Product Overview

The S-85S1AB20-I6T1U is a cost-effective synchronous step-down switching regulator launched by ABLIC, a core model in the S-85S1A Series. It supports a maximum input voltage of 5.5V and a fixed output voltage of 2.0V, adopting unique low-power consumption control technology and Constant On-Time (COT) control with a typical quiescent current of only 260nA. It automatically switches to PFM mode under light load and maintains PWM mode under heavy load, achieving high efficiency across a wide load range. A complete circuit can be built with only an inductor, input capacitor, and output capacitor, with a minimum occupied area of 9.0mm², making it ideal for mobile devices, wearable devices, and other applications requiring strict power consumption and size constraints, providing long-term stable power solutions for small battery-powered devices.

Key Features

• Ultra-Low Quiescent Current for Extreme Power Savings：Typical quiescent current is only 260nA, and it automatically enables PFM control under light load, significantly reducing standby power consumption and extending the lifespan of small batteries (such as button batteries and thin lithium batteries).
• Fast Transient Response for Voltage Stability：Adopting COT control technology, it real-time monitors the output voltage and quickly adjusts the on-time of the high-side MOS FET when the load current changes abruptly, avoiding voltage fluctuations and ensuring stable power supply for devices.
• High Output Voltage Accuracy for Precise Power Supply：The output voltage is 2.0V ± 1.5%, which maintains high accuracy even in the operating temperature range of -40℃ to +85℃, meeting the power requirements of high-precision electronic components (such as sensors and MCUs).
• Automatic PWM/PFM Switching for Wide Load Efficiency：It automatically switches modulation modes based on load current—PWM mode (1MHz fixed frequency) ensures efficiency under heavy load (e.g., device high-load operation), while PFM mode reduces switching loss under light load (e.g., device standby), optimizing efficiency across the entire load range.
• Rich Protection Functions for System Reliability：Built-in overcurrent protection (450mA @ L=2.2μH), thermal shutdown (135℃ typical detection temperature), Under Voltage Lockout (UVLO, 1.8V typical detection voltage), auto-recovery short-circuit protection (hiccup mode), and under-voltage protection (UVP) to prevent circuit damage from abnormalities.

Technical Specifications

Typical Applications

• Wearable Devices：In smart bracelets, smart watches, and other wearable devices, the S-85S1AB20-I6T1U’s 260nA ultra-low quiescent current significantly reduces standby power consumption. With a maximum output current of 200mA, it meets the power requirements for daily device monitoring (e.g., heart rate, step count) while extending the lifespan of small lithium batteries. Additionally, the ultra-small SNT-6A package fits the compact internal structure of wearable devices.
• Bluetooth Devices：For Bluetooth headsets, Bluetooth beacons, and other Bluetooth devices, the product’s wide input voltage range (2.2V~5.5V) is compatible with batteries of different specifications. The 1MHz switching frequency and fast transient response prevent voltage fluctuations during Bluetooth signal transmission, ensuring communication stability. The low-power 特性 in PFM mode reduces device charging frequency.
• Wireless Sensor Network Devices：In wireless temperature-humidity sensors, smart security sensors, and other devices, the S-85S1AB20-I6T1U’s wide operating temperature range (-40℃~+85℃) adapts to harsh outdoor and industrial environments. Overcurrent protection and short-circuit protection prevent circuit damage from sensor abnormalities, while the low-power design supports long-term maintenance-free operation of devices.
• Healthcare Equipment：In portable oximeters, small blood pressure monitors, and other healthcare devices, the product’s high output voltage accuracy of 2.0V±1.5% ensures the precise operation of medical detection components. The thermal shutdown protection (135℃ typical) avoids overheating risks during long-term device operation, meeting the safety and reliability requirements of medical equipment.
• Portable Gaming Devices：For small handheld game consoles, game controllers, and other portable gaming devices, the S-85S1AB20-I6T1U’s maximum output current of 200mA meets the power requirements during device operation. Automatic PWM/PFM switching maintains high efficiency during game loading (heavy load) and reduces power consumption during standby (light load), balancing performance and battery life to enhance user experience.

Why Choose S-85S1AB20-I6T1U?

• Outstanding Low-Power Advantage for Extended Battery Life：Compared with ordinary synchronous step-down regulators (usually quiescent current >1μA), the S-85S1AB20-I6T1U has a typical quiescent current of only 260nA. The PFM mode under light load further reduces power consumption, extending the battery life of small battery-powered devices by more than 30%, especially suitable for wearables and sensors requiring long standby time.
• High Integration Simplifies Design, Saves Cost and Space：A complete step-down circuit can be built with only one 2.2μH inductor, 10μF input capacitor, and 10μF output capacitor, occupying a minimum PCB area of 9.0mm². No additional complex peripheral components are needed, greatly simplifying the hardware design process and reducing material and PCB costs.
• Precise Output and Stable Performance Ensure Device Reliability：The output voltage accuracy of 2.0V±1.5% avoids device failures caused by voltage deviations. The fast transient response (1ms typical soft-start time) brought by COT control copes with sudden load changes. The wide temperature range and multiple protection functions further improve device reliability in different scenarios.
• Compatible with Multiple Battery Types for High Application Flexibility：The input voltage range of 2.2V~5.5V is compatible with various common small batteries (e.g., 3.7V lithium batteries, 2-cell dry batteries (3V)), eliminating the need for additional voltage conversion circuits and meeting the power input requirements of different devices, enhancing product design flexibility.
• Compliant with Environmental Standards, Strong Mass Production Compatibility：The S-85S1AB20-I6T1U adopts 100% lead-free (Sn 100%) and halogen-free packaging, complying with environmental standards such as RoHS. It is packaged in tape (I6T1), supporting SMT automated placement production, suitable for large-scale mass production, and reducing labor costs and error rates in the production process.

SUNTOP COMPANY INTRODUCTION

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