SoC leakage by 35%; Vout2 gating cuts display idle power by 92%. |
| Energy-Harvesting Wireless Sensors | Single-Cell Li-Ion Medical Wearables |
|
Use Scenario: Indoor environmental sensor (temp/humidity/CO₂) powered by indoor PV harvester with 2–4 V intermittent output. IC Role / Device Role / Timing Role: Step-down regulator accepting wide 1.8–5.5 V input; 100% duty cycle sustains output during low-light harvesting gaps. Use Value: 92% efficiency at 10 µA load preserves harvested µJ-level energy; CL pin allows tuning current limit to match harvester's max power point. |
Use Scenario: FDA-cleared ECG patch with 7-day runtime, requiring stable 1.6 V for analog signal chain and 1.8 V for BLE transceiver. IC Role / Device Role / Timing Role: Dual-rail source: VOUT = 1.60 V (D2=1,D1=0,D0=0) for precision ADC; Vout2 = 1.60 V for BLE RF section, enabled only during transmission. Use Value: ±1.5% VOUT accuracy ensures consistent ADC reference; PGOOD enables precise timing of ECG acquisition windows after power-up. |
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 |
|---|---|---|---|
| TI TPS62840YKAR | 400 nA IQ, 1.8–5.5 V input, but fixed 1.8 V output (no digital selection); no AUX switch or PGOOD | Lacks dynamic voltage scaling and auxiliary rail - unsuitable where dual-rail or VDD scaling is required | Choose only if fixed 1.8 V suffices and auxiliary control is unnecessary |
| Analog Devices ADP5302ACBZ-1-R7 | 250 nA IQ, 1.8–5.5 V input, 1.2–3.3 V adjustable via resistor divider; includes PGOOD but no AUX switch | Requires external resistors for VOUT setting - increases BOM count and board area vs. ST1PS02AQTR's pin-strapped simplicity | Select when lowest possible IQ is critical and digital configuration is not needed |
Compared with TPS62840YKAR and ADP5302ACBZ-1-R7, the ST1PS02AQTR uniquely combines nano-IQ, digital VOUT selection, integrated AUX switch, and PGOOD in a 2.0×1.7 mm package-enabling smaller, smarter, and more flexible power architectures for next-gen wearables.
Availability
ST1PS02AQTR is available at Aetrix Electronics and suitable for wearable applications, personal tracking monitors, and single-cell Li-ion battery systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for ST1PS02AQTR 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 microcontrollers, power management ICs, sensors, and analog devices for industrial, automotive, and consumer markets.
The ST1PS02 series belongs to ST's nano-power DC/DC converter product line, engineered specifically for space- and energy-constrained portable electronics-emphasizing ultra-low IQ, minimal external components, and digital configurability without sacrificing reliability.
FAQ
What is the minimum input voltage required for ST1PS02AQTR to start switching?
The device begins regulation when VIN rises above the undervoltage lockout (UVLO) threshold of 1.63 V (typ.). Below this, EN remains inactive and SW stays off. Once VIN exceeds 1.63 V, the internal bias circuits power up, and switching initiates after the 1.7 ms soft-start period-ensuring clean startup even from deeply discharged Li-ion cells.
Can ST1PS02AQTR's output voltage be changed dynamically during operation?
Yes-D0, D1, and D2 pins support real-time reconfiguration of VOUT (e.g., from 1.40 V to 1.75 V) without interrupting regulation. The change occurs within microseconds, and output settles within 20 µs (per Figure 10). This enables firmware-driven voltage scaling for different operating modes, such as low-power sleep vs. active sensing.
How does the auxiliary output (Vout2) behave when AUX pin is left unconnected?
The AUX pin has an internal pull-down; if left floating, it defaults to logic low, disabling Vout2. No current flows from Vout2, and the pin remains at high impedance. For reliable operation, ST recommends explicitly tying AUX to GND when unused-avoiding noise-induced false activation in high-density layouts.
What external components are mandatory for basic ST1PS02AQTR operation?
Four components are mandatory: a 10 µF low-ESR ceramic capacitor on VIN, a 2.2 µH shielded inductor on SW, a 10 µF low-ESR ceramic capacitor on VOUT, and a pull-up resistor (typically 10 kΩ) on PGOOD. All capacitors must be placed adjacent to their respective pins with short, low-inductance traces to ensure stability and low ripple.
ST1PS02AQTR 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)
ST1PS02AQTR FAQ
1.How can I place an order for ST1PS02AQTR through Aetrix?
Please submit a Request for Quotation (RFQ) for ST1PS02AQTR 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 ST1PS02AQTR reliable?
The price and inventory of ST1PS02AQTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST1PS02AQTR is usually 5 days.
3.What payment methods are accepted for ST1PS02AQTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST1PS02AQTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST1PS02AQTR?
ST1PS02AQTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST1PS02AQTR 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 ST1PS02AQTR?
For technical support, including ST1PS02AQTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST1PS02AQTR requirements.
6.How does Aetrix verify that ST1PS02AQTR is sourced from the original manufacturer or authorized distributors?
All ST1PS02AQTR 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 ST1PS02AQTR meets industry standards.
7.What is the process for return or replacement of ST1PS02AQTR?
All ST1PS02AQTR units undergo pre-shipment inspection (PSI). If there is an issue with ST1PS02AQTR, 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 ST1PS02AQTR part is unused and in its original packaging.
Return procedure for ST1PS02AQTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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