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SY21175ADT (SY81053ADT)

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High Efficiency, 3.5A, 18V Input Synchronous Step Down Regulator
Datasheet
SY21175ADT High Efficiency, 3.5A, 18V Input Synchronous Step Down Regulator Datasheet
Part number SY21175ADT
Channel(#) 1
Vin (min) (V) 4.2
Vin (max) (V) 18
Switching frequency (min)(kHz)
Switching frequency (max)(kHz) 500
Vout (min) (V) 0.594
Vout (max) (V) 0.606
Iout (max) (A) 3.5
Vout2 (min)(V)
Vout2 (max )(V)
Iout2 (max)(A)
Vref accuracy (±%) ±1%
Vout accuracy(±%)
Control mode
Duty cycle (max)(%)
Operation mode
Iq (typ) (uA) 250
Features Hic-cup for Short Circuit Protection, Output Auto-Discharge Function
Package TSOT23-6
Operating temperature range(°C) -40°C to 125°C
Functional safety category

·     Low RDS(ON) for Internal Switches (Top/Bottom): 80mΩ/40mΩ

·     4.2-18V Input Voltage Range

·     3.5A Output Current Capability

·     500kHz Switching Frequency Minimize the External Components

·     Stable with 10μF COUT and 3.3μH Inductor

·     Instant PWM Architecture to Achieve Fast Transient Responses

·     Internal Soft-start Limits the Inrush Current

·     Startup from Pre-biased Output

·     Cycle-by-cycle Peak/Valley Current Limitation

·     Hic-cup Mode Output Short Circuit Protection

·     Over Temperature Protection with Auto Recovery

·     Output Auto Discharge Function

·     ±1.0% Internal Reference Voltage

·     RoHS Compliant and Halogen Free

·     Compact Package: TSOT23-6

The SY21175 develops high efficiency 500kHz synchronous step-down DC/DC converter capable of delivering 3.5A current. The device operates over a wide input voltage range from 4.2V to 18V and integrates main switch and synchronous switch with very low RDS(ON) to minimize the conduction loss.

The SY21175 adopts the instant PWM architecture to achieve fast transient responses for high step down applications and high efficiency at light loads. In addition, it operates at pseudo-constant frequency of 500kHz to minimize the size of the inductor and the capacitor.

Evaluation Board

  • 1

    Photo of evaluation board

  • 2

    Photo of evaluation board

EVB_SY21175ADT

EVB_SY21175ADT is intended for evaluating 3.5A, 18V, 500kHz synchronous Buck regulator.

Technical Documentation

Title Date
Silergy_Catalog_Q2_2026 2026-06-12
TSOT23-6 2022-05-20